Absence seizure

An absence seizure is a brief generalized seizure that interrupts awareness, often causing a blank stare and little or no movement. It typically begins and ends abruptly.

Thalamocortical oscillation: Rhythmic activity in connected thalamic and cortical circuits that helps generate brain rhythms. Abnormal rhythms in these circuits are associated with the characteristic spike-and-wave pattern.
Generalized seizure: A seizure involving networks distributed across both cerebral hemispheres from its onset. Absence seizures are generalized seizures, rather than seizures beginning in one localized network.
Absence seizure diagnosis: The clinical and EEG assessment used to determine whether episodes are absence seizures. Abrupt staring spells and generalized spike-and-wave EEG activity guide diagnosis.
Atypical absence seizure: A generalized seizure with a gradual onset and offset, often accompanied by changes in muscle tone. Unlike typical absence seizures, it often occurs with developmental impairment and slower EEG spike-and-wave activity.
Spike-and-wave complex: A repeating electroencephalographic pattern of a sharp spike followed by a slower wave. Generalized spike-and-wave activity is the hallmark EEG pattern during typical absence seizures.
Impaired awareness: Reduced ability to respond to or remember events during a period of altered consciousness. A brief interruption of awareness defines the central experience of an absence seizure.
Valproate: An antiseizure medication used for several seizure types and other neurological conditions. It may be selected when absence seizures occur alongside generalized tonic-clonic seizures.
Focal impaired-awareness seizure: A seizure beginning in one brain hemisphere that disrupts awareness and may cause automatisms. Its focal onset and longer duration distinguish it from the usually brief, generalized absence seizure.
Electroencephalography: A method that records electrical activity from the brain using electrodes placed on the scalp. EEG can reveal seizure activity even when outward behavior shows only a brief pause.
Epilepsy: A neurological disorder marked by an enduring tendency to have unprovoked seizures. Repeated absence seizures can occur as part of an epilepsy syndrome.

Linked from 6 pages