Seizures and Epilepsy: Classification

1 Stephan Eisenschenk, MD Department of Neurology Seizures

– Definition: the clinical manifestation of an abnormal and excessive excitation of a population of cortical neurons – Incidence: approximately 80/100,000 per year – Lifetime prevalence: 9% (1/3 benign febrile convulsions)

2 Stephan Eisenschenk, MD Department of Neurology Epilepsy

– Definition: a tendency toward recurrent seizures unprovoked by systemic or neurologic insults – Incidence: approximately 45/100,000 per year Approximately 181,000 people will develop epilepsy each year – Point prevalence: 0.5-1% (2.5 million with epilepsy) 14 years or younger 13% 15 to 64 years 63% 65 years and older 24% – Cumulative risk of epilepsy: 1.3% - 3.1% – Epilepsy refractory to AEDs: 20-30%

3 Stephan Eisenschenk, MD Department of Neurology Impact of Epilepsy on Adults

 53% reported restrictions in activities of daily living

 46% reported difficulties in concentration and memory

 39% reported concern over having children

 36% reported impaired ability to drive

 28% reported difficulties in relationships with spouses and partners

 21% reported sexual difficulties

 16% reported discrimination at work

Beran RG. Epilepsia. 1999;40(suppl 8):40-43.Fisher RS et al. Epilepsy Res. 2000;41:39-51. 4 Stephan Eisenschenk, MD Department of Neurology Epilepsy and Quality of Life

No seizures/ No seizures/no side effects (17%) side effects (15%) Not taking AED (3%)

No answer (2%)

Recurrent seizures/no side effects Recurrent seizures/ (19%) side effects (44%)

The Roper Organization Inc. Living With Epilepsy: Report of a Roper Poll of Patients on Quality of Life. Research Triangle Park, NC: GlaxoWellcome; 1999. 5 Stephan Eisenschenk, MD Department of Neurology Epidemiology of Epilepsy Epilepsy: Incidence Rates by Seizure Type 90 Vascular Hemorrhage Head Trauma 1% 2% Head Trauma 5% Neoplastic Congenital 7% 80 4% 4% Unknown 24% Degenerative Other* 70 1% 19% Infectious 60 0%

Cerebral Infarct 50 Atherosclerosis 33% 15% Idiopathic 40 85% 30 20 Incidence per 100,000 10 0 0 10 20 30 40 50 60 70 80 Partial Generalized tonic-clonic Age Primary Generalized

Data from Rochester, Minn (1935-1979). Adapted with permission from Annegers JF. In: The Treatment of Epilepsy: Principles and Practice. 2nd ed. Baltimore, Md: Williams & Wilkins; 1997:165-172. . 6 Stephan Eisenschenk, MD Department of Neurology Hauser et al, 1992; Ramsay RE, et al. Neurology. 2004;62(5 suppl 2):S24-S29 Treatment Sequence for Pharmacoresistent Epilepsy

1st Monotherapy AED Trial Sz-free with 1st AED Sz-free with 2nd AED

Sz-free with 3rd AED/Polytherapy 2nd Monotherapy AED Trial Pharmacoresistant 13% 47%

3rd Monotherapy/Polytherapy AED Trial 4%

Epilepsy Surgery/VNS Therapy 36% Evaluation with videoEEG Kwan P, Brodie MJ. NEJM;342:314-319.

Resective Surgery VNS Therapy Polytherapy AED Trials

7 Stephan Eisenschenk, MD Department of Neurology 8 Stephan Eisenschenk, MD Department of Neurology ILAE Classification of Seizures

Seizures

Partial Generalized

Simple Partial Absence

Complex Partial Myoclonic

Secondarily Atonic Generalized

Tonic

Tonic-Clonic

9 Stephan Eisenschenk, MD Department of Neurology Localization of Partial Seizure Focus

20% Seizures

Partial Generalized 10%

Simple Partial 70% Complex Partial

Secondarily Generalized

10 Stephan Eisenschenk, MD Department of Neurology Partial (focal) Seizures

• Simple Partial Seizure – no loss of awareness Seizures – Auras • Temporal lobe: – Smell (uncus) Partial Generalized – Epigastric sensation – déjà vu (hippocampus) – Fear/anxiety (amygdala) Simple Partial • Parietal lobe: Sensory • Occipital lobe: visual – Focal motor clonic mvmt Complex Partial

Secondarily Generalized • Supplementary Motor Seizure – dystonic posturing • upper extremities (fencing) • lower extremities – Bicycling – Short duration 10-30 sec

11 Stephan Eisenschenk, MD Department of Neurology Partial (focal) Seizures

• Complex Partial Seizure – Impaired consciousness/ level Seizures of awareness (staring) – Clinical manifestations vary with origin & degree of spread

Partial Generalized – Presence and nature of aura • Temporal lobe: smell, epigastric sensation, deja Simple Partial vu – Automatisms (manual, oral)

Complex – Other motor activity Partial • Frontal: bicycling and fencing posture

Secondarily Generalized – Duration (typically 30 seconds to 3 minutes) – Amnesia for event and confusion often after event

12 Stephan Eisenschenk, MD Department of Neurology EEG: Partial Seizure

Right temporal seizure with maximal phase reversal in the right temporal lobe

13 Stephan Eisenschenk, MD Department of Neurology EEG: Partial Seizure

Continuation of same seizure

Right temporal seizure with maximal phase reversal in the right sphenoidal electrode

14 Stephan Eisenschenk, MD Department of Neurology Secondarily Generalized Seizures

s Begins focally, with or without focal Seizures neurological symptoms

s Variable symmetry, Partial Generalized intensity, and duration of tonic (stiffening)

and clonic (jerking) Simple phases Partial s Typical duration 1-3 minutes Complex Partial s Postictal confusion, somnolence, with or Secondarily without transient focal Generalized deficit 15 Stephan Eisenschenk, MD Department of Neurology Childhood Absence Seizures

s Brief staring spells (“petit mal”) with impairment of awareness Seizures s 3-20 seconds

s Sudden onset and sudden Partial Generalized resolution s Often provoked by Absence hyperventilation s Onset typically between 4 Myoclonic and 7 years of age s Often resolve by 18 years of Atonic age Tonic s Normal development and intelligence Tonic-Clonic s EEG: Generalized 3 Hz spike- wave discharges 16 Stephan Eisenschenk, MD Department of Neurology EEG: Typical Absence Seizure

17 Stephan Eisenschenk, MD Department of Neurology Juvenile Absence Seizures

s Brief staring spells with variably reduced responsiveness s 5-30 seconds s Gradual (seconds) onset and resolution s Generally not provoked by hyperventilation s Onset typically after 7-8 years of age s Absence seizures are far less frequent than in childhood onset absence seizures s Often evolve into myoclonic and generalized tonic-clonic seizures s Patients continue to have seizures lifelong

18 Stephan Eisenschenk, MD Department of Neurology Myoclonic Seizures

s Brief, shock-like jerk of a Seizures muscle or group of muscles s Epileptic myoclonus Partial Generalized s Typically bilaterally synchronous Absence s Impairment of consciousness difficult to assess (seizures <1 second) Myoclonic s Clonic seizure – repeated myoclonic seizures (may have impaired awareness) Atonic s Differentiate from benign, nonepileptic myoclonus (e.g., while falling asleep) Tonic s EEG: Generalized 4-6 Hz polyspike-wave discharges Tonic-Clonic

19 Stephan Eisenschenk, MD Department of Neurology Myoclonic Seizures

20 Stephan Eisenschenk, MD Department of Neurology Tonic and Atonic Seizures

Tonic seizures Seizures s Symmetric, tonic muscle contraction of extremities with tonic flexion of waist and neck Partial Generalized s Duration - 2-20 seconds. Absence s EEG – Sudden attenuation with generalized, low-voltage fast activity (most common) or Myoclonic generalized polyspike-wave. Atonic seizures Atonic s Sudden loss of postural tone s When severe often results in falls Tonic s When milder produces head nods or jaw drops.

Tonic s Consciousness usually impaired Clonic s Duration - usually seconds, rarely more than 1 minute s EEG – sudden diffuse attenuation or generalized polyspike-wave 21 Stephan Eisenschenk, MD Department of Neurology Atonic Events Causing Falls

22 Stephan Eisenschenk, MD Department of Neurology Epilepsy Syndromes

Epilepsy Syndrome Grouping of patients that share similar: • Seizure type(s) • Age of onset • Natural history/Prognosis • EEG patterns • Genetics • Response to treatment

23 Stephan Eisenschenk, MD Department of Neurology Epilepsy Syndromes

Epilepsy! !

Partial! Generalized!

Idiopathic! Symptomatic! Idiopathic! Symptomatic!

24 Stephan Eisenschenk, MD Department of Neurology Differential Diagnosis of Seizures

Seizures

Nonepileptic Epilepsy (recurrent seizures)

Cardiovascular Drug related Syncopal Metabolic (glucose, Na, Ca, Mg) Idiopathic Symptomatic Toxic (drugs, poisons) (primary) (secondary) Poison Infectious Febrile convulsions Partial (focal) Generalized Pseudoseizure Alcohol/drug withdrawal Substance abuse Psychiatric disorders Sleep disorders (parasomnias, cataplexy)

25 Stephan Eisenschenk, MD Department of Neurology Psychogenic/Non-epileptic Events

• aka pseudoseizures • Represent genuine psychiatric disease • 10-45% of refractory epilepsy at tertiary referral centers • Females > males • Psychiatric mechanism: dissociation, conversion, most unconscious (unlike malingering) • Association with physical, sexual abuse • Epileptic and nonepileptic seizures may co-exist • Video-EEG monitoring often helps clarify the diagnosis • Once recognized, approximately 50% respond well to specific psychiatric treatment

26 Stephan Eisenschenk, MD Department of Neurology