CEREBRAL BLOOD-FLOW IN HYPERTENSIVE PATIENTS - AN INITIAL REPORT OF REDUCED AND COMPENSATORY BLOOD-FLOW RESPONSES DURING PERFORMANCE OF 2 COGNITIVE TASKS

We asked whether the altered cerebral vasculature associated with esse ntial hypertension might dampen or redirect the regional cerebral bloo d flow (rCBF) response to cognitive work. Relative rCBF was assessed w ith [O-15]water positron emission tomography during a working memory t ask, a memory span task, and two perceptual control tasks. Unmedicated hypertensive patients and control subjects differed in rCBF response during both memory tasks. Hypertensives showed relatively diminished r CBF responses in right hemisphere areas combined with compensatory act ivation of homologous areas in the left cerebral cortex. Essential hyp ertension appears to selectively influence the circulatory reserve of portions of cerebral cortex and secondarily induce recruitment of othe r cortical areas to process certain tasks.