Markers of hippocampal interictal epileptiform discharges on scalp electroencephalogram


  • The presence of delta wave slowing ≥1.4 Hz on scalp electroencephalogram (EEG) was correlated with intracranial interictal epileptiform discharges (IEDs) in patients with temporal lobe epilepsy.

Why this matters

  • Localization of IEDs using scalp EEG can identify the epileptogenic zone. However, some IEDs, particularly those within the temporal lobe, cannot be detected with this method.

  • This was the first study to record both intracranial and scalp EEG simultaneously, and may contribute to the development of a scalp marker for intracranial IEDs, allowing less invasive detection in the future.