Abstract

Cerebral cortex perfusion rates (CPR) were measured in 11 patients with dementia. In six patients the dementia appeared to be due to a primary neuronal degeneration and in the remainder it appeared to be secondary to vascular disease. In the context of blood flow measurement, it is suggested that the terms primary and secondary dementia are preferable to the terms presenile and senile dementia, because the latter are classified by age alone and the terms have no aetiological or pathological significance. The perfusion rates in patients with primary dementia were within normal limits for their age, whereas those in patients with secondary dementia were significantly reduced. This difference is likely to apply only if the measurements are made early in the course of the disease.