absence seizure

seizure /sei·zure/ (se´zhur)

1. the sudden attack or recurrence of a disease.

2. a single episode of epilepsy, often named for the type it represents.

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absence seizure  the seizure of absence epilepsy, marked by a momentary break in consciousness of thought or activity and accompanied by a symmetrical 3-cps spike and wave activity on the electroencephalogram.

adversive seizure  a type of focal motor seizure in which there is forceful, sustained turning to one side by the eyes, head, or body.

atonic seizure  an absence seizure characterized by sudden loss of muscle tone.

automatic seizure  a type of complex partial seizure characterized by automatisms, often ambulatory and involving quasipurposeful acts.

clonic seizure  one in which there are generalized clonic contractions without a preceding tonic phase.

complex partial seizure  a type of partial seizure associated with disease of the temporal lobe and characterized by varying degrees of impairment of consciousness and automatisms, for which the patient is later amnestic.

febrile seizures  see under convulsion.

generalized tonic-clonic seizure  the seizure of grand mal epilepsy, consisting of a loss of consciousness and generalized tonic convulsions followed by clonic convulsions.

myoclonic seizure  one characterized by a brief episode of myoclonus.

partial seizure  any seizure due to a lesion in a specific, known area of the cerebral cortex.

reflex seizure  an episode of reflex epilepsy.

sensory seizure 

1. a simple partial seizure manifested by paresthesias or other hallucinations, including several types of aura.

2. a reflex seizure in response to a sensory stimulus.

simple partial seizure  a localized type of partial seizure, without loss of consciousness; if it progresses to another type of seizure it is called an aura.

tonic seizure  one characterized by tonic but not clonic contractions.

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absence seizure

n.

A brief, sudden loss of consciousness symptomatic of petit mal epilepsy.

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absence seizure,

an epileptic seizure characterized by a sudden, momentary loss of consciousness. Occasionally it is accompanied by minor myoclonus of the neck or upper extremities, frequent blinking, slight symmetric twitching of the face, or loss of tonus. Seizures usually occur many times a day without a warning aura and are most frequent in children and adolescents, especially at puberty. Children often outgrow them. The patient experiencing a typical seizure has a vacant facial expression and ceases all voluntary motor activity; with the rapid return of consciousness, the patient may resume conversation at the point of interruption without realizing what occurred. During and between seizures, the patient's electroencephalogram shows 3-Hz spike-and-wave discharges. Anticonvulsant drugs used to prevent absence seizures include ethosuximide, trimethadione, and valproic acid. Also called absentia epileptica, petit mal seizure. See also epilepsy.

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seizure,

n See epilepsy.

seizure, absence,

n a seizure characterized by sudden interruption of conscious physical and mental activities and a short period of unconsciousness. Formerly known as
petit mal, sometimes simply called
absence.

seizure, clonic phase,

n a seizure's convulsion stage.

seizure, complex partial,

n a seizure stemming from a localized part of the brain indicated by the presence of a state similar to a trance, varying degrees of awareness, and the manifestation of purposeless behaviors or motions. The seizure may be followed by an indeterminate period of confusion, garbled speech, poor mood, and an inability to recall the events of the episode.

seizure, generalized,

n a nonfocalized, convulsive spell that has a simultaneous effect on the entire brain. Formerly known as
grand mal seizure.

seizure, grand mal

n See seizure, generalized.

seizure, simple partial,

n a type of seizure in which only one part of the brain is involved. Patients experiencing this type of seizure may feel intense emotions (joy, fear) or involuntary muscle spasms, depending on the region affected.