Electroencephalography - EEG

Monday - Thursday: 7 am - 5 pm

Phone: 863-680-7544


What is Electroencephalography?
An electroencephalography (EEG) is an exam that measures and reports the electrical activity within the brain. 

What does an EEG exam test for?
An EEG test is performed to diagnose epilepsy, to discover the likelihood of recovery after a change in consciousness, to discover if a coma patient is brain-dead, to study sleep disorders, to diagnose a physical or mental health problem, to check for dementia, and to observe brain activity while a patient undergoes general anesthesia during brain surgery.

What happens during the procedure?
For the procedure, patients lie on their back with their eyes closed, while approximately 17 to 21 metal sensor plates or electrodes are attached to the head, with a sticky paste. Alternatively, patients may have a cap containing electrodes fixed to their heads, which can be attached using tiny needles. The electrodes are attached by wires to a computer that records the electrical activity of a patient’s brain through a series of wavy lines. Patients are asked to remain relaxed during the procedure.

Also, patients may be asked to perform different tasks, while being tested to examine their brain’s reaction, including hyperventilating, looking at a strobe light or being asked to sleep or given a sedative.

The test usually lasts 1 to 2 hours, and normal activity can resume afterwards.

What should you do before the procedure?
Patients will need to consult their physicians before the procedure to determine pre-EEG preparing. Typically, patients are instructed to not consume any medications the day before that may interfere with the test, such as sedatives. Also patients should not consume any form of caffeine 12 hours before the EEG, and should make sure their hair is clean prior to the procedure, clear of conditioner or any oils.

If patients will have to sleep during the procedure, they may be requested to alter their sleep schedule by sleeping a shorter amount of time or not at all the night before.

How does the EEG test feel and what are the risks?
No pain is involved during the EEG test; however, if needle electrodes are used, patients will feel a slight prick on their scalp.

The actual test is safe, as no electric currents are run through a patient’s body.

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