Experimental cerebral oligemia and ischemia produced by intracranial hypertension. Part 1: Pathophysiology, electroencephalography, cerebral blood flow, blood-brain barrier, and neurological function.
Cerebral blood flow, electrical activity, and neurological function were studied in rabbits subjected to either 15 minutes of oligemia (20 torr cerebral perfusion pressure) or complete cerebral ischemia produced by cisterna magna infusion. During oligemia, flow was reduced from 68.4 +/- 4.2 ml/100 gm/min to 26.3 +/- 4.4 (p less than .01), and during ischemia animals had no proven flow. By 5 minutes after oligemia or ischemia significant symmetrical hyperemia occurred and there was no evidence of the no-reflow phenomenon. The electroencephalogram became isoelectric significantly later and returned significantly sooner in oligemia than in ischemia. Oligemic animals had earlier and better return of neurological function than their ischemic counterparts, although postinsult hypocapnia improved functional recovery in both groups. These experiments do not support the concept that oligemia is a more severe insult than complete ischemia. In intracranial hypertension produced by this model, the no-reflow phenomenon does not occur.
D000818:Animals; D000983:Antipyrine; D001345:Autoradiography; D001794:Blood Pressure; D001812:Blood-Brain Barrier; D001921:Brain / Q000098:blood supply*; D002250:Carbon Radioisotopes; D002421:Caudate Nucleus / Q000098:blood supply; D002560:Cerebrovascular Circulation; D003342:Corpus Striatum / Q000098:blood supply; D004569:Electroencephalography; D005625:Frontal Lobe / Q000098:blood supply; D006624:Hippocampus / Q000098:blood supply; D007427:Intracranial Pressure; D007511:Ischemia / Q000150:complications / Q000503:physiopathology*; D010264:Paraplegia / Q000209:etiology; D010296:Parietal Lobe / Q000098:blood supply; D011654:Pulmonary Edema / Q000209:etiology; D011699:Putamen / Q000098:blood supply; D011817:Rabbits; D012021:Reflex, Abnormal / Q000209:etiology; D013997:Time Factors
D002250:Carbon Radioisotopes; D000983:Antipyrine