Giralt-Steinhauer E, et al. - Researchers ascertained if brainstem white matter hyperintensities (B-WMH) affect clinical outcome after acute ischemic stroke (AIS) or transient ischemic attack (TIA). For this analysis, B-WMH were assessed in three hundred thirteen prospectively identified patients with AIS/TIA and registered as absent or present based on magnetic resonance imaging evidence. Findings revealed that brainstem white matter hyperintensities were an independent predictor of poor outcome after AIS/TIA and this association persists after adjustment for important prognostic factors. In addition, leukoaraiosis in this location identifies patients with a specific risk factor profile, suggesting differences in the underlying pathogenesis.