Seizures and Epilepsy:
Classification Stephan Eisenschenk, MD Department of Neurology
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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)
Stephan Eisenschenk, MD Department of Neurology
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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 15 to 64 years
13% 63%
65 years and older
24%
– Cumulative risk of epilepsy: 1.3% - 3.1% – Epilepsy refractory to AEDs: 20-30%
Stephan Eisenschenk, MD Department of Neurology
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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. Stephan Eisenschenk, MD Department of Neurology
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Epilepsy and Quality of Life No seizures/
side effects (17%)" "
No seizures/no side effects (15%) Not taking " AED (3%)" No answer " (2%)"
Recurrent seizures/
side effects (44%)"
Recurrent seizures/no side effects" (19%)"
The Roper Organization Inc. Living With Epilepsy: Report of a Roper Poll of Patients on Quality of Life. Research Triangle Park, NC: GlaxoWellcome; 1999. Stephan Eisenschenk, MD Department of Neurology
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Epidemiology of Epilepsy Epilepsy: Incidence Rates by Seizure Type 90 Head Trauma 5% Congenital 4%
Incidence per 100,000
80
Vascular 1%
Neoplastic 4%
Hemorrhage 2% Unknown 24%
Head Trauma 7% Other* 19%
Degenerative 1%
70
Infectious 0%
60 50
Cerebral Infarct 33%
40
Atherosclerosis 15%
Idiopathic 85%
30 20 10 0 0
10
20
Partial Generalized tonic-clonic Primary Generalized
Stephan Eisenschenk, MD Department of Neurology
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40 Age
50
60
70
80
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. . Hauser et al, 1992; Ramsay RE, et al. Neurology. 2004;62(5 suppl 2):S24-S29
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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 Pharmacoresistant
2nd Monotherapy AED Trial
13%
47%
3rd Monotherapy/Polytherapy AED Trial 4%
Epilepsy Surgery/VNS Therapy Evaluation with videoEEG
36%
Kwan P, Brodie MJ. NEJM;342:314-319.
Resective Surgery
Stephan Eisenschenk, MD Department of Neurology
VNS Therapy
Polytherapy AED Trials 7
Stephan Eisenschenk, MD Department of Neurology
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ILAE Classification of Seizures Seizures
Partial
Generalized
Simple Partial
Absence
Complex Partial
Myoclonic
Secondarily Generalized
Atonic
Tonic
Tonic-Clonic
Stephan Eisenschenk, MD Department of Neurology
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Localization of Partial Seizure Focus
Seizures
Partial
Simple Partial
Complex Partial
20% 10%
Generalized
70%
Secondarily Generalized
Stephan Eisenschenk, MD Department of Neurology
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Partial (focal) Seizures Seizures
• Simple Partial Seizure – no loss of awareness – Auras • Temporal lobe:
Partial
Simple Partial
Complex Partial
Secondarily Generalized
Generalized
– – – –
Smell (uncus) Epigastric sensation déjà vu (hippocampus) Fear/anxiety (amygdala)
• Parietal lobe: Sensory • Occipital lobe: visual
– Focal motor clonic mvmt
• Supplementary Motor Seizure – dystonic posturing • upper extremities (fencing) • lower extremities
– Bicycling – Short duration 10-30 sec Stephan Eisenschenk, MD Department of Neurology
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Partial (focal) Seizures • Complex Partial Seizure Seizures
Partial
Simple Partial
Complex Partial
Secondarily Generalized
Generalized
– Impaired consciousness/ level of awareness (staring) – Clinical manifestations vary with origin & degree of spread – Presence and nature of aura • Temporal lobe: smell, epigastric sensation, deja vu – Automatisms (manual, oral) – Other motor activity • Frontal: bicycling and fencing posture – Duration (typically 30 seconds to 3 minutes) – Amnesia for event and confusion often after event
Stephan Eisenschenk, MD Department of Neurology
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EEG: Partial Seizure Right temporal seizure with maximal phase reversal in the right temporal lobe
Stephan Eisenschenk, MD Department of Neurology
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EEG: Partial Seizure
Continuation of same seizure Right temporal seizure with maximal phase reversal in the right sphenoidal electrode
Stephan Eisenschenk, MD Department of Neurology
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Secondarily Generalized Seizures s Begins focally, with or without focal neurological symptoms s Variable symmetry, intensity, and duration of tonic (stiffening) and clonic (jerking) phases s Typical duration 1-3 minutes s Postictal confusion, somnolence, with or without transient focal deficit Stephan Eisenschenk, MD Department of Neurology
Seizures
Partial
Generalized
Simple Partial
Complex Partial
Secondarily Generalized 15
Childhood Absence Seizures s Brief staring spells (“petit mal”) with impairment of awareness
Seizures
s 3-20 seconds s Sudden onset and sudden resolution s Often provoked by hyperventilation s Onset typically between 4 and 7 years of age s Often resolve by 18 years of age s Normal development and intelligence s EEG: Generalized 3 Hz spikewave discharges Stephan Eisenschenk, MD Department of Neurology
Partial
Generalized Absence Myoclonic Atonic Tonic Tonic-Clonic 16
EEG: Typical Absence Seizure
Stephan Eisenschenk, MD Department of Neurology
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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
Stephan Eisenschenk, MD Department of Neurology
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Myoclonic Seizures s Brief, shock-like jerk of a muscle or group of muscles s Epileptic myoclonus s Typically bilaterally synchronous s Impairment of consciousness difficult to assess (seizures 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 Stephan Eisenschenk, MD Department of Neurology
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