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

1966; BMJ; Volume: 29; Issue: 5 Linguagem: Inglês

10.1136/jnnp.29.5.383

1468-330X

E Otomo,

EEG and Brain-Computer Interfaces

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 (1958) also observed similar electroencephalographic findings in a case in which massive haemor- rhages ruptured into the ventricle invading the upper one-third of the pons.A patient was reported (Lundervold, Hauge, and Loken, 1956), who re- mained unconscious for one year and a half without any appreciable E.E.G. changes, following vertebral arteriography.In this patient, the area supplied by the posterior cerebral arteries had not been flushed by the contrast medium due to an obstruction of these arteries at their origin from the basilar artery.They were filled via the carotid system.At necropsy, the pontine region, including its reticular substance, was found to be severely damaged.In addition, there was bilateral atrophy ofthe posterior mesencephalon, including the pyramidal tract, the medial lemniscus, the cerebellum, and other structures supplied by the vertebral arterial system.Kaada, Harkmark, and Stokke (1961) also re- ported a similar case.This patient died on the fourth day after the beginning of the disease, and showed bursts of 12 c/s alpha waves, 4-6 c/s theta waves, and low-voltage fast activity in the E.E.G.At necropsy, a fresh thrombus occluded the basilar artery from the vertebral to the posterior cerebral arteries, and damage to the pons and midbrain was found.Chatrian, White, and Shaw (1964) found 8-10