Vascular Dementia: A Cognitive SPET-CBF Activation Study

Objective: We investigated the pattern of regional cerebral blood flow (rCBF) responses to a cognitive task in vascular patients with and without dementia. Method: We studied 8 controls and 18 vascular patients by quantitative rCBF assessed by 133 Xe inhalation method and SPET, both at rest and during a cognitive figure recognition task. Eight were mildly demented and 10 were nondemented vascular patients. According to their task performance, 12 patients were classified as ‘good performers’ (GPs) and 6 patients as ‘poor performers’ (PPs). Results: Vascular patients activated a larger number of brain areas than controls. No differences were observed between controls, nondemented and mildly demented patients in the pattern of rCBF activation. GPs presented a lower mean percentage of rCBF increase than either controls or PPs. GPs had lower values than PPs in the left temporal, parietal and occipital regions and in the right posterior cingulate and occipital regions. Conclusions: These data suggest that vascular patients may functionally compensate for vascular damage by activating more brain areas than controls do and, consequently, by increasing the rate of regional activation.