Acute stroke, a sudden neurologic deficit of presumed vascular origin, is a treatable condition that requires accurate diagnosis and early management. After subarachnoid hemorrhage has been ruled out, two types of stroke remain. Ischemia secondary to atherothrombotic occlusion or an embolism accounts for 85 percent of episodes, and primary hemorrhage accounts for 15 percent. Hemorrhage causes neuronal injury, and the pressure effect causes adjacent ischemia. Ischemic injury may be reversible if reperfusion is obtained quickly. Bath and Lees reviewed the evaluation and management of patients with stroke.
Symptoms and signs of acute stroke are listed in the accompanying table. Patients with stroke should be assessed immediately at a hospital because treatments such as thrombolysis must be administered within as little as three hours after stroke. Brain imaging distinguishes ischemia from primary intracranial hemorrhage. The table also illustrates how the pattern of neurologic signs can help distinguish subtypes of stroke. If the neurologic symptoms resolve within 24 hours, the diagnosis of transient ischemic attack rather than stroke, is made. Because many transient ischemic attacks are associated with permanent cerebral damage, a better label would be ministroke.
Because in the early hours of cerebral ischemia part of the brain may die, continued oxygenation and certain hemodynamic and metabolic factors are essential for successful treatment. Emergency management includes stabilization and assessment of factors that may lead to complications (such as dysphagia or dehydration). Dysphagia affects 35 percent of stroke patients and predisposes to aspiration and pneumonia. The presence of a gag reflex is not adequate evaluation of safe swallowing; more formal evaluation is necessary. Dysphagic patients should be fed through a nasogastric tube or a percutaneous endoscopic feeding tube until it is determined that they can safely swallow. Most dysphagic patients do not need enteral feedings beyond a few weeks.
|Anterior circulation strokes|
|Unilateral sensory loss or inattention|
|Posterior circulation strokes|
|Isolated homonymous hemianopia|
|Diplopia and disconjugate movement of eyes|
|Nausea and vomiting|
|Incoordination and unsteadiness|
|Unilateral or bilateral weakness and/or sensory loss|
|Loss of consciousness|
Computed tomography distinguishes between ischemic and hemorrhagic stroke and identifies any condition that may mimic stroke. Magnetic resonance imaging, when available, provides additional information about blood flow and brain perfusion, age of lesions and presence of carotid stenosis. Some conditions that can mimic stroke include the following: cerebral neoplasm, subdural hematoma, epileptic seizure, traumatic brain injury, migraine, multiple sclerosis and cerebral abscess. Other useful diagnostic tests include electrocardiography, chest radiography, complete blood count, clotting screen and determination of electrolyte and creatinine concentrations. Additional investigations, such as carotid scanning, echocardiography, lower-extremity deep venous system evaluation, immunology screen and syphilis testing are useful in individual cases.
Aspirin therapy has been used in early stroke but has a minimal effect on subsequent disability and death. Heparin therapy may be useful in certain patients, but its general efficacy, even in patients with presumed embolic stroke, is uncertain. Thrombolysis, within three hours of stroke onset, significantly increases the chance of a nearly complete recovery when administered by trained staff. Treatment within up to six hours of stroke onset is less effective. Patients need to be carefully chosen for early thrombolytic therapy because of safety concerns. Neuroprotectant drugs have shown no benefit to date. Patients with large cerebellar infarct or hemorrhage should have early neurosurgical evaluation to consider evacuation of the clot or infarct or shunting for acute hydrocephalus if appropriate.
Hyperglycemia, fever and hypertension are associated with poor stroke prognosis. Glucose levels should be normalized, and acetaminophen used for fever. Hypertension should not be treated aggressively in the first week because of the risk of reducing cerebral blood flow. Rehabilitation should be started early to help restore function.
The authors conclude that early stroke evaluation and management can help reduce mortality and morbidity, but more research is needed to clarify appropriate interventions.