GUIDELINE American Clinical Neurophysiology Society Guideline 7: Guidelines for EEG Reporting William O. Tatum,* Selioutski Olga,† Juan G. Ochoa,‡ Heidi Munger Clary,§ Janna Cheek,║ Frank Drislane,¶ and Tammy N. Tsuchida# *Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, U.S.A.; †University of Rochester, Rochester, New York, U.S.A.; ‡University of South Alabama, Mobile, Alabama, U.S.A.; §Wake Forest University, Winston Salem, North Carolina, U.S.A.; ║Tulsa, Oklahoma, U.S.A.; ¶Harvard University, Boston, Massachusetts, U.S.A.; and #George Washington University, Washington, DC, U.S.A.

Summary: This EEG Guideline incorporates the practice of parameters and type of EEG recording. Sleep feature structuring a report of results obtained during routine adult documentation is also expanded upon. More descriptive terms electroencephalography. It is intended to reflect one of the are included for background features and interictal discharges current practices in reporting an EEG and serves as a revision that are concordant with efforts to standardize terminology. In of the previous guideline entitled “Writing an EEG Report.” The the clinical correlation section, examples of common clinical goal of this guideline is not only to convey clinically relevant scenarios are now provided that encourages uniformity in information, but also to improve interrater reliability for reporting. Including digital samples of abnormal waveforms is clinical and research use by standardizing the format of EEG now readily available with current EEG recording systems and reports. With this in mind, there is expanded documentation of may be beneficial in augmenting reports when controversial the patient history to include more relevant clinical waveforms or important features are encountered. information that can affect the EEG recording and Key Words: EEG, Reporting, Routine, Adult, Pediatric, Guideline. interpretation. Recommendations for the technical conditions of the recording are also enhanced to include post hoc review (J Clin Neurophysiol 2016;33: 328–332)

he purpose of this guideline is to provide a standardized format of EEG terms.6 This guideline intends to provide a framework for Tfor reporting the results of adult routine scalp electroenceph- the EEG report to address the features as normal or abnormal, alography (rsEEG). The moderate interobserver reliability of with subsequent specification of their clinical importance. The EEG interpretation may be partly explained by the different significance should be evident to the clinician and the findings reporting styles utilized,1 and there is significant variability in the readily interpretable within the patient-specific context of the observation of guidelines for EEG reporting.2 Computer-based rsEEG recording. remote access technology has become more sophisticated, and When reporting specialized types of EEG (e.g., electro- video is now “routine” during rsEEG, prompting the need to cerebral inactivity, or neonatal EEGs) or EEG recordings in revise and update the earlier ACNS guideline on “Writing an special settings, or for prolonged durations (e.g., continuous EEG Report”.3 To assist in producing useful information for EEG in critical illness or during video-EEG monitoring), clinical and research purposes, standardized terminology and there may be modification with special formats more appli- following an orderly approach to EEG reporting is cable to those specific settings. In these situations, the recommended.4 description of technical details should be enhanced and more This guideline is designed to outline the conditions and complete than is required for standard rsEEG reporting. Also, parameters of EEG recording, including a description of the the guidelines described below are not intended to be the sole record obtained and the final impression that summarizes the means of reporting for institutions where research indexing EEG’s visual analysis. Its framework is intended to be useful to may apply. Guidelines have been developed by the American a clinician providing general neurologic care (including in the Clinical Neurophysiology Society (ACNS) to provide the primary care setting) who may not be an expert on the technical appropriate means of recording in some special situations. aspects of EEG or on the terminology in the rsEEG report.5 Standardized reporting of clinical neurophysiologic proce- Proper interpretation of the results reported depends on minimum dures has been implemented successfully.7 The current technical standards for the performance of an EEG [see guideline on “EEG Reporting” complements the earlier “Minimum Technical Requirements for Performing Clinical “Writing an EEG Report” and supplements those on non- EEG” available at http://www.acns.org/practice/guidelines]. routine recording situations and locations, available at http:// Also, it is clear that consistently higher interobserver agreement www.acns.org/practice/guidelines. occurs when there is a forced choice paradigm using a limited set

Address correspondence and reprint requests to William O. Tatum, DO, FACNS, Mayo Clinic, 4500 San Pablo Boulevard, Jacksonville, FL 32224, U.S.A.; FORMAT FOR REPORTING e-mail: [email protected]. A standard format for rsEEG reporting should include five Copyright Ó 2016 by the American Clinical Neurophysiology Society ISSN: 0736-0258/16/3304-0328 sections: History, Technical Description, EEG Description, DOI 10.1097/WNP.0000000000000319 Impression, and Clinical Correlation.

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History drug and dose (e.g., “lorazepam 1 mg was administered before The history section is an aid to interpretation of the rsEEG the recording”). Other conditions that can influence the EEG and should be succinct, including the reason for obtaining the should also be documented, including sleep deprivation, potential recording and any relevant clinical information, as well as dietary influences (e.g., fasting or NPO status), and modality identification of the patient and EEG recording. used (rsEEG, ambulatory EEG etc.). Templates for reporting EEGs should supply information The patient’s state of consciousness should be documented, and demographics about the patient. Personal information should including if the patient is awake, drowsy, asleep, or in include patient identification, including the medical record a compromised level of consciousness such as coma or coma- number (or other unique patient identifier) and clinical/hospital like states. This information on the patient’s state, i.e., the level EEG record number, in addition to the last name, first name, sex, of consciousness, helps guide the interpretation of the EEG and and date of birth and age at the time of the recording. The electroclinical correlation. purpose of the EEG should also be documented, e.g.,: (1) to evaluate patients with spells of altered consciousness, (2) to document and classify epileptiform discharges in patients with EEG Description recurrent seizures and epilepsy, and (3) to evaluate patients for This section should include a description of the background nonconvulsive seizures and for status epilepticus. This essential electrocerebral activity, including all the essential characteristics information should be entered by the person who prepares the of waveforms in the record, detailed as objectively as possible. recording for the final interpretation. Relevant clinical informa- The EEG signals are complex, and extraction of clinically tion should be available in the worksheet prepared by the relevant features by visual analysis alone is subject to individual technologist performing the EEG recording (Guideline 1: variability. Although automated software application enhances Minimum Technical Requirements for Performing Clinical our ability to detect and quantify the power of specific Electroencephalography, section 3.1). This should include bandwidths of EEG, human extraction of the clinically relevant relevant medical history, neuroactive medications including features requires identification, integration of various band- sedatives and antiseizure drugs, neuroimaging results, note of widths, and interpretation of the significant features in the any cranial operations, and whether previous EEGs have been context of the overall recording. performed. Description of the record should provide an objective means of analysis for review at a different time or by another interpreter. It should use technical terminology and metrics to detail the Technical Description waveforms present for the duration of the recording. The aim is The technical description should detail the conditions and to provide a complete, objective, and orderly description of the parameters of the recording, including the date and location of state of the patient, the background activity, and the most salient acquisition and interpretationdto ensure that both are identified features of the EEG to allow a conclusion of “normal” or in case the rsEEG is interpreted days after the recording. “abnormal.” It should also identify and describe normal variants Technical parameters should include the number of electrodes in addition to abnormal findings. When an abnormality is used and that the placement was in accordance with the 10 to identified, the degree of abnormality should be stated. 20 or 10 to 10 International System of Electrode Placement. The rsEEG description should begin with a complete Minimum standards for performing an EEG (e.g., head mea- description of the background activity, including the posterior surement) are required (see also, Guideline 1: Minimum Techni- dominant rhythm, additional features of the background, and cal Requirements for Performing Clinical EEG). Additional special features. The description of the best posterior dominant electrodes (e.g., T1/T2, sphenoidal, or subtemporal electrodes), rhythm in units of frequency (Hertz (Hz), or cycles per second) special electrodes (e.g., eye movement monitors), and modifica- and amplitude (microvolts per millimeter) should be reported tions of the 10 to 20 and 10 to 10 System (e.g., “prime” with the patient in the most alert state. Records obscured by electrodes used when there are skull defects or alteration) should artifact, recordings in infants, and some normal records may not be included. Special parameters (outside those recommended in have a clearly defined posterior dominant frequency, and the Guideline 1, sections 3.3–3.6) used during post hoc review of the report should reflect this. Response or reactivity to external rsEEG should be included in this section. An example of the stimuli should also be noted. Subsequent nondominant back- technical description follows: “This is a 21-channel digital EEG ground activity should be identified by principal frequencies, recording with time-locked video and single-channel electrocardio- amount of each present, degrees of symmetry, location/distribu- gram. Electrodes are placed according to the 10 to 20 (or 10–10) tion, morphology, amplitude, and rhythmicity, using the same International System. Portions of this record are reviewed using units as for the posterior dominant frequency. Description of bandpass filters of 2 to 35 Hz and sensitivity of 20 mV/mm.” nondominant background activity should include beta, theta, and Reporting the total recording duration may also be helpful, delta activity. Terms such as “low,”“medium,” and “high” especially if it deviates from the minimum technical requirements voltage may be used but should be quantified with numerical for performing clinical EEG (Guideline 1, section 3.7). This is measures. particularly advisable when it is shorter or longer than recom- State changes in the patient should be documented. The mended for routine scalp EEG recording. level of alertness, the organization of the EEG background The conditions of the recording should be elucidated. A frequency and amplitude over time, and the spatial features of the statement regarding the use of premedication should include the recording should be noted. Sleep patterns and architecture should clinicalneurophys.com Journal of Clinical Neurophysiology Volume 33, Number 4, August 2016 329 W. O. Tatum, et al. ACNS Guideline 7: Guidelines for EEG Reporting

be reported to reflect all sleep stages attained during the EEG or excessive (e.g., eye movements or muscle activity), when they recording. Abnormal patterns such as rapid sleep cycling, sleep- interfere with interpretation of the record (.50% of the tracing onset rapid eye movements, and asymmetry or attenuation in the involving .50% of the electrodes), or when they provide valuable normal sleep elements (e.g., spindles) should be noted. diagnostic information (e.g., myokymia, nystagmus, etc.). Hyperventilation and intermittent photic stimulation are A single-channel electrocardiogram should be included in routine activating procedures used to trigger abnormalities during every EEG. Reporting electrocardiogram findings in the EEG rsEEG. They should be performed and their effects noted. When description will vary and depend on the interpreter’s level of omitted, the reason for their omission should be stated. If expertise. Other channels such as eye movement monitors (used augmentation of slowing or any epileptiform abnormalities are by some laboratories routinely), channels monitoring respiration, encountered in the rsEEG during or after activating procedures, movement, EMG, and noncephalic monitors should be reported these responses should be detailed. Documentation of poor effort and described when applicable and when their significance is with hyperventilation is relevant to rsEEG interpretation. If questioned (Guideline 1: Minimum Technical Requirements for additional methods are used to enhance EEG abnormalities, they Performing Clinical EEG). should also be documented. Video recording is a routine part of most proprietary systems Any special characteristics present in the background, such for performing rsEEG. Including video descriptions in the report as voltage attenuation or augmentation, suppression-burst activ- is important for providing additional information involving ity, or electrocerebral inactivity should be detailed using the same electroclinical episodes and seizures, and in assessing artifacts. terminology used to describe the background. Descriptions The main features should include a description of the clinical should note morphology (monomorphic, polymorphic, or irreg- event and, when possible, terminology used by the International ular), rhythmicity, voltage, continuous versus intermittent fea- League Against Epilepsy seizure classification system8 reporting tures, laterality (e.g., left or right; bilateral, or diffuse), region of the duration, level of responsiveness/consciousness, and any involvement (e.g., frontal, temporal, central, parietal, occipital), intervention provided. and frequency (e.g., theta, delta slowing). For epileptiform and nonepileptiform features with bilateral localization, amplitude Impression symmetry (e.g., . 50%) and synchrony (e.g., secondary bilateral The impression (or interpretation) is a synthesis of the synchrony vs. bilateral synchronous) should be included in the significance of the EEG findings. It is written primarily for the description, as well as the temporal pattern of their occurrence referring clinician and should, therefore, be as succinct as (e.g., bursts, prolonged runs, or sporadic). possible, and readily understandable to a clinician of any level Salient abnormal features should be noted following iden- of expertise or specialty. It should include an initial, clear tification of the state and background activity. When interictal summary statement as to whether it is a normal or an abnormal epileptiform discharges are present, one should document the record. When the EEG is abnormal, the reasons why should location, morphology (e.g., spike, sharp, polyspike 6 slow be listed in a clear and concise line item format, in part to wave), pattern (e.g., single, run, random, rhythmic, periodic), simplify the results for comparison among successive records. and incidence (e.g., rare, intermittent, occasional, frequent, It is desirable to list the abnormalities by degrees of continuous). Further description of the frequency in Hertz should importance (examples: (1) a left focal temporal electrographic be included and the pattern of occurrence (e.g., single, couplet, seizure; (2) left anterior temporal spike-and-waves; (3) left bursts, and a train), as well as their duration. In addition, some temporal delta slowing; and (4) mild slowing of the back- abnormal findings may be influenced by external stimulation ground activity). (e.g., stimulus-induced, rhythmic periodic ictal-like discharges). The summary of the findings should be stated succinctly Quantifying paroxysmal abnormalities is often expressed in in layman’s terms. When reporting several types of abnor- a subjective manner and is relative to individual reporting malities, the list should be limited to the most salient findings designs.1,7 and to the minimum number necessary to convey the Snapshots of a reported abnormality are encouraged to be significance of those findings (preferably no more than three included in the EEG report. This will help facilitate an under- or four). Often, the impression will be the only part of the standing of what is being identified as an abnormality (Fig. 1). By report of major interest to the clinician, so the importance of providing a patient sample of the EEG abnormality, more universal this section is stressed. The impression should avoid confus- validation will be enabled, beyond the report’stext. ing terminology and technical jargon, but “epileptiform The presence of an electroclinical seizure or electrographic discharges,” including “spikes and sharp waves” are univer- (i.e., without clinical manifestations) seizure should include sally accepted terms. description of the electrographic onset, field of propagation, and postictal period, defining the temporal and spatial character- istics and using terminology to define the location, distribution, Clinical Correlation morphology, amplitude, and rhythmicity, in addition to the The clinical correlation is the ultimate translation of the duration and frequency of recurrence. When present, any clinical EEG. It should integrate the reason for referral for the EEG and changes and the qualitative nature of the change should be the findings to be used jointly to assist with patient management. documented, as described below under video recording. The clinical correlation should clearly express the relevance of Artifacts are present in virtually every rsEEG. They should be the findings to the clinician. Avoiding technical terminology is reported when they mimic cerebral activity, when they are unusual helpful to convey the message to the least experienced clinician

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FIG. 1. A single right temporal spike-and-wave with a regional temporal field during drowsiness. on the team caring for the patient. A good litmus test is that this 3. “Diffuse slowing of the background activity reflects a (include section should be understandable to a general practitioner or degree: mild, moderate, and severe) diffuse cortical dysfunc- nurse.4 tion, which can be seen with toxic-metabolic or systemic Phrases such as “no focal or lateralizing abnormality,”“no causes, or neurodegenerative disorders, and also with cortical epileptiform abnormality,” and “no electrographic seizures or injury.” evidence of status epilepticus were present” are helpful in the 4. “The generalized spike-and-waves seen in this tracing imply clinical correlation when the clinical request is explicit. Some a generalized mechanism in a patient with a clinical diagnosis common scenarios will be consistent from patient to patient. of epilepsy but may also represent an inherited trait indepen- ” Although individual reporting styles vary and wording differs dent of clinical seizures. “ slightly, the following are examples of clinical correlations that 5. The left anterior temporal spikes suggest focal hypersyn- chrony in a patient with a clinical diagnosis of epilepsy and may be used to express such concepts: carry a heightened risk for focal-onset seizures of temporal 1. “A normal interictal EEG does not exclude nor support the lobe origin.” diagnosis of epilepsy.” 6. “The suppression-burst pattern following normothermic car- 2. “Focal slowing suggests an underlying lesion involving the diac arrest (in the absence of anesthetic drugs) suggests a poor white matter of the ipsilateral hemisphere.” prognosis for neurologic outcome.” clinicalneurophys.com Journal of Clinical Neurophysiology Volume 33, Number 4, August 2016 331 W. O. Tatum, et al. ACNS Guideline 7: Guidelines for EEG Reporting

Although the clinical correlations in these cases may help criteria for choosing to use a specific procedure, neither is it standardize reporting, specific therapeutic suggestions such as intended to exclude any reasonable alternative methodologies. “this pattern warrants antiseizure drugs” or “clinical correlation is The ACNS recognizes that specific patient care decisions are strongly advised” should be avoided, recognizing the diagnostic the prerogative of the patient and the physician caring for the limits of an rsEEG. Suggestions for further testing may be made patient, based on all of the circumstances involved. The clinical within this section, e.g., suggesting a repeat EEG with sleep- context section is made available to place the evidence-based deprivation, ambulatory EEG, video-EEG monitoring, referral to guidelines into perspective with current practice habits and a sleep laboratory when sleep apnea is suspected, or further challenges. Formal practice recommendations are not intended cardiologic evaluation when the electrocardiogram is abnormal. to replace clinical judgment. When previous EEGs are available, comparison of the current record to previous tracings should be included. Note: Some electroencephalographers prefer to combine the Impression and Clinical Correlation, especially when they are simply stated and brief, e.g., “Normal routine EEG in wakeful- REFERENCES ” ness and in sleep. If a combined report is used, it should start 1. Beniczky S, Aurlien H, Brøgger JC, et al. Standardized computer-based with the neurophysiologic findings (usually the abnormalities), organized reporting of EEG: SCORE. Epilepsia 2013;54:1112–1124. followed by comments about the clinical significance. 2. Tatum WO. How not to read an EEG: introductory statements. Neurology 2013;80(suppl 1):S1–S3. This standardized reporting format is intended to maximize 3. American Clinical Neurophysiology Society. Guideline 7: guidelines for clear communication among different reviewers of the same writing EEG reports. J Clin Neurophysiol 2006;23:118–121. patient’s rsEEG. It is hoped that this will facilitate interobserver 4. Kaplan PW, Benbadis SR. How to write an EEG report. Neurology – reliability of EEG reporting for clinical care of patients and 2013;80(suppl 1):S43 S46. 5. Chatrian GE, Bergamini L, Dondey M, et al. A glossary of terms most increase consistency for research studies. commonly used by clinical electroencephalographers. Electroencephalogr Clin Neurophysiol 1974;37:538–548. 6. Gerber PA, Chapman KE, Chung SS, et al. Interobserver agreement in the interpretation of EEG patterns in critically ill adults. J Clin Neurophysiol DISCLAIMER 2008;25:241–249. 7. Hirsch LJ, LaRoche SM, Gaspard N, et al. American clinical neurophys- This statement is provided as an educational service of the iology society’s standardized critical care EEG terminology: 2012 version. American Clinical Neurophysiology Society (ACNS). It is J Clin Neurophysiol 2013;30:1–27. basedonanassessmentofcurrentscientific and clinical 8. Berg AT, Berkovic SF, Brodie MJ, et al. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE information. It is not intended to include all possible proper commission on classification and terminology, 2005–2009. Epilepsia methods of care for a particular problem or all legitimate 2010;51:676–685.

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Contents lists available at ScienceDirect

Clinical Neurophysiology Practice

journal homepage: www.elsevier.com/locate/cnp

A revised glossary of terms most commonly used by clinical electroencephalographers and updated proposal for the report format of the EEG findings. Revision 2017 ⇑ Nick Kane a, , Jayant Acharya b, Sandor Beniczky c, Luis Caboclo d, Simon Finnigan e, Peter W. Kaplan b, Hiroshi Shibasaki f, Ronit Pressler a, Michel J.A.M. van Putten g a UK b USA c Denmark d Brazil e Australia f Japan g Netherlands

This glossary includes the terms most commonly used in clinical Activation procedure: Any procedure designed to modulate EEG. It is based on the previous proposals (Chatrian et al., 1974; EEG activity, for instance to enhance physiological waveforms or Noachtar et al., 1999) and includes terms necessary to describe the elicit abnormal paroxysmal activity. Examples include: eye closing, EEG and to generate the EEG report. All EEG phenomena should be hyperventilation, photic stimulation, natural or drug-induced described as precisely as possible in terms of frequency, amplitude, sleep, sensory stimulation (acoustic, somatosensory or pain). phase relation, waveform, localization, quantity, and variability of Active sleep: Normal sleep stage in neonates characterized by these parameters (Brazier et al., 1961). The description should be inde- eye closure, intermittent periods of rapid eye movements, irregular pendent of the recording parameters such as amplification, montages, respirations and scant body movements. The EEG shows activité and computer program/display. Biological and technical artifacts that moyenne in term and near term infants, and tracé discontinue (dis- interfere with an adequate EEG interpretation should either be elimi- continuous pattern) in preterm infants <34 weeks of post men- nated or, if this is not possible, be noted in the description. strual age (PMA); the inter-burst interval depends on the PMA. The EEG report should follow a standard format that includes a (See quiet sleep, activité moyenne, tracé discontinue, REM sleep). factual description and a clinical interpretation of the EEG record. Activity, EEG: An EEG wave or sequence of waves of cerebral The interpretation of the EEG requires knowledge of the patient’s origin. age, past medical and medication history, their clinical condition Activité moyenne: Neonatal EEG pattern of wakefulness and during the EEG, particularly level of consciousness/vigilance and active sleep in term and near term infants characterized by ability to co-operate. The EEG interpretation summarizes the continuous, low to medium amplitude mixed frequency activity results of the EEG and gives a clinical interpretation in light of (25–50 mV) with a predominance of theta and delta and overriding the diagnosis and the questions posed by the referring physician. beta activity. Synonym: mixed frequency activity. (See active The terminology of the EEG interpretation should follow common sleep). neurological and clinical practice and use terms understandable After-discharge: (1) EEG seizure pattern following single or to other physicians not specialized in EEG. A proposal for the EEG repetitive electrical stimulation of a discrete area of the brain via report form is given in Appendix A. cortical or intracerebral electrodes. (2) Burst of rhythmic activity following a transient such as an evoked potential or a spike. Aliasing: Distortion of the EEG signal leading to misidentifica- Glossary tion of frequency, which occurs when the signal is sampled at less than twice the highest frequency present. The Nyquist theorem Absence: A generalized seizure type. Use of term discouraged states that sampling rates should be at least twice the highest fre- when describing EEG patterns. Terms suggested, whenever appro- quency, but accurate digitization of EEG signals requires even priate: spike-and-slow-wave complex, 3 c/s spike-and-slow-wave higher sampling rates. Comment: Distortion and aliasing can occur complex, sharp-and-slow wave complex. at the Nyquist theorem frequency (see Nyquist theorem, sampling rate). ⇑ Corresponding author at: North Bristol NHS Trust, Grey Walter Department of Alpha band: Frequency band of 8–13 Hz inclusive. Greek Clinical Neurophysiology, Southmead Hospital, Bristol, BS10 5NB, UK. letter: a. E-mail addresses: [email protected], [email protected] (N. Kane). http://dx.doi.org/10.1016/j.cnp.2017.07.002 2467-981X/Ó 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 171

Alpha rhythm: Rhythm at 8–13 Hz inclusive occurring during Array, electrode: A regular arrangement of electrodes over the wakefulness over the posterior regions of the head, generally with scalp or brain, or within the brain substance. Synonym: electrode maximum amplitudes over the occipital areas. Amplitude varies montage. but is mostly below 50 mV in the adult, but often much higher in Artifact: (1) A physiological potential difference due to an children. Best seen with the eyes closed, during physical relaxation extracerebral source present in EEG recordings, such as eye blinks and relative mental inactivity. Blocked or attenuated by attention, and movements, electrocardiogram (ECG) or muscle contractions especially visual, and mental effort. Comment: use of term rhythm (EMG). (2) A modification of the EEG caused by extracerebral fac- must be restricted to those rhythms that fulfill these criteria. Activ- tors, such as instrumental distortion or malfunction, movement ities in the alpha band which differ from the alpha rhythm as of the patient, or ambient electrical noise. regards their topography and/or reactivity, should either have Asymmetry: Unequal amplitude, frequency or morphology of specific appellations (for instance: the mu rhythm and alpha coma) EEG activity in channels over homologous areas of the two hemi- or should be referred to as rhythms of alpha frequency or alpha spheres. To be considered abnormal in practice if the amplitude activity. (See blocking, attenuation). Synonym: posterior dominant difference exceeds 50% or frequency difference is equal to or rhythm. greater than 1 Hz in the posterior dominant rhythm, although it Alpha variant rhythms: An EEG rhythm recorded most should be recognized that these are essentially arbitrary values. prominently over the posterior regions of the head that differs in It can be quantified by quantitative EEG (qEEG) measures, such frequency, but resembles in reactivity, the alpha rhythm. Com- as the Brain Symmetry Index (BSI). (See quantitative EEG). ments: (1) often at a supra- or sub-harmonic of alpha frequency Asynchrony: The non-coherent occurrence of EEG activities and may occur when no alpha rhythm is visible. (2) Not to be con- over regions on the same or opposite sides (hemispheres) of the fused with posterior slow waves of youth. (See fast alpha variant head. For example, two similar waveforms occurring at separate rhythm, slow alpha variant rhythm, and posterior slow waves of electrodes or channels, but not simultaneously due to a time lag youth). between the channels. Alpha wave: Wave with duration of 1/8–1/13 s (77–125 ms). Attenuation: Reduction in amplitude of EEG activity (for exam- Amplitude, EEG: Is a measure of the change of EEG signals with ple, the alpha rhythm is usually attenuated or blocked on eye respect to the mean value, usually measured in microvolts (mV), opening). May occur transiently in response to a physiological or and often expressed as the difference between the maximum and other stimulus, such as electrical stimulation of the brain, or more minimum deviation (i.e. peak-to-peak), or in rectified EEG from permanently as a result of pathological conditions, such as cerebral baseline-to-peak. For a variable EEG activity or modulating sinu- atrophy or ischemia. soidal rhythm a range can be provided. Comment: EEG amplitude Auditory evoked potential (AEP): Evoked potential in response depicts the difference in electrical potential between electrode to auditory stimulus (see evoked potential, brainstem auditory pairs. Size of the output deflections are dependent upon the evoked potential). method of derivation (i.e. montage), inter-electrode distance, and Augmentation: Increase in amplitude of EEG activity (for may be distorted by intervening structures, particularly the skull. example the alpha rhythm is characteristically augmented upon Synonym: in practice voltage is synonymous with EEG amplitude, closing the eyes). and the visual size of waveforms can be manipulated by the dis- Average (potential) reference electrode: Use of term discour- play gain (see voltage and display gain). aged. Term suggested: common average reference. Synonym: Amplitude-integrated EEG (aEEG): Involves customized dis- Goldman-Offner reference (use of term also discouraged). play of EEG activity following signal processing which includes Background activity: Any underlying EEG activity representing an asymmetric band-pass filter (2–15 Hz), logarithmic amplitude the setting in which focal or transient activity, either normal or display, rectification, smoothing and time compression (such that abnormal, appears and from which such underlying pattern is dis- several hours can be viewed on a screen). Widely used in neonatal tinguished. Comment: there may be no background activity and it intensive care unit monitoring, for example of infants suffering an is not a synonym of an individual rhythm, such as the alpha hypoxic ischemic encephalopathy. Comment: concurrent review of rhythm. Synonym: on-going activity. conventional raw EEG traces is recommended. Synonym: cerebral Background slowing: The frequency of the background rhythm function monitor (CFM). which is below the normal value for age and state. Comment: not Analog-to-digital conversion (AD conversion): Transforma- to be confused with slowing of the posterior dominant rhythm. tion of a continuous, analog signal EEG into its digital representa- Band: Range of EEG frequency in a spectrum for a given record- tion (a discontinuous series of discrete amplitudes). AD ing or epoch, i.e. delta, theta, alpha, beta, gamma bands and high conversion is characterized by the sampling rate, which is the frequency oscillations. number of times per second at which the signal is transformed into Bandwidth: The stated range of frequencies (for example 1– digits, and the amplitude resolution, the number of numerical val- 70 Hz) between which the response of an EEG channel is within, ues which can be distinguished within the dynamic range of the determined largely by the filters (see frequency response). system (usually expressed as the number of binary digits). (See Basal electrode: Any electrode located in proximity to the base sampling rate). of the skull (see foramen ovale electrode, nasopharyngeal elec- Anterior (slow) dysrhythmia: A normal EEG activity seen in trode, sphenoidal electrode). term and near term infants at 32–44 weeks of post menstrual Baseline: (1) Strictly: line obtained when an identical voltage is age; characterized by bilateral frontal delta waves (50–100 mV), applied to the two input terminals of an EEG amplifier or the ‘‘zero seen in isolation or brief runs, typically synchronously and amplitude value” (assumed or perceived) in a given EEG trace or symmetrically. epoch. (2) Loosely: imaginary line corresponding to the approxi- Application, electrode: The process of establishing fixation and mate mean values of the EEG activity assessed visually in an EEG electrical connection between an electrode and the subject’s scalp derivation over a period of time. or brain. Benign epileptiform discharges of childhood: Use of term dis- Arrhythmic activity: A sequence of EEG waves with an incon- couraged. Terms suggested, depending on topographical location, stant periodicity. (See rhythmic). occipital, centro-temporal or rolandic spikes (see rolandic spikes). Arousal: Change from a lower to a higher level of alertness as Benign epileptiform transient of sleep (BETS): Use of term manifest in EEG activity. discouraged. A normal variant. Small sharp spikes of very short 172 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 duration (<50 ms) and low amplitude (<50 mV), often followed by a response to click stimulus and recorded from the surface as a result small theta wave, occurring in the temporal regions during drowsi- of volume conduction (see evoked potential, far-field potential, ness and light sleep. Comment: this pattern is of no clinical signif- volume conduction). icance and in spite of the name is in fact not epileptiform. Breach rhythm: EEG activity recorded over or nearby a defect Synonym: small sharp spikes (preferred term). in the skull vault (for example after a fracture, burr hole or cran- Beta band: Frequency band of 14–30 Hz inclusive. Greek letter: iotomy), of increased amplitude when compared to homologous b. areas on the opposite side of the head (usually by a factor of less Beta rhythm or activity: Any EEG rhythm between 14 and than 3). The rhythm is composed of fast activity with a spiky 30 Hz (wave duration 33–72 ms). Most characteristically recorded appearance along with alpha and/or mu rhythms, due to lack of over the fronto-central regions of the head during wakefulness. attenuation and distortion by the skull. Comment: a physiological Amplitude of fronto-central beta rhythm varies but is mostly variant to be distinguished from epileptiform activity, although it below 30 mV. Blocking or attenuation of the beta rhythm by con- may be associated with underlying brain injury and therefore a lia- tralateral movement or tactile stimulation is especially obvious bility to focal seizures. in electrocorticograms. Other beta rhythms are most prominent Buffer amplifier: An amplifier, generally with a voltage gain of in other locations or are diffuse, and may be drug-induced (for 1, a high input impedance, and a low output impedance, used to example alcohol, barbiturates, benzodiazepines and intravenous isolate the input signal from the loading effects of an immediately anaesthetic agents). following circuit. In some electroencephalographs, each input is Bilateral: Involving both sides of the head (or body). connected to a buffer amplifier located in the jack box to reduce Bilateral independent periodic discharges (BIPDs): BIPDs are cable artifact and interference. 2 bilateral independent (i.e. asynchronous) surface-negative Build-up: Colloquialism. Used to describe progressive increase bi- or di-, tri- or poly-phasic complexes consisting of spike, sharp, in voltage of EEG activity or the appearance of slow waves of or polyspike components, with variably following slow waves, increasing amplitude. For example during hyperventilation when lasting 60–600 ms (typically 200 ms) that occupy at least 50% of often associated with decrease in frequency. Sometimes applied a standard 20 minute EEG. Amplitude ranges from 50 to 150 mV to seizure pattern (see seizure pattern). (occasionally up to 300 lV), which may be asymmetric, usually Burst: A group of waves with a minimum of four phases and recurring at 0.5–2 c/s (but very occasionally with intervals of up duration longer than 500 ms which appear and disappear abruptly to 10 s). BIPDs are broadly distributed and waveform morphology and are distinguished from background activity by differences in stays fairly constant for a given patient and EEG, with intervening frequency, form and/or amplitude. Comments: (1) term does not background activity usually attenuated and slow. Most BIPDs are imply abnormality. (2) Not a synonym of paroxysm (see ephemeral phenomena that usually resolve within weeks. They paroxysm). occur with acute marked focal destructive lesions (for example Burst suppression: Pattern characterized by paroxysmal bursts cerebral infarcts, tumors or herpes simplex encephalitis) or more of theta and/or delta waves, at times intermixed with sharp and subacute/chronic pathologies (for example epilepsy and vascular faster waves, alternating with intervening periods of attenuation compromise). Synonyms: bilateral independent periodic epilepti- or suppression (below 10 mV) lasting more than 50% of the record. form discharges, cerebral bigeminy (use of terms discouraged). Comments: EEG pattern that indicates either severe brain dysfunc- (See periodic discharges). tion or is typical for some anesthetic drugs at certain levels of anes- Bilateral independent periodic lateralized epileptiform dis- thesia. Comment: burst suppression pattern with identical bursts charges (BIPLEDs): Use of term discouraged. See bilateral indepen- after anoxic brain injury has been reported to portend a poor neu- dent periodic discharges (preferred term). rological prognosis. Bin width: Time, usually expressed in milliseconds (ms), elaps- Calibration: Historically, analogue procedure of testing and ing between two successive sampling points in digital EEG (see recording the responses of EEG channels to voltage differences digital EEG). Synonym: ordinate period. applied to the input terminals of their respective amplifiers. DC Biological calibration: See calibration and common EEG input (usually) or AC voltages of magnitude comparable to the ampli- test. tudes of EEG waves are used in this procedure. In the digital era, Biphasic wave: Complex consisting of two wave components instrumental system calibration is either performed with an exter- developed on alternate sides of the baseline. Synonym: diphasic nal signal generator or verified by an internal signal generator wave. within the instrument, which is governed by the software of the Bipolar derivation: (1) Recording from a pair of exploring elec- system. trodes. (2) Method of organizing the linkages of electrodes to Cap, head: A cap that is fitted over the head to hold electrodes recording channels. (See exploring electrode, bipolar montage, in position. Synonym: electrode cap. channel). Channel: Complete system for the detection, amplification and Bipolar montage: Multiple bipolar channels, with no electrode display of potential differences between a pair of electrodes, or a being common to all channels. In most instances, bipolar channels computed reference (for example common average reference). Dig- are linked, i.e. adjacent channels from electrodes along the same ital EEG machines simulate a multichannel display by tracing sev- line of electrodes, or chain, have one electrode in common; so eral voltage time plots on a visual display. the reference electrode (input terminal 2) in one channel becomes Circumferential bipolar montage: A montage consisting of the exploring electrode (input terminal 1) in the next channel of linked bipolar derivations encircling the head. Commonly bilateral the chain (see channel, reference and exploring electrode). longitudinal temporal electrode chains are linked together. Blocking: (1) Apparent, temporary obliteration or attenuation Clipping: Distortion of the recorded signal which makes it of EEG rhythms in response to physiological or other stimuli, such appear flat-topped in the display, caused by excess output voltage as eye opening on alpha rhythm, or a change in state (see attenu- overloading the amplifiers (see blocking). ation). (2) A condition of temporary EEG amplifier saturation, Closely spaced electrodes: Additional scalp electrode placed at caused when the output voltages of the amplifier exceed its oper- a shorter distance than that specified by the International ten- ating range sensitivity (see clipping). twenty system (for example see the ten-ten system). Brainstem auditory evoked potential (BAEP): Far-field audi- Common average reference: Computational average potential tory evoked potentials generated largely in the brainstem in of all or most electrode signals used as a reference electrode. Syno- N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 173 nyms: average (potential) reference and Goldman-Offner electrode Cortical electrode: Electrode applied directly upon or inserted (use of terms discouraged). (See reference electrode, Laplacian in to the cerebral cortex. montage). Cortical electroencephalogram: See electrocorticogram. Common EEG input test: Procedure in which the same pair of Cortical electroencephalography: See electrocorticography. EEG electrodes is connected to the two input terminals of all chan- Cycle: The complete sequence of recurrent almost sinusoidal nels of the electroencephalograph. Comment: used as adjunct to oscillatory potential changes undergone by individual waveform calibration procedure (see calibration). Synonym: biological components of regularly repeated EEG waves or complexes. calibration. Cycles per second (c/s): Unit of frequency defined as the num- Common mode rejection: A characteristic of differential ber of complete cycles in one second. Synonym: hertz (Hz). (See amplifiers whereby they provide markedly reduced amplification frequency). of common mode signals, compared to differential signals. Deep sleep: Non-REM sleep stage N3 is dominated (20%) by Expressed as common mode rejection ratio (CMRR), i.e. ratio of slow delta waves of frequency 0.5 to 2 Hz and peak-to-peak ampli- amplifications of differential and common mode signals. tude >75 mV, measured over the frontal regions. Synonym: slow Example: wave sleep. (See light sleep). d amplification; differential 100; 000 Delta band: Frequency band of 0.1–<4 Hz. Greek letter: . Com- ¼ ¼ 100; 000 : 1 ment: for practical purposes lower frequency limit is 0.5 Hz, as DC amplification; common mode 1 potential differences are not monitored in conventional EEGs. Common mode signal: Common component of the two signals Delta brush: Normal neonatal graphoelement, seen at 26– applied to the two input terminals of a differential EEG amplifier. 40 weeks of post menstrual age (PMA), maximal around 32– Comment: in EEG recording, external capacitive interference fre- 34 weeks, and rare at term; combination of delta wave (0.3– quently occurs as a common mode signal. 1.5 c/s; 50–300 mV) with superimposed fast activity (>8 Hz; 10– Common reference electrode: A reference electrode that is 60 mV). Localization changes with PMA. Synonyms: ripples of pre- common to all channels. maturity, spindle-delta bursts (use of terms discouraged). (See also Common reference montage: A montage in which each of the extreme delta brush). channels have the same reference electrode (see channel, referen- Delta wave: Wave with duration of ¼-2 s (250–2000 ms). tial derivation, reference electrode). Depth electrode: Electrode (usually a multicontact electrode) Complex: A sequence of two or more waveforms having a char- implanted within the brain substance. acteristic composite morphology; and when recurring are seen Depth electroencephalogram: Recording of electrical activity with a fairly consistent form, distinguished from background activ- of the brain by means of electrodes implanted within the brain ity. (For example see spike-and-slow-wave complex). substance, usually deep structures such as both hippocampi (see Contingent negative variation (CNV): An event-related slow for example stereotactic [stereotaxic] depth negative potential elicited in the interval between a conditional electroencephalogram). stimulus and an associated contingent second ‘imperative’ stimu- Depth electroencephalography: Technique of recording intra- lus, to which the subject is required to make a voluntary response. cranial depth electroencephalogram (see for example stereotactic It comprises a progressive negative-going change maximal at the [stereotaxic] depth electroencephalography). vertex, which requires special recording techniques so not seen Derivation: (1) The process of recording from, or computing in conventional EEG recording. Synonym: ‘‘expectancy wave”. voltage differences between, a pair of electrodes in an EEG channel. (See event-related potential). (2) The EEG record obtained by this process. Continuous EEG (cEEG): Prolonged EEG recording and often Desynchronization: Terms suggested: blocking or attenuation, analysis for monitoring of electrical brain activity. Data may be col- depending on circumstance. The term desynchronization is accept- lected with analog or digital systems, the latter enabling post- able when referring to the mechanisms presumably responsible for acquisition processing with a number of quantitative EEG tech- blocking or attenuation. It is also used in describing attenuation of niques. cEEG is generally practiced in the intensive care unit with a frequency band based on power spectra analysis of the EEG signal application varying according to the clinical situation: monitoring (for instance ‘‘event-related desynchronization”). (See blocking the EEG as a surrogate of cerebral metabolism (to detect hypoxia or and attenuation). ischemia), nonconvulsive seizures or status epilepticus, and to Diffuse: Colloquialism: an EEG activity spread over large areas monitor the effects of treatment. The aim is to detect EEG changes of both sides of the head (see generalized). This does not imply when the cerebral dysfunction is reversible. There have been rec- abnormality as a normal rhythm may be diffusely distributed (for ommendations that cEEG is used to improve prognostication of example alpha activity in some individuals, or slow waves in deep coma after cardiac arrest. (See quantitative EEG). sleep). Comment: where possible the topographic distribution, Continuous slow activity: Uninterrupted ongoing slow activity symmetry and synchrony should be specified. (theta and delta bands) which may be rhythmic, arrhythmic or Differential amplifier: An amplifier whose output is propor- polymorphic, which may wax and wane but not regress, and is of tional to the voltage difference between its two input terminals. variable amplitude and morphology. Typically it is non-responsive Comment: electroencephalographs make use of differential ampli- to external stimuli and clearly exceeds the amount considered fiers in their input stages. physiologically normal for the patient’s age. (See intermittent slow Differential signal: Difference between two signals applied to activity). the respective two input terminals of a differential EEG amplifier. Continuous spike and waves during sleep (CSWS): An epilep- Digital EEG: (1) The representation of an analog EEG signal by a tic encephalopathy syndrome of electrical status epilepticus during series of numbers related to successive measurements of the mag- sleep (ESES) associated with neurocognitive dysfunction. Seizures nitude of the signal at equal time intervals. (2) The practice of elec- are typically infrequent. Comment: often used interchangeably troencephalography using digital representation of EEGs. with electrical status epilepticus during sleep (ESES). Synonyms: Diphasic wave: Complex consisting of two wave components encephalopathy with status epilepticus during slow sleep. (See developed on alternate sides of the baseline. Synonym: Biphasic slow wave sleep, electrical status epilepticus during sleep). wave. Coronal bipolar montage: Synonym: see transverse bipolar Dipole: An EEG signal vector produced by a separation of neg- montage. ative (sink) and positive (source) potential poles (or current). A 174 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 dipole is characterized by its strength, location and orientation. Electrocorticography (ECoG): Technique of recording electrical Depending on their orientation, dipoles can be radial (perpendicu- activity of the brain by means of electrodes applied over or lar to the surface), tangential (parallel to the surface) or a combina- implanted in to the cerebral cortex. Comment: electrocorticogra- tion of these (oblique). Comment: an equivalent current dipole is a phy can be performed intraoperatively and extraoperatively after theoretical construct commonly used in source imaging to model a surgical implantation (see subdural electrode). generator of an EEG signal located in the center of gravity of the Electrode, EEG: A conducting device applied over or inserted in source (for example an evoked potential, or an epileptiform dis- a region of the scalp or brain. charge). Distributed source models are computed using a large Electrodecrement: A period of amplitude attenuation usually number of small dipoles, distributed within the source space. with superimposed fast activity. Direct coupled amplifier: An amplifier in which successive Electrode impedance: Total effective resistance to alternating stages are connected (coupled) by devices, the performance of current (AC), arising from ohmic resistance and reactance. Mea- which is not frequency dependent. sured between pairs of electrodes or, in some electroencephalo- Direct current (DC-) amplifier: An amplifier that is capable of graphs, between each individual electrode and all the other recording DC (zero frequency) voltages and slowly varying electrodes connected in parallel. Expressed in ohms (generally voltages. kilo-ohms, kO). Comments: (1) over the EEG frequency range, Discharge: Waveforms with no more than 3 phases (i.e. crosses because the capacitance factor is small, electrode impedance is the baseline no more than twice) or any waveform lasting 0.5 s or usually equal to electrode resistance. (2) Not a synonym of input less, regardless of the number of phases. Interpretive term of action impedance of EEG amplifier (see electrode resistance, input potentials and post-synaptic potentials commonly used to desig- impedance). nate interictal epileptiform and seizure patterns (see epileptiform Electrode resistance: Total effective resistance to direct current pattern, seizure pattern). (DC), through the interface between an EEG electrode and the scalp Disk electrode: Typically a metal disk attached to the scalp or brain. Measured between pairs of electrodes or, in some elec- with an adhesive such as collodion or adherent conductive paste. troencephalographs, between each individual electrode and all Disorganization: Gross alteration in frequency, form, topogra- the other electrodes connected in parallel. Expressed in ohms (gen- phy and/or quantity of physiologic EEG rhythms in: (1) an individ- erally kilo-ohms, kO). Comment: measurement of electrode resis- ual record, relative to previous records in the same subject or the tance with DC currents results in varying degrees of electrode rhythms of homologous regions on the opposite side of the head, polarization (see electrode impedance). or (2) relative to findings in normal subjects of similar age and sim- Electroencephalogram (EEG): Record of electrical activity of ilar state of vigilance. (See organization). the brain taken by means of electrodes placed on the surface of Display Gain: Manipulation of the data after acquisition to the head, unless otherwise specified. change the visual size of waveforms in order to aid visual inspec- Electroencephalograph (EEG): Instrument employed to record tion. Comment: results of increase or decrease of the display gain electroencephalograms. are similar to changes of sensitivity during acquisition. Electroencephalographic: Appertaining to bioelectrical record- Distortion: An instrument-induced alteration of waveform (see ing, irrespective of the method employed (in the present context artifact, clipping). EEG, ECoG, SEEG, etc.). Duration: (1) The interval from beginning to end of an individ- Electroencephalography (EEG): (1) The science relating to the ual wave or complex. Comment: the duration of the cycle of indi- electrical activity of the brain. (2) The practice of recording and vidual components of a sequence of regularly repeating waves or interpreting electroencephalograms. complexes is referred to as the period of the wave or complex. Encoche frontale: Normal neonatal graphoelement in term and (2) The time that a sequence of waves or complexes or any other near term infants, between 34 and 44 weeks post menstrual age. distinguishable feature lasts in an EEG record. Frontal broad diphasic sharp waves (50–100 mV); typically bilat- Electrical status epilepticus during sleep (ESES): an EEG pat- eral, but may be unilateral. Usually seen in transition from active tern seen in childhood which consists of continuous or near contin- to quiet sleep. Synonym: anterior sharp transient, transient frontal uous spike-and-slow-waves during sleep. Discharges may be seen sharp wave. (See active and quiet sleep). in wakefulness, often with a frontal or temporal emphasis, but Epicortical electrode: Use of term discouraged. Synonym: sub- increase markedly in sleep and typically abate in REM sleep. Quan- dural electrode (preferred term). tification of epileptiform activity is not standardized but some use Epidural electrode: Electrode located over the dural covering spike-and-slow-wave index of >50% or >85%. Most children have or of the cerebrum. develop seizures and present with neurocognitive dysfunction. Epileptiform pattern: Describes transients distinguishable Comment: often used synonymously with continuous spike and from background activity with a characteristic morphology typi- waves during sleep (CSWS). (See index, slow wave sleep, continu- cally, but neither exclusively nor invariably, found in interictal ous spike and waves during sleep). EEGs of people with epilepsy. Epileptiform patterns have to fulfill Electrocerebral inactivity: Absence over all regions of the head at least 4 of the following 6 criteria: of identifiable electrical activity of cerebral origin, whether sponta- neous or induced by physiological stimuli or pharmacological (1) Di- or tri-phasic waves with sharp or spiky morphology (i.e. agents. Comment: strict technical recording standards should be pointed peak). observed in suspected cerebral death (Stecker et al., 2016). Trac- (2) Different wave-duration than the ongoing background activ- ings of electrocerebral inactivity should be clearly distinguished ity, either shorter or longer. from low voltage EEGs (see low voltage EEG). Synonyms: electro- (3) Asymmetry of the waveform: a sharply rising ascending cerebral silence, flat or isoelectric EEG (use of terms discouraged). phase and a more slowly decaying descending phase, or vice Electrocorticogram (ECoG): Record of EEG activity obtained by versa. means of electrodes applied directly over or inserted in to the cere- (4) The transient is followed by an associated slow after-wave. bral cortex. Comment: electrocorticograms can be performed (5) The background activity surrounding epileptiform dis- intraoperatively and extraoperatively after surgical implantation charges is disrupted by the presence of the epileptiform (see subdural electrode). discharges. N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 175

(6) Distribution of the negative and positive potentials on the Fast alpha variant rhythm: A normal variant. Characteristic scalp suggests a source of the signal in the brain, rhythm at 14–20 Hz, detected most prominently over the posterior corresponding to a radial, oblique or tangential orientation regions of the head. May alternate or be intermixed with alpha of the source (see dipole). This is best assessed by rhythm, of which it is usually a harmonic frequency. Blocked or inspecting voltage maps constructed using common-average attenuated by attention, especially visual, and mental effort. reference. Fast ripples: Part of the high frequency oscillation (HFO) band- Synonyms: interictal epileptiform discharge, epileptiform width, usually defined as being in the range 250–1000 Hz (see high activity. frequency oscillations). Epoch: EEG segment with a defined duration. Duration of Fast wave: Wave with duration shorter than alpha waves, i.e. epochs is determined arbitrarily but should be specified. under 1/13 s. Equipotential: Applies to regions of the head or electrodes that Focal: Limited to a small area of the brain in one hemisphere are at the same potential at a given instant in time. Synonyms: (see regional, multifocal). Focal epileptic seizures are conceptual- isopotential line, isopotential. ized as originating within networks limited to one hemisphere, Event-related potential (ERP): Refer to long latency responses and usually associated with an initially localized epileptiform (>70 ms) associated with an event, such as a deviant stimulus (as in EEG pattern (see epileptiform pattern). mismatch negativity, P3 or P300), anticipation of a response (as in Focus: A limited region of the scalp, cerebral cortex, or depth of Bereitschaftspotential), or anticipation of a stimulus demanding a the brain displaying a given EEG activity, either normal or response (as in contingent negative variation). Applied mainly to abnormal. slow (on account of their lower frequency content) ‘endogenous’ Foramen ovale electrode: A multicontact electrode bundle evoked potentials elicited by controlled manipulation of the psy- inserted through the foramen ovale to lie in proximity to the chological context. Thought to reflect some aspect of higher sen- mesial temporal cortex. Comment: used for presurgical assessment sory processing, and therefore sometimes referred to as of epilepsy of suspected mesial temporal lobe origin. (See basal ‘‘cognitive potentials”, such as: attention, expectancy, novelty electrode). detection, stimulus salience, target recognition, task relevance, Fourteen and 6-Hz positive burst or spikes: A normal variant. information delivery, decision making, stimulus evaluation time, Burst of arch-shaped waves or spikes at 13–17 c/s and/or 5–7 c/s, template matching, memory, and closure of cognitive epoch. (See but most commonly at 14 and/or 6 c/s, usually seen bilaterally over evoked potential, contingent negative variation, mismatch negativ- the posterior temporal and adjacent areas, typically during drowsi- ity, P3 or P300). ness and light sleep, with incidence peaking in adolescence. The Evoked magnetic field: Magnetic counterpart of EEG evoked sharp peaks of its component waves are positive with respect to potential. (See evoked potential, magnetoencephalography). other regions. Amplitude varies but is generally below 75 mV. Com- Evoked potential (EP): Wave or complex elicited by and time- ments: (1) best demonstrated by referential recording using con- locked to a physiological or non-physiological stimulus or event, tralateral earlobe or common average reference electrodes. (2) the timing of which can be reliably assessed. Comment: computer This pattern has been termed ‘‘pseudo-epileptiform” (i.e. not asso- summation (averaging) techniques are especially suitable for ciated with a liability to epileptic seizures). Synonym: ctenoids detecting these and other event-related potentials from the surface (use of term discouraged). of the head. See event-related potential. Frequency: Number of complete cycles of repetitive waves or Exploring electrode: An electrode that registers electrical complexes in 1 s. Measured in cycles per second (c/s) or Hertz potentials from excitable tissue of the nervous system, historically (Hz). Comment: the term Hz seems appropriate when applied to connected to the input terminal 1 of an EEG amplifier, against a ref- sinusoidal waves such as alpha activity, but seems inappropriate erence electrode, connected to the input terminal 2. Synonym: when applied to complex waveforms such as spike-and-slow- active electrode (use discouraged as all recording electrodes may waves, which may be more correctly quantified by c/s. This princi- be considered ‘active’, including any reference electrode). (See ref- ple has been applied throughout this glossary. erence electrode). Frequency response: Characteristics of an amplifier showing Extracerebral potential: Any potential that does not originate the relative response to the activities of different frequencies with in the brain, generally referred to as an artifact in EEG. May arise respect to the response of 10 Hz activity. The bandwidth of EEG from electrical interference external to the subject and recording channels is determined by the low and high frequency filters and system, the subject, the electrodes and their connections to the the particular frequency response characteristics of the recording subject and the electroencephalograph, and the electroencephalo- system. graph itself (see artifact). Frequency response curve: A graph depicting the relationships Extreme delta brush: A particular pattern characterized by between output trace detection or amplifier output and input fre- near continuous widespread rhythmic delta activity (1–3 c/s) with quency, for a particular setting of low and high frequency filters. superimposed bursts of beta frequency activity (20–30 Hz) on top Frequency spectrum: The distribution of amplitude and phases of each delta wave. Mostly symmetric and synchronous; do not of different frequency components against frequency. This is typi- vary with sleep-wake cycles or significantly with stimulation. cally demonstrated by a Fourier transform of the EEG. Comment: In The pattern has been described in autoimmune encephalitis asso- most applications the amplitude spectrum is presented only (for ciated with anti-N-Methyl D-Aspartate receptor antibodies. Named example in delta, theta, alpha, beta, gamma bands), and not phase after a resemblance to the delta brush seen in preterm infants (see information. (See power spectrum, quantitative EEG). delta brush). Frontal intermittent rhythmic delta activity (FIRDA): Fairly Far-field potential: A potential generated in a deep neural regular, approximately sinusoidal or sawtooth waves, mostly structure and recorded by electrodes on the head at a distance occurring in bursts at 1.5–2.5 Hz synchronously over the frontal from the generator, as a result of volume conduction and not medi- areas of both sides of the head (occasionally unilateral). Comment: ated by neuronal activity. (See volume conduction, and for exam- most commonly associated with mild to moderate unspecified ple brainstem auditory evoked potentials). encephalopathy in responsive ambulant patients, often in associa- Fast activity: Activity of frequency higher than the alpha band, tion with cerebrovascular disease. Synonym: occasional frontally i.e. beta and gamma activity, and high frequency oscillations. predominant brief 2/s GRDA. 176 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185

Fronto-central theta: A normal variant. Theta rhythm located invariably. Synonym: generalized periodic epileptiform discharges in the midline, just anterior to the vertex, that occurs during (use of term discouraged). (See periodic discharges). psychological stress and cognitive tasks, particularly problem Generalized periodic epileptiform discharges (GPEDs): Use of solving. It appears predominantly in young healthy adults term discouraged. See generalized periodic discharges (preferred (<30 years of age). The pattern is considered to be a normal term). response to cognitive tasks. Synonyms: frontal midline theta, Graphoelement: Any EEG pattern (transient, potential or Ciganek rhythm. rhythm) that is distinguished from the ongoing background activ-

Gain, voltage: The ratio of output signal voltage, Vo, to input ity, which may be physiological or pathological. It is characterized signal voltage, Vi, of an EEG channel. For example: by its name, morphology, location, duration, frequency (when rhythmic), mode of appearance and the relationship to activating V 10V Voltage gain ¼ o ¼ ¼ 1; 000; 000 or modulating factors (for example hypnagogic hypersynchrony). V i 10 lV Ground connection: Conducting path between the subject, the electroencephalograph and earth. The voltage gain (G) is often expressed in decibels (dB), a loga- Ground projection: Projection of an artifact, such as blink arti- rithmic ratio, defined as fact, recorded from a ground electrode into an exploring electrode ¼ ð = Þ whose impedance is high. G 20log10 V o V i dB Harness, head: A combination of straps fitted over the head to Examples: a voltage gain of 10 corresponds to G = 20 dB, of hold pad electrodes in position. Commercial EEG recording elec- 1,000 to G = 60 dB, of 1,000,000 to G = 120 dB. Gain controls are trodes caps are an alternative. used to attenuate and equalize the sensitivities of all channels Hertz (Hz): Unit of frequency. Synonym: cycles per second (c/s). (see sensitivity). High frequency filter (or low pass filter): A circuit that reduces Gamma band: Frequency band from >30 to 80 Hz. Greek letter: the sensitivity of the EEG signals to relatively high frequencies (for c. Comment: The graphic resolution of computer displays may example above 70 Hz). For each setting of the high frequency filter, limit the visual appreciation of higher frequencies. However, this this attenuation is expressed as percent reduction in signal ampli- does not justify limiting unduly the high frequency response of tude at a given frequency, relative to frequencies unaffected by the the EEG channels; for EEG waves include transients such as spikes filter, i.e. in the mid-frequency band of the signal. Synonym: low and sharp waves with components at frequencies above 50 Hz. pass filter. Comment: at present high frequency filter designations Gamma rhythm or activity: An EEG rhythm above >30–80 Hz and their significance are not yet standardized for all instruments (wave duration 12.5–33 ms). Comment: most commonly recorded of different manufactures. For instance, for a given instrument, a with intracranial electrodes from actively engaged or driven neural position of the high frequency filter control designated as 70 Hz networks. may indicate a 30% (3 dB), or other stated percent, reduction in Generalization: Bilateral propagation of EEG activity from lim- sensitivity at 70 Hz, compared to the sensitivity, for example, at ited areas to all regions of the head (see generalized). 10 Hz. Generalized: Loosely: an EEG activity spread over all regions of High frequency oscillations (HFOs): Transient bursts of EEG the head, usually with a frontal, but rarely with an occipital, max- activity, spontaneous or evoked, with frequencies beyond 80 Hz. imum (see diffuse). Strictly: bilateral EEG discharges appearing Divided into ripples (80–250 Hz) and fast ripples (250–500 Hz). reasonably symmetrically and synchronously over homologous (See ripples and fast ripples). regions of the head (see symmetric and synchronous). For example High frequency response: Sensitivity of an EEG channel to rel- generalized epileptic seizures are conceptualized as originating at atively high frequencies. Determined by the high frequency some point within, and rapidly engaging (i.e. synchronizing), bilat- response of the amplifier and the high frequency filter used. erally distributed networks. Comment: ‘‘generalized” is still used Expressed as percent reduction in output trace deflection at certain as a term for describing seizure types and epilepsy syndromes, specific high frequencies, relative to other frequencies in the mid- although no seizure pattern involves the whole brain simultane- frequency band of the channel. ously (see secondary bilateral synchrony). High pass filter: Synonym: low frequency filter. Generalized paroxysmal fast activity (GPFA): Bilateral syn- Hypersynchrony: When describing EEG patterns that are chronous bursts of spikes of 2–10 s duration, with frequency attributed to increased synchronization of neuronal activity (for between 10 and 25 Hz (typically around 10 Hz) and maximum in example hypnagogic hypersynchrony). the frontal regions that only occurs during sleep. GPFA is consid- Hyperventilation: Deep and regular respiration performed for a ered a feature of Lennox-Gastaut syndrome. Comment: when the period of several minutes. Used as an activation procedure. Syno- bursts are longer than 5 s a tonic seizure is often recorded (this nym: overbreathing (see activation). may be discrete, and only detected with surface EMG electrodes). Hypnagogic hypersynchrony: A normal variant. Paroxysmal Synonyms: bursts of fast rhythms, fast paroxysmal rhythms, runs bursts of 3–5 c/s, high amplitude (75–350 mV) diffuse, but maximal of rapid spikes (use of terms discouraged). fronto-central, sinusoidal activity occurring at the onset of sleep in Generalized periodic discharges (GPDs): GPDs are generalized, normal infants and children, aged 3 months to 13 years (but typi- synchronous, periodic or quasi-periodic complexes that occupy at cally 4–9 years). least 50% of the record. They are high amplitude (typically Hypsarrhythmia: Characteristic interictal EEG pattern typi- >100 mV) and have duration of about 0.5 s, with an intervening cally, but not invariably, seen in infants with Infantile Spasms background activity amplitude usually not more than 35 mV. The (West syndrome). Consists of diffuse very high amplitude morphology of GPDs is variable and consists of sharp or spike (>300 mV) irregular slow waves interspersed with multiregional and slow wave complexes, triphasic-like waves, and slow wave spikes and sharp waves over both hemispheres, usually with a complexes. Repetition rate usually lies between 0.5 and 2.0 c/s. highly disorganized and asynchronous appearance. It is most fre- They occur most commonly in coma, usually after severe cerebral quent during Non-REM sleep, followed by waking and arousal, anoxia following cardiac arrest, in Creutzfeldt-Jacob disease, and and is absent or minimal during REM sleep. Variations include with toxicity (for example baclofen or lithium). With anoxic asymmetry, predominant single focus (within widespread abnor- insults, the periodicity typically ranges from 1.5 to 3.5 c/s. Most malities), episodes of attenuation or fragmentation, increased peri- patients have a poor neurological prognosis or die, although not odicity and preservation of interhemispheric synchrony (all N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 177 termed ‘modified hypsarrhythmia’). Comment: the ictal pattern of Intermittent slow activity: Slow EEG activity that occurs inter- spasms usually consists of one or more of following: diffuse high mittently and is not caused by drowsiness (usually >100 mV). Inter- amplitude slow wave, low to medium amplitude fast activity, or mittent slow activity varies by more than 50% or regresses electrodecrement (see low amplitude fast activity, completely between times of its appearance, and can be polymor- electrodecrement). phic, arrhythmic or rhythmical (see continuous slow activity). Ictal EEG pattern: See seizure pattern, EEG. Intracerebral depth electroencephalogram: See: depth Impedance meter: An instrument used to measure impedance electroencephalogram. (see electrode impedance). Intracerebral electrode: Various conducting devices for record- Inactivity, record of electrocerebral: See electrocerebral ing EEG from the surface or within the substance of the brain. inactivity. Examples include epicortical/subdural, epidural, foramen ovale, Incidence: Descriptor used to characterize how often a tran- and stereotactic [stereotaxic] implanted depth electrodes. Syno- sient or isolated discharge is seen throughout the recording. Sug- nym: depth electrode. gested ranges for describing this: 1/10 s are abundant, 1/min Irregular: Applies to EEG waves and complexes of inconstant but less than 1/10 s are frequent, 1/h but less than 1/minute period and/or uneven contour or morphology. are occasional, and <1/h are rare. Comment: the equivalent Isoelectric: (1) The record obtained from a pair of equipotential descriptor for rhythmic EEG patterns is prevalence. Synonym: electrodes (see equipotential). (2) Use of term discouraged when quantity. (See prevalence). describing record of electrocerebral inactivity (see electrocerebral Independent (temporally): Not dependent on some other EEG inactivity). activity. Synonym: asynchronous. Isolated: Occurring singly. Index: Percent of time an EEG activity is present in an EEG sam- Isopotential: See synonym equipotential. ple. For example: alpha index, spike wave index, daily pattern K complex: A normal graphoelement. A well delineated nega- index. tive sharp wave followed by a positive component standing out Infraslow activity: EEG activity with frequencies in the EEG from the background EEG, with total duration 0.5 s, usually max- below 0.1 Hz. Synonym: subdelta activity. imal in amplitude when recorded from fronto-central derivations In-phase signals: Waves with no phase difference between and often associated with a sleep spindle. (See vertex sharp tran- them (see common mode signal – not a synonym). sient or vertex sharp wave). Input: The signal fed into an EEG amplifier (see input terminal Lambda wave: A normal graphoelement. Diphasic sharp tran- 1; input terminal 2). sient occurring over the occipital regions of the head of awake sub- Input circuit: System consisting of the EEG electrodes and jects during visual exploration. The main component is positive intervening tissues, the electrode leads, jack box, input cable, and relative to other areas. Time-locked to saccadic eye movements. electrode selectors. Amplitude varies but is generally below 50 mV. Greek letter: k (note Input impedance: Impedance that exists between the two morphology resembling the Greek capital letter lambda). inputs of an EEG amplifier. Measured in ohms (generally mega- Laplacian montage: Montage that consists of a mathematical ohms, MO) with or without the additional specification of input transformation involving the second spatial derivative; the Lapla- shunt capacitance (measured in picofarads, pF). Comment: not a cian source of the potential may be approximated by using the synonym of electrode impedance. weighted average of all the neighbouring electrodes as a reference Input terminal 1: The input terminal of the differential EEG for each site or electrode. This montage may be used for localiza- amplifier at which negativity, relative to the other input terminal, tion of focal abnormalities on digital EEG (see common average produces an upward trace deflection (see polarity convention). reference). Synonyms: ‘‘grid 1” (G1), black lead (use of terms discouraged). Lateralized: Independently involving the right and/or left side Comment: customarily the connection of an electrode to the input of the head (or body) (see unilateral). terminal 1 of the EEG amplifier is represented in diagrams as a Lateralized periodic discharges (LPDs): LPDs are unilateral solid line. surface negative discharges of spike, sharp or sharp slow-wave Input terminal 2: The input terminal of the differential EEG polyphasic morphology, usually lasting from 100 to 300 ms that amplifier at which negativity, relative to the other input terminal, typically recur at quasiperiodic intervals of up to 3/s. The incidence produces a downward trace deflection (see polarity convention). of clinical or electrographic seizures associated with LPDs is high, Synonyms: ‘‘grid 2” (G2), white lead (use of terms discouraged). ranging from 50 to 100%, but there is debate as to whether they Comment: the connection of an electrode to the input terminal 2 represent seizures proper. When contralateral motor movements of the EEG amplifier is represented in diagrams as a dotted or are time-locked to LPDs they are considered to represent seizure dashed line. patterns. Most LPDs are ephemeral phenomena occurring with Input voltage: Potential difference between the two input ter- both acute focal destructive lesions (for example cerebral infarcts, minals of a differential EEG amplifier (see differential amplifier). tumors or herpes simplex encephalitis) and more subacute/chronic Inter-electrode distance: Spacing between pairs of electrodes. pathologies (for example epilepsy and vascular compromise). Comment: distances between adjacent electrodes placed according Synonym: periodic lateralised epileptiform discharges (use of term to the standard 10–20 system or more closely spaced electrodes discouraged). (See discharge, periodic discharges). are frequently referred to as short or small inter-electrode dis- Lead: Strictly: wire connecting an electrode to the electroen- tances (i.e. 10–10 system). Larger distances (such as double) cephalograph. Loosely: synonym of electrode, its wire and between standard electrode placements are often termed widely connector. spaced, long or large inter-electrode distances. Light sleep: Non-REM (NREM) sleep stages N1 and N2, which Interhemispheric derivation: Recording between a pair of are characterized by sinusoidal eye movements, low amplitude electrodes located on opposite sides of the head (for example F3- mixed frequency EEG activity, vertex sharp waves, K complexes F4). and sleep spindles. (See deep sleep). Intermittent photic stimulation: Delivery of intermittent Linkage: The connection of a pair of electrodes to the two flashes of light to the eyes of a subject. Used as EEG activation pro- respective input terminals of a differential EEG amplifier (see cedure. Synonym: photic stimulation (PS). derivation). 178 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185

Longitudinal bipolar montage: A montage consisting of con- by relatively stereotyped delta activity (up to 200 mV) predomi- tiguous channels of electrode pairs along longitudinal, mainly nantly over the posterior regions (occipital, temporal and central). antero-posterior, arrays (for example, Fp1-F3, F3-C3, C3-P3, P3- Montage: The arrangement or array of channels on the EEG O1 etc). Synonym: ‘‘double-banana” montage. machine display, defined by the exploring and reference electrodes Low frequency filter (high pass filter): A circuit that reduces (for example see bipolar and referential montages). the sensitivity of the EEG signal to relatively low frequencies (for Morphology: Refers to the form of EEG waves (i.e. their shape example below 0.5 Hz). For each position of the low frequency fil- and physical characteristics). ter control, this attenuation is expressed as percent reduction of Motor evoked potential (MEP): Evoked potential recorded the signal at a given stated frequency, relative to frequencies unaf- from muscle following direct stimulation of the exposed motor fected by the filter, i.e. in the mid-frequency band of the channel. cortex, or transcranial stimulation of the motor cortex, either mag- Comment: at present low frequency filter designations and their netically or electrically. significance are not yet standardized for instruments of different Mu rhythm: Rhythm at 7–11 Hz, composed of arch-shaped manufacturers. For instance, in a given instrument a low frequency waves occurring over the central or centro-parietal regions of the filter setting designated 1 Hz may indicate a 30% (3 dB), or other scalp during wakefulness. Amplitude varies but is mostly below stated percent, reduction in sensitivity at 1 Hz, compared to the 50 mV. Blocked or attenuated most clearly by contralateral move- sensitivity for example at 10 Hz. The same position of the low fre- ment, thought of movement, readiness to move or tactile stimula- quency filter setting may also be designated by the time constant. tion. Greek letter: l. Synonyms: rhythm rolandique en arceau, Synonym: high pass filter. comb rhythm (use of terms discouraged). Low frequency response: Sensitivity of an EEG channel to rel- Multifocal: Three or more spatially separated independent foci atively low frequencies. Determined by the low frequency (see focal). response of the amplifier and by the low frequency filter (time con- Multiple spike-and-slow-wave complex: Use of term discour- stant) used. Expressed as percent reduction in output trace deflec- aged. An epileptiform graphoelement consisting of two or more tion at certain stated low frequencies, relative to other frequencies spikes associated with one or more slow waves (see epileptiform in the mid-frequency band of the channel (see low frequency filter, pattern). Synonym: polyspike and-slow-wave complex (preferred time constant). term). Low pass filter: Synonym: high frequency filter. Multiple spike complex: Use of term discouraged. A sequence Low voltage EEG: A normal variant. Waking record character- of two or more spikes. Synonym: polyspike complex (preferred ized by activity of amplitude not greater than 20 mV over all head term). regions. With appropriate instrumental sensitivities this activity Multiregional: Three or more lobar foci (see regional). can be shown to be composed primarily of beta, theta and, to a les- Nasopharyngeal electrode: Rod electrode introduced through ser degree, delta waves, with or without alpha activity over the the nose and placed against the nasopharyngeal wall with its tip posterior areas. Comments: (1) low voltage EEGs are susceptible lying near the body of the sphenoid bone. (See basal electrode). to change under the influence of certain physiological stimuli, Needle electrode: Small needle inserted into the subdermal sleep, pharmacological agents and pathological processes. (2) They layer of the scalp. should be clearly distinguished from tracings of electrocerebral Noise, EEG channel: Small fluctuating output of an EEG channel inactivity, suppression and low voltage fast activity (see electro- recorded when high sensitivities are used, even if there is no input cerebral inactivity, suppression and low voltage fast activity). signal. Measured in microvolts (mV), referenced to the input. Low voltage fast activity: Refers to fast activity (beta rhythm Non-cephalic reference: Reference electrode that is placed on and above), often recruiting, which can be recorded at the onset body parts other than the head (for example sternospinal of an ictal discharge, particularly in intra-cranial depth EEG record- reference). ing of a seizure. Non-REM sleep (NREM): Term summarizing all sleep stages Magnetoencephalography (MEG): Recording of magnetic except REM sleep (see REM sleep). fields generated from the cortical neurons. Notch filter: A filter that selectively attenuates a very narrow Map, voltage: Topographical display of the voltage distribution frequency band, thus producing a sharp notch in the frequency on the scalp, using equipotential lines and color-codes to express response of an EEG signal. Commonly applied to attenuate electri- the steps of gradient changes between the peak negativity and cal noise from mains interference (the frequency of which differs the peak positivity. The voltage difference between peak negativity between countries, 50 or 60 Hz), which may occur under unfavor- and peak positivity is 100%, and the fall-off of the potential is able technical conditions. shown in arbitrary steps of, for example, 10% of the maximum Nyquist theorem: Accurate digital representation of an EEG sig- amplitude. Usually blue color symbolizes negativity, and red color nal requires that the sampling rate is at least twice the highest fre- positivity. Inspecting voltage maps allows estimation of the loca- quency of the signal, i.e. a frequency component of 30 Hz requires tion and orientation of the source. Comment: it is recommended at least a sampling rate of 60 Hz. Comment: sampling at twice the to calculate voltage maps using common average reference (that Nyquist frequency only ensures an accurate representation of fre- include all electrodes on the scalp and preferably the inferior tem- quency content. Tolerable reproduction of waveforms requires at poral electrode chain too). (See Quantitative EEG). Synonyms: dia- least a sampling rate 5 times above the fastest frequency compo- gram of equipotential lines, isopotential map or amplitude map. nents present. Mismatch negativity (MMN): Is an automatic (i.e. attention Occipital intermittent rhythmic delta activity (OIRDA): Fairly independent) event-related response to physically deviant audi- regular or approximately sinusoidal waves, mostly occurring in tory stimuli occurring among frequent (standard) stimuli (e.g. bursts at 2–3 Hz over the occipital areas of one or both sides of tones or phonetic stimuli). MMN is a surface negative potential the head. Frequently blocked or attenuated by eye opening. An with an onset latency of about 130 ms and lasting 250–300 ms, abnormal pattern seen in children’s EEGs more frequently than with maximal amplitude over the fronto-central region. (See adults, often but not exclusively in association with genetic gener- event-related potential). alized epilepsies. Monorhythmic delta activity: A normal graphoelement in pre- Ohmmeter: An instrument used to measure resistance (see term infants (24–34 weeks of post menstrual age). Characterized electrode resistance). N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 179

Ordinate period: Time in milliseconds (ms) elapsing between wave recorded simultaneously in another derivation. (2) Time or two successive sampling points in digital EEG. (See bin width). angular relationships between a point on a wave and the onset Organization: Degree to which the posterior dominant rhythm of the cycle of the same wave. Usually expressed in degrees or (PDR) conforms to certain characteristics displayed by a majority radians. of subjects in the same age group, without personal or family his- Phase reversal: Simultaneous trace deflections in opposite tory of neurologic and psychiatric diseases, or other illnesses that directions from two or more channels in a bipolar recording mon- might be associated with dysfunction of the brain. Comments: tage. Assuming a single generator, phase reversal is due to the the organization of PDR progresses from birth to adulthood. same signal being applied to the input terminal 2 of one differen- Out-of-phase signals: Two waves of opposite phases (see dif- tial amplifier and to the input terminal 1 of the other amplifier. ferential signal; phase reversal - not a synonym). Comment: When observed in two linked bipolar channels, phase Output voltage: The voltage across the trace display of an EEG reversal indicates that the potential field is maximal or minimal channel. at or near the electrode common to such derivations. A phase Overbreathing: Synonym: hyperventilation. reversal seen in a referential recording, when assessed using map- Overload: Condition caused by applying voltage differences ping of the potential fields, indicates that the dipole source is hor- which are larger than the channel is designed for or set to handle izontally located in the sulcal wall across the borderline of the two by the input terminals of an EEG amplifier. Displays clipping of fields of opposite polarity. (See bipolar and referential montages, EEG waves and/or blocking of the amplifier depending on its mag- dipole, input terminal). nitude (see clipping, blocking). Photic driving: Physiologic response consisting of periodic P3 or P300: Is an event-related potential response usually eli- activity elicited over the posterior regions of the head, usually cited using the oddball paradigm, in which low-probability target induced by repetitive photic stimulation at frequencies of about stimuli are mixed with high-probability non-target (or standard) 1–30 Hz. Comments: (1) term should be limited to activity time- stimuli. P3 is a surface positive potential with an onset latency of locked to the stimulus and of frequency identical or harmonically about 250 to 500 ms and maximal amplitude over the centro-pari- related to the stimulus frequency. (2) Photic driving should be dis- etal region, with two subcomponents denoted P3a and P3b. Syno- tinguished from the visual evoked potentials elicited by isolated nym: late positive component (LPC). (See event-related potential). flashes of light or flashes repeated at low frequencies (<5 Hz). Pad electrode: Metal electrode covered with a cotton or felt (See photic stimulation). and gauze pad, held in position by a head cap or harness. Photic evoked potential (PEP): Evoked potential generated in Paper speed: Velocity of movement of paper through an ana- the occipital cortex in response to flash stimulation. Synonym: logue EEG machine. Expressed in centimeters per second (cm/s) Flash EP. or millimeters per second (mm/s). Synonym: time base (in digital Photic stimulation: Delivery of intermittent flashes of light to EEG). the eyes of a subject, usually from 1 to 60 Hz. Used as EEG Paroxysm: Graphoelement phenomenon with sudden onset, activation procedure. Synonym: intermittent photic stimulation rapid attainment of a maximum, and abrupt termination; distin- (IPS). guished from background activity. Comment: commonly used to Photic stimulator: Device for delivering intermittent flashes of refer to epileptiform and seizure patterns (see epileptiform pattern light. and seizure pattern). Photomyogenic response: A non-cerebral response to inter- Paroxysmal fast: Fast frequencies in the beta range or above mittent photic stimulation characterized by the appearance in occurring in trains (see paroxysm, low voltage fast activity). the record of brief repetitive muscle spikes (electromyography Pattern: Any characteristic regular or repetitive EEG activity of artifact) over the anterior regions of the head. These often increase approximately constant period (see regular and rhythmic). gradually in amplitude as stimuli are continued and cease Peak: Point of maximum amplitude of a wave. promptly when the stimulus is withdrawn. Comments: (1) this Period: Duration of complete cycle of individual graphoelement response is frequently associated with flutter of the eyelids and in a sequence of regularly repeated EEG waves or complexes. Com- vertical oscillations of the eyeballs and sometimes with discrete ment: the period of the graphoelement of an EEG rhythm is the jerking mostly involving the musculature of the face and head, reciprocal of the frequency of the rhythm. (For example, the (2) it is a physiological artifact contaminating the EEG. duration of a spike-and-slow-wave complex in 3 c/s spike-and- Photoparoxysmal response (PPR): Abnormal response to slow-waves is 1/3 = 0.333). intermittent photic stimulation characterized by spike-and-slow- Periodic: Applies to: (1) EEG waves or complexes occurring in a wave or polyspike-and-slow-wave complexes. Responses are sub- sequence at an approximately regular rate, (2) EEG waves or com- classified in to 4 phenotypically different types, from focal occipital plexes occurring intermittently at approximately regular intervals, spikes (type 1 PPR) time-locked to the flashes to generalized (type generally of one to several seconds. (See periodic discharges). 4 PPR) epileptiform discharges, which may outlast the stimulus by Periodic discharges (PDs): Repetition of a waveform with a few seconds. Comment: only the more generalized spike-and- relatively uniform morphology and duration, with a quantifiable wave responses (type 3 and 4 PPRs) show a strong association with inter-discharge interval between consecutive waveforms, and epilepsy. recurrence of the waveform at nearly regular intervals. Comments: Polarity convention: International agreement whereby differ- PDs may be generalized (GPDs), lateralized (LPDs), bilateral ential EEG amplifiers are constructed so that negativity at input independent (BIPDs). Old nomenclature for these new terms are terminal 1 relative to input terminal 2 of the same amplifier results GPEDs (=GPDs), PLEDs (=LPDs) and BIPLEDs (=BIPDs). The use of in an upward trace deflection. For example, for a bipolar derivation ‘‘epileptiform” as an interpretative term is now avoided, since C3-Cz (input 1 terminal -input terminal 2), an ‘upward deflection’ these periodic patterns may or may not be associated with clinical implies that C3 is more negative than Cz, while a ‘downward seizures (Hirsch et al., 2013). deflection’ implies that Cz is more negative than C3. Comment: this Periodic lateralized epileptiform discharges (PLEDs): Use of convention is contrary to that prevailing in some other biological term discouraged. See lateralized periodic discharges (preferred and non-biological fields. (See input terminal 1 and 2). term). Polarity, EEG wave: Sign of potential difference, either positive Phase: (1) Time or polarity relationships between a point on a or negative, existing at a given time between one electrode and wave displayed in a derivation and the identical point on the same another electrode (see polarity convention); which may be an 180 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 exploring and reference electrode in a referential derivation, or two Prevalence: Proportion of the record or a specified epoch that exploring electrodes in a bipolar derivation. includes a particular EEG pattern. For example: 90% is continu- Polygraphic recording: Simultaneous monitoring of multiple ous, 50–89% is abundant, 10–49% is frequent, 1–9% is occasional, physiological parameters such as the EEG, respiration, electrocar- and <1% is rare. Comment: the equivalent descriptor for transients diogram, electromyogram, eye movements (electrooculogram), or isolated discharges is incidence or quantity. (See incidence, oxygen saturation, and leg movements, etc. Comment: some may quantity). be part of routine EEG recording but are recommended in Propagation: The active neural process whereby electric polysomnography. (See polysomnography). activity spreads from one area of the brain to another. For Polymorphic activity: Irregular EEG waves having multiple example, propagation from a focus to the contralateral, forms, which may also vary in frequency and amplitude. Synonym: homologous brain region, which then leads to bilateral irregular. synchronous discharges, is called secondary bilateral synchrony Polyphasic wave: Wave consisting of more than two phases or secondary generalization. (See secondary bilateral synchrony, developed on alternating sides of the baseline (for example see volume conduction). triphasic wave). Psychomotor variant: Use of term discouraged. Synonym: Polysomnography (PSG): Polygraphic recording of sleep rhythmic temporal theta burst of drowsiness. including EEG, electrooculogram, electromyogram (chin and leg), Quantitative EEG (qEEG): Processing and analysis of portions of airflow parameters and oxygen saturation, along with video. A test digitized EEG data, such as frequency specific power typically used to diagnose sleep disorders. Synonym: sleep studies. derived by Fourier transform, displayed in various formats. Polyspike-and-slow-wave complex: An epileptiform pattern Statistical variables can be compared, such as wave phase and consisting of two or more spikes associated with one or more slow coherence. Clinically it is most used in the intensive care unit to waves (see epileptiform pattern). Synonym: multiple spike-and- evaluate cerebral function trends and following treatment inter- slow-wave complex (use of term discouraged). ventions. (See map voltage, power spectrum, continuous EEG). Polyspike complex: A sequence of two or more spikes. Com- Quantity: Amount of EEG activity with respect to number of ment: may or may not be an epileptiform pattern (for examples transients or waves. For example, interictal epileptiform dis- see generalized paroxysmal fast activity and wicket spikes, respec- charges: 1/10 s are abundant, 1/min but less than 1/10 s are fre- tively). Synonym: multiple spike complex (use of term quent, 1/h but less than 1/min are occasional, and <1/h are rare. discouraged). Synonym: incidence. (See also prevalence). Positive occipital sharp transient of sleep (POSTS): A normal Quasiperiodic: Loosely: applies to EEG waves or complexes graphoelement. Sharp transient maximal over the occipital that occur at random intervals, which only approach regularity regions, positive relative to other areas, apparently occurring spon- and that are not an exact repeating frequency. Strictly: determined taneously during sleep. May be single or repetitive. Amplitude var- by quantitative computer analysis and defined as having a cycle ies but is generally below 50 mV. length (i.e. period) varying by 25–50% from one cycle to the next Positive rolandic sharp waves (PRSW): Abnormal transients in in the majority (>50%) of cycle pairs. (Synonym: pseudoperiodic). neonatal period, surface positive, broad-based sharp waves with (Hirsch et al., 2013). duration of <0.5 s, localized to central regions (C3/C4/Cz). Associ- Quiet sleep: Normal sleep stage in neonates characterized by ated with white matter injury in preterm infants. Synonym: posi- eye closure, absence of rapid eye movements, and scant body tive sharp wave transients. movements, except for occasional sucking activity or myoclonic Posterior basic rhythm (PBR): Synonym: posterior dominant jerks. The EEG shows tracé alternant in term and near term infants rhythm. and tracé discontinue (discontinuous pattern) in preterm infants; Posterior dominant rhythm (PDR): Rhythmic activity seen at the interburst interval depend on the post menstrual age. (See the occipital or parietal regions predominantly during wakefulness active sleep, tracé alternant and tracé discontinue). while the eyes are kept closed. Comment: usually in the alpha fre- Reactivity: A phenomena in which the EEG pattern clearly and quency band in healthy adults. Synonym: posterior basic rhythm. reproducibly changes with sensory (visual, auditory or noxious) Posterior slow waves of youth: A normal graphoelement. Iso- stimulation. Changes may occur in frequency, morphology and/or lated slow waves intermixed with the posterior dominant rhythm amplitude, including attenuation of activity after the stimulus. in young people (typically 4–25 years of age). See slow-fused Comment: appearance of muscle activity or eye blink artifacts or transients. heart rate does not qualify as reactive. In general terms reactivity Potential: (1) Strictly: voltage. (2) Loosely: synonym of electri- of the EEG in comatose patients is a favorable prognostic sign. cal activity (waveforms) generated by the nervous system. Record: The end product of the EEG recording process. Syno- Potential field: Amplitude distribution of the negative and pos- nyms: recording, tracing. itive potentials of an EEG signal at the surface of the head, or cere- Recording: (1) The process of obtaining an EEG record. Syno- bral cortex or in the depth of the brain, measured at a given instant nym: tracing. (2) The end product of the EEG recording process, in time. Represented in diagrams by color codes for negativity and most commonly on to digital storage media. Synonyms: record, positivity, and by equipotential lines (see map isopotential, power tracing. spectrum). Record of electrocerebral inactivity: See electrocerebral Power Spectrum: Display of the distribution of frequency- inactivity. specific power (i.e. amplitude squared), with the waveform Reference electrode: (1) In general: any electrode against frequency plotted on the abscissa and the power plotted on the which the potential variations of another electrode are measured. ordinate of a spectrogram display. (See frequency spectrum, (2) Specifically: a suitable reference electrode is historically con- quantitative EEG). nected to the input terminal 2 of an EEG amplifier and placed so Premature temporal theta: Normal graphoelement of preterm as to minimize the likelihood of recording the same EEG activity infants (24–34 weeks post menstrual age, highest incidence as detected by an exploring electrode (connected to the input ter- 29–31 weeks). Temporal sharp transients occurring in bursts of minal 1 of the same amplifier), or of other activities. Comments: (1) rhythmic sharp waves at 4–7 c/s (25–125 mV). Typically bilateral Whatever the location of the reference electrode, the possibility but often asynchronous. Synonyms: rhythmic temporal theta, tem- that it might be affected by appreciable EEG potentials should poral sawtooth waves. always be considered. (2) A reference electrode connected to the N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 181 input terminal 2 of all EEG amplifiers is referred to as a common appellations (such as mu rhythm and alpha coma) (see alpha reference electrode. (See exploring electrode). rhythm). Referential derivation: Recording from a pair of electrodes Ripples: Part of the high frequency oscillations (HFOs) band- consisting of an exploring electrode historically connected to the width, usually defined as being in the range of 80–250 Hz (see high input terminal 1 and a reference electrode usually connected to frequency oscillations). the input terminal 2 of an EEG amplifier (see exploring and refer- Rolandic spikes: Uni-or bilateral triphasic sharp waves in the ence electrode, input terminal 1 and 2, referential montage). centro-temporal area seen in childhood epilepsy with centro-tem- Referential montage: A montage consisting of referential poral spikes. They often have a tangential (horizontal) dipole ori- derivations. Comment: a referential montage in which the refer- ented with negativity in centro-temporal/parietal areas and ence electrode is common to multiple derivations is referred to positivity in the frontal region, and increase during sleep with a as a common reference montage (see referential derivation). tendency to appear in series. Synonym: centro-temporal spikes Reformatting: Transformation of digitized EEG into different or discharges (see benign epileptiform discharges of childhood: montages. Reformatting requires that the raw EEG signal is use of term discouraged). recorded to a common reference electrode. Only those electrodes Sampling rate: Frequency in Hz used for sampling the digital can be included in the reformatting montages which are connected EEG. Sampling rates in the 250–500 Hz range are common. Higher to amplifier input 1. sampling rates may be appropriate for specific applications, for Regional: EEG activity that is limited to a region of the scalp example 1000–2000 Hz in intra-cranial depth EEG. (See analog- overlying a lobe (i.e. frontal, temporal, parietal, occipital). (See to-digital conversion, Nyquist theorem). focal, multiregional). Sawtooth (saw-tooth) waves: Brief runs of rhythmic sharp Regular: Applies to waves or complexes of approximately con- waves of 4–7 c/s, often of quite high amplitude (up to 125 mV). stant period and relatively uniform appearance. Synonyms: rhyth- (See premature temporal theta). mic, monomorphic (use of latter term discouraged). Scalp electrode: Electrode held against, attached to, or needle REM: Rapid eye movements characterizing REM sleep. Conju- inserted in the scalp. gate, irregular, sharply peaked eye movements with an initial Scalp electroencephalogram: Record of electrical activity of deflection lasting <0.5 s (see REM sleep). Comment: not to be con- the brain by means of electrodes placed on the surface of the head. fused with saccadic eye movements in an awake subject during The term should be used only to distinguish between scalp and visual scanning. other electroencephalograms, such as intra-cranial depth elec- REM atonia: Normal reduction of tonic skeletal muscle activity troencephalograms. In all other instances, a scalp electroen- during REM sleep. cephalogram should be referred to simply as an REM sleep: Sleep stage characterized by low amplitude mixed electroencephalogram (EEG). frequency EEG activity, episodic bursts of predominantly horizon- Scalp electroencephalography: Technique of recording scalp tal rapid eye movements (REM) and reduction of axial tonic muscle electroencephalograms. Should be referred to simply as electroen- activity; frequently associated with dreams; phasic muscle activ- cephalography (EEG). ity, sawtooth waves and changes in respiration may occur. (See Secondary bilateral synchrony: Spreading by propagation of active sleep, Non-REM sleep). an initially focal or regional epileptiform discharge to become gen- Resistance-capacitance (RC) coupled amplifier: A multistage eralized (see generalized). Synonym: secondary generalization. amplifier wherein successive stages of amplifiers are connected Seizure pattern, EEG: Phenomenon consisting of repetitive (coupled) using a combination of a resistor and a capacitor. (See epileptiform EEG discharges at >2 c/s and/or characteristic pattern also Direct coupled amplifier). with quasi-rhythmic spatio-temporal evolution (i.e. gradual Resolution: The resolution of an analogue–digital (AD) con- change in frequency, amplitude, morphology and location), lasting verter (see digital EEG) is specified in binary digits or ‘‘bits”, which at least several seconds (usually >10 s). Two other short duration approximates to the fineness of detail in the amplitude domain. For (<10 s) EEG seizure patterns are: electrodecrement and low voltage example, a dynamic range of ±1023 mV (a total span of 2046 mV), fast activity seen during clinically apparent epileptic seizures. Fre- converted at 12-bit resolution, will allow the digitized signal to quent interictal epileptiform discharges are usually not associated take on values every 0.5 mV. with clinical seizures and thus should be differentiated from EEG Rhythm: EEG activity consisting of waves of approximately seizure patterns. Comment: EEG seizure patterns unaccompanied constant period. by clinical epileptic manifestations should be referred to as electro- Rhythmic: Applied to regular waves occurring at a constant graphic or subclinical seizures. (See electrodecrement and low period and of relatively uniform morphology. Synonyms: regular, voltage fast activity). Synonym: ictal EEG pattern. monomorphic (use of latter term discouraged). Sensitivity: Ratio of input voltage to output trace deflection in Rhythmic temporal theta: A normal graphoelement in preterm an EEG channel. Sensitivity is measured in microvolts per millime- infants (GA 24–34 weeks of post menstrual age, maximal ter (mV/mm). Example: 29–32 weeks). Consisting of brief theta bursts (4.5–6 c/s) over the temporal regions, typically symmetrical but not necessarily input voltage 50 lV Sensitivity ¼ ¼ ¼ 5 lV=mm synchronous. Synonyms: premature temporal theta, temporal output trace deflection 10 mm sawtooth bursts. Rhythmic temporal theta burst of drowsiness: A normal vari- Sharp wave: An epileptiform transient clearly distinguished ant. Characteristic burst of 4–7 c/s waves whose morphology is fre- from the background activity, although amplitude varies. A pointed quently notched by faster waves, occurring over the temporal peak at a conventional time scale and duration of 70–200 ms, usu- regions of the head during drowsiness, bilaterally or indepen- ally with a steeper ascending phase when compared to the dently. Synonyms: rhythmic midtemporal discharge, psychomotor descending phase. Main component is generally negative relative variant pattern (use of terms discouraged). to other areas, and may be followed by slow wave of the same Rhythm of alpha frequency: (1) In general: any rhythm in the polarity. Comments: (1) term should be restricted to epileptiform alpha band. (2) Specifically: term should be used to designate those discharges, and does not apply to: (a) distinctive physiological activities in the alpha band which differ from the alpha rhythm as events such as vertex sharp transients, lambda waves and positive regards their topography and/or reactivity and do not have specific occipital sharp transients of sleep, (b) sharp transients poorly dis- 182 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 tinguished from background activity (without or with a slow wave during drowsiness and light sleep. Synonym: benign epileptiform for example six Hz spike-and-slow-wave). (2) Sharp waves should transients of sleep (use of term discouraged). be differentiated from spikes, i.e. transients having similar charac- Somatosensory evoked potential (SEP): Evoked potential in teristics but shorter duration. However, it should be kept in mind response to somatosensory stimulus, usually electrical stimulation that this distinction is largely arbitrary and primarily serves of a sensory or mixed nerve (see evoked potential). descriptive purposes. Special electrode: Any electrode other than standard ten- Sharp-and-slow-wave complex: An epileptiform pattern con- twenty system scalp electrodes (for example surface sphenoidal sisting of a sharp wave and an associated following slow wave, or anterior ‘‘cheek” electrode, and closely spaced electrodes; see clearly distinguished from background activity. May be single or ten-ten system). multiple. (See sharp wave). Sphenoidal electrode: Strictly needle or wire electrode Simultaneous: Occurring at the same time. Synonym: inserted through the soft tissues of the face below the zygomatic synchronous. arch so that its tip lies near the base of the skull in the region of Sine wave: Wave having the form of a sine curve, describing a the foramen ovale, designed to record from the medial temporal smooth periodic repetitive oscillation. lobe structures. (See basal electrode). Sinusoidal: Term applies to EEG waves resembling sine waves Spike: A transient, clearly distinguished from background activ- (see sine wave). ity, with pointed peak at a conventional time scale and duration Six Hz spike-and-slow-wave: Spike-and-slow-wave complexes from 20 to less than 70 ms. Amplitude varies but typically at 4–7 c/s, but mostly at 6 c/s occurring generally in brief bursts >50 lV. Main component is generally negative relative to other bilaterally and synchronously, symmetrically or asymmetrically, areas. Comments: (1) term should be restricted to epileptiform dis- and either confined to or of larger amplitude over the posterior charges. EEG spikes should be differentiated from sharp waves, i.e. or anterior regions of the head. Amplitude varies but is generally transients having similar characteristics but longer durations. How- smaller than that of spike-and-slow-wave complexes repeating at ever, it should be kept in mind that this distinction is largely arbi- slower rates. Comment: when low amplitude, posterior and during trary and primarily serves descriptive purposes. (2) EEG spikes drowsiness this pseudo-epileptiform pattern should be distin- should be clearly distinguished from the brief unit spikes recorded guished from epileptiform discharges. Synonym: phantom spike- from single cells with microelectrode techniques. (See sharp wave). and-wave (use of term discouraged). Spike-and-slow-wave complex: An epileptiform pattern con- Sleep onset REM (SOREM): Occurrence of REMs less than sisting of a spike and an associated following slow wave, clearly 15 min after falling asleep, typically seen in association with nar- distinguished from background activity. May be single or multiple. colepsy (but may be seen in apneic patients and even healthy vol- Spindle: Group of rhythmic waves characterized by a progres- unteers). (See REM). sively increasing, then gradually decreasing, amplitude (see sleep Sleep spindle: A normal graphoelement. Train of distinct waves spindle). with frequency at 11–16 Hz (most commonly at 12–14 Hz) with a Spread: Propagation of EEG waves from one region of the scalp duration 0.5 s. Generally higher amplitude over the central and/or brain to another (see generalization, propagation). regions of the head, occurring during sleep. Amplitude varies but Standard electrode: Conventional scalp electrode (see disk is maximal using central derivations. electrode, needle electrode, pad electrode, special electrode). Sleep stages: Distinctive phases of sleep best demonstrated by Standard electrode placement: Scalp electrode location(s) polygraphic recordings of the EEG and other variables, including at determined by the ten-twenty system (see ten-twenty system). least eye movements and activity of certain voluntary muscles. Status epilepticus, EEG: The occurrence of virtually continuous Comment: classified by various systems (see Iber et al., 2007 and or repetitive epileptiform seizure pattern in an EEG. Term should Silber et al., 2007, based on the frameworks of Dement and be distinguished from clinical status epilepticus, although they Kleitman, 1957, Rechtschaffen and Kales, 1968). may co-exist. (See seizure pattern). Synonym: electrographic sta- Slow activity: Any activity of frequency less than alpha rhythm, tus epilepticus. i.e. theta and delta bands. Stereotactic (stereotaxic) electroencephalogram (SEEG): Slow alpha variant rhythms: A normal variant. Rhythms mostly Intracerebral EEG recordings using electrodes implanted stereotac- at 4–5 Hz, recorded over the posterior regions of the head, that tically, thus permitting the calculation of electrode coordinates behave like the posterior dominant rhythm in response to activa- that can be projected on a stereotactic brain atlas or magnetic res- tion (i.e. are blocked or attenuated by attention, especially eye onance images to create three-dimensional pictures. Note the opening and mental effort). Generally alternate, or are intermixed, abbreviation SDEEG is also used for stereotactic depth electroen- with the alpha rhythm to which they often are harmonically cephalogram. Synonym: stereoelectroencephalography. related. They may have a notched morphology but are not generally Stereotactic (stereotaxic) electroencephalography (SEEG): considered abnormal. Amplitude varies but is frequently close to Technique of recording stereotactic (stereotaxic) electroencephalo- 50 mV. Comment: slow alpha variant rhythms should be distin- grams. Synonym: stereoelectroencephalogram. guished from posterior slow waves of youth, characteristic of Sternospinal reference: A non-cephalic reference achieved by children and adolescents and occasionally seen in young adults interconnecting two electrodes placed over the right sternoclavic- (see posterior dominant rhythm, posterior slow waves of youth). ular junction and the spine of the seventh cervical vertebra, respec- Slow-fused transient: A normal graphoelement. A sharply con- tively, and balancing the voltage between them by means of a toured component of the normal posterior dominant rhythm pre- potentiometer to reduce ECG artifact. cedes a posterior slow wave of youth, giving the false impression Stimulus-induced rhythmic, periodic or ictal discharges of a spike-and-slow-wave. (SIRPIDs): Sharp transients that are rhythmic, periodic or ictal Slow wave: Wave with duration longer than alpha waves, i.e. appearing discharges in comatose patients that are consistently over 1/8 s (>125 ms). induced by alerting stimuli including: auditory and other sensory Slow wave sleep: Non-REM sleep stage N3. Synonym: deep stimulation, such as noxious (airway suctioning) and other sleep. (See deep sleep, REM sleep). patient-care activities. SIRPIDs may be regional or lateralized, Small sharp spikes (SSS): A normal variant. Small sharp spikes bilateral or generalized, and of variable duration. Their pathophys- of very short duration (<50 ms) and low amplitude (<50 mV), often iology and clinical significance is uncertain, but on occasions may followed by a small theta wave, occurring in the temporal regions be associated with clinical seizures. N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 183

Subclinical rhythmic discharges of adults (SREDA): This paroxysm), (2) are bilaterally synchronous in their onset and ter- paroxysmal pattern is usually seen in the adult age group (typically mination (i.e. ‘‘generalized”), and usually of maximal amplitude over 50 years) and consists of a mixture of frequencies, often pre- over the frontal areas, and (3) remain approximately synchronous dominantly in the theta range, lasting 40–80 s. It may resemble a and symmetrical on the two sides of the head throughout the seizure discharge but is not accompanied by any clinical signs or paroxysmal burst. Amplitude varies but can reach values of symptoms. The significance of this pattern is uncertain, but it 1000 mV (1 mV). Characteristic seizure pattern associated with should be distinguished from an epileptiform seizure pattern. Childhood Absence Epilepsy. Subdural electrode: Electrode inserted under the dural cover- Time constant (TC): Historically the product of the values of the ing of the cerebrum for recording of electrocorticogram as a pre- resistance (in mega-ohms, MO) and the capacitance (in micro- surgical evaluation of medically intractable partial epilepsy, usu- farads, lF) which make up the time constant control of an EEG ally in the form of electrode strips. Synonym: epicortical electrode channel. This product represents the time required for the trace (use of term discouraged). to fall to 37% of the deflection initially produced when a DC voltage Suppression: Entirety of an EEG record showing activity below difference is applied to the input terminals of the amplifier. 10 mV (reference derivation). (See burst suppression pattern). Expressed in seconds (s). Comment: for a simple Resistance-Capac- Symmetry: Approximately equal amplitude, frequency and itance coupling network, the TC is related to the percent reduction form of EEG activities over homologous areas on opposite sides in sensitivity of the channel at a given stated low frequency by the of the head. equation TC =1/2pf, where f is the frequency at which a 30% (3 dB) Synchrony: The simultaneous occurrence of EEG waves over attenuation occurs. For instance, for a TC of 0.3 s, an attenuation of distinct regions on the same or opposite sides of the head with 30% (3 dB) occurs at 0.5 Hz. Thus, either the time constant or the the same speed and phase. Comment: term simultaneous only percent attenuation at a given stated low frequency can be used implies a lack of possible delay that is measurable with standard to designate the same position of the low frequency filter of the computer display. Certain electrodes are so close (for example EEG channel (see low frequency filter). In the digital era this pro- Fp1-Fp2 and 01–02 respectively) that volume conduction can cess is internally governed by the software of the system. affect the signal on the other side, making these electrodes unsuit- Topography: Spatial distribution of EEG features (rhythm, volt- able for assessing synchrony). (See volume conduction). age fields, spectra, evoked potential etc.) over the scalp or cerebral Temporal intermittent rhythmic delta activity (TIRDA):An cortex. (See map voltage). EEG pattern characterized by short trains of intermittent and Tracé alternant: Neonatal EEG pattern of quiet (non-REM) rhythmic delta activity (1–3.5 Hz), often with sawtooth morphol- sleep seen in term and near term infants from 34 to 36 weeks post ogy, recorded predominantly over the anterior temporal regions. menstrual age onwards, which may persist up to 4 weeks after TIRDA usually occurs during drowsiness and light sleep and may birth. It is characterized by high amplitude bursts of predomi- either be unilateral or bilateral, occurring independently. It is asso- nantly slow waves (50–150 mV) alternating with periods of rela- ciated with temporal lobe epilepsy, and when unilateral is virtually tively low amplitude activity mixed activities (25–50 mV). (See indicative of ipsilateral pathology. quiet sleep). Temporal slow activity of the elderly: Pattern of uncertain sig- Tracé continu: Continuous background activity, consisting of nificance but usually not considered abnormal. Unilateral (most theta and/or delta frequencies (>25 mV), replacing a previously often on the left side) or bilateral, short runs of theta or delta activ- markedly intermittent record during evolution of EEG in preterm ity intermixed with the background activity over the temporal infants. Present in active sleep (see active sleep). region(s), in subjects >50 years of age, without clinical abnormali- Tracé discontinu: Normal discontinuous pattern in preterm ties. Often accentuates during drowsiness and hyperventilation. infants which is characterized by bursts of high amplitude (up to Ten-ten (10–10) system: System of standardized scalp elec- 300 mV) mixed frequency activity regularly interrupted by low trode placement. According to this system, additional scalp elec- amplitude interburst activity (<25 mV). The pattern can still be trodes are placed at half distance between the standard called discontinuous if there is a modest amount of EEG activity electrodes of the ten-twenty system, i.e. 10 percentile increments in a single channel or a single transient in multiple channels. The of the reference curve (see ten-twenty system, closely spaced elec- interburst interval depends on the post menstrual age (PMA). It trodes). Comment: use of additional supplementary scalp elec- is seen in wakefulness, active and quiet sleep until 30 weeks trodes is indicated for instance during epilepsy monitoring, PMA, then only in quiet sleep, and is rarely seen in infants of theoretically in order localize epileptiform discharges more pre- 38 weeks PMA. (See active and quiet sleep). cisely (for example surface sphenoidal or anterior ‘‘cheek” elec- Tracing: Synonyms: record, recording. trode). (See special electrode). Transient, EEG: Any isolated wave or complex, distinguished Ten-twenty (10–20) system: System of standardized scalp from background activity. electrode placement recommended by the International Federation Transverse bipolar montage: A montage consisting of contigu- of Clinical Neurophysiology. According to this system, the place- ous channels of electrode pairs along transverse/coronal (i.e. side- ment of electrodes is determined by measuring the head from 4 to-side) arrays (for example F7-F3, F3-Fz, Fz-F4, F4-F8, etc.). Syno- external landmarks and taking 10 or 20 percentiles of these mea- nym: coronal bipolar montage. surements. Comment: the use of additional supplementary scalp Triangular bipolar montage: A historic montage consisting of electrodes, such as electrodes in the inferior temporal chain of derivations from pairs of electrodes in a group of 3 electrodes electrodes, is indicated in various circumstances (for example focal arranged in a triangular pattern. Use of this montage is discour- epilepsy investigation). aged, because false lateralization may occur. Theta band: Frequency band from 4<8 Hz. Greek letter: h. Triphasic wave (TW): High amplitude (over 70 mV) positive Theta rhythm: Rhythm with a frequency of 4<8 Hz. sharp transients (with respect to common average), which are pre- Theta wave: Wave with duration of 1/4 to over 1/8 s (125– ceded and followed by relatively low amplitude negative waves. 250 ms). The first negative wave generally has lower amplitude than the Three Hz or three per second spike-and-slow-wave complex: negative afterwave, and has a steeper slope, which on occasions Characteristic ictal paroxysmal pattern consisting of a regular may be sharp. Usually bilateral with an antero-posterior or a pos- sequence of spike-and-slow-wave complexes which: (1) repeat at tero-anterior lag, and repetition rate of about 1<2 c/s. TWs occur around 3–3.5 c/s (measured during the first few seconds of the typically in runs, and can either regress or increase with arousal or 184 N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 noxious stimuli. Often there is little ongoing or low amplitude reviewer is guided through the structured reporting system by (<40 mV) slow background activity between TWs. They are seen choosing the features from a predefined list. SCORE (Standardized in a range of conditions, often present concurrently, associated Computer-based Organized reporting of EEG) has been developed with metabolic encephalopathy. The patient is usually comatose, under the auspices of ILAE and IFCN (Beniczky et al., 2013). We sug- and TW may decrease with sleep and after intravenous benzodi- gest the following template for reporting EEG in clinical practice: azepines. Synonym: continuous 2/s GPDs (with triphasic morphology). Patient information Unilateral: Confined to one side of the head (or body). Com- Report Items Essential ments: (1) unilateral EEG activities may be focal, regional or later- features/explanations alized to one hemisphere. (2) They are said to be lateralized to the right or left side of the head. (See lateralized). ID Identity information as Vertex sharp transient or vertex sharp wave (V wave): A nor- required by local mal graphoelement. Sharply contoured wave with duration <0.5 s, guidelines maximal at the vertex, negative relative to other areas, apparently Age and date of birth For newborn infants occurring spontaneously during light sleep or in response to a sen- also gestational age. sory stimulus (usually auditory). Vertex sharp waves may be single Referral information or repetitive. Amplitude varies but rarely exceeds 250 mV. (See Referring physician light sleep, K complex). History Visual evoked potential: Cortical evoked potential generated in Diagnosis at referral Including neurological response to visual stimulus, either unstructured diffuse flashes or condition patterned (for example pattern-reversal stimulus). (See evoked Neuroimaging results potential). Previous EEG results Voltage: The difference in electric potential between two points Medication Particularly CNS drugs. (units: volts). (See amplitude). Information on sleep deprivation Volume conduction: The passive process by which electrical Last seizure activity, originating from a generator, spreads through a conduc- Clinical question/reason for referral tive medium to be detected quite widely by distant (i.e. far-field) recording electrodes, without being mediated by neural activity (for example, see Brainstem Auditory Evoked Potential). (See propagation). Recording conditions Wave: Any change of the potential difference between pairs of Report Items Essential features/explanations electrodes in EEG recording, which may arise in the brain (an EEG wave) or outside of it (i.e. extracerebral potential). Electrode array Type of EEG electrode array Waveform (wave form): The shape or morphology of an EEG Specify polygraphic channels wave (see morphology). Type of recording Standard awake/sedated/sleep Wicket spikes or wicket waves: Spike-like monophasic surface duration deprived/ambulatory/long-term negative single waves or trains of waves occurring over the tempo- video-EEG monitoring ral regions, typically unilateral, during drowsiness that have an Activation Eye closure (obligatory at any age, arcuate or mu-like appearance. These are mainly seen in older indi- procedures/ active or passive); hyperventilation; viduals and represent a benign physiological variant, but may also modulators photic stimulation; external sensory be seen in patients with a clinical diagnosis of epilepsy. stimulation; medication given during Writer: Historically a system for direct write-out of the output the recording of an EEG channel. Most writers used ink delivered by a pen, but in Level of Including cooperation of patient certain instruments the ink was sprayed in a jet stream, and in consciousness/ others the pen writer used carbon paper. Used infrequently since vigilance/ the advent of digital EEG, where laser printers are used to write- out EEGs.

Description Appendix A. EEG report Report Items Essential features/explanations Ongoing activity/ Symmetry, synchrony The purpose of the EEG report is to document clinically relevant Background activity items, and this determines its format: patient demographics, rea- Wake Posterior Dominant Rhythm son for EEG, specification of techniques, description of pattern Other ongoing rhythms seen, and finally the clinical interpretation and conclusion within Sleep Stages reached that clinical context. Interictal activity For each type of observed Standardizing the structure and content of the report is essential interictal pattern, describe the for quality assurance. A standardized report format helps commu- following features: nication between the patient’s primary physician and EEG depart- Morphology (specify the type of ments, and lists all items that have clinical relevance. The epileptiform activity, abnormal importance of the report goes beyond communicating the results: slowing or special pattern – using it also points out the features that have to be assessed in clinical the nomenclature from the EEG recordings. Several EEG report-templates have been previously glossary) proposed (Noachtar et al., 1999; ACNS, 2006; Kaplan and Benbadis, Location 2013; Shibasaki et al., 2014, Tatum et al., 2016). More recently com- puter-based reporting systems have been developed, where the N. Kane et al. / Clinical Neurophysiology Practice 2 (2017) 170–185 185

Time-related features: how often committee of the International Federation for Electroencephalography and Clinical Neurophysiology. Electroenceph. Clin. Neurophysiol. 13, 646–650. the pattern occurs during the Chatrian, G.E., Bergamini, L., Dondey, M., Klass, D.W., Lennox Buchthal, M., Petersén, recording; does it occur as single I., 1974. A glossary of terms most commonly used by clinical discharges or in runs/burst (in electroencephalographers. Electroenceph. Clin. Neurophysiol. 37, 538–548. Dement, W., Kleitman, N., 1957. The relation of eye movements during sleep to that case specify duration and dream activity: an objective method for the study of dreaming. J. Exp. Psychol. frequency) 53, 339–346. Clinical episodes/seizures Semiology; ictal EEG; seizure Hirsch, L.J., LaRoche, S.M., Gaspard, N., Gerard, E., Svoronos, A., Herman, S.T., Mani, R., Arif, H., Jette, N., Minazad, Y., Kerrigan, J.F., Vespa, P., Hantus, S., Claassen, J., classification (for each type if Young, G.B., So, E., Kaplan, P.W., Nuwer, M.R., Fountain, N.B., Drislane, F.W., several) 2013. American Clinical Neurophysiology Society’s Standardized Critical Care Normal variants/pattern EEG Terminology: 2012 version. J. Clin. Neurophysiol. 30, 1–27. of uncertain Iber, C., Ancoli-Israel, S., Chesson, A.L., Jr., Quan, S.F. for the American Academy of Sleep Medicine. The AASM manual for the scoring of sleep and associated significance events: rules, terminology and technical specifications. 1st ed. Westchester, IL: Artifacts Impact on diagnostic value of American Academy of Sleep Medicine; 2007. recording Kaplan, P.W., Benbadis, S.R., 2013. How to write an EEG report Dos and don’ts. Neurology 80 (Suppl. 1), S43–S46. Effect of modulators Changes with activation Noachtar, S., Binnie, C., Ebersole, J., Mauguière, F., Sakamoto, A., Westmoreland, B. A procedures and sleep glossary of terms most commonly used by clinical electroencephalographers and proposal for the report form for the EEG findings. Recommendations for the Practice of Clinical Neurophysiology: Guidelines of the International Federation of Clinical Physiology (EEG Suppl. 52: 21–41) Editors: G. Deuschl and A. Eisen, 1999. International Federation of Clinical Neurophysiology. Elsevier Science B.V. Noachtar, S., Binnie, C., Ebersole, J., Mauguière, F., Sakamoto, A., Westmoreland, B. A glossary of terms most commonly used by clinical electroencephalographers Interpretation and proposal for the report form for the EEG findings. Recommendations for the Report Items Essential features/explanations Practice of Clinical Neurophysiology: Guidelines of the International Federation of Clinical Physiology (EEG Suppl. 52: 21–41) Editors: G. Deuschl and A. Eisen, Classification Normal/No definite abnormality/Abnormal 1999. International Federation of Clinical Neurophysiology. Elsevier Science B.V. Rechtschaffen, A., Kales, A. A Manual of Standardized Terminology, Techniques and Synopsis Short summary of essential findings Scoring System for Sleep Stages of Human Subjects. Brain Information Service/ Diagnostic Interpreting EEG findings in the clinical Brain Research Institute, Los Angeles, CA, 1968. significance context Silber, M.H., Ancoli-Israel, S., Bonnet, M.H., Chokroverty, S., Grigg-Damberger, M.M., Hirshkowitz, M., Kapen, S., Keenan, S.A., Kryger, M.H., Penzel, T., Pressman, M.R., Clinical Answers to specific questions in referral; Iber, C., 2007. The visual scoring of sleep in adults. J. Clin. Sleep Med. 3, 121– comments suggestion of additional investigations 131. Stecker, M.M., Sabau, D., Sullivan, L., Das, R.R., Selioutski, O., Drislane, F.W., Tsuchida, T.N., Tatum, W.O., 2016. American Clinical Neurophysiology Society guideline 6: minimum technical standards for EEG recording in suspected cerebral death. J. Clin. Neurophysiol. 33, 324–327. References Shibasaki, H., Nakamura, M., Sugi, T., Nishida, S., Nagamine, T., Ikeda, A., 2014. Automatic interpretation and writing report of the adult waking electroencephalogram. Clin. Neurophysiol. 125, 1081–1094. American Clinical Neurophysiology Society, 2006. Guideline 7: guidelines for Tatum, W.O., Olga, S., Ochoa, J.G., Munger Clary, H., Cheek, J., Drislane, F., Tsuchida, writing EEG reports. J. Clin. Neurophysiol. 23, 118–121. T.N., 2016. American Clinical Neurophysiology Society Guideline 7: guidelines Beniczky, S., Aurlien, H., Brogger, J.C., Fuglsang-Frederiksen, A., Martins-da-Silva, A., for EEG reporting. J. Clin. Neurophysiol. 33, 328–332. Trinka, E., Visser, G., Rubboli, G., Hjalgrim, H., Stefan, H., Rosen, I., Zarubova, J., Dobesberger, J., Alving, J., Andersen, K.V., Fabricius, M., Atkins, M.D., Neufeld, M., Plouin, P., Marusic, P., Pressler, R., Mameniskiene, R., Hopfengartner, R., van Emde, Boas W., Wolf, P., 2013. Standardized computer-based organized reporting of EEG: SCORE. Epilepsia 54 (6), 1112–1124. Brazier, M.A.B., Cobb, W.A., Fischgold, H., Gastaut, H., Gloor, P., Hess, R., Jasper, H., Loeb, C., Magnus, O., Pampiglione, G., Rémond, A., Storm van Leeuwen, W., Grey, W., 1961. Preliminary proposal for an EEG terminology by the terminology

Epilepsy Update 2017 Quality Measurement Set

Approved by the Epilepsy Quality Measurement Update Work Group on December 11, 2017. Approved by the AAN Quality and Safety Subcommittee on January 20, 2018. Approved by AAN Practice Committee on January 21, 2018. Approved by AANI Board of Directors on February 15, 2018.

©2017. American Academy of Neurology Institute. All Rights Reserved. 1 CPT® Copyright 2004-2017 American Medical Association.

Disclaimer Quality Measures published by the American Academy of Neurology and its affiliates are assessments of current scientific and clinical information provided as an educational service. The information: 1) should not be considered inclusive of all proper treatments, methods of care, or as a statement of the standard of care; 2) is not continually updated and may not reflect the most recent evidence (new evidence may emerge between the time information is developed and when it is published or read); 3) addresses only the question(s) or topic(s) specifically identified; 4) does not mandate any particular course of medical care; and 5) is not intended to substitute for the independent professional judgment of the treating provider, as the information does not account for individual variation among patients. In all cases, the selected course of action should be considered by the treating provider in the context of treating the individual patient. Use of the information is voluntary. AAN provides this information on an “as is” basis, and makes no warranty, expressed or implied, regarding the information. AAN specifically disclaims any warranties of merchantability or fitness for a particular use or purpose. AAN assumes no responsibility for any injury or damage to persons or property arising out of or related to any use of this information or for any errors or omissions.

©2017 American Academy of Neurology Institute. All rights reserved. Limited proprietary coding is contained in the measure specifications for convenience. Users of the proprietary coding sets should obtain all necessary licenses from the owners of these code sets. The AAN and its members disclaim all liability for use or accuracy of any Current Procedural Terminology (CPT®) or other coding contained in the specifications. ICD-10 copyright 2012 International Health Terminology Standards Development Organization

CPT ® is a registered trademark of the American Medical Association and is copyright 2017. CPT® codes contained in the Measure specifications are copyright 2004-2016 American Medical Association.

©2017. American Academy of Neurology Institute. All Rights Reserved. 2 CPT® Copyright 2004-2017 American Medical Association.

Contents Work Group Members ...... 4 Improving Outcomes for Patients with Epilepsy ...... 5 Rationale for Measures ...... 5 Measure Development Process ...... 5 Importance and Prevalence of Epilepsy ...... 6 Opportunity for Improvement ...... 6 Clinical Evidence Base ...... 6 Common Abbreviations and Definitions for the Measurement Set ...... 7 2017 Epilepsy Quality Measurement Set Update ...... 8 Other Potential Measures ...... 8 Retired 2014 Measures ...... 9 Technical Specifications Overview ...... 10 Testing and Implementation of the Measurement Set...... 11 2017 Epilepsy Measure Specifications ...... 12 Counseling for Women of Childbearing Potential with Epilepsy ...... 12 Flow Chart Diagram: Counseling for Women of Childbearing Potential with Epilepsy ...... 15 Comprehensive Epilepsy Care Center Referral or Discussion for Patients with Intractable Epilepsy ... 17 Flow Chart Diagram: Comprehensive Epilepsy Care Center Referral or Discussion ...... 20 Quality of Life Assessment for Patients with Epilepsy ...... 23 Flow Chart Diagram: Quality of Life for Patients with Epilepsy ...... 26 Quality of Life Outcome for Patients with Epilepsy ...... 28 Flow Chart Diagram: Quality of Life for Patients with Epilepsy ...... 30 Depression and Anxiety Screening for Patients with Epilepsy ...... 32 Flow Chart Diagram: Depression and Anxiety Screening for Patients with Epilepsy ...... 36 Seizure Frequency for Patients with Epilepsy ...... 38 Flow Chart Diagram: Seizure Frequency for Patients with Epilepsy ...... 40 Contact Information ...... 42 Appendix A AAN Statement on Comparing Outcomes of Patients ...... 43 Appendix B Disclosures ...... 44

©2017. American Academy of Neurology Institute. All Rights Reserved. 3 CPT® Copyright 2004-2017 American Medical Association.

Work Group Members

Co-Chairs Anup Patel, MD, FAAN (Content Chair) S. Andrew Josephson, MD, FAAN (Facilitator Chair)

American Academy of Neurology Gary Franklin, MD, MPH, FAAN Heidi Munger Clary, MD, MPH Lidia Moura, MD, MPH Mary Jo Pugh, PhD, RN, FAAN

American Epilepsy Society Marianna Spanaki, MD, PhD, MBA

Child Neurology Society Inna Hughes, MD, PhD

Epilepsy Foundation Rebecca Schultz, PhD, RN, CPNP Lisa Meunier

My Epilepsy Story Brandy Parker-McFadden

National Association of Epilepsy Centers Susan Herman, MD, FAAN

Facilitator Christine Baca, MD, MSHS

American Academy of Neurology Staff Amy Bennett, JD Gina Gjorvad Katie Hentges Erin Lee Karen Lundgren, MBS Becky Schierman, MPH

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Improving Outcomes for Patients with Epilepsy Rationale for Measures The American Academy of Neurology Institute (AANI) charged this work group with updating previously developed epilepsy quality measures and developing new measures focused on improving outcomes for patients diagnosed with epilepsy.

Measure Development Process The AAN Quality and Safety Subcommittee approved a modified, pilot measure development process for this update. The AAN seated a standing work group for a two-year term. The work group includes physician, nursing, patient, and care giver representatives from professional associations and patient advocacy organizations to ensure measures developed included input from all members of the healthcare team and other relevant stakeholders. All members are required to disclose relationships with industry and other entities to avoid actual, potential, or perceived conflicts of interest. Individuals were instructed to abstain from voting on individual measure concepts if a conflict was present.

The AAN anticipates this work group will revisit measures every six months evaluating new evidence statements, new measure released by other developers, and AAN epilepsy measure implementation and performance data to nimbly respond to developments in these areas. The work group is charged with updating measures as needed over the two-year period and developing supporting materials and implementation guides as appropriate. The AAN measure development process involves a modified Delphi review by the work group to reach consensus on measures to be developed prior to a 21-day public comment and following public comment further refinement.i Below is an illustration of the measure development process from proposals, discussion, research, evaluation, to approval.

Medical librarian search Data Review via Concept Public comment and Ranking Refinement

8 Existing Measures Reviewed and 18 Measure 8 new concepts removed 6 measures approved Concepts Proposed 6 new concepts advanced

Data Review via Concept Group Discussions Ratings

7 measures retired 2 measures removed 5 new concepts removed - not feasible - lack of evidence 1 Concept split into process - not feasible and outcome - little impact on care 5 measures advanced

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Importance and Prevalence of Epilepsy Epilepsy data is lacking. In 2012, the Institute of Medicine released Epilepsy across the Spectrum: Promoting Health and Understanding, detailing epilepsy research disparities and highlighting specific areas where further research is needed, including the extent of epilepsy, consequences, comorbid conditions and outcomes of epilepsy.ii The following statistics only touch on the magnitude of epilepsy given lack of research and stigma:

• In the United States, “epilepsy is not a rare condition”. It is estimated 3.4 million people have active epilepsy, totaling about 1.2% of the populationiii • Epilepsy prevalence might be underestimated because of underreporting associated with repercussions and stigma in disclosing epilepsy.iii • Epilepsy affects persons of all ages, races, and ethnicities, especially those with the lowest incomes.ii,iii • Common comorbidities among people with epilepsy include somatic (i.e., fractures, asthma, diabetes, and heart disease), neurological (i.e., stroke, heart disease, developmental delays, chronic pain), and mental health conditions (i.e., mood disorders, attention deficit hyperactivity disorders, anxiety disorders, suicidality).ii,iii, iv • It is estimated the number of people with epilepsy who die of sudden unexpected death in epilepsy (SUDEP) range from 1 of every 10,000 who are newly diagnosed to 9 of every 1,000 candidates for epilepsy surgery.ii • People with epilepsy are more likely to be unemployed or unable to work, have low annual household incomes, be obese and physically inactive, and to smoke. ii, iv • People with epilepsy have poorer overall health status, impaired intellectual and physical functioning, a greater risk for accidents and injuries, and negative side effects from anti-seizure medications. ii, iv • It is estimated the annual direct medical cost of epilepsy in the United States is $9.6 billion; combined with indirect costs the total rises to $15.5 billion yearly. ii

Opportunity for Improvement The AANI partnered with other key stakeholders in 2009 to draft the original epilepsy quality measurement set. In 2014, the measurement set was reviewed and updated as appropriate. For this update, the work group reviewed known epilepsy quality measurement data and implementation feedback made available via CMS, CMS’ MIPS benchmarkingv and AAN’s Axon Registry®. Additional information on treatment gaps in care and opportunity for improvement are included in the individual measure specifications that follow. Clinical Evidence Base A comprehensive search to identify published guidelines, measures, and consensus recommendations in the National Guidelines Clearinghouse, the National Quality Measures Clearinghouse, PubMed, MEDLINE, EMBASE, and the Cochrane Library occurred. The work group reviewed past literature used to support prior sets and 1030 newly identified abstracts selecting 133 articles for review. The work group consulted the following clinical practice guidelines and systematic reviews with the following serving as the base of the measure drafts: 1. Viale L, Allotey J, Cheong-See F, et al. Epilepsy in pregnancy and reproductive outcomes: a systematic review and meta-analysis. Lancet 2015; 386: 1845-1852. 2. Sabers A. Treatment guidelines: Women of fertile age. Epileptology 2013;1:11-16.

3. Labiner DM, Bagic AI, Herman ST, et al.; for the National Association of Epilepsy Centers. Essential services, personnel, and facilities in specialized epilepsy centers. Revised 2010 guidelines. Epilepsia 2010;51:2322-2333

4. Wiebe S, et al A Randomized, Controlled Trial of Surgery for Temporal-Lobe Epilepsy N Engl J Med 2001; 345:311-318

5. Scottish Intercollegiate Guidelines Network(SIGN). Diagnosis and management of epilepsy in adults. Edinburgh: SIGN; 2015. (SIGN publication no. 143). [May 2015] Available at: http://www.sign.ac.uk Accessed on June 21, 2017. 6 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

6. Patient-Reported Outcome Measurement Group, Oxford. A Structured Review of Patient-Reported Outcome Measures (PROMs) For Epilepsy: An Update 2009. Available at: http://phi.uhce.ox.ac.uk/pdf/PROMs_Oxford_Epilepsy_17092010.pdf Accessed on August 2, 2017.

7. Kerr MP, Mensah S, Besag F, et al. International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy. Epilepsia 2011; 52(11):2133-2138.

8. Harden CL, Pennell PB, Koppel BS et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Vitamin K, folic acid, blood levels, and breastfeeding: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):142-149. 9. Harden CL, Meador KJ, Pennell PB, et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Teratogenesis and perinatal outcomes: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):133-141. 10. Harden CL, Hopp J, Ting TY, et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Obstetrical complications and change in seizure frequency: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):126-132.

Common Abbreviations and Definitions for the Measurement Set The work group has chosen to use the term intractable epilepsy for this document to reflect what is also known as drug- resistant epilepsy, refractory epilepsy, and pharmacoresistant epilepsy. The work group chose to use intractable epilepsy given its appearance in ICD-9 and ICD-10 systems. For location via a registry it is recommended ICD-10 codes be utilized, and ICD-9 codes used for historical data. For location search term in a registry, the work group recognizes the alternate terms: “drug-resistant epilepsy”, “refractory epilepsy”, and “pharmacoresistant epilepsy”.

Below is a list of acronyms utilized in this document. The AAN has a Quality Improvement Glossary, which provides more in-depth explanations and is available at aan.com/practice/quality-measures/quality-resources. • ADL: Activities of Daily Living • CMS: Centers for Medicare & Medicaid Services • EHR: Electronic Health Record • NQF: National Quality Forum • MIPS: Merit-based Incentive Payment System • PQRS: Physician Quality Reporting System • QOL: Quality of Life

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2017 Epilepsy Quality Measurement Set Update The following measures were approved by the work group. There is no requirement that all measures in the measurement set be used. Providers are encouraged to identify the one or two measures that would be most meaningful for their patient populations and implement these measures to drive performance improvement in practice. 2017 Epilepsy Quality Measurement Set Update Counseling for Women of Childbearing Potential with Epilepsy Updated Comprehensive Epilepsy Care Center Referral or Discussion for Patients with Intractable Epilepsy Quality of Life Assessment for Patients with Epilepsy Quality of Life Outcome for Patients with Epilepsy Depression and Anxiety Screening for Patients with Epilepsy Seizure Frequency

Other Potential Measures The work group proposed eighteen measure concepts at the start of the update. Prior to seating the work group, Axon Registry users were questioned about potential outcome and intermediate outcome measures. It was suggested that anti- seizure medication therapeutic ranges be evaluated as a potential intermediate outcome measure, but upon investigation of EHR data lab values are not consistently documented resulting in the concept having low feasibility. The AAN encourages work groups to focus development of measure concepts that are feasible, meaningful to quality improvement efforts, and address a known treatment gap. Ultimately the work group cannot develop all appropriate concepts due to resource limitations and efforts to reduce provider reporting burden. The work group eliminated thirteen proposed new concepts prior to discussion (See graphic above) to focus on measures with link to improved outcomes, greater feasibility, and opportunity to drive improvement. These concepts were: 1. Sudden Unexplained Death in Epilepsy (SUDEP) counseling, 2. Injury and pressure ulcers occurring on epilepsy monitoring unit, 3. Quality of life adjusted for seizure type, 4. Assessing bone health for patients on anti-seizure medications for two years or more, 5. Referral for cognitive behavioral therapy for patients diagnosed with psychogenic nonepileptic seizures, 6. Evaluation of anti-seizure medication side effects, 7. Patient adherence to anti-seizure medication prophylaxis, 8. Adherence to anti-seizure monitoring regimens, 9. Zero seizure frequency for patients with non-treatment resistant epilepsy, 10. Folic acid use for women with epilepsy 11. Driving safety for patients with epilepsy, 12. Patient confirmation of counseling for women of childbearing potential with epilepsy was provided, 13. Discontinuation of acute anti-seizure medication.

Two additional concepts were discussed, but not approved for public comment:

• Epilepsy-related Emergency Department (ED) Visit Rate The concept was not further developed due to feasibility concerns and concerns data would not drive meaningful improvement. An EHR or e-specified measure cannot be developed now due to lack of interoperability limiting outpatient provider awareness of ED visits for patients. Providers are dependent upon patients to alert them to an ED visit, and often months pass before a patient relays this information to the provider during their next scheduled appointment. Development of a claims based measure maybe feasible at a system level, however, this data would be delayed and providers and systems unable to respond in real-time to ED visit rate information rendering it limited for quality improvement projects. Further, there are situations where patients are encouraged to receive ED (e.g., recurrent status epilepticus crises) and measurement may unintentionally result in discouragement of ED 8 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

care for patients for whom ED care is appropriate. For these reasons, the work group encourages further research and development of interoperability to assist in the provision of meaningful data in real-time to providers, which may lead to future measures on this high-value concept. • Anti-seizure Rescue Medication Two potential process measure concepts were discussed: Patients with an active prescription for benzodiazepine “rescue” medication to abort prolonged or recurrent seizures and Patients with a rescue plan documented. The active rescue medication prescription poses several quality improvement challenges, as having an active prescription does not mean the medication will be used during time of emergency (e.g., adult patients may not have anyone available to administer medication or prescription may not be filled due to personal or financial reasons) and a prescription for rescue medications might be prescribed for alternate reasons other than for rescue reasons (e.g., lorazepam for anxiety attacks and not daily seizure clusters or prolonged seizures). Given these concerns, the concept was determined to not be feasible for implementation. The rescue plan or seizures action plan concept was not approved for similar concerns. Evidence has demonstrated that a seizure action plan’s presence does not reduce health care utilization.vi Additionally, there is no unified place or structured data field in EHRs for rescue action plan to be documented. The work group discussed measuring the administration of rescue medications, but the goal of such medications is to be used in non-medical, out-of-hospital situations where there will not be formal documentation of administration (such as at home, daycare, or school,) or may be administered in outpatient or outside Emergency Room settings with use not consistently relayed to and/or documented by the outpatient provider. As a result, the work group encourages further efforts in the field to unify documentation, specifically better and uniform documentation on medication rationale, administration, and discontinuation. These changes may result in opportunities for further quality improvement measures. Additionally, creation of standardized instruments for documenting a seizure action plan may assist in increasing utility of this tool toward improved outcomes.

These measures were not included in this measurement set, but these high-value concepts will be retained for future measurement set updates as more evidence may support development or a treatment gap in care at that time.

The AAN has developed additional measures that may be of interest to clinicians and teams treating patients with epilepsy. All AAN measures are available for free at: aan.com/practice/quality-measures/ Additional measures for patients with seizures and/or epilepsy are included in the Inpatient and Emergency, Child Neurology, and Universal Neurology measurement sets. Retired 2014 Measures The work group retired all the 2014 epilepsy measures, except two. 2014 Epilepsy Quality Measurement Set Update Seizure Frequency Seizure Intervention Retired Etiology, Seizure Type, or Epilepsy Syndrome Retired Querying and Intervention for Side Effects of Anti-seizure Therapy Retired Personalized Epilepsy Safety Issue and Education Provided Retired Screening for Psychiatric or Behavioral Health Disorders for Patients with Epilepsy Retired Counseling for Women of Childbearing Potential with Epilepsy Updated Referral to Comprehensive Epilepsy Center Retired

The work group had proposed retiring seizure frequency, but following the public comment period, the work group reviewed comments regarding retirement recommendations. The work group voted again on if each individual measure 9 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association. should be retired after discussion on each of the 2014 epilepsy quality measures. The work group voted not to retire the seizure frequency measure following discussion and includes the 2014 specification of the measure to meet user needs. The work group noted seizure frequency measure has been retired from use in CMS accountability programs due to the inability to link documentation to improved outcomes and lack of a gap in care with consistent high performance rates reporting capture of seizure frequency is standard of care. The work group also noted there is a lack of specificity and uniformity in collecting quantity of seizures across providers, which results in feasibility issues. The Axon Registry has implemented the measure through use of a data dictionary and search terms. The work group will collaborate with organizational partners and the many current Learning Healthcare Collaboratives evaluating this issue to update the specifications during future updates when additional evidence supports standardization in documentation of seizure frequency (i.e., standardized tool, standardized reporting period, or other). The rationale for individual measure retirement is discussed below. Retirement decisions should not be viewed as supporting the belief there is no value in measuring these processes or concepts. The AAN is of the belief no one measurement set can meet the measurement needs of all providers, and prioritizes measure concepts with specificity, feasibility, link to outcomes, and strong evidence. Many lessons on feasibility have been learned since the development of the 2014 measurement set, and some of the prior measures lacked specificity to make the measures feasible or provide meaningful data to drive improvement in practice. Further, many of the process measures could not be linked to improved patient outcomes. Additionally, CMS phased most of the epilepsy measures out of their PQRS and MIPS programs due to the concerns noted below.

• Seizure intervention was retired due to inability to link documentation to improved outcomes and burdensome process requirements. The work group noted the measure was dropped from use in CMS accountability programs in 2017 due to low level evidence and failure to link the measure to improved care. • Etiology, seizure type, or syndrome was retired as existing specifications had little impact on quality improvement efforts. The work group noted the measure was dropped from use in CMS accountability programs in 2017 due to low level evidence and failure to link the measure to improved care. • Querying and interventions for side effects of anti-seizure therapy was retired due to difficulty in locating uniform data in a medical record impacting feasibility. • Personalized epilepsy safety issue and education provided was retired as potential counseling options were too broad to inform providers on meaningful interventions for quality improvement efforts and because the definition of education was so broad there was no meaningful performance gap to address. The broad definition of education impacted feasibility of abstraction from the medical record. • Screening for psychiatric or behavioral health was retired to reduce duplicative measures in the field. The measure was overly broad and inclusive of numerous behavioral health conditions that made abstraction from the medical record difficult. The work group planned to develop an outcome measure addressing depression improvement. However, the work group determined development of an outcome measure on this issue was not feasible now given treatment is delivered by psychiatry, primary care physicians, or other treatment team members. The work group developed a refined depression and anxiety screening measure with greater specificity for quality improvement purposes. • Referral to comprehensive epilepsy center was retired due to feasibility concerns. The denominator required identifying individuals with failure of two anti-seizure medications, and this is not uniformly documented in the medical record.

Technical Specifications Overview The Work Group developed technical specifications for measures that includes data from: • Electronic Health Record (EHR) Data • Administrative Data • Registry 10 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Administrative claims specifications are not provided for measures given the AMA’s decision to discontinue the maintenance of CPT II codes. The AAN is in the process of creating code value sets and the logic required for electronic capture of the quality measures with EHRs, when possible. A listing of the quality data model elements, code value sets, and measure logic (through the CMS Measure Authoring Tool) for each of the measures will be made available at a later date. These technical specifications will be updated as warranted. Testing and Implementation of the Measurement Set The measures in this set are being made available without any prior testing. The AAN encourages testing of this measurement set for feasibility and reliability by organizations or individuals positioned to do so. Select measures will be beta tested once the set has been released, prior to submission to the National Quality Forum for possible endorsement.

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2017 Epilepsy Measure Specifications Counseling for Women of Childbearing Potential with Epilepsy Measure Title Counseling for Women of Childbearing Potential with Epilepsy Description Percentage of all patients of childbearing potential (12-44 years old) diagnosed with epilepsy who were counseled at least once a year about how epilepsy and its treatment may affect contraception and pregnancy. Measurement January 1, 20xx to December 31, 20xx Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Care Ages Between 12-44 years old Event Office visit Diagnosis Epilepsy Denominator All females, including all individuals of childbearing potential (12-44 years old) with a diagnosis of epilepsy. Numerator Patients or caregivers counseled* at least once a year about how epilepsy and its treatment may affect contraception and/or pregnancy. Measure is met if patient has documentation they are pre- menstrual, post-menopausal, surgically sterile, or reproductive organs absent.

*Counseling must include a discussion of at least two of the following three counseling topics: • Need for folic acid^ supplementation (1), • Drug to drug interactions with contraception medication (2,3), • Potential anti-seizure medications effect(s) on fetal/child development and/or pregnancy (2,3).

^Note a folic acid prescription alone will not meet the measure, as there are multiple reasons folic acid may be prescribed. The work group note the intent is to ensure counseling is provided, as many patients are prescribed folic acid without knowing the rationale for the prescription. Required None Exclusions Allowable None Exclusions Exclusion Not Applicable Rationale Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Process Level of Provider Measurement Risk Not Applicable Adjustment For Process Epilepsy is associated with reduced fertility, increased pregnancy risks, and risks for Measures malformations in the infant.(4) Treatment of seizures with anti-seizure medications may alter Relationship to hormone levels, render oral contraceptives less effective and may interfere with embryonic and Desired fetal development.(5-8) Certain anti-seizure medications have higher risks for congenital Outcome malformations and cognitive or behavioral developmental risks.(7,8) Folic acid supplementation, monotherapy for epilepsy, using lower doses of medication when possible, and proper obstetrical,

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prenatal and pre-pregnancy care all should be discussed with the patient, so they understand the risks involved and how to mitigate these risks.

Process Intermediate Outcome Outcomes • Counseled annually on how • Folic Acid Prescribed • Reduced complications and epilepsy and its treatment may seizures during pregnancy affect contraception OR • Reduction of birth deformities pregnancy attributed to anti-seizure • Increased treatment planning to medications support patient family planning • Reduced unplanned pregnancy wishes rates

Opportunity to Counseling and discussion for women with epilepsy can have important and beneficial effects Improve Gap in (9,10) with the goal of reducing unplanned pregnancies, birth/cognitive deficits to infants, and Care complications that can occur during pregnancy and/or delivery for women with epilepsy. Guidelines (11) and interventions (12) are available in the literature to assist in how to provide such important information. However, gaps in providing such counseling to women with epilepsy exist (13-15). The denominator language has been expanded to require counseling be provided to all patients of childbearing potential, including self-identified males who may be capable of bearing children. This language was added to capture LBGTQ+ populations who may have counseling needs overlooked. The numerator counseling definition was drafted for simplicity of data collection. When addressing drug-to-drug interactions this counseling should include information on possible interactions leading to higher rates of unplanned pregnancy for women with epilepsy. Potential anti-seizure medications effect(s) on fetal/child development and/or pregnancy counseling should include information on the risks of stopping medication(s) without consulting treatment team providers if a patient with epilepsy becomes pregnant unexpectedly. Harmonization There are no known similar measures. with Existing Measures

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References 1. Harden CL, Pennell PB, Koppel BS et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Vitamin K, folic acid, blood levels, and breastfeeding: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):142-149. 2. Harden CL, Meador KJ, Pennell PB, et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Teratogenesis and perinatal outcomes: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):133-141. 3. Harden CL, Hopp J, Ting TY, et al. Practice Parameter update: Management issues for women with epilepsy – Focus on pregnancy (an evidence-based review): Obstetrical complications and change in seizure frequency: Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):126-132. 4. Viale L, Allotey J, Cheong-See F, et al. Epilepsy in pregnancy and reproductive outcomes: a systematic review and meta-analysis. Lancet 2015; 386: 1845-1852. 5. Herzog AG. Differential impact of antiepileptic drugs on the effects of contraceptive methods on seizures: Interim findings of the epilepsy birth control registry. Seizure 2015; 28:71-75. 6. Herzog AG, Mandle HB, Cahill KE, et al. Contraceptive practices of women with epilepsy: Findings of the epilepsy birth control registry. Epilepsia 2016; 57(4):630-637. 7. Hernández-Díaz S, Smith CR, Shen A, et al., for the North American AED (Antiepileptic Drug) Pregnancy Registry. Comparative Safety of Antiepileptic Drugs during Pregnancy. Neurology 2012;78:1692-1699.

8. Pennell PB. Antiepileptic drugs during pregnancy: what is known and which AEDs seem to be safest? Epilepsia 2008;49(suppl 9):43-55. 9. Espinera AR, Gavvala J, Bellinski I, et al. Counseling by epileptologists affects contraceptive choices of women with epilepsy. Epilepsy Behav 2016;65:1-6. 10. Laganà AS, Triolo O, D’Amico V, et al. Management of women with epilepsy: from preconception to post-partum. Arch Gynecol Obstet 2016;293:493-503. 11. Sabers A. Treatment guidelines: Women of fertile age. Epileptology 2013;1:11-16. 12. Mody SK, Haunschild C, Farala JP, et al. An educational intervention on drug interactions and contraceptive options for epilepsy patients: a pilot randomized controlled trial. Contraception 2016; 93: 77-80. 13. Moura LMVR, Yacaman Mendez D, De Jesus J, et al. Quality care in epilepsy: Women’s counseling and its association with folic acid prescription or recommendation. Epilepsy Behav 2015; 44: 151-154. 14. Fitzsimons M, Dunleavy B, O’Byrne P, et al. Assessing the quality of epilepsy care with an electronic patient record. Seizure 2013;22(8):604-610. 15. George IC. How do you treat epilepsy in pregnancy? Neurology Clinical Practice. August 2017. Published online before print. Available at: http://cp.neurology.org/content/early/2017/08/01/CPJ.0000000000000387.full.pdf+html Accessed on August 8, 2017.

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Flow Chart Diagram: Counseling for Women of Childbearing Potential with Epilepsy

Was the patient gender documented as Patient NOT female or patient identified as having child Included in No bearing potential? Data Yes Submission No Was the patient aged 12-44 years old on the No

first day of the measurement period? No Yes No Did patient have a diagnosis of epilepsy on any Did the patient have at least one new or contact during the current or prior established patient visit with an eligible measurement period OR on their active problem provider during the measurement period? Yes list during the measurement period?

Yes

Patient Patient INCLUDED in INCLUDED in Denominator Eligible Population

During the measurement period, was patient counseled* at least once on two out of three counseling topics about how epilepsy and its treatment may affect contraception or pregnancy?

Yes No

Patient met During the measurement period, was there numerator Yes documentation patient pre-menstrual, post- criteria menopausal, surgically sterile, or reproductive organs absent?

No

Patient did NOT meet numerator criteria

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Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient Gender Female Age 12-44 years old ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.60 Infantile spasms, without mention of intractable epilepsy ICD-9 345.61 Infantile spasms, with intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

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Comprehensive Epilepsy Care Center Referral or Discussion for Patients with Intractable Epilepsy Measure Title Comprehensive Epilepsy Care Center Referral or Discussion for Patients with Intractable Epilepsy Description Percentage of patients who were referred or had a discussion of evaluation at a comprehensive epilepsy care center*. Measurement January 1, 20xx to December 31, 20xx Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Care Ages All Event Office visit Diagnosis Epilepsy Denominator Patients diagnosed with intractable epilepsy (See Appendix of Codes) OR Patients diagnosed with epilepsy who were prescribed three or more distinct anti-seizure medications in past 2 years.

The work group has chosen to use the term intractable epilepsy for this document to reflect what is also known as drug-resistant epilepsy, refractory epilepsy, and pharmacoresistant epilepsy. The work group chose to use intractable epilepsy given its appearance in ICD-9 and ICD-10 systems. For location via a registry it is recommended ICD-10 codes be utilized, and ICD-9 codes used for historical data. For location search term in a registry, the work group recognizes the alternate terms: “drug-resistant epilepsy”, “refractory epilepsy”, and “pharmacoresistant epilepsy”. Numerator Patients with an order for referral to a comprehensive epilepsy care center, who had a discussion of evaluation at a comprehensive epilepsy care center, OR who received treatment at a comprehensive epilepsy care center during the measurement period.

*Comprehensive Epilepsy Care Center: Epilepsy centers that provide comprehensive diagnostic and treatment modalities and access to multidisciplinary teams to address comorbidities that are common in epilepsy. The National Association of Epilepsy Centers has provided details of the essential services, personnel, and facilities at comprehensive epilepsy centers.(1) In general, comprehensive centers will provide diagnostic evaluation including inpatient video electroencephalogram (EEG) monitoring, epilepsy surgery evaluation, access to epilepsy surgery, and staff to address psychiatric and psychosocial issues. The Work Group notes the intent of the referral to a Comprehensive Epilepsy Care Center is to reinforce detection of refractory cases, confirm classification of epilepsy, improve access to other treatments including ketogenic diet and neuromodulation, and evaluation of potential co-morbid symptom or social counseling, and not solely for presurgical evaluation and surgery.

For location via search term in a registry, the work group encourages providers to document comprehensive epilepsy care center in following format: • “Comprehensive epilepsy care center”, “CEC”, or “CECC” • “Level 3 epilepsy care center” • “Level 4 epilepsy care center” Required None Exclusions Allowable None Exclusions Measure will be evaluated for future updates to address potential unintended consequences that may include false positive identifications in the denominator of patients with migraine or other neurological conditions warranting prescription of anti-seizure medications. Exclusion None Rationale 17 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Process Level of Provider Measurement Risk Not Applicable Adjustment For Process Appropriate evaluation must occur for patients diagnosed with intractable epilepsy or who have Measures indications of treatment resistant epilepsy, as suggested by three distinct seizure medication Relationship to prescriptions. By creating a measure ensuring these patient populations are referred or have Desired comprehensive epilepsy care center services discussed it is anticipated that there will be an Outcome increase in appropriate evaluations, which would confirm diagnostic accuracy and result in offering of effective non-drug and non-surgical treatment options. This may include psychiatric, psychological, and social counseling to address consequences of epilepsy.

Evidence suggests that epilepsy surgery is superior to medical treatment in controlling seizures, improving quality of life, rates of unemployment and school attendance. (2-5) Prolonged unsuccessful medical treatment can lead to unnecessary disability and even death. (3) Most importantly, in patients with either temporal lobe or extratemporal lobe epilepsy, favorable and seizure-free outcome rates remained stable after surgery over long-term follow-up. Therefore, pre- surgical evaluation should be considered in all patients with refractory epilepsy. (5)

Additionally, referral to comprehensive epilepsy centers may result in earlier diagnosis of psychogenic seizures; remission of psychogenic nonepileptic seizures is more likely the earlier diagnosis is made related to onset. (6)

Process Process Outcomes • Referral to comprehensive • Assessed at a comprehensive • Increased surgical and epilpesy care center epilepsy care center refractory seizure interventions • Discussion of evaluation at provided comprehensive epilepsy care • Reduced seizures center • Improved QOL • Early correct diagnosis of nonepileptic spells

Opportunity to Despite the strong evidence of superior outcomes among those who receive epilepsy surgery and Improve Gap in other specialized services at comprehensive epilepsy centers, only a small fraction of patients are Care referred within 2 years of developing drug-resistant epilepsy, and many years of delay before referral for epilepsy surgery is common (7-9). Contributors to the delay in referral include gaps in 18 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

knowledge related to epilepsy surgery guidelines and definition of drug resistance (10). Among those ultimately found to have psychogenic seizures, history of multiple seizure medication prescriptions is associated with delay to diagnosis (11). This measure aims to increase awareness of the need for timely referral among practitioners. Harmonization There are no known similar measures. with Existing Measures References 1. Labiner DM, Bagic AI, Herman ST, et al.; for the National Association of Epilepsy Centers. Essential services, personnel, and facilities in specialized epilepsy centers. Revised 2010 guidelines. Epilepsia 2010;51:2322-2333 2. Wiebe S, Blume WT, Girvin JP, et al. A Randomized, Controlled Trial of Surgery for Temporal-Lobe Epilepsy N Engl J Med 2001; 345:311-318. 3. Wasade VS, Elisevich K, Tahir R, et al. Long-term seizure and psychosocial outcomes after resective surgery for intractable epilepsy. Epilepsy Behav. 2015; 43: 122-127. 4. Gonzalez-Martinez et al. Epilepsy Surgery of the Temporal Lobe in Pediatric Population: A Retrospective Analysis Neurosurgery (2012) 70 (3): 684-692. 5. Scottish Intercollegiate Guidelines Network(SIGN). Diagnosis and management of epilepsy in adults. Edinburgh. SIGN publication no. 143. May 2015. Available at: http://www.sign.ac.uk Accessed on June 21, 2017. 6. Selwa L, Geyer J, Nikakhtar N, et al. Nonepileptic seizure outcome varies by type of spell and duration of illness. Epilepsia. 2000; 41: 1330-1334. 7. Jette N, Sander J, Keezer M. Surgical treatment for epilepsy: the potential gap between evidence and Practice. Lancet Neurology. 2016 ; 15: 982-984. 8. Burneo J, Shariff S, Liu K, et al. Disparities in epilepsy surgery among patients with epilepsy in a universal health system. Neurology. 2016; 86: 72-78. 9. Pieters H, Iwaki T, Vickrey B, et al. “It was five years of hell”: Parental experiences of navigating and processing the slow and arduous time to pediatric resective epilepsy surgery. Epilepsy Behavior. 2016; 62: 276-284. 10. Roberts J, Hrazdil C, Wiebe S, et al. Neurologists’ knowledge of and attitudes toward epilepsy surgery: a national survey. Neurology. 2015; 84: 159-166. 11. Rodriguez-Urrutia A, Toledo M, Eiroa-Orosa F, et al. Psychosocial factors and antiepileptic drug use related to delayed diagnosis of refractory psychogenic nonepileptic seizures. Cogn Behav Neurol. 2014; 27: 199-205.

19 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Flow Chart Diagram: Comprehensive Epilepsy Care Center Referral or Discussion

Did the patient have at least one new or No Patient NOT established patient visit with an eligible provider during the measurement period? Included in Data Submission

Yes No

Did patient have a diagnosis of intractable Did patient have a diagnosis of epilepsy on any contact epilepsy on any contact during the current or No during the current or prior measurement period OR on prior measurement period OR on their active their active problem list during the measurement period problem list during the measurement AND have 3 prescriptions or more for distinct anti- period? seizure medication the past 2 years?

Yes Yes

Patient INCLUDED in Eligible Population

During the measurement period was Patient Patient met Yes No INCLUDED in numerator patient receiving care at a Denominator criteria comprehensive epilepsy care center?

During the measurement period, did the patient have referral documentation to a comprehensive epilepsy care center or a discussion of evaluation at a comprehensive epilepsy care center?

No Yes

Patient did Patient met NOT meet numerator numerator criteria criteria 20 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient AND ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.61 Infantile spasms, with intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

OR

CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient AND ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.60 Infantile spasms, without mention of intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus

21 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus

AND 3 of the following anti-seizure medications within 2 years of office visit RxNorm Brivaracetam RxNorm Carbamazepine RxNorm Carbamazepine-XR RxNorm Clobazam RxNorm Clonazepam RxNorm Divalproex Sodium RxNorm Divalproex Sodium-ER RxNorm Eslicarbazepine Acetate RxNorm Ethosuximide RxNorm Ezogabine RxNorm Felbamate RxNorm Gabapentin RxNorm Lacosamide RxNorm Lamotrigine RxNorm Levetiracetam RxNorm Levetiracetam XR RxNorm Oxcarbazepine RxNorm Oxcarbazepine XR RxNorm Perampanel RxNorm Phenobarbital RxNorm Phenytoin RxNorm Pregabalin RxNorm Primidone RxNorm Rufinamide RxNorm Tiagabine Hydrochloride RxNorm Topiramate RxNorm Topiramate XR RxNorm Valproic Acid RxNorm Vigabatrin RxNorm Zonisamide

22 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Quality of Life Assessment for Patients with Epilepsy Measure Title Quality of Life Assessment for Patients with Epilepsy Description Percentage of patients with age-appropriate condition-specific quality of life assessed at least once in the measurement period. Measurement January 1, 20xx to December 31, 20xx Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Ages Aged 4 years and older Event Office Visit Diagnosis Epilepsy Denominator Patients aged 4 years and older diagnosed with epilepsy Numerator Patients with age-appropriate condition-specific quality of life assessed* at least once in the measurement period.

*Assessed is defined as completion of one of the following age appropriate, validated quality of life tool: Quality of Life in Epilepsy (QOLIE)-10(1), QOLIE-31(2), QOLIE- AD-48(3), Personal Impact of Epilepsy Scale (PIES)(4), Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55)(5), Global Assessment of the Severity of Epilepsy (GASE)(6), Child Health Questionnaire (CHQ)(7), PedsQL Epilepsy Module(8), and Epilepsy Surgery Inventory 55 Survey ESI-55(9). Other tools with reasonable correlation with quality of life scores may be used as an alternative (i.e., Seizure Severity Questionnaire (SSQ)(10), PROMIS-10(11), WHO Disability Assessment Schedule (WHODAS 2.0)(12)). Required None Exclusions Allowable Patients who are unable or decline to complete the instrument and for these patients, a caregiver Exclusions is not present to provide proxy report.

For location via search term in a registry, the work group encourages providers to document this exclusion in following format: “Patient declines quality of life (or “QOL”) assessment; no proxy available”, “Patient unable to complete quality of life (or “QOL”) assessment; no proxy available”, or “Patient refuses quality of life (or “QOL”) assessment; no proxy available”.

Exclusion Patients need to be willing to complete the screening tool for performance scores to be valid, and Rationale if patients are unwilling and caregivers are not present to supplement information by proxy scores would not be valid. Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Process Level of Provider Measurement Risk Not Applicable Adjustment For Process Assessments of health-related quality of life are considered a necessary requirement to Measures implement a quality of life outcome measure that will inform about the quality of care for Relationship to epilepsy patients.(13–16) Quality of Life (QOL) assessments in patients with epilepsy are Desired associated with patient’s general physical and mental health status.(17) Providers may use QOL Outcome 23 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

scores as a broad and dynamic measure of how seizures and seizure prophylaxis affects patient's life.(15,16,18–20)

Process Outcomes • Patients quality of life • Improved QOL assessed • Quality of life scores reviewed and appropriate action taken

Opportunity to Many studies showing improvement in QOL occurs with decreased seizure frequency, treatment Improve Gap in of depression.(21) Measurement of QOL allows patients and physicians to identify areas of Care concern / needed treatments. However, collection rates of patient reported outcomes in practice remains low. (17)

The Work Group would like to emphasize the fact that QOL data is important for both, clinical and research purposes at the individual and at the population level. The QOL measures proposed are intended to improve clinical practice, irrespective of the type of measure chosen. For instance, patients living with epilepsy often report concerns that are often captured in several of the proposed QOL instruments, including medication side effects, driving/transportation.(13) In an office visit, the clinician may use QOL data to further investigate what is the component of the patient's life that has been affected (e.g., addressing medication side effects). Additionally, a clinician may look at individual trends over time to examine the impact of therapeutic decisions (e.g., an overtime improvement in QOL scores after optimizing anti-seizure medication doses to an individual might be used as pertinent patient-reported documentation of the benefit of that epilepsy-care intervention). Harmonization No similar measures are currently available in the field. The AAN is in the process of developing with Existing a quality of life measure that will apply to all patients with a neurologic condition. Those Measures specifications will be reviewed by this work group once available. The AAN’s Axon Registry will implement a measure using PROMIS data in 2017. References 1. Cramer JA, Perrine K, Devinsky O, et al. A Brief Questionnaire to Screen for Quality of Life in Epilepsy The QOLIE-10. Epilepsia 1996;37(6):577-582 2. Cramer JA, Perrine K, Devinsky Ok, et al. Development and cross-cultural translation of a 31-item quality of life questionnaire (QOLIE-31). Epilepsia 1998;39:81-88. 3. Cramer JA, Westbrook L, Devinsky O, et al. Development of a quality of life inventory for adolescents: The QOLIE-AD-48. Epilepsia 1999;40:1114-1121. 4. Fisher RS, Nune G, Roberts SE, et al. The Personal Impact of Epilepsy Scale (PIES). Epilepsy Behav 2015;42:140-146.

24 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

5. Goodwin SW, Lambrinos AI, Ferro MA, et al. Development and assessment of a shortened Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55). Epilepsia 2015;56(6): 864-872. 6. Chan CJ, Zou G, Wiebe S, et al. Global assessment of the severity of epilepsy (GASE) Scale in children: Validity, reliability, responsiveness. Epilepsia 2015;56(12):1950-1956. 7. Landgraf JM, Abetz L, Ware JE. Child Health Questionnaire (CHQ): A user’s manual. Boston, MA: The Health Institute, New England Medical Center. 1996. 8. Modi AC, Junger KF, Mara C, et al. Validation of the Peds QL™ Epilepsy Module: A pediatric epilepsy-specific health-related quality of life measure. Epilepsia. (in press) 9. Devinsky O. Clinical use of the quality of life in epilepsy inventory. Epilepsia 1993;34:S39-44. 10. Cramer JA, Baker GA, Jacoby A. Development of a new seizure severity questionnaire: Initial reliability and validity testing. Epil Res. 2002; 48: 187-197. 11. Cella D, Riley W, Stone A, et al. Initial Adult Health Item Banks and First Wave Testing of the Patient-Reported Outcomes Measurement Information System (PROMIS™) Network: 2005-2008. J Clin Epidemiol. 2010;63(11):1179-1194. 12. Üstün TB, Chatterrji S, Kostanjsek N, et al. Developing the World Health Organization Disability Assessment Schedule 2.0. Bulletin of the World Health Organization 2010;88:815–823. 13. Martin R, Vogtle L, Gilliam F FE. What are the concerns of older adults living with epilepsy? Epilepsy Behav. 2005;7(2):297–300. 14. Fayers P, Machin D. Quality of Life: The Assessment, Analysis and Interpretation of Patient-reported Outcomes. 2nd ed. New York: John Wiley & Sons; 2013. 568 p. 15. Birbeck GL, Hays RD, Cui X, Vickrey BG. Seizure reduction and quality of life improvements in people with epilepsy. Epilepsia 2002;43(5):535–538. 16. Vickrey BG, Berg AT, Sperling MR, et al. Relationships Between Seizure Severity and Health-Related Quality of Life in Refractory Localization-Related Epilepsy. 2000;41(6):760–4. 17. Moura LMVR, Schwamm E, Moura Jr V., et al. Feasibility of the collection of patient-reported outcomes in an ambulatory neurology clinic. Neurology. 2016;87:1-8. 18. Choi H, Hamberger MJ, Munger Clary H, et al. Seizure frequency and patient- centered outcome assessment in epilepsy. Epilepsia 2014;55(8):1205–1212. 19. Moura LMVR, Carneiro TS, Thorn EL, et al. Patient perceptions of physician- documented quality care in epilepsy. Epilepsy Behav; 2016;62:90–96. 20. French JA, Kanner AM, Bautista J, et al. Efficacy and tolerability of the new antiepileptic drugs II: Treatment of refractory epilepsy - Report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epil. Neurology 2004;62(8):1261–1273. 21. Patient-Reported Outcome Measurement Group, Oxford. A Structured Review of Patient-Reported Outcome Measures (PROMs) For Epilepsy: An Update 2009. Available at: http://phi.uhce.ox.ac.uk/pdf/PROMs_Oxford_Epilepsy_17092010.pdf Accessed on August 8, 2017.

25 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Flow Chart Diagram: Quality of Life for Patients with Epilepsy

Patient NOT Included in Data Submission

No No

Did patient have a diagnosis of epilepsy on any Did the patient have at least one new or contact during the current or prior established patient visit with an eligible measurement period OR on their active problem provider during the measurement period? Yes list during the measurement period?

Yes

Did the patient refuse or was unable to complete QOL assessment and a Patient Patient NOT Yes Included in caregiver was unavailable for proxy INCLUDED in Denominator reporting? Eligible Population No

Patient INCLUDED in Denominator

During the measurement period, was an age- appropriate condition-specific quality of life assessment completed and review of the patient’s quality of life scores occur at least once?

No Yes

Patient did Patient met NOT meet numerator numerator criteria criteria

26 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.60 Infantile spasms, without mention of intractable epilepsy ICD-9 345.61 Infantile spasms, with intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

27 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Quality of Life Outcome for Patients with Epilepsy Measure Title Quality of Life Outcome for Patients with Epilepsy Description Percentage of patients whose quality of life assessment results are maintained or improved during the measurement period. Measurement January 1, 20xx in Year 1 to December 31, 20xx in Year 2 Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Ages Age 18 years and older Event Office Visit Diagnosis Epilepsy Denominator Patients aged 18 years and older diagnosed with epilepsy who had two office visits during the two- year measurement period which occurred at least 4 weeks apart. Numerator Patients whose most recent QOLIE-10-P score is maintained or improved from the prior QOLIE-10- P score^ obtained in the measurement period.

^For patients who have more than two QOLIE-10-P scores in a calendar year, the last score recorded in the calendar year will be compared to the first score recorded in the calendar year. Required None Exclusions Allowable None Exclusions Exclusion Not Applicable Rationale Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Outcome Level of Provider Measurement Risk See Appendix A AAN Statement on Comparing Outcomes of Patients Adjustment This measure is being made available in advance of development of a risk adjustment strategy. Individuals commenting on the measures are encouraged to provide input on potential risk adjustment or stratification methodologies. The work group identified the following potential data elements that may be used in a risk adjustment methodology for this measure: • Seizure frequency • Co-morbid anxiety and mood disorders • 3 or more comorbid medical conditions Desired The QOLIE-10 has been validated for patients with epilepsy (1) and directly assesses quality of life Outcome from the patient perspective. Measuring quality of life allows patients and providers to identify areas of concern and develop appropriate treatment plan adjustments as needed. Opportunity to Collecting quality of life data via the QOLIE-10-P in a neurology ambulatory setting is feasible.(2) Improve Gap The QOLIE-10-P has been demonstrated to be responsive to changes in epilepsy treatment, although in Care concern has been raised on the strong influence of mood on QOLIE scores.(3) By monitoring quality of life scores, providers may be able to offer interventions to improve patients quality of life, such as medication interventions, surgical interventions, co-morbid conditions, including behavioral health needs, or motivational interviewing.(3-5)

28 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

The work group chose the QOLIE-10-P for several reasons (i.e., the brief questionnaire reduces likelihood of respondent fatigue, ease of access for providers to obtain right to use the tool (6), and prior use in the field). The work group will revisit this decision during future updates to the measurement set evaluating the use of the QOLIE-10-P as well as possible similar measures for adolescent and child populations. The QOLIE-10-P requires respondents to provide input on their feelings during the past 4 weeks. The work group incorporated this time frame as a result.

The measurement period for this measure is two years allowing for individuals who see their physician yearly for monitoring to be included in the measurement base. Harmonization There are no known similar measures applicable to patients with epilepsy. The AAN is in the with Existing process of developing a quality of life measure that will apply to all patients with a neurologic Measures condition. Those specifications will be reviewed by this work group once available. References 1. Cramer JA, Perrine K, Devinsky O, et al. A Brief Questionnaire to Screen for Quality of Life in Epilepsy The QOLIE-10. Epilepsia 1996;37(6):577-582 2. Moura LMVR, Schwamm E, Moura Jr V., et al. Feasibility of the collection of patient-reported outcomes in an ambulatory neurology clinic. Neurology. 2016;87:1- 8. 3. Patient-Reported Outcome Measurement Group, Oxford. A Structured Review of Patient-Reported Outcome Measures (PROMs) For Epilepsy: An Update 2009. Available at: http://phi.uhce.ox.ac.uk/pdf/PROMs_Oxford_Epilepsy_17092010.pdf Accessed on August 2, 2017. 4. Wassenaar M, Leijten FSS, Sander JW, et al. on behalf of the OPPEC study group. Anti-epileptic drug changes and quality of life in the community. Acta Neurol Scand 2016; 133:421-426. 5. Hosseini N, Mokhtari S, Momeni E, et al. Effect of motivational interviewing on quality of life in patients with epilepsy. Epilepsy & Behavior 2016;55:70-74. 6. QOLIE Development Group. QOLIE-10 Permission for Academic and Commercial Use. Available at: http://www.epilepsy.com/sites/core/files/atoms/files/permission%20to%20use%20QO LIE-10-P%20web.pdf

29 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Flow Chart Diagram: Quality of Life for Patients with Epilepsy

Was the patient 18 years and older during the measurement period? No Yes

Did the patient have at least two patient

visits with an eligible provider during the measurement period? No Patient NOT Yes Included in Data Submission

Did patient have a diagnosis of epilepsy on any contact OR on their active problem list during the current measurement period? No

Yes

Patient INCLUDED in Eligible Population

Patient INCLUDED in Did the patient complete the QOLIE-10 Denominator during at least two office visits in the Yes measurement period occurring at least 4 weeks apart?

No

During the measurement period, was the most recent QOLIE10 score was maintained or improved from prior QOLIE10 score? Patient NOT Included in Denominator Yes No

Patient met Patient did numerator NOT meet criteria numerator criteria

30 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.60 Infantile spasms, without mention of intractable epilepsy ICD-9 345.61 Infantile spasms, with intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

31 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Depression and Anxiety Screening for Patients with Epilepsy Measure Title Depression and Anxiety Screening for Patients with Epilepsy Description Percentage of patients with a diagnosis of epilepsy who were screened for depression and anxiety. Use Quality Improvement. Measure will not be submitted for use in accountability programs. Measurement January 1, 20xx to December 31, 20xx Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Ages Age 12 and older Event Office Visit Diagnosis Epilepsy Denominator Patients age 12 and older diagnosed with epilepsy Numerator Patients with epilepsy who were screened for both depression* and anxiety^ at every office visit.

*Depression Screening is use of the following age appropriate validated tool: • Patient Health Questionnaire 2 Questions (PHQ-2) (1), • Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) (2), • Patient Health Questionnaire 9 Questions (PHQ-9) (3, 4), • Patient Health Questionnaire for Adolescents (PHQ-A) (5), • Beck Depression Inventory (BDI) (6), • BDI II (7), • Strengths and Difficulties Questionnaire (SDQ) (8), • Emotional Thermometer (ET4 and ET7) (9, 10).

^Anxiety Screening is use of the following age appropriate validated tool: • Generalized Anxiety Disorder – 2 Scale (GAD-2) (11) • Generalized Anxiety Disorder – 7 Scale (GAD-7) (11) • Strengths and Difficulties Questionnaire (SDQ) (8), • State-Trait Anxiety Inventory (STAI) (13), • STAI- Short Form (14), • Emotional Thermometer (ET 4 and ET7) (9, 10).

The work group recommends use of the PHQ-2 and GAD-2 for measurement purposes, but have provided other tools allowing providers to identify the tools that best meet their practice needs. The work group discussed more and less prescriptive ways to select these tools, eventually determining that multiple tools should be offered to allow providers to determine which tool best meets their individual practice needs. In some cases, tools may be subject to copyright and require licensing fees. For location via search term in a registry, the work group encourages providers to document this screening in the following format: “Patient screened with validated depression and anxiety tools”. Documentation of validated tool scores will meet measure. (e.g., “Patient screened with NDDI-E score 23 and GAD-7 score 15.”) Required None Exclusions Allowable Patients who are unable or decline to complete epilepsy specific screening tool. For location via Exclusions search term in a registry, the work group encourages providers to document this exclusion in the following format: “Patient declines assessment”, “Patient unable to complete assessment”, or “Patient refuses assessment”.

Patient has a diagnosis of depression or anxiety on active problem list. 32 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Exclusion Patients need to be willing to complete the screening tool for performance scores to be valid and Rationale those with an active depression or anxiety concern recorded on the problem list do not need further screening. Lack of further screening should not signify lack of treatment, as it is assumed once diagnosed treatment would be initiated for the patient. Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Process Measure Quality improvement. This measure will not be submitted to accountability programs for their Purpose consideration. Level of Provider Measurement Risk Not Applicable Adjustment For Process People with epilepsy have high rates of psychiatric disorders, with approximately 20% of patients Measures having comorbid depression or anxiety.(11) Such comorbidities result in substantive morbidity and Relationship to place patients with epilepsy at higher risk for poor quality of life (12, 13), poor adherence to Desired medication (14, 15) and potentially increased risk of suicide.(16) Anti-seizure medications can place Outcome patients at risk for mood related changes and suicidality.(17) Symptoms of depression and anxiety can be screened for effectively using a number of different psychometrically validated, reliable screening instruments with validity in the epilepsy population.(2, 13, 18,19) Screening for symptoms of anxiety and depression in patients with epilepsy is imperative to identify high risk patients in need of evaluation and treatment for such comorbidities. Adherence to screening for psychiatric needs has been associated with better seizure control.(20)

Process Intermediate Outcome Outcomes • Patients assessed for depression • Treatment for depression and/or • Improved depression and/or and anxiety anxiety initiated anxiety • Referral to treatment provided as appropriate

Opportunity to There is a need to improve the frequency of screening for depression and anxiety in people with Improve Gap epilepsy and ongoing assessment of adherence to such screening. Comorbid depression and anxiety in Care amongst people with epilepsy can often be undiagnosed and therefore untreated. International consensus statement guidelines recommend screening for depression and anxiety disorders as an integral step in identification and diagnosis of such patients with comorbidity, in order to then evaluate and initiate appropriate treatment.(21) Current evidence, however, suggests low adherence (41%) to the recommendation for screening people with epilepsy for psychiatric and behavioral disorders.(20) Harmonization The work group noted multiple measures exist for depression screening in the field (See below), and with Existing reviewed these concepts identifying additional need for anxiety screening in this population. The Measures work group developed a measure addressing the anxiety needs as a result. MIPS Measure #134 Preventive Care and Screening: Screening for Clinical Depression and Follow- up Plan 33 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

MIPS Measure #371: Depression Utilization of the PHQ-9 Tool MIPS Measure #370: Depression Remission at Twelve Months MIPS Measure #411: Depression Remission at Six Months References 1. Kroenke K, Spitzer RL, Williams JB. The Patient Health Questionnaire- 2: validity of a two- item depression screener. Med Care 2003;41:1284–1292. 2. Gilliam FG, Barry JJ, Hermann BP, et al. Rapid detection of major depression in epilepsy: a multicentre study. Lancet Neurol 2006;5:399–405. 3. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med 2001;16:606–613. 4. Rathore JS, Jehi LE, Fan Y, et al. Validation of the Patient Health Questionnaire-9 (PHQ-9) for depression screening in adults with epilepsy. Epilepsy Behav. 2014;37:215-220. 5. Johnson JG, Harris ES, Spitzer RL, Williams JBW: The Patient Health Questionnaire for Adolescents: Validation of an instrument for the assessment of mental disorders among adolescent primary care patients. J Adolescent Health 2002;30:196–204. 6. Beck AT, Ward CH, Mendelson M, et al. An inventory for measuring depression. Arch Gen Psychiatry 1961;4:561–571. 7. Beck AT, Steer RA, Brown GK. BDI-II: Beck Depression Inventory Manual. 2nd ed. San Antonio: Psychological Corporation; 1996. 8. Goodman R. The Strengths and Difficulties Questionnaire: A Research Note. J Child Psychol. Psychiat 1997;38(5):581-586. 9. Rampling J, Mitchell AJ, Von Oertzen T, et al. Screening for depression in epilepsy clinics. A comparison of conventional and visual-analog methods. Epilepsia. 2012; 53(10):1713- 1721. 10. Gur-Ozmen S, Leibetseder A, Cock HR, et al. Screening of anxiety and quality of life in people with epilepsy. Seizure. 2017;45:107-113. 11. Kroenke K, Spitzer RL, Williams JBW, et al. Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection. Ann Intern Med 2007, 146: 317–325. 12. Spielberger CD, Gorsuch RL, Lushene RE. Manual for the state-trait anxiety inventory. Consulting Psychological Press, Palo Alto; 1970. 13. Marteau T, Bekker H. The development of a six-item short-form of the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) British Journal of Psychology. 1992;31(3):301–306. 14. Pham T, Sauro KM, Patten SB, et al. The prevalence of anxiety and associated factors in persons with epilepsy. Epilepsia 2017 Jun 9. [epub ahead of print] doi: 10.1111/epi.13817. 15. Baca CB, Vickrey BG, Caplan R, et al. Psychiatric and Medical Comorbidity and Quality of Life Outcomes in Childhood-Onset Epilepsy. Pediatrics. 2011;128(6):e1531-1543. 16. Gur-Ozmen S, Leibetseder A, Cock HR, et al. Screening of anxiety and quality of life in people with epilepsy. Seizure 2017;45:107-113. 17. DiMatteo MR, Lepper HS, Croghan TW. Depression is a risk factor for noncompliance with medical treatment: meta-analysis of the effects of anxiety and depression on patient adherence. Arch Intern Med. 2000;160(4):2101-2107. 18. Guo Y, Ding XY, Lu RY, et al. Depression and anxiety are associated with reduced antiepileptic drug adherence in Chinese patients. Epilepsy Behav. 2015;50:91-95. 19. Mula M. Depression in epilepsy. Curr Opin Neurol. 2017; 30(2):180-186. 20. Mula M, Kanner AM, Schmitz B, et al. Antiepileptic drugs and suicidality: an expert consensus statement from the Task Force on Therapeutic Strategies of the ILAE Commission on Neuropsychobiology. Epilepsia 2013; 54(1):199-203. 21. Gill SJ, Lukmanji S, Fiest KM, et al. Depression screening tools in persons with epilepsy: A systematic review of validated tools. Epilepsia 2017;58(5):695-705. 22. Micoulaud-Franchi JA, Bartolomei F, McGonigal A. Ultra-short screening instruments for major depressive episode and generalized anxiety disorder in epilepsy: The NDDIE-2 and the GAD-SI. J Affect Disord. 2017;210:237-240.

34 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

23. Moura LM, Mendez DY, Jesus JD, et al. Association of adherence to epilepsy quality standards with seizure control. Epilepsy Res 2015; 117:35-41. 24. Kerr MP, Mensah S, Besag F, et al. International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy. Epilepsia 2011; 52(11):2133-2138.

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Flow Chart Diagram: Depression and Anxiety Screening for Patients with Epilepsy

Was the patient 12 years and older during the measurement period? No Yes

Did the patient have at least one new or established patient visit with an eligible provider during the measurement period?

No Yes Patient NOT Included in Data Submission Did patient have a diagnosis of epilepsy on any contact during the current or prior measurement period OR on their active problem list during the measurement No period?

Yes

Patient INCLUDED in Eligible Population

Patient INCLUDED in Did the patient decline or was unable to Denominator complete depression and anxiety Yes assessment?

No

At every office visit, was patient assessed for depression and anxiety? Patient NOT Included in Denominator Yes No

Patient met Patient did numerator NOT meet criteria numerator criteria

36 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

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Seizure Frequency for Patients with Epilepsy Measure Title Seizure Frequency for Patients with Epilepsy Description Percentage of all visits for patients with a diagnosis of epilepsy where seizure frequency of each seizure type was documented. Measurement January 1, 20xx to December 31, 20xx Period Eligible Eligible Providers Medical Doctor (MD), Doctor of Osteopathy (DO), Physician Assistant Population (PA), Advanced Practice Registered Nurse (APRN) Care Setting(s) Outpatient Ages All Event Office Visit Diagnosis Epilepsy Denominator All visits for patients with a diagnosis of epilepsy. Numerator Patient visits with current seizure frequency* documented for each seizure type.

*Current seizure frequency: A record of the exact number of seizures gathered from patient records, journal, or calendar OR the average or typical recent seizure frequency, often expressed as the average daily, weekly, or monthly seizure frequency since the last visit. Required None Exclusions Allowable • Caregiver is unavailable for a patient who is non-communicative or has an intellectual Exclusions disability. • Patient or caregiver declines to report seizure frequency. Exclusion For accuracy in reporting a patient or caregiver must be willing to provide data. Rationale Measure Percentage Scoring Interpretation Higher Score Indicates Better Quality of Score Measure Type Process Measure Quality improvement. This measure will not be submitted to accountability programs for their Purpose consideration. Level of Provider Measurement Risk Not Applicable Adjustment For Process The following clinical recommendation statements are quoted verbatim from the referenced Measures clinical guidelines and represent the evidence base for the measure: Relationship to • The seizure type(s) and epilepsy syndrome, aetiology, and co-morbidity should be Desired determined, because failure to classify the epilepsy syndrome correctly can lead to Outcome inappropriate treatment and persistence of seizures.(1) • When a patient with epilepsy receives follow-up care, then an estimate of the number of seizures since the last visit and assessment of drug side-effects should be documented. (Level D 1+/ Primary)2 • If a patient is thought to have a diagnosis of epilepsy then the diagnosis should include a best estimation of seizure types. (Level C 2+/Secondary)(2) The main objective in treating epilepsy is to reduce the frequency of seizures and achieve seizure freedom without side effects. In order to determine whether a patient is seizure-free the seizure frequency must be known. Seizure freedom is associated with improvement in health-related quality of life.

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Opportunity to Provider performance may improve as seizure frequency is not gathered effectively.(3-5) This Improve Gap in measure will help assess the gap and inform quality improvement efforts. For example, after Care implementation of an epilepsy quality measure checklist in an epilepsy clinic without any other intervention, documentation of compliance with this measure increased from 65% to 75%, illustrating that the measure has the intended consequence of increasing compliance.(6) Harmonization There are no known similar measures. with Existing Measures References 1. National Institute of Clinical Health and Excellence. The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care (update). 2012. Clinical guideline 137. Available at: http://www.nice.org.uk/nicemedia/live/13635/57779/57779.pdf Accessed on February 18, 2014. 2. Pugh MJ, Berlowitz DR, Montouris G, et al. What constitutes high quality of care for adults with epilepsy? Neurology 2007;69:2020-2027. 3. Fountain NB, Van Ness PC, Swain-Eng R, et al. Quality improvement in neurology: AAN epilepsy quality measures. Neurology 2011;76:94-99. 4. Wasade VS, Spanaki M, Iyengar R, et al. AAN Epilepsy Quality Measures in clinical practice: a survey of neurologists. Epilepsy Behav. 2012;24(4):468-473. 5. Wicks P, Fountain NB. Patient assessment of physician performance of epilepsy quality- of-care measures. NeurolClinPract 2012;2(4):335-342. 6. Cisneros-Franco JM, Díaz-Torres MA, Rodríguez-Castañeda JB, et al. Impact of the implementation of the AAN epilepsy quality measures on the medical records in a university hospital. BMC Neurology 2013;13:112. Available at: http://www.biomedcentral.com/1471-2377/13/112. Accessed on February 18, 2014.

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Flow Chart Diagram: Seizure Frequency for Patients with Epilepsy

Did the patient have at least one new or established patient visit with an eligible provider during the measurement period? No

Yes

Did patient have a diagnosis of epilepsy on any contact during the current or prior No measurement period OR on their active Patient NOT problem list during the measurement Included in Data period? Submission

Yes

Patient INCLUDED in Eligible Population

Did the patient or caregiver decline to report seizure frequency? Yes No Patient NOT Included in Was a caregiver unavailable for a patient Denominator who is non-communicative or who has an intellectual disability? Yes

No

Patient At every office visit, was patient’s current seizure INCLUDED in frequency documented for each seizure type? Denominator Yes No

Patient met Patient did numerator NOT meet criteria numerator criteria

40 ©2017. American Academy of Neurology Institute. All Rights Reserved. CPT Copyright 2004-2017 American Medical Association.

Code System Code Code Description CPT 99201-99205 Office or Other Outpatient Visit - New Patient (E/M Codes) CPT 99211-99215 Office or Other Outpatient Visit - Established Patient (E/M Codes) CPT 99241-99245 Office or Other Outpatient Consultation – New or Established Patient ICD-9 345.00 Generalized nonconvulsive epilepsy, without mention of intractable epilepsy ICD-9 345.01 Generalized nonconvulsive epilepsy, with intractable epilepsy ICD-9 345.10 Generalized convulsive epilepsy, without mention of intractable epilepsy ICD-9 345.11 Generalized convulsive epilepsy, with intractable epilepsy ICD-9 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, without mention of intractable epilepsy ICD-9 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures, with intractable epilepsy ICD-9 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, without mention of intractable epilepsy ICD-9 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures, with intractable epilepsy ICD-9 345.60 Infantile spasms, without mention of intractable epilepsy ICD-9 345.61 Infantile spasms, with intractable epilepsy ICD-9 345.70 Epilepsia partialis continua, without mention of intractable epilepsy ICD-9 345.71 Epilepsia partialis continua, with intractable epilepsy ICD-9 345.90 Epilepsy, unspecified, without mention of intractable epilepsy ICD-9 345.91 Epilepsy, unspecified, with intractable epilepsy ICD-10 G40.A09 Absence epileptic syndrome, not intractable, without status epilepticus ICD-10 G40.A11 Absence epileptic syndrome, intractable with status epilepticus ICD-10 G40.A19 Absence epileptic syndrome, intractable, without status epilepticus ICD-10 G40.109 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus ICD-10 G40.119 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus ICD-10 G40.209 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus ICD-10 G40.219 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus ICD-10 G40.309 Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus OR G40.409 Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus ICD-10 G40.319 Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus ICD-10 G40.419 Other generalized ICD-10 G40.822 Epileptic spasms, not intractable, without status epilepticus ICD-10 G40.824 Epileptic spasms, intractable, without status epilepticus ICD-10 G40.909 Epilepsy, unspecified, not intractable, without status epilepticus ICD-10 G40.919 Epilepsy, unspecified, intractable, without status epilepticus

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Contact Information American Academy of Neurology 201 Chicago Avenue Minneapolis, MN 55415 [email protected]

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Appendix A AAN Statement on Comparing Outcomes of Patients

Why this statement: Characteristics of patients can vary across practices and differences in those characteristics may impact the differences in health outcomes among those patients. Some examples of these characteristics are: demographics, co-morbidities, socioeconomic status, and disease severity. Because these variables are typically not under the control of a clinician, it would be inappropriate to compare outcomes of patients managed by different clinicians and practices without accounting for those differences in characteristics among patients. There are many approaches and models to improve comparability, but this statement will focus on risk adjustment. This area continues to evolve (1), and the AAN will revisit this statement regularly to ensure accuracy, as well as address other comparability methods (2) should they become more common.

AAN quality measures are used primarily to demonstrate compliance with evidence-based and consensus-based best practices within a given practice as a component of a robust quality improvement program. The AAN includes this statement to caution against using certain measures, particularly outcome measures, for comparison to other individuals/practices/hospitals without the necessary and appropriate risk adjustment.

What is Risk Adjustment: Risk adjustment is a statistical approach that can make populations more comparable by controlling for patient characteristics (most commonly adjusted variable is a patient’s age) that are associated with outcomes but are beyond the control of the clinician. By doing so, the processes of care delivered and the outcomes of care can be more strongly linked.

Comparing measure results from practice to practice: For process measures, the characteristics of the population are generally not a large factor in comparing one practice to another. Outcome measures, however, may be influenced by characteristics of a patient that are beyond the control of a clinician.(3) For example, demographic characteristics, socioeconomic status, or presence of comorbid conditions, and disease severity may impact quality of life measurements. Unfortunately, for a particular outcome, there may not be sufficient scientific literature to specify the variables that should be included in a model of risk adjustment. When efforts to risk adjust are made, for example by adjusting socioeconomic status and disease severity, values may not be documented in the medical record, leading to incomplete risk adjustment.

When using outcome measures to compare one practice to another, a methodologist, such as a health researcher, statistician, actuary or health economist, ought to ensure that the populations are comparable, apply the appropriate methodology to account for differences or state that no methodology exists or is needed.

Use of measures by other agencies for the purpose of pay-for-performance and public reporting programs: AAN measures, as they are rigorously developed, may be endorsed by the National Quality Forum or incorporated into Centers for Medicare & Medicaid Services (CMS) and private payer programs. 14

It is important when implementing outcomes measures in quality measurement programs that a method be employed to account for differences in patients beyond a clinicians’ control such as risk adjustment.

References and Additional Reading for AAN Statement on Comparing Outcomes of Patients 1. Shahian DM, Wolf RE, Iezzoni LI, Kirle L, Normand SL. Variability in the measurement of hospital-wide mortality rates. N Engl J Med 2010;363(26):2530-2539. Erratum in: N Engl J Med 2011;364(14):1382. 2. Psaty BM, Siscovick DS. Minimizing bias due to confounding by indication in comparative effectiveness research: the importance of restriction. JAMA 2010;304(8):897-898. 3. National Quality Forum. Risk Adjustment for Socioeconomic Status or Other Sociodemographic Factors. August 2014. Available at: http://www.qualityforum.org/Publications/2014/08/Risk_Adjustment_for_Socioeconomic_Status_or_Other_Sociodemographic_Factors.as px Accessed on January 8, 2015. • Sharabiani MT, Aylin P, Bottle A. Systematic review of comorbidity indices for administrative data. Med Care. 2012;50(12):1109-1118. • Pope GC, Kauter J, Ingber MJ, et al. for The Centers for Medicare & Medicaid Services’ Office of Research, Development, and Information. Evaluation of the CMS-HCC Risk Adjustment Model. March 2011. Available at: http://www.cms.gov/Medicare/Health- Plans/MedicareAdvtgSpecRateStats/downloads/evaluation_risk_adj_model_2011.pdf Accessed on January 8, 2015.

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Appendix B Disclosures

Work Group Member Disclosures Anup Patel, MD Research Funding: Pediatric Epilepsy Research Foundation (PERF), Upsher-Smith, LivaNova, and Greenwich Biosciences Consulting: Greenwich Biosciences, Supernus, LivaNova Scientific Advisory Board: UCB Pharma S. Andrew Josephson, MD, FAAN No relevant disclosures for this project. (non-voting work group member) Christine Baca, MD, MSHS Research Funding: Epilepsy Foundation/American Epilepsy Society (non-voting work group member) Gary Franklin, MD, MPH, FAAN No disclosures. Susan Herman, MD, FAAN Dr. Herman serves as Vice President of the National Association of Epilepsy Centers; Research Funding: Neuropace, Inc., Sage Therapeutics, Acorda Therapeutics, UCB Pharma, and NIH/NINDS. Inna Hughes, MD, PhD No disclosures. Lisa Meunier No disclosures. Lidia Moura, MD, MPH Dr. Moura is the recipient of a Career Development Award sponsored by the American Academy of Neurology to study predictors of treatment adherence and outcomes in geriatric epilepsy. Heidi Munger-Clary, MD, MPH No disclosures. Brandy Parker-McFadden No disclosures. Mary Jo Pugh, PhD, RN No disclosures. Rebecca Schultz, PhD, RN, CPNP Royalties from UpToDate on topic of Rett Syndrome; HRSA-13-244 -The State and Regional Approaches to Improving Access to Services for Children and Youths with Epilepsy. Marianna Spanaki, MD, PhD, MBA No disclosures.

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i Quality and Safety Subcommittee. American Academy of Neurology Quality Measurement Manual 2014 Update. 21p. January 2015. Available at: https://www.aan.com/uploadedFiles/Website_Library_Assets/Documents/3.Practice_Management/2.Quality_Improvement/1.Quality_ Measures/2.About_Quality_Measures/2015%2002%2011%20Process%20Manual%20Final.pdf Accessed on July 21, 2016. ii England MJ, Liverman CT, Schultz AM, and Strawbridge LM. Epilepsy across the Spectrum: Promoting health and understanding. 1st ed. Washington, D.C.: The National Academies Press; 2012. Available at: http://www.iom.edu/Reports/2012/Epilepsy-Across-the- Spectrum.aspx Accessed February 4, 2014.

iii Zack MM, Kobau R. National and State Estimates of the Numbers of Adults and Children with Active Epilepsy — United States, 2015. MMWR Morb Mortal Wkly Rep 2017;66:821–825. Available at: https://www.cdc.gov/mmwr/volumes/66/wr/mm6631a1.htm?s_cid=mm6631a1_w Accessed on August 15, 2017. iv Kobau R, Zahran H, Thurman DJ, et al. Epilepsy surveillance among adults-19 states, Behavioral Risk Factor Surveillance System, 2005. Morbidity and Mortality Weekly Report Surveillance Summaries 2008;57(6):1-20. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5706a1.htm Accessed February 18, 2014. v CMS “2017 Quality Benchmarks” file. Available at: https://qpp.coms.gov/resources/education Quality Benchmarks zip file “MIPS_Benchmark_Results_120816_Remediated.” Accessed on May 24, 2017. vi Roundy LM, Filloux FM, Kerr L, et al. Seizure Action Plans Do Not Reduce Health Care Utilization in Pediatric Epilepsy Patients. J Child Neurol. 2016;31(4):433-438.

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