It is known that the increased impact of thyroid hormone in thyrotoxicosis produces a number of symptoms involving the central nervous system. Thyrotoxicosis can even produce such gross neurological phenomena as coma, bulbar palsies, athetotic and choreiform movements, as has been well demonstrated by Waldenstrom (1945).
It is thus not surprising that electroencephalographic (EEG) abnormalities occur in the presence of thyrotoxicosis. In normal subjects Lindsley & Rubinstein (1937) found a correlation between the alpha frequency and the basal metabolic rate. This correlation was also demonstrated in a subject whose metabolic rate was increased by the administration of thyroxine. Ross & Schwab (1939) observed a similar correlation between the alpha frequency and the basal metabolic rate in a group of 12 patients with myxedema and 22 patients with thyrotoxicosis. They pointed out, however, that this correlation was not so close during the basal state (patient fasting and resting one half hour