Severity of leukoaraiosis correlates with clinical outcome after ischemic stroke

Abstract

Background: Leukoaraiosis (LA) is closely associated with aging, a major determinant of clinical outcome after ischemic stroke. In this study we sought to identify whether LA, independent of advancing age, affects outcome after acute ischemic stroke.

Methods: LA volume was quantified in 240 patients with ischemic stroke and MRI within 24 hours of symptom onset. We explored the relationship between LA volume at admission and clinical outcome at 6 months, as assessed by the modified Rankin Scale (mRS). An ordinal logistic regression model was developed to analyze the independent effect of LA volume on clinical outcome.

Results: Bivariate analyses showed a significant correlation between LA volume and mRS at 6 months (r = 0.19, p = 0.003). Mean mRS was 1.7 +/- 1.8 among those in the lowest (< or =1.2 mL) and 2.5 +/- 1.9 in the highest (>9.9 mL) quartiles of LA volume (p = 0.01). The unfavorable prognostic effect of LA volume on clinical outcome was retained in the multivariable model (p = 0.002), which included age, gender, stroke risk factors (hypertension, diabetes mellitus, atrial fibrillation), previous history of brain infarction, admission plasma glucose level, admission NIH Stroke Scale score, IV rtPA treatment, and acute infarct volume on MRI as covariates.

Conclusions: The volume of leukoaraiosis is a predictor of clinical outcome after ischemic stroke and this relationship persists after adjustment for important prognostic factors including age, initial stroke severity, and infarct volume.

Figure 1 Example of infarct and leukoaraiosis (LA) volume assessment Diffusion-weighted imaging (DWI) (A) obtained at 18 hours after symptom onset shows an acute ischemic lesion consistent with right middle cerebral artery branch occlusion. The signal in regions corresponding to the DWI lesion appears to be increased on fluid-attenuated inversion recovery images as well (B), acquired at the same session with DWI. Despite partial obscuration of the boundaries of LA by the ischemic lesion signal, it is still possible to distinguish them by differences in signal intensities and with guidance by DWI.

Figure 2 Ranges of modified Rankin Scale are shown for each leukoaraiosis (LA) volume quartile (n = 60) The results are not adjusted for potential covariates.