EEG Test Explained: When Your Doctor Recommends It

 An electroencephalogram, commonly known as an EEG, is a test that helps measure electrical activity in the brain. This test utilizes small, metal discs called electrodes that attach to the scalp. The brain cells communicate through electrical impulses, which show up as wavy lines on the recording. This test is primarily used to diagnose epilepsy. That said, it can be used to diagnose other brain conditions as well.

Why is an EEG Test Recommended?

Your doctor may recommend this test for different reasons, depending on your symptoms. The results confirm one of the following conditions.

Seizure Disorders

If you have had seizures in the past or experience fainting spells or sudden blackouts, the doctor will suggest opting for an EEG. It will help them to check for epilepsy in adults or febrile seizures in children. This test also helps them find the cause of blackouts if it is not clear in other tests.

Brain Disorders

EEG is used to monitor brain disorders. People who have had a stroke, a brain tumor, or any serious head injury are recommended to opt for this test. The test results allow doctors to check how well the brain is functioning. This test also helps in diagnosing memory loss or dementia.

Sleep Disorders

If you experience tiredness even after sleeping for enough hours or snore more heavily or stop breathing during your dreams, the doctor may recommend this test. EEG helps detect things such as sleep apnea, REM behaviour disorder, or narcolepsy.

Brain Function Evaluation in Coma

If the patient has gone into a coma or is unconscious for a long time, this test is used by the doctor to see if their brain is still active and how much.

What are the Different Types of EEG Tests?

Depending on your symptoms, the doctor may recommend different variations of EEG tests.

• Routine EEG: It records brain waves while you are awake and may involve procedures such as photic stimulation or flashing lights to trigger specific patterns. The test takes 30-60 minutes to complete.

• Ambulatory EEG: This type of EEG is recommended for symptoms that are infrequent. An ambulatory device allows for continuous recording up to 72 hours while you maintain your routine at home.

• Video EEG Monitoring: This test includes simultaneous video and electrical recording in a hospital setting to correlate physical movements with brain wave changes. It is essential for differentiating epileptic seizures from psychogenic non-epileptic seizures.

• Sleep EEG: This test is conducted if the patient is asleep and is used to rule out abnormalities appearing during sleep, such as K-complexes, sleep spindles, or more.

How do I Prepare for an EEG?

Before the day of your test, the doctor will recommend that you follow a few instructions to ensure that the test results are accurate.

• Avoid caffeine and other stimulants, such as nicotine, for at least 12 hours before the test. These substances may interfere with brain activity and may not give accurate results.

• Clean your hair before the test, but avoid using products like oils, gels, and sprays.

• If you are on prescription medication, inform your doctor about these medications before the test.

• Ensure you are well rested the night before the test. Sleep deprivation may affect brain wave patterns and lead to inaccurate findings.

• Wear comfortable and loose-fitting clothing, as it allows for easy access to your scalp.

• Bring a list of symptoms or events that have led to the test request by the doctors so that they can interpret the results of the test in the right context.

What Happens During an EEG?

• The technician will attach small electrodes to your scalp with the help of a gel. You may experience slight discomfort in this step.

• You will be asked to relax to keep yourself calm. You may breathe deeply or hyperventilate to provoke abnormal brain activity.

• At each step, the electrodes will record your brain’s electrical activity. It will be displayed on the computer screen and printed out simultaneously. The recording may last from 20 minutes to an hour.

• In some cases, you may be asked to perform simple tasks such as blinking or opening your eyes. You may as well be asked to sleep during the test to gather additional data.

• Once the test is completed, they will remove the electrodes and ask you to resume your normal activities. As no anesthesia is involved, you can return to your routine right away.

After the test results are out, the doctor will discuss the treatment with you. If the results show typical brain wave patterns, it is considered normal. If there is excessive slow-wave activity, the results may be abnormal and indicate brain injury, seizure disorders, or any cognitive dysfunction. Irregular spikes or sharp waves may indicate seizure activity or epilepsy.

Takeaway

EEG is an invaluable test to diagnose and monitor neurological conditions. It is a quick and non-invasive procedure with no side effects. The test provides critical information about electrical activity in the brain. Whether you are getting tested for sleep disorders, seizures, or any other reason, the test report will help the doctor confirm the diagnosis and devise a suitable treatment plan.