The background EEG is normal.
CAUTION Focal slowing
consistently over one area
consider structural brain abnormality.
The EEG may demonstrate rare frontal or fronto-temporal sharp waves or spikes. Epileptiform abnormalities may only be present during sleep.
Activation of interictal abnormalities occurs with sleep deprivation or in sleep (or these abnormalities may be only seen in sleep).
Ictal scalp EEG may be normal or may only demonstrate movement artefact. When present, ictal patterns include sharp waves or repetitive 8-11 Hz spikes (rarely in the form of a recruiting pattern), rhythmic theta activity (bifrontal or unilateral frontal) or diffuse attenuation.