Cerebral hemodynamics in cerebrovascular dementia

To investigate the correlation between cerebral hemodynamic responses and CT lesions in cerebral infarction at the chronic stage, the regional cerebral blood flow (rCBF) was studied in patients suffering from cerebral infarction with mental deterioration (38 cases) and patients with chronic cerebrovascular disease without mental deterioration (CVD, 58 cases). Following intra-carotid injection of Xenon-133, rCBF was calculated according to Initial Slope Index (ISI). These 38 demented patients were all found to fall in the category of cerebrovascular dementia by means of evaluating them with Hasegawa's score and Loeb's modified ischemic score (added X-ray CT findings). They were classified into two subgroups, single infarct dementia (SID, No.=15) and multiple infarcts dementia (MID, No.=23) on the basis of X-ray CT lesion. With regard to the distribution of CT lesions in SID most of the lesions were located in the left parieto-temporal area and in MID most of them in the anterior half of the basal ganglia. The mean rCBF was compared between age matched groups of CVD without dementia and the two subgroups of SID and MID. The results obtained were as follows. 1) In both SID and MID patients, reduction of mean rCBF was below 30ml/100g brain/minute in most cases. Oxygen consumption (CMR-O2) was also reduced. 2) The response to 5% CO2 inhalation was decreased in MID. 3) Most cases (66%) of SID and MID showed no focal ischemic pattern. There was no specific rCBF pattern in MID. Left and right mean rCBF values were different in SID, but not in MID. 4) There was a significant correlation between Hasegawa's score and mean rCBF in MID (p