Regional Cerebral Blood Flow in Cerebrovascular Disorders

Abstract

The majority of cerebrovascular disorders are regional in character. A cerebral thrombosis, an embolus, or a cerebral hemorrhage does not as a rule involve the whole of the brain but only a circumscribed part of it. To study the pathophysiology of these disorders it is therefore a prerequisite that methods for the measurement of regional cerebral blood flow (rCBF) are available. This is a review of some principal findings concerning rCBF in focal cerebrovascular disorders. Multiple simultaneous measurements of regional cerebral blood flow in patients with focal cerebrovascular lesions have revealed new details in the pathophysiology of such disorders. An acute focal occlusive lesion sets up a regional vasodilatation in the surrounding, which can both be seen in the acute phase directly on the angiogram, and measured by means of isotope clearance as a regional hyperemia. In larger lesions an ischemic region with low flow can be actually found, corresponding to an expansive mass shown on the angiogram. In the chronic phase the over-all reduction of the cerebral blood flow gives a measure of the general functional sequelae of the primary focal lesion. These findings would seem to have a general bearing on the problem of focal cerebral ischemia encountered in neurosurgical disorders of traumatic, neoplastic or vascular origin.