Cerebrovascular disease. Pathophysiology and diagnosis.

Cerebrovascular disease is a heterogeneous group of disorders which are set apart from one another by their unique pathophysiologic mechanisms and clinical manifestations. When classified in this manner, stroke is divided into two major categories: hemorrhagic stroke--which results from rupture of a cerebral blood vessel into the subarachnoid space (subarachnoid hemorrhage) or brain parenchyma (intraparenchymal hemorrhage); and ischemic stroke--which results from occlusion of a cerebral artery due to degenerative vessel wall disease (atherosclerosis or lipohyalinosis) or emboli. Early recognition of the specific stroke types promises to lead to more effective diagnosis and treatment of cerebrovascular disease.