THE ELECTROENCEPHALOGRAM AFTER PROLONGED BRAIN ASPHYXIATION

Abstract

The brain was asphyxiated for periods of 10-30 mins. by raising the intracranial pressure above the blood pressure. After this, the electroencephalogram (Eeg.) was recorded for several hrs. at regular intervals. The Eeg. after the shorter asphyxiations was characterized by short (1-2 sec. duration) bursts of activity, with a wave frequency of 7-12/sec, repeated 10-20 times/min. Evidence is presented for the cortical origin of these bursts. The Eeg. after the longer asphyxiations is characterized by spindles of activity of longer (10-20 sec.) duration, with a wave frequency of 12-16/sec. which are repeated with intervals varying between a few sees, and about 1 min. Evidence is presented for the view that the source of the potentials recorded as spindles is an unidentified subcortical structure centrally located in the brain.