Electroencephalograph (EEG)

An electroencephalograph (EEG) is an electronic, computerized device used to record the electrical activity of the brain by means of a series of electrodes affixed to the scalp. It is often used in conjunction with video recording of the patient.

Male patient undergoing an MEG (magnetoencephalography)

Male patient undergoing an MEG (magnetoencephalography)
(US National Institute of Mental Health)

As a diagnostic tool, EEGs have been used to diagnose epilepsy and other seizure activity, strokes, infections, hemorrhages, adequacy of blood supply to the brain, efficacy of biofeedback and neurofeedback and to localize certain tumors. They are especially useful because they can pinpoint the location of seizure activity as well as tumors and injuries to the brain. EEGs are also used to monitor patients in a coma and, during certain types of surgery, to indicate the effectiveness and depth of anesthesia.

See also Brain ; Brain disorders ; Electrical stimulation of the brain (ESB); Psychosurgery .



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eMedicineHealth. “Electroencephalography.” http://www.mayoclinic.org/tests-procedures/eeg/basics/definition/prc–20014093 (accessed September 18, 2015).

Johns Hopkins Medicine. “Electroencephalogram: EEG.” http://www.hopkinsmedicine.org/healthlibrary/test_procedures/neurological/electroencephalogram_eeg_92,P07655/ (accessed September 18, 2015).

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