Clinical Evaluation and Therapeutic Options in Stroke

Timing and Evolution

In intracerebral hemorrhage patients, symptoms and signs gradually develop over minutes or hours. Improvements and fluctuations do not occur during this time. In aneurysmal subarachnoid hemorrhage, symptoms begin instantaneously. In ischemia, the severity of the decreased perfusion, the ability of collateral circulation to accommodate for blockages, and the vulnerability of various brain structures vary greatly. Arteries bring oxygen, sugar, and other nutrients necessary for survival of the brain. The underperfusion can be temporary, resulting in a focal deficit that lasts only a few minutes; these episodes are referred to as transient ischemic attacks (TIAs). At times the ischemia is sufficient to cause more persistent symptoms and signs but not sufficient to cause brain infarction. Brain tissue is stunned but can recover if the supply of nutrients is restored soon enough. In ischemic patients, the time course varies and can fluctuate with periods of improvement, worsening, and stabilization.

Transient ischemic attacks are very important to recognize. Many studies show that patients with TIAs have a high risk of having a stroke during the succeeding hours and days. TIAs demand urgent diagnosis and management of the cause. TIAs provide a window of opportunity for clinicians to intervene before a stroke happens, and strokes do happen often in patients who have had TIAs. Most TIAs are very brief, lasting minutes and usually less than an hour. Recent magnetic resonance imaging (MRI) studies of patients with clinical TIAs who have no residual symptoms or signs shows that many actually have had brain infarcts—strokes. The distinction between TIAs and strokes is blurred and has been overemphasized in the past. Many clinicians now prefer the term acute ischemic cerebrovascular syndrome, which includes both TIAs and acute strokes. Management depends on the nature, location, and severity of the causative cardiocerebrovascularhematologic cause of the brain ischemia. Finding the cause and treating it is much more important than characterizing the time course.

Therapeutic strategies relate to four different time epochs. Prevention involves strategies of identifying and controlling potential risk factors before a stroke occurs. Strategies during acute ischemia involve reperfusion of the ischemic area and neuroprotection (rendering the ischemic area more resistant to infarction). After a stroke, recovery and rehabilitation are facilitated.

CLINICAL EVALUATION AND TREATMENT OF STROKE

The most important diagnostic information is gained from a thorough history from the patient and sometimes a loved one or a colleague, with subsequent thoughtful vascular and neurologic examinations. The history is directed to answering what (the cause of the condition—the pathology and pathophysiology) and where (brain and vascular location) queries. The neurologic symptoms and signs and vascular examinations yield information about the where question. The differential diagnosis of the what question depends on information from the history about (1) the time and activity at and before the onset of symptoms; (2) the course of the symptoms—transient, gradually progressive, remitting, fluctuating, and so forth; (3) the past and present known medical and surgical conditions, especially hypertension, diabetes, heart disease, smoking, excess alcohol intake, drug use, peripheral vascular disease, and obesity; (4) past strokes; (5) the presence, nature, and timing of any transient ischemic attacks; (6) headache before, at, or after stroke onset; and (7) the occurrence of a seizure, vomiting, or change in level of consciousness.

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