When a person has frequent seizures, memory lapses, and other suspicious signs of epilepsy, a number of tests will be used to make a diagnosis, including an EEG or electroencephalography. An EEG is able to detect brain activity and show patterns of abnormal or unusual activity on a computer screen for the doctor to see.
An EEG is a simple procedure that generally causes no pain or discomfort. The EEG uses an amplifier and a machine that records the brain’s activity. Attached to that equipment are wires with small, flat circular electrodes on the ends. These tiny metal disks are placed all over the head with a sticky paste or glue, and they pick up electrical impulses firing inside the brain so the EEG machine can record them.
The EEG’s recorder then turns those electrical readings into a pattern that appears in a computer screen.
The pattern of activity in the brain is specific, and when seizures occur, there are clear deviations from typical or normal activity.
Baseline EEG
Baseline EEG is a basic EEG test that is most often used to diagnose epilepsy and other neurological conditions. It provides a 20 to 40 minute sample of brain activity.
Ambulatory EEG
If the sample of brain activity gathered from the routine EEG isn’t enough, an ambulatory EEG may be recommended to capture more activity and give a better idea of when seizures occur. An ambulatory EEG can capture as much as 72 hours worth of brain activity, which is recorded while you go about your normal daily activities outside the doctor’s office
