An EEG (electroencephalogram) test is a non-invasive neurodiagnostic test that measures the electrical activity of the brain. The test records the electrical signals generated by the neurons in the brain through electrodes placed on the scalp. The electrodes are attached to wires that are connected to an EEG machine that amplifies the signals and records them on a computer.
During an EEG test, the patient lies down on a bed or sits in a chair, and the technician applies a conductive gel to the scalp to ensure a good connection between the electrodes and the skin. The test usually takes 30-60 minutes, and the patient is asked to remain still and relaxed, and may be asked to perform specific tasks, such as hyperventilating or looking at flashing lights.
EEG tests are used to diagnose and monitor a range of conditions affecting the brain, including epilepsy, sleep disorders, and brain injuries. The test can also help identify brain activity associated with specific tasks or conditions, such as memory or attention. In some cases, an EEG test may be done while the patient is sleeping, to evaluate sleep patterns and diagnose sleep disorders.
EEG tests are safe and painless, and do not involve any radiation. The results of the test are usually interpreted by a neurologist or other healthcare provider trained in neurophysiology, who can use the information to diagnose and treat the patient's condition.