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General Considerations
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Stroke is a cerebrovascular disorder resulting from impairment of cerebral blood supply by occlusion (eg, by thrombi or emboli) or hemorrhage. It is characterized by the abrupt onset of focal neurologic deficits. The clinical manifestation depends on the area of the brain served by the involved blood vessel. Stroke is the most common serious neurologic disorder in adults and occurs most frequently after age 60 years. The mortality rate is 40% within the first month, and 50% of patients who survive will require long-term special care.
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Ischemic strokes, comprising thrombotic, embolic, and lacunar occlusions, account for over 80% of all strokes and result in cerebral ischemia or infarction. A variety of disorders of blood, blood vessels, and heart can cause occlusive strokes, but the most common by far are atherosclerotic disease (especially of the carotid and vertebrobasilar arteries) and cardiac abnormalities.
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Essentials of Diagnosis
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- Secondary to thrombosis or embolism
- Consider in acute neurologic deficit (focal or global) or altered level of consciousness
- No historical feature distinguishes ischemic from intracerebral hemorrhagic stroke, although headache, nausea and vomiting, and altered level of consciousness are more common in intracerebral hemorrhagic stroke
- Abrupt onset of hemiparesis, monoparesis, or quadriparesis; dysarthria, ataxia, vertigo; monocular or binocular visual loss, visual field deficits, diplopia
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Stabilize Ventilation
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Assess adequacy of airway and ventilation in all stroke patients, especially in the presence of depressed level of consciousness, absent gag reflex, respiratory difficulty, or difficulty managing secretions.
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Patients with inadequate ventilation (respiratory acidosis) or difficulty managing secretions will require intubation.
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Search for Head Trauma
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Stroke patients may sustain head injury due to incoordination or weakness. Conversely, patients with focal neurologic findings due to head trauma may be mistakenly diagnosed as suffering from stroke. If head injury is suspected from the history or clinical findings, immobilize the cervical spine. Refer to Chapter 22 for management.
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Deterioration of neurologic status or the presence of brain-stem involvement (depressed sensorium, pupillary or extraocular movement abnormality, decorticate or decerebrate posturing) suggests significant cerebral edema and impending herniation. Mannitol 20% 0.5–1.5 g/kg hourly or 23.4% hypertonic saline solution 0.5–2.0 ml/kg, maintaining the head of the bed at greater than a 30° angle are medical therapies for elevated intracranial pressure associated with cerebral edema from ischemic stroke. However, medical therapy for cerebral edema associated with ischemic stroke does not appear to alter the patient's outcome.
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(See Chapter 19 for management of seizures.) Consider prophylaxis for seizure. Give intravenous phenytoin, 15–18 mg/kg at a rate not greater than 50 mg/min, ...