Educational Material

ERS Annual Congress Amsterdam 26–30 September 2015

EDUCATIONAL MATERIAL

Educational Skills Workshop 25, 27 Hands-on polysomnography

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Wednesday, 30 September 2015 ESW25 08:00–10:20 ESW27 10:40–13:00

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Educational Skills Workshop 25, 27 Hands-on polysomnography

AIMS: To introduce and provide an overview of polysomnography, including wiring up, troubleshooting signals, scoring studies, and interpreting the report.

TARGET AUDIENCE: Absolute beginners and anyone wishing to refresh their understanding of full polysomnographic sleep studies, including physicians, nurses, allied health professionals, students, and researchers with a professional interest in sleep medicine.

CHAIRS: R. L. Riha (Edinburgh, United Kingdom)

FACILITATORS: S. De Lacy (London, United Kingdom), E. Hill (Edinburgh, United Kingdom), A. Morley (Glasgow, United Kingdom)

WORKSHOP PROGRAMME PAGE

Four 30-minute workstations run simultaneously on the following topics:

Workstation 1 – Approach to full polysomnography, setting up and wiring up: the basic techniques 10-20 system EEG Placement 5

Workstation 2 – Data acquisition: what can go wrong? What does it look like when it goes right? PSG Artifact Recognition and Resolution 17

Workstation 3 – Scoring sleep using AASM guidelines. A brief introduction to scoring respiratory events, arousals and limb movements. 73

Additional resources 132

Faculty disclosures 133

Faculty contact information 134

Answers to evaluation questions 135

ERS monograph Obstructive Sleep Apnoea Edited by Ferran Barbé and Jean-Louis Pépin ISBN 978-1-84984-059-0

Comprehensive and up-to-date chapters provide the reader with a concise overview of obstructive sleep apnoea, making this book a useful reference for pulmonologists concerned with the management of this disease.

To buy printed copies, visit the ERS Bookshop at the ERS International Congress 2015 (Hall 1, Stand 1.D_12).

If you’re an ERS member, you automatically have full online access to the ERS Monographs.

Find out more ERSPUBLICATIONS.COM The International 10-20 EEG system: A brief introduction

Dr Andrew Morley Royal Hospital for Sick Children 79 Hardgate Rd G51 4SX Glasgow UNITED KINGDOM [email protected]

SUMMARY

The non‐invasive method for recording electrical activity of the brain Electroencephalography (EEG) in relation to sleep is a key element of any Polysomnography assessment. This workstation will focus on how to set‐up an EEG sleep montage in accordance with the American Academy of Sleep medicine.

This element of the workshop will be mainly a practical session. It will provide small group teaching, hands‐on experience with equipment and will ensure that all participants will be fully involved.

EVALUATION

1. Why should you perform bio‐calibrations before the start of a polysomnography sleep study? a. To check the reliability of signals. b. Confirm the polarity of signals. c. Establish a baseline reference for the study. d. All of the above.

2. An eye movement to the left should result in ______when using standard convention for polarity. a. An upward deflection of the signals for both channels b. An upward deflection of the signal for the LOC channel and a downward deflection on the ROC channel c. A downward deflection of the signal for LOC channel and an upward deflection on the ROC channel. d. A downward deflection of the signal for both channels.

3. The total circumference of the head is 48cm. What is the distance from Oz to O2 a. 24cm b. 9.6cm c. 2.4cm d. 4.8cm

4. Which electrode site is found half way between M1 & M2 a. Fz b. Cz c. Oz d. Fpz

5. For EEG electrodes what is the recommended level for impedance? a. < 1K Ohms b. <5 k Ohms c. < 10k Ohms d. ≤ 10 k Ohms

5 Slide 1 ______10-20 system EEG Placement ______

Andrew Morley (BSc Hons, RPSGT) ______Chief Respiratory (Sleep) Physiologist, Royal Hospital for Sick Children, Glasgow ______

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Slide 2 Conflict of interest disclosure ______x I have no, real or perceived, direct or indirect conflicts of interest that relate to this presentation.  I have the following, real or perceived direct or indirect conflicts of interest that relate to ______this presentation: Affiliation / financial interest Nature of conflict / commercial company name

Tobacco-industry and tobacco corporate affiliate related conflict of interest

Grants/research support (to myself, my institution or ______department):

Honoraria or consultation fees: Participation in a company sponsored bureau: ______Stock shareholder:

Spouse/partner: Other support or other potential conflict of interest: ______

This event is accredited for CME credits by EBAP and speakers are required to disclose their potential conflict of interest going back 3 years prior to this presentation. The intent of this disclosure is not to prevent a speaker with a conflict of interest (any significant financial relationship a speaker has with manufacturers or providers of any commercial products or services relevant to the talk) from making a presentation, but rather to provide listeners with information on which they can make their own judgment. It remains for audience members to determine whether the speaker’s interests or relationships may influence the presentation. ______Drug or device advertisement is strictly forbidden. ______

Slide 3 ______10-20 EEG Placement ______AIMS • Demonstrate the International 10‐20 EEG system ______• Understand steps required to set‐up a10‐20 EEG montage for a Polysomnography sleep study. ______• Give each delegate a practical experience setting up a Sleep EEG montage using the 10‐20 EEG system. ______

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6 Slide 4 ______10-20 EEG Placement ______Workshop Plan •This session is going to be a mainly practical session. ______• Brief presentation : 10‐20 basics • Split into pairs and have a go. ______• Slides from the session are available as part of the workshop materials –via website ______

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Slide 5 ______10-20 EEG Placement ______Focus •Head measuring ______•Location of EEG, EOG, EMG •Skin preparation / application (incl. differing techniques) ______

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Slide 6 ______10-20 EEG Placement ______What is the 10-20 system? ______

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7 Slide 7 ______10-20 EEG Placement ______What is the 10-20 system?

• An internationally recognised method that allows EEG electrode placement to be standardised.

• Ensures inter‐electrode spacing is equal ______

•Electrode placements proportional to skull size & shape ______•Covers all brain regions

F = Frontal T = Temporal P = Parietal O = Occipital ______• Numbering system Odd = left side, Even = right side, Z = midline ______

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Slide 8 ______10-20 EEG Placement ______Routine EEG Montage

• 16 Channel ( + references e.g. Cz, Ground) ______

M1 M2 M M11 M2 ______

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Slide 9 ______10-20 EEG Placement ______American Academy of Sleep Medicine • Utilises 10‐20 for polysomnography studies ______

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8 Slide 10 ______10-20 EEG Placement ______Sleep Montage

Sleep PSG montage (8 Channels + References & ground) ______

Recommended Back‐up •F3‐M2 •F4‐M1 •C3‐M2 •C4‐M2 •O1‐M2 •O2‐M1 ______

(There are other acceptable derivations.)

“A minimum of 3 EEG derivations are required ______in order to sample activity from the frontal central and occipital regions” The AASM Manual for the Scoring of Sleep and Associated Events. Version 2.0 ______

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Slide 11 ______10-20 EEG Placement ______Why a minimum of 3 EEG derivations? F4‐M1 –best for slow waves ______

C4‐M1 –best for spindles ______

O2‐M1 –best for alpha rhythm ______

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Slide 12 ______10-20 EEG Placement ______Preparation ______Be prepared ______

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9 Slide 13 ______10-20 EEG Placement ______Preparation You will need: • Measuring tape • Wax pencil ______• Measurement ‘cheat sheet’ • Alcohol wipes • Scarify skin –Stick / blunt needle • Abrasive paste ______• Conductive paste/gel • Collodion glue • Razor? Measurement 10% 20% ______30.0 3.0 6.0 31.0 3.1 6.2 32.0 3.2 6.4 33.0 3.3 6.6 34.0 3.4 6.8 35.0 3.5 7.0 36.0 3.6 7.2 37.0 3.7 7.4 ______

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Slide 14 ______10-20 EEG Placement ______Skin Preparation How ? ______• Isopropyl alcohol wipes to clean (removes grease) • Abrasive paste & cotton tip to reduce skin impedance (removes dead skin cells) ______

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Slide 15 ______10-20 EEG Placement ______Why is it important

Need to have good electrical contact Impedance < 5kOhms ______

Consequences of poor placement ______• ECG artifact • Movement artifact High impedance • High impedance • Electrode popping ______• Movement artifact • Sweat sway ______

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10 Slide 16 ______10-20 EEG Placement ______Why bother?

“Garbage In, Garbage Out” ______Computers will unquestioningly process the most nonsensical of input data (garbage in) and produce nonsensical output (garbage out). ______

Sleep study signal pathway ______

Patient Sensor Headbox Amplifier Computer ______

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Slide 17 ______10-20 EEG Placement ______What is the 10-20 system? ______

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Slide 18 ______10-20 EEG Placement ______Four Skull Landmarks

•Nasion Nasion •Inion ______•Left Pre‐auricular point •Right Pre‐auricular point ______

Inion ______

Pre-auricular point ( Left & right) ______

______

11 Slide 19 ______10-20 EEG Placement ______Measurement of Cz

• Measure the distance from pre‐auricular point to pre‐ auricular point ______

• Mark the midpoint (50%) with a vertical line

• This cross represents Cz which has been correctly aligned ______M in the horizontal & vertical planes M ______

______

Slide 20 ______10-20 EEG Placement ______Measurements - T3, C3, Cz, C4, T4

• Reapply the tape transversally between the pre‐auricular points • The midpoint (50%) should cross with previous point marking for Cz, confirming its location. ______• Mark 10%, 20%, 20%, 20%, 20%, 10% =T3,C3, Cz, C4, T4 ______MM ______

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Slide 21 ______10-20 EEG Placement ______Measurements - Fpz, Fz, Cz, Pz, Oz • Reapply the tape along the midline from nasion to inion ______• Mark 10%, 20%, 20%, 20%, 20%, 10% =Fpz, Fz, Cz, Pz, Oz

M M ______

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12 Slide 22 ______10-20 EEG Placement ______Measurements - Fp1, F7, T3, T5, O1, Oz • Measure the distance between Fpz & Oz by applying the tape around the head via T3. ______• Mark at 10%, 20%, 20%, 20%, 20%, 10% =Fp1, F7, T3, T5, O1, Oz ______

(Repeat the process using T4 to mark O2) ______

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Slide 23 ______10-20 EEG Placement ______Measurement - F3 • Measure Fp1 to C3 and mark midpoint ______• Measure Fz to F7 and mark midpoint • Mark 50% = F3 ______(Repeat the process using Fp2 to C4 & Fz to F8 to mark F4) ______

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Slide 24 ______10-20 EEG Placement ______Measurements M1 & M2 • M1 & M2 are the reference electrodes (formally known as A1 & A2) ______• M1 & M2 are placed on the mastoid (M) process. • These are the bony prominences behind the ears. ______

M2 ______

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13 Slide 25 ______10-20 EEG Placement ______C3

O1 ______M1 ______You have now completed a 10‐20 EEG montage !! ______

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Slide 26 ______10-20 EEG Placement ______Electro-oculogram

• Recording of the movement of the corneo‐retinal potential difference, not the movement of eye muscle. ______

• Electrodes are placed at outer canthus of eyes offset 1cm above/below the horizontal

• Right out and up / Left out and down ______

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Slide 27 ______10-20 EEG Placement ______Electromyogram (Chin EMG) • 3 electrodes ______• 1 on mentalis • 2 on submentalis –2 cm apart (1cm in Paediatrics) ______1 Mentalis 2 Submentalis ______

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14 Slide 28 ______10-20 EEG Placement ______

M1 M2 ______

You have now completed the EOG & EMG elements of a sleep montage setup !! ______

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Slide 29 ______10-20 EEG Placement ______Calibration (Checking the signals) • Eyes closed for 30 seconds Ask the patient to close his/her eyes & lie quietly.

• Eyes open for 30 seconds Ask the patient to open his/her eyes & look straight ahead. ______• Look right & left Ask the patient without their head to look to the right then to the left several times.

• Look up & down Ask the patient without moving their head to look up then down several times. ______• Blink eyes Ask the patient to blink their eyes 5 times.

•Clench jaw Ask the patient clench their jaw. • Flex foot ______Ask the patient to point & flex their foot. Repeat for other foot. Repeat for each leg and document on study.

• Breathe in & out Ask the patient to breathe normally, and then take a breath in and out. Check polarity and mark IN & OUT on study. • Snore sound Ask the patient to imitate a snore sound. ______

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Slide 30 ______10-20 EEG Placement ______Practical Session ______Your turn !!! ______

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15 Slide 31 ______Further Reading The AASM annual for the Scoring of Sleep and Associated Events: Rules, Terminology and technical Specifications. Version 2.1 American Academy of Sleep Medicine (2014) ______Sleep Medicine Textbook (European Sleep Research Society (ESRS) Claudio Bassetti, Zoran Dogas, Philippe Peigneux, Regensburg, (2014)

Essentials of Polysomnography. William H. Spriggs; Jones & Bartlett Publishers (2008) ______Essentials of Sleep Technology Richard S. Rosenberg; American Academy of Sleep Medicine (2010)

Atlas of Clinical Polysomnography Second Edition (Two-volume Set) Nic Butkov Media matrix , (2011) ______The ten twenty system of the International Federation. Electroencephalography and Clinical Jasper, H.H. , Neurophysiology, 1958, 10:371-375.

Polysomnographic technique: An overview. In: Sleep disorders medicine, 2nd ed. Boston Chokroverty S. Butterworth Heinemann (1999) ______Fundamentals of EEG technology, Volume 1: Basic concepts and methods. Tyner F, Knott J, Mayer W Jr. New York: Raven Press; (1983).

Sleep medicine. Lee-Chiong T, Sateia M, Carskadon M, (Hanley & Belfus, 2002) ______

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Slide 32 ______Further Training

• Practical Polysomnography – Edinburgh, UK ______– Various dates

• Edinburgh Sleep Medicine Course – Edinburgh, UK ______– March 2016

• European Sleep School – Orihuela Costa, Spain ______– Various dates

• International Sleep Medicine Course – Cardiff, UK ______– June 2016 ______

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Slide 33 ______Any Questions? [email protected] ______

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16 PSG Artifact Recognition and Resolution

Prof. Dr Simone De Lacy European Sleep School Orihuela Costa SPAIN [email protected]

SUMMARY

Recording physiological signals using surface electrodes and sensors invariably includes picking up extraneous signals from other sources, be they externally or internally generated. Recognition of these ‘unwanted’ intrusions to desired physiological signals is an important part of the PSG analysis.

Some of these artifact can be addressed and resolved, using various techniques and software capabilities. Others are indeed evidence of sleep or physiological pathologies and should be identified and reported.

EVALUATION

1. The major determinant of signal impedance is: a. The length of the electrode lead b. The preparation of the stratum corneum c. The thickness of the skull d. The material used on the electrode surface

2. A low frequency filter set at 0.3 Hz will do all of the following except: a. Reduce the amplitude of delta activity b. Leave faster frequencies intact c. Reduce the amplitude of sleep spindles d. Reduce respiratory artifact

3. A ‘Low Pass’ filter set at 35 Hz will do all of the following except: a. Increase the amplitude of sleep spindles b. Reduce muscle artefact c. Leave alpha, delta and theta frequencies intact d. Reduce external electrical artifact

4. Which of the following is an example of physiological artifact on an EEG channel: a. ECG signal on C4:M1 b. Electrode ‘popping’ c. 50 Hz frequencies d. 0.1 Hz frequencies

5. All of the following might be used to reduce signal artifact except: a. Cleaning and scarification of the skin b. Notch filters c. Cooling the patient by lowering the ambient temperature d. Waking the patient to remove and replace a dislodged mastoid electrode

17 PSG: Artifact Recognition and Resolution

Simone de Lacy BSc RPSGT EST

Director, European Sleep School, Spain

18 Conflict of interest disclosure

I have no, real or perceived, direct or indirect conflicts of interest that relate to this presentation.

Affiliation / financial interest Nature of conflict / commercial company name

Tobacco-industry and tobacco corporate affiliate related None conflict of interest

Grants/research support (to myself, my institution or None department):

Honoraria or consultation fees: None

Participation in a company sponsored bureau: None

Stock shareholder: None

Spouse/partner: None

Other support or other potential conflict of interest: None

This event is accredited for CME credits by EBAP and speakers are required to disclose their potential conflict of interest going back 3 years prior to this presentation. The intent of this disclosure is not to prevent a speaker with a conflict of interest (any significant financial relationship a speaker has with manufacturers or providers of any commercial products or services relevant to the talk) from making a presentation, but rather to provide listeners with information on which they can make their own judgment. It remains for audience members to determine whether the speaker’s interests or relationships may influence the presentation. Drug or device advertisement is strictly forbidden. 19 AIMS

• To recognise common artefact in PSG recordings

• To determine if the artefact is physiological or extraneous

• To learn how to minimise, resolve or report it.

20 SIGNAL ARTIFACT

• Signal artifact refers to extraneous signals appearing within desired or pure signal waveforms • Some artifact is extrinsic: environmental or equipment related • Some artifact is intrinsic (i.e. generated within the body; physiological/ Pathological) • Artifact needs to be recognised and resolved

4 21 INTRINSIC AND EXTRINSIC ARTIFACT Extrinsic Artifact Intrinsic Artifact • High impedance Physiological: • Electrode ‘popping’ • Eyes movements, Blinks • Mains interference • Muscle/ movement • Polarity reversal • Heart: ECG pick-up • Over amplification • Sweat: LF artifact • Incorrect referencing • Respiration: LF artifact Pathological: Bruxism, excessive spindling, muscle fasciculation, seizure activity, etc

This is not strictly artifact but definitely needs to be recognised 5 22 ARTIFACT RESOLUTION

• Differential Amplification • Referencing • Impedance • Polarity • Filtering • Ground and Reference Electrodes

23 DIFFERENTIAL AMPLIFICATION

Differential amplifiers reduce or eliminate environmental noise by inverting and subtracting the reference electrode signal from the exploring electrode signal.

Both electrodes carry the same background noise but only the exploring electrode will pick up the additional EEG signal which will be retained after differential amplification.

Environmental Noise [EN] EEG - EN EEG + EN + Differential EN Amplifier - C4

7 24 EXPLORING & REFERENCE ELECTRODES

• Exploring electrodes obtain a signal from a specific area, e.g. central, frontal or occipital • Reference electrodes are placed in EEG inactive areas e.g. mastoid process and are used to compare with the exploring electrode on the opposite side of the skull

F4:M1

C3:M2

8 25 PATIENT GROUND & 2ND REFERENCE ELECTRODES

PGND: 2nd Reference Electrode

26 RE-REFERENCING

• Some systems allow you to add additional channels to your montage by referencing the signal between any of the electrodes

• If both M1 and M2 electrodes should be lost: -F3 and C3 could be re-referenced to O2 -F4 and C4 could be re-referenced to O1

27 REF-REFERENCING

In this example, although A(M)2 and A(M)1 are intact, a new channel has been created by selecting F3 on the montage and referencing to O2. The new channel F3O2 appears at the top of the display

28 IMPEDANCE

• Impedance is the resistance to the flow of an electrical current • The lower the impedance the better the signal quality • High impedance decreases the amplitude of a signal • Skin preparation is a major determinant of electrode impedance

AASM recommended impedance < 5kΩ (EMG may be as much as 10kΩ)

12 29 FACTORS INFLUENCING IMPEDANCE [Ω]

• Stratum corneum (outermost layer of epidermis- mainly dead skin cells and sebum) • Skull thickness • Length, gauge and continuity of the electrode wire

• To reduce the impedance you abrade the skin thus reducing the thickness of the stratum corneum

13 30 ELECTRODE ‘POPPING’ & SWEAT SWAY

• Electrode ‘popping’ occurs when the electrode has partially lost contact with the skin and air forms a barrier to the conduction of the signal

• Sweat between the skin and the electrode will also affect the signal baseline ‘Sweat Sway’

31 SIGNAL POLARITY

• A negative output signal causes an upward deflection on the visible trace • A positive output signal produces a downward deflection on the visible trace • Occasionally the signal is very obviously inverted from the outset or sometimes spontaneously inverts during the recording- this needs to be recognised

15 32 FILTERS

• Filters give us the ability to focus on only the signal frequencies that we want to see • They attenuate (reduce) unwanted signals • Different filters can be applied to each channel to allow us to view the desired frequency range of each type of signal, EEG, EMG, ECG etc • They can also be used (carefully) to remove signal artifact but caution should be applied as some of the desired physiological can be lost through over-filtering

16 33 EEG FREQUENCIES

• Beta: ≥14 Hz (normal, waking anterior) • Alpha: 8 – 13 Hz (normal, waking posterior) • Theta: 4 – 7 Hz (normal drowsy, light sleep)

• Spindles & K complexes

• Delta: <4Hz (normal deep sleep)

34 LOW FREQUENCY FILTER (LFF)

• Also known as the ‘high pass’ filter • The LFF allows higher frequencies to pass unchanged • Lower frequencies are attenuated (reduced) • LFF can be used to reduce respiratory artefact and sweat sway • LFF should be used with caution as it may also attenuate desired frequencies such as slow wave sleep if applied inappropriately

18 35 LFF ON EEG

• LFF can be used to reduce respiratory artefact and sweat sway • LFF should be used with caution as it may also attenuate desired frequencies such delta waves LFF set at 0.3 (AASM)

19 36 HIGH FREQUENCY FILTER (HFF)

• Also known as the ‘low pass’ filter • The HFF allows slower waves to pass through unchanged and attenuates higher frequencies • The HFF can eliminate muscle artefact or external electrical artefact in EEG channels • It may also remove desired high frequencies such as arousals or sleep spindles

20 37 HFF ON EEG

• The HFF can eliminate muscle artefact or external electrical artefact in EEG channels

• It may also remove desired high frequency waveforms such as sleep spindles

21 NB: HFF is usually set at 35Hz for EEG/EOG (AASM) 38 50HZ/NOTCH FILTER

• 50Hz artifact is a high frequency artifact which can be caused by high signal impedance, interference from external electrical equipment and poor application of electrodes 50Hz noise due to poor electrode application

• Notch filters attenuate specific frequencies (in reality they attenuate a small range around the desired frequency) • A 50Hz filter will also attenuate important signals in this range such as muscle activity or epileptiform activity

22 39 FILTER SETTINGS (AASM)

LFF Hz HFF Hz

EEG 0.3 35 EOG 0.3 35 EMG 10 70 ECG 0.3 70 Respiration 0.1 15 Snoring 10 100

23 40 ECG PICK-UP & ELIMINATION

• ECG is a much larger amplitude signal than EEG and may be picked up if the mastoid electrodes are positioned too low on an obese patient

• Some systems have the ability to differentially reference channels to the ECG channel which will help cancel out any extraneous ECG pick- up on the EEG, EOG and EMG.

• An ECG signal will also be present on the Leg EMG if only one electrode is placed on each leg instead of two

41 Same epoch with ECG Elimination applied to all EEG channels

42 IDENTIFYING AND RESOLVING INTRINSIC AND EXTRINSIC ARTIFACT Extrinsic Artifact Intrinsic Artifact • High impedance Physiological: • Electrode ‘popping’ • Eyes movements, Blinks • Mains interference • Muscle/ movement • Polarity reversal • Heart: ECG pick-up • Over amplification • Sweat: LF artifact • Incorrect referencing • Respiration: LF artifact Pathological: Bruxism, excessive spindling, muscle fasciculation, seizure activity, body rocking, head banging, sleep walking, RBD…

26 43 EXTRINSIC ARTIFACT

HF artifact on C3M2 & O1M2 Channels

Cause: Poor electrode contact M2 (electrode common to both channels) Solutions: 1. Reapply electrode 2. Apply 50Hz notch filter to M2 27 3. Reference C3 and O1 to M1 electrode 44 Extrinsic Artifact: LF artifact on O1M2

Cause: Sweat & O1 lead too tight, being pulled on inspiration, affecting impedance Solutions: 1. loosen the lead from the bundle at the top of the head 2. Apply LFF to this channel 28 45 Extrinsic Artifact: Inverted ECG signal

Cause: ECG Electrodes correctly positioned but leads plugged into wrong polarity port + / -

Solutions: 1. Invert signal display for this trace 2. Swap ECG leads into correct polarity port - / + on patient interface 29 46 Extrinsic Artifact: K Complex with arousal V’s electrical artifact M2

47 Extrinsic Artifact: Irregular abdominal effort signal

Cause: Abdominal band too loose, gain turned up too much to compensate

Solutions: 1. Tighten Abdominal belt and then reduce gain

31 48 Extrinsic Artifact: Periods of airflow and effort cessation alternating with periods of airflow with ‘paradoxical’ respiratory effort

Cause: Abdominal band polarity reversed (piezo-electric belts) Solution: Reverse polarity of abdominal belt (see below)

32 49 Extrinsic Artifact: LF artifact on C3M2channel

Cause: Air trapping or poor contact of C3 electrode causing electrode ‘popping’

Solutions: 1. Reapply electrode if necessary 2. Remove trace from recording view if C4-M1 giving good signal

33 50 Extrinsic Artifact: LF artifact on C3M2 and O1M2 channels

Cause: Air trapping or poor contact of M2 electrode causing electrode ‘popping’ Solutions: 1. Reapply electrode if necessary, inject more gel into electrode 34 2. Re-reference C3 and O1 to M1 51 INTRINSIC ARTIFACT EXAMPLES

Physiological Artifact: Eye movement pick-up on EEG

Eyes open left to right Eyes open up and down Eye blinks

35 52 Physiological Artifact: HF muscle activity on EEG, EOG and EMG signals

Jaw clenching during bio-calibration

36 53 Physiological Artifact: ECG pick-up on single channel leg EMG

Cause: One electrode on L leg, one on R leg gives summation of EMG activity on both legs but also acts as 2 lead ECG channel. Solutions: Use 2 electrodes on each leg, separate L Leg EMG from R Leg Alternatively, record using 2 electrodes on 1 leg only-but this may miss or

underestimate severity of PLMD 37 54 Physiological Artifact: ECG pick-up on EEG, EOG (and Leg EMG Channel)

Cause: M1 and M2 electrodes situated on soft tissue rather than mastoid bone

Solutions: - Reposition M1 and M2 electrodes nd - 2 Reference to ECG channel 38 55 Physiological Artifact: LF Sweat artifact on O2M1 EEG

Cause: Patient too hot, sweat affecting impedance Actions: 1. Cool the patient down

2. Apply LFF to this channel 39 56 Pathological Artifact: Cyclical, HF artifact all AC channels

Cause: Bruxism: Cyclical muscle activity picked up on EEG, EOG & EMG

Actions: None, Tech comment and print epoch for PSG report

40 57 Pathological Artifact: Episodes of HF simultaneous ‘artifact’ all channels

Cause: Rhythmic Movement Disorder , body rocking sometimes seen in ADHD and psychological disturbances Actions: None necessary, Tech comment and print for PSG report

58 Pathological Artifact: Cyclical bursts of faster EEG waveforms

Cause: Excessive sleep spindles: often seen in benzodiazepine use

Actions: None necessary, Tech comment and print for PSG report

42 59 Pathological Artifact: Atypical waveforms on ECG channel

Cause: Cardiac arrhythmia: Intermittent and runs of PVCs, Solutions: None necessary, Tech comment and print epoch for PSG report NB: A prolonged run of PVC’s may be cause for emergency protocol initiation especially if there is no mention of cardiac problems in the 43 patient’s notes. 60 Pathological Artifact: HF artifact superimposed on LF waveforms during N3 sleep

Cause: Movement: Movement during N3 sleep e.g. position change or even sleep walking This is muscle activity on delta waveforms. Note patient is in N3 sleep before and after 14 second event Actions: None necessary, Tech comment and print epoch for PSG report 44 61 Pathological Artifact: High amplitude spike and wave artifact on EEG High muscle tone on Chin and Leg EMG

Cause: Seizure: Characteristic spike and wave activity on EEG Actions: Follow protocol for seizures, Tech comment and print epochs for PSG

report 45 NB Prolonged seizures (>5mins) can be life threatening 62 Pathological Artifact: Irregular, prolonged bursts of HF activity on Leg EMG

Cause: REM Behaviour Disorder: Limb movements due to lack of REM atonia Actions: Tech note and print epoch for PSG report 46 63 A FEW TECHNICAL TIPS-:

64 ELECTRODE INTEGRITY & ORIENTATION

O2 O1

The electrode wires should C4 C3

M2 be kept as short as possible, M1 in good condition and all of F4 F3 equal length and type R.EOG L.EOG

48 65 Electrode orientating and gathering: Always ask yourself –”where does the headbox end up in relation to the patient?” Gather up and direct electrode wires towards this. This is not only more comfy for the patient (they not lying on a bunch of wires) but it also reduces pulling and displacement of the sensors and gives a longer ‘umbilicus’.

Soft Velcro loop holds electrodes in place- take some time to equalise these so they have equal tension and make sure you ask the patient to twist their head round and make sure nothing is pulling Orientating leads towards CZ and gathering at the top of the head pointing directly towards the head box

headbox

66 Electrode Application Tips

Electrode gluing with gauze -Advantages include, makes gluing a bit quicker, mainly much less glue in hair and on your fingers! Electrode head fits 10-20 Paste Ring of collodion on the gauze with a in middle of glue filled electrode space for the electrode head.

To remove use acetone with cotton wool to soak gauze off.

67 Take time to equalise and sort all wires out:- Try not to have one pulling more than another. Try not to trap hair in the velcro loop

Make sure there are none swinging in the breeze. They should all be attached at either end to the patient and the headbox!

Unless they are colour coded, apply and plug-in as you go. 68 The quick release leg loop- to prevent the loss of leg electrodes

Quick release on kick

69 Golden Rules: • Keep your equipment in good working • Check and replace any faulty electrodes/sensors • Good skin preparation and careful cleaning & application of electrodes and sensors is paramount • Always perform bio-calibration • Re-check impedances prior to lights out and during the study • Don’t wake the patient up to change electrodes unless really necessary • Only use filters to attenuate artifact as a last resort

70 FURTHER READING

• The AASM annual for the Scoring of Sleep and Associated Events: Rules, Terminology and technical Specifications Version 2.1. American Academy of Sleep Medicine (2014) • Essentials of Polysomnography 2nd Edition. William H. Spriggs; Jones & Bartlett Publishers (2014) • Essentials of Sleep Technology Richard S. Rosenberg; American Academy of Sleep Medicine (2010) • Sleep Medicine Textbook, European Sleep Research Society (2014)

71 ANY QUESTIONS?

72 Scoring sleep using AASM guidelines: A brief introduction

Ms. Elizabeth Hill Paediatric Respiratory Physiology Department of Respiratory&Sleep Medicine Royal Hospital for Sick Children 9 Sciennes Road, Scotland EH9 1LF Edinburgh UNITED KINGDOM [email protected]

SUMMARY

Early pioneers used EEG to “look inside” the brain using sleep. Over time, this was developed into polysomnography (PSG), which was first used to define sleep stages in the 1960s. PSG is now the recognised gold-standard technique for measuring sleep, allowing classification of sleep stages, assessment of sleep architecture and diagnosis of sleep disorders.

This workshop aims to review the criteria for scoring of sleep stages as described in The AASM Manual for Scoring of Sleep and Associated Events Version 2.1 (American Academy of Sleep Medicine, 2014). The benefits and drawbacks of these guidelines will be discussed. Delegates will have the opportunity to apply the current guidelines in small groups during a practical exercise, identifying sleep stages using real-world examples.

EVALUATION

1. Which of the following statements is not true regarding alpha rhythm? a. The frequency is 8-13Hz b. It is commonly observed during stage W with the eyes closed c. It can be seen most clearly on the frontal EEG d. Around 10% of individuals do not generate alpha rhythm

2. According to the AASM V2.1 guidelines, when scoring stage N1: a. The EEG shows a low voltage, mixed frequency pattern of 4-7Hz b. Vertex sharp waves may be seen, predominantly on the central EEG c. N1 should not be scored after N3, unless there is an intervening arousal d. All of the above

3. Stage N2 should be scored: a. When a spindle or K complex is present in the first half of an epoch b. After a page of N3 if it does not meet the criteria for W, N3 or R c. Both A and B d. Neither A nor B

4. Which of the following is a scoring criteria for stage N3? a. Absence of sleep spindles b. Slow waves of 0-2Hz and ≥75µV in ≥20% of the epoch c. Low voltage, mixed frequency EEG d. Transient muscle activity

73 5. Which of the following features are not required to score “Definite Stage R”? a. Very low chin EMG tone (atonia) b. Sawtooth waves on the central EEG c. Rapid eye movements on the EOG d. Low amplitude, mixed frequency EEG without spindles or K complexes

74 SCORING SLEEP USING AASM GUIDELINES: A BRIEF INTRODUCTION

Lizzie Hill BSc RPSGT EST

Specialist Respiratory Clinical Physiologist, Royal Hospital for Sick Children, Edinburgh Final Year PhD Research Student, The University of Edinburgh

75 Conflict of interest disclosure

I have no, real or perceived, direct or indirect conflicts of interest that relate to this presentation.

Affiliation / financial interest Nature of conflict / commercial company name

Tobacco-industry and tobacco corporate affiliate related None conflict of interest

Grants/research support (to myself, my institution or None department):

Honoraria or consultation fees: None

Participation in a company sponsored bureau: None

Stock shareholder: None

Spouse/partner: None

Other support or other potential conflict of interest: None

This event is accredited for CME credits by EBAP and speakers are required to disclose their potential conflict of interest going back 3 years prior to this presentation. The intent of this disclosure is not to prevent a speaker with a conflict of interest (any significant financial relationship a speaker has with manufacturers or providers of any commercial products or services relevant to the talk) from making a presentation, but rather to provide listeners with information on which they can make their own judgment. It remains for audience members to determine whether the speaker’s interests or relationships may influence the presentation. Drug or device advertisement is strictly forbidden. 76 AIMS

• To review criteria for staging sleep as defined by international guidelines (AASM V2.1, 2014).

• To discuss the benefits and drawbacks of these guidelines.

• To apply the current AASM guidelines by identifying sleep stages during a practical exercise.

77 EXPERIENCE

• Completely new to scoring?

• A little experience of scoring PSG?

• Regularly scoring PSG?

• RPSGT (Registered Polysomnographic Technologist)?

• EST (ESRS Somnologist – Technologist)?

78 INTRODUCTION

• Early pioneers used EEG to “look inside” brain using sleep

• Developed into polysomnography

• Rechtshaffen & Kales used PSG to define stages of sleep

• PSG now standard technique for measuring sleep

Deak & Epstein, 2009

79 POLYSOMNOGRAPHY

• Objective measurement of sleep & wake (overnight or during the day)

• Gives information on – Duration/amount of sleep – Patterns of sleep – Quality of sleep – Behaviours during sleep

• Information from PSG can be used to define sleep stages

80 POLYSOMNOGRAPHY

Sensors applied in standard positions Workstation 1

Studies scored using standard rules by skilled technolologist This workstation

81 AASM MONTAGE

82 SCORING SLEEP STAGES

• Based on unit of epoch – 30s in most labs

• Each epoch reviewed in turn and assessed as a whole for its sleep stage

• In some situations, the page before or after can influence the decision

• To score a certain stage of sleep at least half the epoch (15 seconds) must be classified as that stage

83 SCORING POLYSOMNOGRAPHY Scroll through study several times:

– Sleep staging – 30s epoch – EEG arousals – 30s epoch – Respiratory events – 2min / 5min epoch • 10min epoch to screen for Cheyne-Stokes – Periodic leg movements – 5min epoch

84 SCORING CRITERIA

• Each stage of sleep defined by certain characteristics

– Rechtschaffen and Kales (1968)

– AASM Manual for the Scoring of Sleep and Associated Events (2007) • Version 2.0 2012 • Version 2.0.1, 2.0.2 2013 • Version 2.0.3 January 2014 • Version 2.1 July 2014

85 AASM VERSION 2.1 - 2014

• Current version of guidelines

• Published July 2014

• Online & print versions

86 BENEFITS OF AASM GUIDELINES

• Standardised international guidelines

• Comprehensive manual – Setting up lab – Training staff – Reference guide – Lab accreditation

• Flexible online format – Updated annually

87 LIMITATIONS OF AASM GUIDELINES

• Staggered implementation → variation between centres

• Frequent revisions → “shifting goalposts” – Many changes related to US Medicare reimbursement

• Based on scoring full PSG – AASM also recommends use of portable monitoring Collop et al, JCSM, 2007 – Transferable to limited studies? – ERS Task Force TF-2014-02 (2014-2016)

88 SCORING SLEEP STAGES

89 ADULT SLEEP

• Comprises 2 states – NREM : non-rapid eye movement sleep – REM : rapid eye movement sleep

• Alternate cyclically over a period of sleep – Ultradian rhythm

• Sleep stages with distinct, measurable features

90 INFANT SLEEP

• 2 distinct stages: – Active sleep (REM) – Quiet sleep (NREM)

• Normal for infants < 3 months to have sleep- onset REM (active sleep)

• NREM (quiet sleep) becomes clearly demarcated aged 3 – 6 months

91 SCORING SLEEP STAGES

This session based on adult scoring rules –

AASM Version 2.1 (2014)

92 STAGE W • Alpha rhythm / posterior dominant rhythm – 8-13Hz – Majority of individuals(~10% do not generate alpha) – clearest on occipital EEG

AND / OR

• Other findings consistent with W – Eye blinks – Rapid eye movements (REMs) with normal/high chin EMG – Reading eye movements

93 STAGE W – EYES OPEN

From AASM

94 STAGE W – EYES CLOSED Eye blinks

Alpha rhythm

From AASM

95 STAGE N1 Appearance of any of:

• Low amplitude, mixed frequency EEG (LAMF) – 4-7Hz

• Vertex sharp waves (V waves) – Central EEG – <0.5s duration

• Slow eye movements (SEMs)

96 STAGE N1

• Score N1 if majority of stage meets criteria for N1 in the absence of evidence for any other sleep stage

• Keep scoring N1 until there is evidence of another sleep stage – Usually W, N2 or R

97 STAGE N1

From AASM

98 STAGE N2

Characteristic waveforms:

• Sleep spindle – fast burst (≥0.5s) of 11-16Hz activity – clearest on central EEG

• K complex – -ve EEG deflection followed by +ve (≥0.5s) – clearest on frontal EEG

99 STAGE N2

• Start scoring N2 if a K complex and/or sleep spindle is present in the first half of the epoch or last half of preceding epoch – “Definite stage N2”

• Continue to score N2 in absence of spindle/K- complex if no arousals

• Epochs after a page of N3 are scored as N2 if they do not meet criteria for W, N3 or R – Do not score N1 after N3

100 STAGE N2 • Stop scoring N2 when – Transition to stage W, N3 or R – Arousal followed by LAMF (N1) – Major body movement followed by SEM and LAMF (N1)

101 K complex STAGE N2 Sleep spindles

From AASM

Low voltage, mixed frequency background EEG

102 STAGE N3

• Slow waves in ≥20% (≥6s) of epoch – 0-2 Hz – ≥75µV in amplitude in frontal EEG – Irrespective of age

• Do not confuse K complexes with slow waves – K complexes separated in time – slow waves tend to occur in runs – K complexes develop into slow waves at transition from N2 to N3

• Spindles can persist into N3

103 STAGE N3

Delta activity / slow waves

From AASM

104 STAGE R

Characteristic waveforms:

• Bursts of rapid eye movements (REMs) on EOG

• Very low amplitude EMG (atonia)

• Sawtooth waves – clearest on central EEG – Often precede bursts of REMs

Adapted from AASM • Phasic twitches on EMG – Transient muscle activity

105 STAGE R

• “Definite stage R” scored in epochs with ALL of – LAMF without spindles/K complexes – Low chin EMG tone (atonia) – REMs

• Pages before and after “Definite stage R” scored as R in absence of REMs with ALL of – LAMF without spindles/K complexes – Low chin EMG tone (atonia) – No arousal – No SEMs

• R takes precedence over N2

106 STAGE R • Stop scoring R if ANY of – Transition to W or N3 –  EMG tone and meets criteria for N1 – Arousal followed by LAMF and SEMs (N1) – Major body movement followed by LAMF and SEMs without a sleep spindle or K complex (N1) – Sleep spindle or K complex in first half of epoch in absence of eye movements (even if chin EMG still low)

107 Burst of rapid eye movements STAGE R

Delta activity / slow waves

From AASM Phasic twitch

Loss of muscle tone (atonia)

108 HYPNOGRAM • Once scored, all sleep stages collated to produce hypnogram

• Visual representation of sleep architecture

109 NORMAL SLEEP • Normally enter sleep through NREM in adults

• Cycles with REM sleep at approx. 90 minute intervals (90 – 110 minutes)

• 4-5 REM periods in young adults

• Short awakenings are normal

110 SLEEP ARCHITECHURE

• Normal

• Severe OSAHS

• Treatment with CPAP

111 PRACTICAL SESSION

• Split into groups of 3 – 4

• Set of laminated sample epochs

• Assess each example as a group – EEG frequency – Distinct, measurable features

• Decide which sleep stage to score

112 EXAMPLE 1

Delta activity / slow waves

From AASM

113 EXAMPLE 2

Delta activity / slow waves

From AASM

114 EXAMPLE 3

Delta activity / slow waves

From AASM

115 EXAMPLE 4

Delta activity / slow waves

From AASM

116 EXAMPLE 5

Delta activity / slow waves

From AASM

117 EXAMPLE 6

Delta activity / slow waves

From AASM

118 EXAMPLE 7

Delta activity / slow waves

From AASM

119 EXAMPLE 8

Delta activity / slow waves

From AASM3.73

120 EXAMPLE 9

Delta activity / slow waves

From AASM

121 EXAMPLE 10

Delta activity / slow waves

From AASM

122 EXAMPLE 11

Delta activity / slow waves

From AASM

123 EXAMPLE 12

Delta activity / slow waves

From AASM

124 EXAMPLE 13

Delta activity / slow waves

From AASM

125 EXAMPLE 14

Delta activity / slow waves

From AASM

126 EXAMPLE 15

Delta activity / slow waves

From AASM

127 CONCLUSION • Electrophysiological changes during sleep can be measured using polysomnography.

• Distinct, measurable electrophysiological features are used to define different stages of sleep.

• Classifying sleep stages allows us to examine sleep architecture.

• International guidelines for sleep staging are available.

128 FURTHER READING

• The AASM annual for the Scoring of Sleep and Associated Events: Rules, Terminology and technical Specifications Version 2.1. American Academy of Sleep Medicine (2014)

• Essentials of Polysomnography 2nd Edition. William H. Spriggs; Jones & Bartlett Publishers (2014)

• Essentials of Sleep Technology Richard S. Rosenberg; American Academy of Sleep Medicine (2010)

129 FURTHER TRAINING

• Practical Polysomnography – Edinburgh, UK – Various dates

• Edinburgh Sleep Medicine Course – Edinburgh, UK – March 2016

• European Sleep School – Orihuela Costa, Spain – Various dates

• International Sleep Medicine Course – Cardiff, UK – June 2016

130 Any questions?

[email protected] [email protected]

www.ed.ac.uk/clinical-sciences/sleep-research uk.linkedin.com/in/lizziehillsleeptechservices

131 Recommended reading list and E-learning resources

1. The AASM annual for the Scoring of Sleep and Associated Events: Rules, Terminology and technical Specifications. Version 2.1 American Academy of Sleep Medicine (2014) 2. Bassetti C., Dogas Z., Peigneux P., Sleep Medicine Textbook (European Sleep Research Society (ESRS), Regensburg, (2014) 3. Spriggs W. H.; Essentials of Polysomnography, Jones & Bartlett Publishers (2008) 4. Rosenberg R. S. Essentials of Sleep Technology, American Academy of Sleep Medicine (2010) 5. Butkov N., Atlas of Clinical Polysomnography Second Edition (Two‐volume Set), Media matrix, (2011) 6. Jasper, H.H. The ten twenty system of the International Federation. Electroencephalography and Clinical, Neurophysiology, 1958, 10:371‐375. 7. Chokroverty S., Polysomnographic technique: An overview. In: Sleep disorders medicine, 2nd ed. Boston Butterworth Heinemann (1999) 8. Tyner F, Knott J, Mayer W Jr., Fundamentals of EEG technology, Volume 1: Basic concepts and methods. New York: Raven Press; (1983). 9. Lee‐Chiong T, Sateia M, Carskadon M, Sleep medicine, Hanley & Belfus, 2002 10. Spriggs W. H, Essentials of Polysomnography 2nd Edition. Jones & Bartlett Publishers (2014) 11. Sleep Medicine Textbook; European Sleep Research Society (2014)

132 Faculty disclosures

There are no faculty disclosures for this workshop.

133 Faculty contact information

Prof. Dr Simone De Lacy Dr Andrew Morley European Sleep School Royal Hospital for Sick Children Orihuela Costa 79 Hardgate Rd SPAIN G51 4SX Glasgow [email protected] UNITED KINGDOM [email protected] Ms. Elizabeth Hill Paediatric Respiratory Physiology Dr Renata L. Riha Department of Respiratory&Sleep Medicine Department of Sleep Medicine Royal Hospital for Sick Children Royal Infirmary Edinburgh 9 Sciennes Road, Scotland 51 Little France Crescent EH9 1LF Edinburgh EH16 4SA Scotland, Edinburgh UNITED KINGDOM UNITED KINGDOM [email protected] [email protected]

134 Answers to evaluation questions

Please find all correct answers in bold below

WS2. Data acquisition: what can go wrong? What does it look like when it goes right – Prof. Dr Simone De Lacy

4. Which of the following is an example of physiological artifact on an EEG channel: a. ECG signal on C4:M1 b. Electrode ‘popping’ c. 50 Hz frequencies d. 0.1 Hz frequencies

WS3. Scoring sleep using AASM guidelines: A brief introduction - Ms. Elizabeth Hill

5. Which of the following features are not required to score “Definite Stage R”? a. Very low chin EMG tone (atonia) b. Sawtooth waves on the central EEG c. Rapid eye movements on the EOG d. Low amplitude, mixed frequency EEG without spindles or K complexes