Clinical and imaging outcomes after stroke with normal angiograms

BACKGROUND AND PURPOSE: Information about the prognosis of patients with acute ischemic stroke and normal angiography is limited. We report clinical and imaging outcomes of patients seen within 6 hours of symptom onset who were considered candidates for thrombolysis. METHODS: Between November 1994 and December 1999, patients with stroke onset of less than 6 hours who were thrombolytic candidates underwent cerebral angiography. Patients with normal angiograms (defined as no sign of occlusive disease in the head or neck in the symptomatic artery) were included. Admission National Institutes of Health Stroke Scale (NIHSS) scores and discharge modified Rankin scores (mRS) were obtained. CT or MR images were obtained 24 hours or longer after symptom onset. Good outcome was defined as an mRS score < or =2. For analysis, follow-up CT or MR imaging findings were classified as showing cortical infarct, subcortical infarct > or =1.5 cm, subcortical infarct < or =1.5 cm, or no new infarct. The mechanism of the normal angiogram was assumed on the basis of these results. RESULTS: Twenty-one patients with stroke had normal angiograms. About 43% (9/21) of the patients had a favorable hospital discharge clinical outcome, and an additional 33% (7/21) had favorable clinical outcomes at subsequent follow-up. New infarct on follow-up imaging was seen in 71% (15/21). Discharge mRS scores were not correlated with admission NIHSS scores or the mechanism of the normal angiogram. CONCLUSION: Approximately 76% of acute stroke patients with normal angiograms have a favorable clinical outcome, and 71% have associated new infarctions. Given these outcomes, further study is needed before recommendations regarding thrombolytic treatment can be made in this population.