sharp wave
An epileptiform discharge with duration of 80-200 milliseconds, indicating cortical hyperexcitability and potential seizure activity.
Full Definition
A sharp wave is a type of epileptiform discharge characterized by a clearly distinguished waveform that stands out from the background EEG activity. It has a pointed peak with an asymmetric rise and fall, lasting between 80-200 milliseconds. Sharp waves are pathological findings that indicate cortical irritability or hyperexcitability and are associated with epilepsy or other seizure disorders. They may occur independently or be followed by a slow wave component. The morphology, frequency, and distribution of sharp waves provide important diagnostic information about seizure focus localization and seizure risk assessment.
Usage
Usage note: Distinguish from spikes (shorter duration) and normal sharp transients in reports.
In Context
- "Frequent sharp waves were noted over the left temporal region during sleep." — EEG interpretation
- "The sharp wave morphology was consistent with a mesial temporal seizure focus." — Epilepsy evaluation report