Stroke
This chapter focuses on the primary causes and preventions of stroke. Ischemic stroke occurs when a localized area in the nervous system is deprived of glucose and oxygen because of inadequate cerebral blood flow. The severity of injury is a function of how much the blood flow has been reduced and for how long. In most cases, strokes can be diagnosed purely on the basis of the history and examination. After a stroke occurs, it will continue to manifest as a region of impeded diffusion (also referred to as “restricted diffusion”) on MRI for about two weeks, but MRI scans are unnecessary when the history and examination provide compelling evidence of a stroke and the mechanism of stroke is apparent. Some studies have shown that early rehabilitation allows stroke patients to recover more quickly and perhaps to a higher level of function. Stroke prevention will continue to be the cornerstone of stroke management. Primary prevention is directed toward the early recognition and treatment of risk factors that predispose to the development of cerebrovascular disease.