Stroke syndromes present clinically as neurologic deficits of sudden onset. Symptoms depend upon the affected region of brain, which in turn is defined by the arterial anatomy involved. Although some features are more or less typical of hemorrhagic forms of stroke, as distinct from ischemic stroke, none are sufficiently discriminatory to allow clinical diagnosis of stroke type. Therefore, brain and neurovascular imaging in the acute phase is required for all strokes. Common symptoms of stroke in the left hemisphere include aphasia, right hemiparesis and right hemianopia, and in the right hemisphere, left hemispatial neglect, left hemiparesis and left hemianopia. The majority (90%) of strokes are supratentorial; as such, the public can be taught to recognize and act upon stroke using the acronym FAST, for facial droop, arm drop, speech disturbance and time. Posterior circulation or infratentorial stroke has a multitude of additional symptoms, including diplopia, bulbar palsies, dysphagia, unilateral dysmetria and incoordination, as well as reduced levels of consciousness. Although headache or head, facial or neck pain may be an ancillary symptom, stroke is typically painless. The most important historical feature of stroke is the suddenness of its onset.

Identification of a stroke syndrome is relatively easy: sudden onset of acute neurologic symptoms, peaking within a few minutes, is deemed a stroke until proven otherwise. However, detailed diagnosis and management are highly dependent upon clinical assessment of the history and physical examination, because symp-