absence seizure(redirected from Epilepsy, absence)
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1. the sudden attack or recurrence of a disease.
absence seizure the seizure seen in petit mal epilepsy, marked by a momentary break in the stream of thought and activity, accompanied by a symmetrical spike and wave at 3 cycles per second on the electroencephalogram. Called also petit malseizure. See epilepsy.
atonic seizure an absence seizure characterized by sudden loss of muscle tone.
complex partial seizure see partial seizure.
febrile seizure febrile convulsion.
focal seizure partial seizure.
focal motor seizure a simple partial seizure consisting of clonus or spasm of a muscle or muscle group, occurring either singly or in a continuous repetitive series.
generalized tonic-clonic seizure (grand mal seizure) the seizure seen in grand mal epilepsy, marked by loss of consciousness and generalized tonic convulsions followed by clonic convulsions. See epilepsy.
jackknife s's infantile spasms.
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; symptoms vary with different lesion locations. A simple partial seizure is the most localized type, with a discharge that is predominantly one-sided or presents localized features without loss of consciousness. A complex partial seizure is associated with disease of the temporal lobe and characterized by varying degrees of impairment of consciousness. See epilepsy.
petit mal seizure absence seizure.
reflex seizure (sensory seizure) an epileptic seizure in response to a sensory stimulus, which may be tactile, visual, auditory, or musical.
simple partial seizure see partial seizure.
tonic-clonic seizure see generalized tonic-clonic seizure.
a seizure characterized by impaired awareness of interaction with, or memory of, ongoing events external or internal to the person; may comprise the following elements: mental confusion, diminished awareness of environment, inability to respond to internal or external stimuli, and amnesia. (The term absence was first used by Louis-Florentin Calmeil [1798-1895] to introduce the concept of epileptic absence for the brief loss of consciousness or confusion seen in epileptic patients.)
A generalized seizure marked by transient loss of consciousness and the absence of convulsions, occurring mostly in children. Also called petit mal 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.
Absence SeizureA type of generalised seizure, which is a common form of childhood (usually between age 6 and 12) epilepsy and is characterised by episodic arrest of sensation and voluntary activity. Absence seizures occur in symptomatic and idiopathic generalised epilepsies, the latter of which includes childhood absence epilepsy (pyknolepsy), juvenile absence epilepsy, and juvenile myoclonic epilepsy (impulsive petit mal), and may be associated with other types of seizures.
Clinical findings Transient “unplugging” from the environment. Absences last a few seconds, with full recovery, and no residual confusion, which appear as staring episodes or "absence spells" during which the child's activity or speech ceases. The child may stop talking in mid sentence or stop walking. One to several seconds later, speech or activity resume with no memory of the seizure. "Spells" can be infrequent or occur many times per hour, interfering with school function and learning, as the child’s teachers may interpret absence seizures as lack of attention or other misbehaviour, and can occur for weeks to months before being noticed because they commonly occur during quiet rest periods rather than during activity. Aypical petit mal seizures begin slower, last longer, may have more noticeable muscle activity than typical absence seizures, and may be associated with other neurologic disorders.
Aetiology Idiopathic, congenital brain abnormalities, complications of kidney or liver disease, or brain injuries from trauma or birth complications
Diagnosis 3-minute hyperventilation test may elicit an “absence”
Management Ethosuximide—which is only effective for absence seizures, and valproic acid, which is effective for absence, generalized tonic-clonic, and myoclonic seizures
ab·sence sei·zure(ab'sĕns sē'zhŭr)
A brief seizure characterized by arrest of activity and occasionally clonic movements. There is loss of consciousness or slowing of thought. Electroencephalograms typically show generalized spike wave discharges greater than 2.5 Hz. More prolonged absence seizures may have automatisms.
ab·sence sei·zure(ab'sĕns sē'zhŭr)
A seizure characterized by impaired awareness of interaction with, or memory of, ongoing events external or internal to the person; may comprise the following elements: mental confusion, diminished awareness of environment, inability to respond to internal or external stimuli, and amnesia.