OverviewAn electroencephalogram (EEG) is a test that measures electrical activity in the brain using small, metal discs (electrodes) attached to the scalp. Brain cells communicate via electrical impulses and are active all the time, even during asleep. This activity shows up as wavy lines on an EEG recording. Show
An EEG is one of the main diagnostic tests for epilepsy. An EEG can also play a role in diagnosing other brain disorders. Why it's doneAn EEG can find changes in brain activity that might be useful in diagnosing brain disorders, especially epilepsy or another seizure disorder. An EEG might also be helpful for diagnosing or treating:
An EEG might also be used to confirm brain death in someone in a persistent coma. A continuous EEG is used to help find the right level of anesthesia for someone in a medically induced coma. More Information
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unsubscribe link in the e-mail. RisksEEGs are safe and painless. Sometimes seizures are intentionally triggered in people with epilepsy during the test, but appropriate medical care is provided if needed. How you prepareFood and medicationsTake your usual medications unless instructed otherwise. Other precautions
What you can expectDuring the testYou'll feel little or no discomfort during an EEG. The electrodes don't transmit any sensations. They just record your brain waves. Here are some things you can expect to happen during an EEG:
Ambulatory EEGs (aEEGs) allow for longer monitoring outside an office or a hospital setting. But these types of EEGs aren't always an option. This test can record brain activity over several days, which increases the chances of recording during seizure activity. However, compared with inpatient video EEG monitoring, an ambulatory EEG is not as good at determining the difference between epileptic seizures and nonepileptic seizures. After the testThe technician removes the electrodes or cap. If you didn't have a sedative, you should feel no side effects after the procedure. You should be able to return to your typical routine. If you used a sedative, it will take time for the medication to begin to wear off. Arrange to have someone drive you home. Once you're at home, rest and don't drive for the rest of the day. ResultsDoctors trained to analyze EEGs interpret the recording and send the results to the doctor who ordered the EEG. You might need to schedule an office appointment to discuss the results of the test. If possible, bring along a family member or friend to the appointment to help you remember the information you're given. Write down questions to ask your doctor, such as:
Clinical trialsExplore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions. EEG (electroencephalogram)
What are the rules for an EEG?Other precautions. Wash your hair the night before or the day of the test, but don't use conditioners, hair creams, sprays or styling gels. ... . If you're supposed to sleep during your EEG , your health care provider might ask you to sleep less or avoid sleep the night before your EEG .. How long does it take to do EEG?Routine EEG: Routine EEG scans take 23 minutes. Your EEG technologist may ask you to breathe differently or look at flashing lights during the procedure. Prolonged EEG: A prolonged EEG test usually takes one hour and 15 minutes, but some types can last several days.
Can you talk during an EEG?People who have relatively good movement control of an EEG-based BCI may be able to speak and perform other cognitively engaging activities with only a minor drop in BCI-control performance.
Can you walk around during an EEG?Ambulatory EEG
Because it is portable you can move around and carry on with your normal day-to-day routine while the recording happens.
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