An electroencephalogram (EEG) is a test used to evaluate the electrical activity in the brain that may be associated with certain brain disorders.
What are the prerequisites before doing an EEG?
- Wash your hair the night before the EEG, and don’t put any products (such as sprays or gels) in your hair on the day of the test.
- Ask your doctor if you should stop taking any medications before the test. You should also make a list of your medications and give it to the technician performing the EEG.
- Avoid consuming any food or drinks containing caffeine for at least eight hours prior to the test.
Your doctor may ask you to sleep as little as possible the night before the test if you’re required to sleep during the EEG. You may also be given a sedative to help you to relax and sleep before the test begins.
What is the procedure in doing an EEG?
An EEG may be done at a hospital, at your doctor’s office, or at a laboratory by a specialized technician. It usually takes 30 to 60 minutes to complete.
- You’ll be asked to lie down on your back in a reclining chair or on a bed.
- The technician will measure your head and mark where the electrodes will be placed. These spots are then scrubbed with a special cream that helps the electrodes get a high-quality reading.
- The technician will put a sticky gel adhesive on 16 to 25 electrodes. They will then be attached to various spots on your scalp.
- Once the test begins, the electrodes send electrical impulse data from your brain to the recording machine. This machine converts the electrical impulses into visual patterns that can be seen on a screen. These patterns are saved to a computer.
- The technician may instruct you to do certain things while the test is in progress. They may ask you to lie still, close your eyes, breathe deeply, or look at stimuli (such as a flashing light or a picture).
- After the test is complete, the technician will remove the electrodes
What is an EEG Test?
The test tracks and records brain wave patterns. The electrodes analyze the electrical impulses in the brain and send signals to a computer, where the results are recorded. The electrical impulses in an EEG recording look like wavy lines with peaks and valleys. These lines allow doctors to quickly assess whether there are abnormal patterns. Any irregularities may be a sign of seizures or other brain disorders.
There are no risks associated with an EEG. It is a painless and safe procedure.