Types of EEG

The main types of EEG are explained below.

Routine EEG

A routine EEG recording lasts for about 20 to 40 minutes.

During the test, you'll be asked to rest quietly and open or close your eyesfrom time to time. In most cases, you'll also be asked to breathe in and outdeeply (known as hyperventilation) for a few minutes.

At the end of the procedure a flashing light may be placed nearby to see if this affects your brain activity.

Sleep EEG or sleep-deprived EEG

A sleep EEG is carried out while you're asleep. It may be used if a routine EEG doesn't give enough information, or to test for sleep disorders.

In some cases, you may be asked to stay awake the night before the test to help ensure you can sleep while it's carried out. This is called a sleep-deprived EEG.

Ambulatory EEG

An ambulatory EEG is where brain activity is recorded throughout the day and night over a period of one or more days. The electrodes will be attached to asmall portable EEG recorder that can be clipped on to your clothing.

You can continue with most of your normal daily activities while the recording is being taken, although you'll need to avoid getting the equipment wet.

Video telemetry

Video telemetry, also known as video EEG, is a special type of EEG where you're filmed while arecording is taken. This can help provide more information about your brain activity.

The testis usually carried out overa few days while staying in a purpose-built hospital suite.

The EEG signals are transmitted wirelessly to acomputer. The video isalso recorded by the computer and kept under regular surveillance by trained staff.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018