Why it's done
By Mayo Clinic staffAn EEG can determine changes in brain activity that may be useful in diagnosing brain disorders, especially epilepsy. An EEG may be helpful to confirm, rule out or provide information that helps with management of the following disorders:
- Epilepsy or other seizure disorder
- Brain tumor
- Head injury
- Brain dysfunction that may have a variety of causes (encephalopathy)
- Inflammation of the brain (encephalitis)
- Stroke
- Sleep disorders
- Memory impairment
An EEG can't measure intelligence or detect mental illness. It may be used to confirm brain death in someone in a persistent coma.
- Aminoff MJ. Electrophysiology. In: Goetz CG. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2007:477.
- Hirsch LJ, et al. Electroencephalography (EEG) in the diagnosis of seizures and epilepsy. http://www.uptodate.com/home/index.html. Accessed March 23, 2011.
- Aminoff MJ. Electrodiagnostic studies of nervous system disorders: EEG, evoked potentials and EMG. In: Fauci AS, et al. Harrison's Online. 17th ed. New York, N.Y.: The McGraw-Hill Companies; 2008. http://www.accessmedicine.com/content.aspx?aID=2885536. Accessed March 23, 2011.
- Importance of EEG tests. Epilepsy Foundation. http://www.epilepsyfoundation.org/about/quickstart/newlydiagnosed/qstreatment/qstreeg.cfm. Accessed March 23, 2011.
- Neurological diagnostic tests and procedures. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/misc/diagnostic_tests.htm. Accessed March 23, 2011.
- Devinsky O. Epilepsy: Patient and Family Guide. 3rd ed. New York, N.Y.: Demos Medical Publishing LLC; 2008:76.
- Sedation analgesia. American Society of Anesthesiologists. http://www.lifelinetomodernmedicine.com/Types-Of-Anesthesia/Sedation-Analgesia.aspx. Accessed March 23, 2011.

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