electrodecremental response
Sudden reduction in EEG amplitude and increase in frequency, often occurring at seizure onset in certain epilepsy types.
Full Definition
An electrodecremental response is an abrupt change in EEG activity characterized by a sudden decrease in amplitude (voltage) accompanied by an increase in frequency, creating a flattened appearance on the recording. This pattern often marks the onset of seizures, particularly in temporal lobe epilepsy and some generalized seizure types. The electrodecremental response represents massive neuronal depolarization that temporarily reduces the synchronized activity typically seen in normal EEG rhythms. While it can occur as an isolated finding, it is most significant when associated with clinical seizure activity and may be followed by other ictal patterns such as rhythmic theta or delta activity.
Usage
Usage note: Specify location and duration when documenting this pattern in seizure analysis.
In Context
- "Seizure onset was marked by an electrodecremental response over the left temporal region." — Video-EEG monitoring report
- "The electrodecremental response preceded the development of rhythmic theta activity." — Ictal pattern description