Etiology Pathology And Clinical Aspects Of Stroke

The incidence and mortality of stroke are high. An estimated 500,000 to 700,000 new cases occur every year. Despite early identification and treatment of risk factors, it remains the third leading cause of death in Western countries. The most disabling neurologic disease of the elderly, stroke commonly affects individuals over 55 years of age, and the incidence increases with advancing age. It is more common among men and among African Americans. Importantly, stroke also occurs among younger subjects, even children, in whom etiologies comprise a broader spectrum.

Stroke presents with a sudden onset and rapid progression of focal neurologic symptoms and signs, culmi nating within minutes or hours—at most within 24 to 48 hours. It results from a sudden alteration of cerebral blood flow in an arterial territory (regional cerebral blood flow, rCBF). This alteration occurs in one of two ways: A reduction of rCBF causes ischemia and eventually an infarction, or B bleeding into the brain parenchyma or into the subarachnoid space causes a massive intracerebral hematoma or a subarachnoid hemorrhage.

Thus, a stroke is either ischemic or hemorrhagic; its pathologic substrate is either an infarct or a hemorrhage.

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