Electroencephalographic abnormalities in hyperthyroidism.

IT WAS recognized early in the course of our electroencephalographic studies on endocrine disorders that some hyperthyroid patients had abnormal electroencephalograms (1). Gibbs and Gibbs (2) in their Atlas of Electroencephalography reported that the electrical activity of the cortex tends to be abnormally fast in hyperthyroid patients. Lindsley and Rubenstein (3) found a correlation in normal subjects between the alpha frequency and the basal metabolic rate. Odoriz et al. (4), in their study of parathyroid insufficiency, observed fast activity, simple spike discharges, and slow waves (2 to 3 per second). Ross and Schwab (5) reported that when the cortical alpha rhythm is determined during a “basal state” (patient fasting and resting one half hour) the correlation is not as good as when the patient is well fed, satisfied and relaxed. Fabrykant (6) noted that, in a group of 15 labile diabetics, electroencephalographic abnormalities were recorded in 80 per cent and severely disordered patterns consistent wi...