How long do eeg tests take

Talk with your healthcare provider about what you will experience during your test. Once the test is completed, the electrodes will be removed and the electrode paste will be washed off with warm water, acetone, or witch hazel. In some cases, you may need to wash your hair again at home. If you took any sedatives for the test, you may be required to rest until the sedatives have worn off.

You will need to have someone drive you home. Skin irritation or redness may be present at the locations where the electrodes were placed, but this will wear off in a few hours. Your healthcare provider will inform you when you may resume any medicines you stopped taking before the test.

Your healthcare provider may give you additional or alternate instructions after the procedure, depending on your particular situation. Health Home Treatments, Tests and Therapies. Why might I need an EEG? There may be other reasons for your healthcare provider to recommend an EEG. What are the risks of an EEG?

Certain factors or conditions may interfere with the reading of an EEG test. These include: Low blood sugar hypoglycemia caused by fasting Body or eye movement during the tests but this will rarely, if ever, significantly interfere with the interpretation of the test Lights, especially bright or flashing ones Certain medicines, such as sedatives Drinks containing caffeine, such as coffee, cola, and tea while these drinks can occasionally alter the EEG results, this almost never interferes significantly with the interpretation of the test Oily hair or the presence of hair spray How do I get ready for an EEG?

Your healthcare provider will explain the procedure to you and you can ask questions. You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.

Wash your hair with shampoo, but do not use a conditioner the night before the test. Conditions diagnosed by EEG Normal brain waves occur at a rate of up to 30 per second, but in someone with epilepsy, for example, the EEG may show bursts of abnormal discharges in the form of spikes and sharp wave patterns.

Other conditions that may be diagnosed with the aid of an EEG include: Sleep disorders such as narcolepsy Head injuries Brain infection Brain haemorrhage Alzheimer's disease Degeneration of brain tissue Metabolic conditions that affect brain tissue Hormonal conditions that affect brain tissue Certain disorders of the central nervous system Stroke Brain tumour Brain death.

Medical issues to consider An abnormal EEG doesn't automatically mean that you, for example, have epilepsy. EEG procedure Your hair must be thoroughly clean, but most importantly dry. Immediately after the EEG Once the test is complete, the electrodes are removed and you are allowed to get up.

Taking care of yourself at home EEG is a safe procedure. Long-term outlook The EEG technologist can't interpret the test results on the spot. Other diagnostic tests Other diagnostic tests depend on the condition under investigation. Where to get help Your doctor Neurologist Things to remember The electroencephalogram EEG is a medical test used to measure the electrical activity of the brain.

A number of electrodes are applied to your scalp. EEG can help diagnose a number of conditions including epilepsy, sleep disorders and brain tumours. Give feedback about this page. Was this page helpful? Yes No.

View all medical tests. Related information. Content disclaimer Content on this website is provided for information purposes only. Reviewed on: You may be asked to perform a few simple tasks, such as reading, opening and closing your eyes, breathing deeply for a few minutes, or looking at a flashing light.

These activities may trigger a change in the EEG pattern. If your doctor wants you to have a video EEG — where you are monitored by a video camera while the EEG is in progress — you may need to have a short hospital stay.

A video EEG is useful for providing a record of your EEG pattern during the exact time of any suspected seizure activity. Sometimes your doctor will ask for an ambulatory EEG, where brain activity is recorded for a longer period of time usually 24 hours away from the hospital.

The electrodes are attached to the scalp and plugged into a small portable recording device which is usually worn around your waist.

During an ambulatory EEG you can still perform many of your usual activities, but there are some restrictions.

The test itself will take about minutes. Placing the electrodes usually takes 20 minutes, but can take up to an hour, so the entire procedure may take about one to 2 hours. It is important that your scalp is not oily, so wash your hair on the day of the test or the night before , but do not use any hair conditioner or other hair products, such as hair spray or styling gel.

You may be advised to avoid eating or drinking anything that contains caffeine e. You may also need to have an EEG recording done while you are asleep. Some people may need to take a sedative to help them sleep during the test. EEGs are generally very safe.

There is a risk for people with epilepsy that the effect of certain stimuli on the brain may trigger a seizure during the EEG. However, there will be trained medical staff on hand if this does occur. Having an EEG is not painful. The EEG will show patterns of brain waves that can help your doctor determine whether there is a problem. A change in the normal pattern of brain waves may indicate epilepsy and can help determine the type of epilepsy.

It is not necessary for a seizure to occur during the test for epilepsy to be diagnosed, because people with epilepsy often have small changes in brain wave patterns even when they are not having a seizure. However, it is also true that a normal EEG result does not always rule out epilepsy, because some people with seizure disorders have normal EEG readings between seizures.

This content does not have an English version. This content does not have an Arabic version. Request an Appointment at Mayo Clinic. EEG electrodes Open pop-up dialog box Close. Fresh Approach to Epilepsy Treatment Rekindles Zest for Life Janice Breien was anxious to find a better way to manage the seizures that regularly disrupted her daily life.

Share on: Facebook Twitter. Show references Moeller J, et al. Electroencephalography EEG in the diagnosis of seizures and epilepsy. Accessed Feb. Neurological diagnostic tests and procedures fact sheet. National Institute of Neurological Disorders and Stroke. Hirsch LJ, et al. Video and ambulatory EEG monitoring in the diagnosis of seizures and epilepsy. The Epilepsy Foundation.

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