An Experimental Study on the Cerebral Diaschisis in Acute Cerebral Infarction

ABSTRACT

To demonstrate the effect of diaschisis and to evaluate its possible mechanism in acute unilateral infarction, the changes of regional cerebral flows(rCBF's) on the both MCA territories and both cerebellum were measured by the hydrogen clearance method using the unilateral cerebral and cerebellar infarction model. Cerebral infarction model was made by left middle cerebral artery(MCA) occlusion through the transorbital approach and cerebellar infarction was made by coagulation of cerebellar vessels through retromastoid craniectomy. Experimental groups consisted of left MCA occlusion group-12cats, left MCA occlusion with callosal section group-15cats and cerebellar infarction group-13cats. After measurement of rCBF for 8 hours at fixed intervals the animals were sacrificed and immediately thereafter 50ml of 2% triphenyl tetrazolium chloride(TTC) solution was immediately injected in order to examine the size of infarction. The results were as follows ; 1) After occlusion of left MCA, the rCBF of ipsilateral MCA territory decreased abruptly and significantly(p0.05). 3) In the group of cerebellar infarction, the rCBF of contralateral cerebellum and both MCA territories did not decrease significantly in either group of cerebellar blood flow less than 10ml/ 100g/min or 10~20ml/ 100g/min. 4) In the experimental group of left MCA occlusion, infarction revealed 40.2+/-2.8% of coronal plane through the optic chiasm showing high percentage of infarction yield with small standard deviation. In the cerebellar infarction model the extent of infarction was 36.0+/-10.0% of horizontal planes of cerebellum in the group of rCBF below 10ml/100g/min. In the group of rCBF of 10~20ml/100g/min the extent of infarction was 22.0 +/-12.0%. These findings show the crossed cerebellar as well as interhemispheric diaschisis and support the importance of neural pathway in the mechanism of diaschisis. However further studies for long-term results and mechanism of diaschisis are needed.