Electrophysiological changes in the feline brain during 45 minutes occlusion and 3 hours recirculation of the middle cerebral artery.
The electrophysiological effects of unilateral MCA occlusion for 45 minutes and subsequent recirculation for 3 hours were studied in cats. EEG, steady (DC) potentials, tissue available O2 were measured and metabolic changes were studied. Computed EEG analysis was carried out off line, changes in frequency index and total intensity were analyzed and compared to regional metabolic alterations. It is concluded that: 1. Exenteration of the orbita results in significant and long lasting changes of the EEG, so, a less traumatic method of focal ischemia should be elaborated. 2. Changes in EEG (intensity or frequency content) caused by 45 min MCA occlusion seldom exhibit complete restitution by the end of a 3 hours long recirculation period. 3. Diaschisis can often be detected in this focal ischemic model by computed EEG evaluation. 4. Severe electrophysiological alterations after recirculation usually reflected extended metabolic damage. Mild EEG disturbances can cover both biochemically intact or slightly injured brain tissue.
Bereczki
D
D
Department of Neurology and Psychiatry, University Medical School, Debrecen, Hungary.
Csiba
L
L
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D002415:Cats; D002536:Cerebral Arteries / Q000502:physiology*; D003250:Constriction; D004569:Electroencephalography; D005260:Female; D006439:Hemodynamics; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D008564:Membrane Potentials; D010101:Oxygen Consumption / Q000502:physiology; D015424:Reperfusion