Frequency and Clinical Significance of Acute Bilateral Cerebellar Infarcts

Abstract

Background: Unlike acute unilateral cerebellar infarct (UCI), acute bilateral cerebellar infarcts (BCI) have attracted little attention. To evaluate the clinical significance of BCI, we compared UCI and BCI and analyzed potentially prognostic factors. Methods: Patients who were consecutively admitted at a university hospital over a 4-year period with acute cerebellar infarcts, proven by diffusion-weighted imaging, were studied. Cerebellar infarcts were topographically classified, and divided into 2 groups: UCI and BCI. The demographics, involved territories, concomitant lesions outside the cerebellum (CLOC), bilateral involvement, infarct volume, hospital courses, and mechanisms were analyzed. We performed multiple regression analysis to predict the poor outcome at discharge [≧3 on the modified Rankin Scale (mRS)]. Results: Among 162 patients with acute cerebellar infarcts, 31% (n = 50) were BCI. Territorial infarcts were 74% (n = 120) and non-territorial infarcts 26% (n = 42) of the total. Posterior inferior cerebellar artery infarcts were the most common, and combined-territorial infarcts were the rarest. Baseline demographics were not significantly different between UCI and BCI, except for initial stroke severity (modified NIH Stroke Scale and infarct volume) and diabetes. Large-artery atherosclerosis was significantly higher in BCI, whereas undetermined causes were higher in UCI (p = 0.028). By multiple regression analysis, BCI was the only independent radiological factor for poor prognosis (odds ratio, 6.96; 95% CI, 1.80–26.92), and represented a significantly more unstable hospital course, longer hospital stay, worse mRS at discharge, and higher mortality. Conclusions: In acute cerebellar infarcts, bilateral involvement is common and appears to be a superior determinant for early prognosis rather than territories involved or CLOC.