Beta wave activity in the electroencephalogram in cases of coma due to acute brain-stem lesions.

It is well known that the state of deep coma is usually associated with high-voltage slowwaves in the electro-encephalogram (E.E.G.). However, some exceptional cases have been reported which suggest an independ-ence of the comatous state from slow waves in the E.E.G. Loeb and Poggio (1953) reported a patient who fell abruptly into coma and died within 30 hours, showing slight abnormalities in an E.E.G. recorded six hours after the attack of coma, with 8-9 c/s alpha waves, 3-4 c/s theta waves bursts, low-voltage fast activity and positive spike discharges, even in the state of deep coma. At necropsy, massive haemor-rhages of the middle part of the pons reaching to the lower part of the mid-brain were found. Loeb