Stroke, also called a cerebrovascular accident (CVA), is the disruption of blood flow to the brain, resulting in neurological impairment. In the United States, it is the third most common cause of death and the most common cause of permanent disability. The consequences of stroke emphasize the importance of quick and immediate intervention.
Pathophysiology
A stroke can happen in one of several ways. It can be a thrombotic stroke in which an atherosclerotic plaque in a cerebral artery ruptures and platelets clump at the site, obstructing blood flow. It can also be an embolic stroke in which material from elsewhere, such as a blood clot from the heart, travels to and lodges in the brain circulation. A third type of stroke with a different mechanism is hemorrhagic stroke in which a blood vessel bleeds into the brain and exerts pressure on surrounding tissues, interrupting blood flow in this manner.
Neural tissue is very sensitive to oxygen deprivation. Brain tissue death (infarction) can result if enough time elapses. Restoring blood flow as soon as possible is critical in managing a stroke..
Diagnosis
Clinical manifestations of a stroke depend on what part of the brain is affected. Through a patient history and a physical examination, a physician determines what neurological abnormalities are present, including but not limited to paralysis of the extremities, facial palsy, visual disturbances, and impaired communication. In addition, the approximate time the symptoms started is important because treatment is determined by how much time has passed since the onset of stroke.
When a stroke patient arrives at the emergency department, a battery of tests is performed. Two tests are worth mentioning. Computed tomography (CT) of the brain determines if the stroke is hemorrhagic, and coagulation studies determine if the blood is too thin. Information from clinical studies determines the appropriate treatment.
Treatment
Supportive measures, such as blood pressure control, are carried out with any type of stroke. If the stroke is ischemic or embolic, the coagulation studies are not significantly abnormal, and less than three hours have passed since the onset of stroke, then tissue plasminogen activator (tPA) can be administered to break up the obstructing clot; tPA is less likely to benefit the patient beyond three hours. For hemorrhagic stroke, intervention by a neurosurgeon is determined on a case-by-case basis.
Final Words
The preceding is an overview of the events leading up to the treatment of stroke. In reality, the condition and its management are complex and require coordination for best results.
