How do I prepare for an EEG?

Discuss any medicines you are taking with your doctor prior to your procedure. Continue to take any anticonvulsant medications you have been prescribed (unless your doctor specifically tells you otherwise). Wash your hair the night before the test. Do not use hair cream, oils, or spray afterward.

What happens during the EEG?

You lie down on the examining table or bed while about 20 electrodes are attached to your scalp. You are asked to relax and lie first with your eyes open, then closed. You might be asked to breathe deeply and rapidly, or to stare at a flashing light. Both of these activities produce changes in the brain-wave patterns. If you are prone to seizures, it is rare that you might experience one during the test.

Last reviewed by a Cleveland Clinic medical professional on 02/09/2016.


  • Epilepsy Foundation. EEG Accessed 2/11/2016.
  • Aminoff MJ. Electrodiagnostic Studies of Nervous System Disorders: EEG, Evoked Potentials, and EMG. In: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 19e. New York, NY: McGraw-Hill; 2015. Accessed 2/11/2016.
  • Ropper AH, Samuels MA, Klein JP. Chapter 2. Imaging, Electrophysiologic, and Laboratory Techniques for Neurologic Diagnosis. In: Ropper AH, Samuels MA, Klein JP. eds. Adams & Victor's Principles of Neurology, 10e. New York, NY: McGraw-Hill; 2014. Accessed 2/11/2016

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