[Electrophysiological tests in a case of Hashimoto's encephalopathy].

Hashimoto's encephalopathy is regarded as an autoimmune disorder that appears in patients with anti thyroid antibodies. The thyroid function tests of the patients are not necessarily abnormal, which sometimes makes the diagnosis difficult. Since most of the patients show consciousness disturbance, psychiatric symptoms, and cognitive function decline, Hashimoto's encephalopathy must be distinguished from other disorders showing dementia.