Normal interictal EEG

What it means

Lack of observable abnormal electroencephalographic (EEG) patterns in an individual with a history of seizures. About half of individuals with epilepsy show interictal epileptiform discharges upon the first investigation. The yield can be increased by repeated studies, sleep studies, or by ambulatory EEG recordings over 24 hours. Normal interictal EEG is a sign that can be useful in the differential diagnosis.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category