Definition of Terms

• Seizure– Paroxysmal event due to abnormal, excessive, hypersynchronous

discharges from an aggregate of CNS neurons• Epileptic Seizure

– Transient occurrence of signs and/or symptoms due to abnormal excessive or synchronnous neuronal activity in the brain

• Epilepsy– History of at least one seizure– Enduring alteration in the brain that increases the likelihood of

future seizures– Associated neurobiologic, cognitive, psychological and social

disturbances

Definition of Terms

• Stroke– rapidly developing loss of brain function(s) due to disturbance in

the blood supply to the brain– neurological deficit of cerebrovascular cause that persists beyond

24 hours or is interrupted by death within 24 hours• Post stroke seizure

– single or multiple convulsive episode/s (fit/s) after stroke and thought to be related to reversible or irreversible cerebral damage due to stroke regardless of time of onset following the stroke

• Post-stroke Spilepsy– recurrent seizures following stroke with confirmed diagnosis of

epilepsy

Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005–2009

Tonic Clonic Seizures• The seizure usually begins abruptly without warning • Tonic Phase

– tonic contraction of muscles throughout the body – Tonic contraction of the muscles of expiration and the larynx at the onset will produce a loud moan or “ictal

cry.” – Respirations are impaired, secretions pool in the oropharynx, and cyanosis develops. – Contraction of the jaw muscles may cause biting of the tongue. – marked enhancement of sympathetic tone

• increases in heart rate, blood pressure, and pupillary size.

• Clonic Phase (After 10–20 s– superimposition of periods of muscle relaxation on the tonic muscle contraction. – Progressively increase until the end of the ictal phase, which usually lasts no more than 1 min. T

• Postictal Phase – unresponsiveness, muscular flaccidity, and excessive salivation– Patients gradually regain consciousness over minutes to hours– Patients subsequently complain of headache, fatigue, and muscle ache that can last for many hours

• The EEG during the tonic phase of the seizure shows a progressive increase in generalized low-voltage fast activity, followed by generalized high-amplitude, polyspike discharges.

• In the clonic phase, the high-amplitude activity is typically interrupted by slow waves to create a spike-and-wave pattern.

Absence

• Characterized by sudden, brief lapses of consciousness without loss of postural control.

• Lasts for only seconds • usually accompanied by subtle, bilateral motor signs• usually begin in childhood (ages 4–8) or early

adolescence• Provoked by hyperventilation• The electrophysiologic hallmark: Generalized,symmetric,

3-Hz spike-and-wave discharge that begins and ends suddenly, superimposed on a normal EEG background.

Atypical Absence

• Lapse of consciousness is usually of longer duration• Less abrupt in onset and cessation• Seizure is accompanied by more obvious motor signs that

may include focal or lateralizing features. • Atypical absence seizures are usually associated with

diffuse or multifocal structural abnormalities of the brain. • Less responsive to anticonvulsants• The EEG shows a generalized, slow spike-and-wave

pattern with a frequency of ≤2.5/s, as well as other abnormal activity.

Atypical Absence with Special Features

• Myoclonic Absence– The manifestations are abrupt onset of absences

accompanied by bilateral rhythmic myoclonic jerks of severe intensity

– The seizure mainly involves muscles of the shoulders, arms, and legs; facial muscles are less involved.

– May last from 10 to 60 seconds– Hyperventilation, awakening, and stimulation by

intermittent light can precipitate the attack.

Atypical Absence with Special Features

• Eyelid Myoclonia– The eyelid myoclonia consists of rapid 4 to 6 Hz jerking of the

eyelids, which, if brief, may occur in isolation or proceed to an absence also associated with rapid jerking of the eyelids

– Seizures are brief, 3 to 6 seconds, occurring mainly after eye closure, photic stimulation, or both

– Onset is usually in early childhood, 5 to 8 years of age – Consist of eyelid myoclonia that persists through the attack

with or without absences– Photosensitivity

Myoclonic• Myoclonus is a sudden and brief muscle contraction that may involve

one part of the body or the entire body• Myoclonic seizures or twitches are brief contractions, or relaxations, of

a muscle or muscle group, resulting in a sudden, jumpy movement. – Positive myoclonus - muscular contraction– Negative myoclonus - muscular relaxation.

• Consciousness does not usually seem to be impaired• duration of <1 second• The EEG may show bilaterally synchronous spike-and-wave discharges

synchronized with the myoclonus, although these can be obscured by movement artifact.

• Myoclonic seizures usually coexist with other forms of generalized seizure disorders

Clonic

• Consists of rhythmic jerking movements of the arms and legs, sometimes on both sides of the body.

• Rapidly alternating contraction and relaxation of a muscle

• Movements cannot be stopped by restraining or repositioning the arms or legs

• EEG: high-amplitude activity is typically interrupted by slow waves to create a spike-and-wave pattern.

Tonic

• Often occur during sleep• Flexion at the waist and neck, abduction and flexion

or extension of the upper extremities, and flexion or extension of the lower extremities

• Typical duration is 5–20 seconds. • Tonic seizures are generalized, involving bilateral

musculature in a symmetric or nearly symmetric manner

• EEG usually shows generalized, low-voltage, fast polyspikes.

Atonic

• Atonic seizures are characterized by sudden loss of postural muscle tone lasting 1–2 s

• Usually no postictal confusion• The EEG shows brief, generalized spike-and-

wave discharges followed immediately by diffuse slow waves that correlate with the loss of muscle tone.

Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005–2009

Etiology

Algorithm to Seizure Approach