The relationship between the electrical activity of the brain and the development of cerebral infarction
using the thalamic infarction model in the dog
1981 Volume 3 Issue 3 Pages 293-301
Details
1981 Volume 3 Issue 3 Pages 293-301
Changes in the electrical activity of the brain were studied for 7 days following 30 min, 1 hr or 2 hr occlusion of blood flow, using the thalamic infarction model in the dog which was produced by means of simultaneous occlusion of middle cerebral artery, internal carotid artery, anterior cerebral artery and distal portion of posterior communicating artery.
Discussion is made of the relationship between thalamus EEG changes and the histological findings obtained at autopsy on the 7th day with regard to the development of cerebral infarction.
1) All 2 animals which had undergone 30 min vascular occlusion showed, subsequent to release of occlusion, rapid return of fast wave components which had disappeared during occlusion. On the third day, the presence of mildly slow waves was seen, but these disappeared by the 5th day and electrical activity similar to the preoperative state was seen on the 7th day. Histologically, either no signs of infarction or extremely mild signs were seen.
2) Among the animals undergoing 1 hr occlusion, 2 patterns were observed : one in which recovery to a preoperative state occured, and one in which ultimately complete flattening of electrical activity occures. In both groups, slow waves in the 3 Hz region were predominant until the 3rd day, but on th 5th day 2 animals exhibited fast wave components and nearly complete recovery by the 7th day. Histologically, small infarctic foci were found. The second group showed no fast wave components on th 5th day, and in the 1 dog which then showed slow wave components, complete flattening occurred by the 7th day. Infarciec foci were found to cover 1/2 of the thalamus.
3) In the animals undergoing 2 hr occlusion, there was slight slow waves apparent until the 3rd day, but thereafter until the 7th day, complete flattening occurred. Large infarctic foci were seen throughout the thalamus in all of these dogs.
From the above findings, it was concluded that sequential changes in thalamic electrical activity closely correlate with histological findings.
