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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
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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 pupillarysize. • Clonic Phase (After 10–20 s • superimposition of periods of muscle relaxation on the tonic muscle contraction. • Progressively increase until the end of the ictalphase, 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. • Positivemyoclonus- 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 postictalconfusion • 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