Abstract TP220: Volume of White Matter Disease Prior to Ischemic Stroke may Predict Outcome

Abstract

Background: White matter disease (WMD) and microhemorrhages (MH) present at the time of stroke have been linked to outcome, yet few have investigated changes in the time leading up to stroke. Magnetic Resonance Imaging (MRI) characteristics before a stroke may shed light on the severity of outcomes following stroke. Methods: We retrospectively identified patients admitted to our institution for ischemic stroke between 5/16-12/17 who had an MRI in the 1-24 months prior to their stroke. After collecting clinical and demographic data, automatic segmentations of gray and white matter volumes and manual segmentation of WMD and MH (size<10mm) were completed using 3D Slicer 4.5 and 4.9, respectively. Groups were created based on modified Rankin Scale score (mRS) at 90 days; an mRS of 3-6 was considered a poor outcome. Univariate analyses and multivariate regression models were performed to determine factors associated with poor outcome. Results: Among the 48 patients in our study (mean age 68, 50% female), 29 patients (60%) had poor outcome. Poor outcome was associated with pre-existing WMD volume (21.9+/-23.6 vs 6.1+/-5.7mL, p= 0.002), and WMD volume at time of stroke (26.4+/-24.9 vs 8.8+/-6.0mL, p=0.001). There was a trend towards poor outcome in older patients (p=0.073), women (p=0.075), higher NIHSS score (p=0.066), and need for thrombectomy (p=0.065). History of prior stroke was not associated with poor outcome (p=0.74), larger pre-existing WMD volumes (14.3+/-19.3 vs 19.5+/-22.6mL, p=0.47) or larger WMD volumes at time of stroke (18.7±22.5 vs 21.5±18.8mL, p=0.67). After adjusting for confounders, pre-existing WMD volume showed a trend to predict poor outcome (adjusted OR 1.086 per one point increase, 95% CI 0.987-1.195, p=0.09), as did WMD volume at the time of stroke (adjusted OR 1.103 per one point increase, 95% CI 0.992-1.226, p=0.07). Conclusions: Greater volume of WMD at time of and prior to admission for stroke may be independent predictors of poor outcome. These results should be validated in subsequent studies.