An electroencephalogram (EEG) is a test used to evaluate the electrical activity in the brain. Brain cells communicate with each other through electrical impulses. An EEG can be used to help detect potential problems associated with this activity.
An EEG tracks and records brain wave patterns. Small flat metal discs called electrodes are attached to the scalp with wires. The electrodes analyse the electrical impulses in the brain and send signals to a computer that records the results. 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.
The measurements given by an EEG are used to confirm or rule out various conditions, including seizure disorders, altered sensorium, differentiate certain movements from seizures, head injury, encephalitis, brain tumor, encephalopathy, memory problems, sleep disorders etc. When someone is in a coma, an EEG may be performed to determine the level of brain activity. The test can also be used to monitor activity during brain surgery. It is also used to diagnose status epilepticus.
There are no risks associated with an EEG. The test is painless and safe.
Some EEGs do not include lights or other stimuli. If an EEG does not produce any abnormalities, stimuli such as strobe lights, or rapid breathing may be added to help induce any abnormalities.
Preparation before EEG test:
Wash your hair the night before the EEG, and don’t put any products (like 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 eating or drinking anything containing caffeine for at least eight hours before the test.
Your doctor may ask you to sleep as little as possible the night before the test if you have to sleep during the EEG. You may also be given a sedative to help you relax and sleep before the test begins.
After the EEG is over, you can continue with your regular routine.