Investigation of the Patient with Ischemic Stroke

Abstract

Evaluation of a patient with recent stroke is divided into studies that confirm the diagnosis of an ischemic event and those that determine the most likely etiology. While clinical manifestations of hemorrhagic and ischemic stroke overlap, imaging studies (computed tomography, CT, or magnetic resonance imaging, MRI) effectively differentiate these disorders. Imaging studies also define the site and extent of the stroke and provide evidence towards its etiology and prognosis. Imaging also detects complications of stroke or therapy including edema, hydrocephalus or hemorrhagic infarction. MRI also detects very acute, small or posterior fossa infarctions that can be missed by CT. MRI can also detect arterial-flow abnormalities. The role of transcranial Doppler or Duplex imaging in acute ischemic stroke has not been defined. While atherosclerosis is the most common cause of cerebral ischemia, a number of diseases present with or are complicated by stroke. Investigation for the etiology of stroke is justified particularly in patients with atypical presentations. Arteriography is warranted in most patients but may, in the future, be replaced by MRI angiography. Specialized hematologic studies for evaluation of hypercoagulable states are indicated. Transthoracic echocardiography can be supplemented by Doppler or contrast techniques. Transesophageal echocardiography effectively visualizes the left atrium and atrial appendage. Ultrafast CT imaging of the heart may add valuable information in screening patients with stroke.