Does tortuosity in cerebral arterioles impair down-autoregulation in hypertensives and elderly normotensives? A hypothesis and computer model.

A mathematical model of pressure/flow relationships in straight and tortuous intracerebral arterioles is presented. Using this model, it is predicted that patients with severe tortuosity would never be able to tolerate an appreciable decrease in MAP. This morphological alteration may explain the inability of a few hypertensive and normotensive elderly patients to tolerate periods of mild reductions in blood pressure. The alkaline phosphatase histochemical staining technique is potentially an excellent method of establishing the identity of deep white matter signal alterations seen on MRI because of its ability to trace the vascular supply from the brain surface to the lesion.