Diagnosis of acute stroke.

Stroke can be categorized as ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. Awakening with or experiencing the abrupt onset of focal neurologic deficits is the hallmark of the diagnosis of ischemic stroke. The most common presenting symptoms of ischemic stroke are speech disturbance and weakness on one-half of the body. The most common conditions that can mimic a stroke are seizure, conversion disorder, migraine headache, and hypoglycemia. Taking a patient history and performing diagnostic studies will usually exclude stroke mimics. Neuroimaging is required to differentiate ischemic stroke from intracerebral hemorrhage, as well as to diagnose entities other than stroke. The choice of neuroimaging depends on availability of the method, the patient's eligibility for thrombolysis, and presence of contraindications. Subarachnoid hemorrhage presents most commonly with sudden onset of a severe headache, and noncontrast head computed tomography is the imaging test of choice. Cerebrospinal fluid inspection for bilirubin is recommended if subarachnoid hemorrhage is suspected in a patient with a normal computed tomography result. Public education about common presenting stroke symptoms may improve patient knowledge and clinical outcomes.