Stroke Stroke is characterized by the sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. Strokes are classified as either hemorrhagic or ischemic. Acute ischemic stroke refers to stroke caused by thrombosis or embolism and is more common than hemorrhagic stroke. Signs and symptoms Although signs and symptoms of stroke can occur alone, they are more likely to occur in combination. Common stroke signs and symptoms include the following: • Abrupt onset of hemi paresis, mono paresis, or quadric paresis • Acute hemi sensory loss • Complete or partial hemianopia, monocular or binocular visual loss, or diplopia • Visual field deficits • Diplopia • Dysarthria • Ataxia • Vertigo • Nystagmus • Aphasia • Sudden decrease in the level of consciousness In younger patients, a history of recent trauma, coagulopathies, illicit drug use (especially cocaine), migraines, or use of oral contraceptives should be elicited. Diagnosis With the availability of thrombolytic therapy for acute ischemic stroke in selected patients, the physician must be able to perform a brief, but accurate, neurologic examination on patients with suspected stroke syndromes. Essential components of the neurologic examination include evaluations of the following: • Cranial nerves • Motor function • Sensory function • Cerebellar function • Gait • Deep tendon reflexes • Mental status • level of consciousness The patient’s skull and spine also should be examined, and signs of meningismus should be sought. Laboratory studies Laboratory tests performed in the diagnosis and evaluation of ischemic stroke include the following: • Complete blood cell count: The CBC count serves as a baseline study and may reveal a cause for the stroke (eg, polycythemia, thrombocytosis, thrombocytopenia, leukemia) or provide evidence of concurrent illness (eg, anemia) • Basic chemistry panel: The chemistry panel serves as a baseline study and may reveal a stroke mimic (eg, hypoglycemia, hyponatremia) or provide evidence of concurrent illness (eg, diabetes, renal insufficiency) • Coagulation studies: Coagulation studies may reveal a coagulopathy and are useful when thrombolytics or anticoagulants are to be used • Cardiac biomarkers: Cardiac biomarkers are important because of the association of cerebral vascular disease and coronary artery disease • Toxicology screening: Toxicology screening may assist in identifying intoxicated patients with symptoms/behavior mimicking stroke syndromes • Pregnancy testing: A urine pregnancy test should be obtained for all women of childbearing age with stroke symptoms; recombinant tissue-type plasminogen activator (rt-PA) is a pregnancy class C agent • Arterial blood gas analysis: Although infrequent in patients with suspected hypoxemia, arterial blood gas defines the severity of hypoxemia and may be used to detect acid-base disturbances Imaging studies Imaging in ischemic stroke can involve the following modalities: • Several types of magnetic resonance imaging • Several types of computed tomography scanning • Angiography • Ultrasonography • Radiology • Echocardiography • Nuclear imaging Lumbar puncture A lumbar puncture is required to rule out meningitis or subarachnoid hemorrhage when the CT scan is negative but the clinical suspicion remains high Management Ischemic stroke therapies include the following: • Thrombolytic therapy: Thrombolytics restore cerebral blood flow among some patients with acute ischemic stroke and may lead to improvement or resolution of neurologic deficits • Antiplatelet agents: The International Stroke Trial and the Chinese Acute Stroke Trial (CAST) demonstrated modest benefit from the use of aspirin in the setting of acute ischemic stroke • Mechanical thrombolysis: Involves the endovascular treatment of acute ischemic stroke Stroke prevention Primary stroke prevention refers to the treatment of individuals with no previous history of stroke. Measures may include use of the following: • Platelet antiaggregants • 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (ie, statins) • Exercise Secondary prevention refers to the treatment of individuals who have already had a stroke. Measures may include use of the following: • Platelet antiaggregants • Antihypertensives • HMG-CoA reductase inhibitors (statins) • Lifestyle interventions
Posted on: Sat, 28 Sep 2013 06:44:41 +0000
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