A routine EEG can take 20 – 30 minutes with or without video recording. Patients are asked to open and close their eyes intermittently. Standard ‘activation’ procedures are usually performed unless otherwise contraindicated. Activation procedures can increase the yield of capturing abnormalities such as epileptiform activity. Activation procedures include 3 – 5 minutes of ’over breathing’ and photic stimulation (flashing lights).
A prolonged EEG is a recording, usually with video and of at least 3 hours in duration. This can be performed as an inpatient or outpatient with or without activation procedures. Prolonged EEG’s can increase the yield further in capturing epileptiform discharges.
An ambulatory EEG is an outpatient recording lasting anywhere from 24 hours up to 5 days. The patients head is measured with a marker and individual electrodes are placed on the head.
|SLEEP DEPRIVED EEG (SDEEG)|
An SDEEG is performed after a period of sleep deprivation. This can be a partial or up to 24 hours of sleep deprivation.
Indications: Ability to elucidate daytime and nocturnal epileptiform discharges.