Abstract
Regional cerebral blood flow (CBF) and brain atrophy were studied in 41 stroke patients with or without dementia aged over 65 years. CBF was measured using 133Xe inhalation method at chronic stage (more than one month after the onset), and flow through gray matter (F1) and initial slope index (ISI) was calculated in each cerebral hemisphere. A ratio of maximum width of frontal horn of lateral ventricles and outer table of the skull (FHI), and a ratio of minimum width of cella media and outer table of the skull (CMI) were measured on CT scan. The presence and the degree of dementia was evaluated using Hasegawa's dementia rating scale.
F1 and ISI in the affected hemisphere were 37.1, 31.6 ml/100 g/min in dementia (pre-dementia and dementia), respectively, being significantly lower than 47.7, 37.7 ml/100 g/min in non-dementia (p<0.01, respectively). Such CBF reduction was found in the non-affected hemisphere as well as in the affected one. CMI was 0.248 in dementia, which was significantly greater than 0.217 in non-dementia, although there was no difference of FHI between dementia and non-dementia. F1 in severe dementia was 31.2 ml/100 g/min, being significantly lower than 40.1 ml/100 g/min in moderate dementia (p<0.05), although there were no differences of both FHI and CMI between the two groups. No specific localization of the hypoperfused area was noted in dementia.
Present results suggest that diffuse reduction of CBF is closely related with the development of dementia in stroke patients.
