Psychosomatic Medicine 3:38-50 (1941)
© 1941 American Psychosomatic Society

Electroencephalographic Studies on three cases of Frontal Lobotomy

¹ Department of Physiology, Harvard Medical School and McLean Hospital, Waverley, Mass.

Electroencephalograms (EEG's) were recorded on three mental patients at McLean Hospital before and after bilateral frontal lobotomy. The operation was performed in each case for the relief of agitated depression. The EEG's of the patients (McL-27 and 234) before operation showed relatively little differentiation in the activity of different cortical areas (Figs. 1, 2 and 8). There was no asymmetry between left and right sides and no evidence of any unusual degree of cortical overactivity (Figs. 1, 2 and 8). The patients' behavior immediately following their operations was not fundamentally changed. A few weeks later their agitation had disappeared almost completely, enabling them to leave the hospital. Except for an increase in instability, there was no significant change in their EEG's even in the frontal area which had been undercut (Figs. 2 and 8).

The EEG of the second patient (McL-55) showed a mild generalized overactivity in 1936 (Figs. 3 and 4), which in 1938 was greatly exaggerated, distorted and more continuous (Fig. 5). In 1938 there were also specific episodes of "locked" delta activity (Fig. 6) of very high voltage appearing only on the left side of the head and predominantly in the left occipital and parietal areas. At this time he was suffering from excessive uncontrollable motor activity and a continuous jargon of speech. A pneumoencephalogram revealed a left cerebral hemiatrophy, largely in the occipital and the posterior part of the parietal lobes. The abnormalities of behavior were almost completely relieved by the operation. Likewise the superimposed abnormalities in the EEG were greatly reduced and the record was entirely free of high-voltage episodic activity (Figs. 3 and 7). The improvement in the EEG corresponds perfectly to the improvement in his behavior, and a follow-up record taken eleven months post-operatively showed no further change in the pattern.

After operation in both cases the fundamental characteristic alpha frequencies, voltages, wave shapes (and response of the alpha rhythm to opening and closing the eyes) were practically the same as observed in their earliest records.