Duplex sonography in patients with hemispheric symptoms

Many patients with hemispheric neurologic symptoms do not have operative stenoses of the extracranial carotid arteries. In order to assess the frequency of such atherosclerotic lesions, 154 patients with documented hemispheric events underwent duplex Doppler examinations of the extracranial carotid bifurcation to assess if operative stenosis (70% to 80% stenosis) was present. Seventy-two patients with transient ischemic attacks (TIA), 62 patients with cerebrovascular accidents (CVA), and 20 patients with amaurosis fugax (AF) were studied. Sixty-nine percent of patients with TIAs demonstrated a less than 50% stenosis, 52% of patients with CVAs demonstrated a less than 50% stenosis, and 65% of patients with AF demonstrated a less than 50% stenosis on duplex Doppler examination. Intra-arterial digital subtraction angiography (IADSA) was performed in 35 of 154 patients. In all of these 35 cases, ultrasound and angiographic studies agreed with respect to whether or not a greater than 50% stenosis was present. Our findings support the use of duplex Doppler sonography as a triage procedure in patients with hemispheric events in order to determine those patients who have significant carotid stenoses and who may be potential operative candidates.