What does the evidence suggest should be thediagnostic workup for suspected ischemic stroke?

On arrival in the hospital, the patient should be medically stabilized and then evaluated with a noncontrast computed tomography (CT) scan of the head as soon as possible. Noncontrast CT helps to distinguish between an acute ischemic stroke and hemorrhagic stroke and largely rules out structural causes. As the management of these entities is completely different, it is important that the study should be performed without delay, as successful salvage of brain tissue and function by thrombolysis and reperfusion of an infarcted region is time sensitive: “time is brain.” If the patient is within the 4.5-hour time window and the ischemic stroke is severe, then thrombolytic therapy should be strongly considered, although one should realize that the risk of hemorrhagic conversion increases with increasing size of the ischemic lesion. Any evidence of acute intracranial hemorrhage is an absolute contraindication to thrombolytic therapy.

There is much controversy about noncontrast CT versus magnetic resonance imaging (MRI) for the initial assessment of patients with suspected ischemic stroke. Some studies suggest that CT is more sensitive than MRI for detecting acute intracranial hemorrhage, whereas others suggest that MRI may be equally sensitive.9,10 However, MRI is considered superior to CT for detecting chronic hemorrhage and detailed pathologic information.9’10 In practice, CT has become the standard of care in the initial triage of suspected stroke patients because it is readily available in most emergency rooms and is inexpensive.

Bottom line: In practice, noncontrast CT is performed almost solely for the purpose of ruling out a bleed, as its sensitivity for detecting ischemic CVA, particularly in the first 24 hours, is poor.

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