CLINICOPATHOLOGICAL OBSERVATIONS IN MIDDLE CEREBRAL-ARTERY OCCLUSION IN THE CAT

This study was designed to investigate the relationships among neurolo gical deficits, changes in the electroencephalogram (EEG) and morpholo gical damage over a one week period following temporary occlusion (2 h ) of the middle cerebral artery (MCA) in the cat. The animals were gro uped into mild, moderate, and severe stroke based on the EEC alteratio ns produced 30 min after the MCA occlusion. All three grades of stroke showed a precipitous fall in mean EEC amplitude followed by a recover y during a 4h recirculation period. Over the subsequent 7 days there w as a gradual secondary depression in the EEC amplitude. Post-operative ly, a secondary fall in EEC amplitude in the contralateral hemisphere was also noted in all stroke groups corresponding to the clinical phen omenon of 'diaschisis'. The overall neurological score differed signif icantly among the severe, moderate, and mild stroke groups. The neurol ogical deficits on the 7th day were highly correlated with the degree of morphological damage. Additionally, the reduction of EEC was also w ell correlated with the pathological data. This stroke model in the ca t has provided important data concerning the restitution of brain func tion following chronic focal ischaemia.