electroencephalography (EEG) /ilek′trō·ensef′əlog″rəfē/ , the process of recording brain wave activity. Electrodes are attached to various areas of the patient’s head with collodion. During the procedure the patient remains quiet, with eyes closed, and refrains from talking or moving. In certain cases prescribed activities, especially hyperventilation, may be requested. The test is used to diagnose seizure disorders, brainstem disorders, focal lesions, and impaired consciousness. During neurosurgery the electrodes can be applied directly to the surface of the brain (intracranial electroencephalography) or placed within the brain tissue (depth electroencephalography) to detect lesions or tumors. See also electroencephalogram. −electroencephalographic, adj.
