White matter hyperintensity determines ischemic stroke severity in symptomatic carotid artery stenosis

Introduction: The aim of this study is to investigate the influence of white matter hyperintensity (WMH) on stroke severity and prognosis in patients with symptomatic carotid artery stenosis. Methods: Patients with symptomatic carotid artery stenosis were retrieved from the Samsung Medical Center stroke registry from January 2011 to December 2016. Stroke severity was categorized into three levels according to National Institutes of Health Stroke Scale (NIHSS): transient ischemic attack (TIA) or transient symptoms with infarction (TSI), mild stroke, and moderate to severe stroke. WMH volume was measured with medical image processing and visualization. The clinical outcome was assessed using the modified Rankin scale on the 90th day from which the latest onset of the neurological symptom. Logistic regression was used to predict stroke severity, and ordinal regression was used to compare the clinical outcome. Results: Among 158 patients, the numbers of patients with TIA or TSI, mild stroke, and moderate to severe stroke were 48 (30.4%), 59 (37.3%), and 51 (32.3%), respectively. The larger WMH volume was associated with moderate to severe strokes (TIA/TSI vs. moderate to severe strokes, odds ratio (OR) 2.318, 95% confidence interval (CI) 1.194–4.502, p = 0.007; mild vs. moderate to severe strokes, OR 1.972, 95% CI 1.118–3.479, p = 0.013). Patients with larger volume of WMH showed poorer clinical outcome (cutoff value: 9.71 cm³, OR 2.099, 95% CI 1.030–4.311, p = 0.042). Conclusion: Our study showed that larger WMH volume is associated with more severe stroke and poorer prognosis in patients with symptomatic carotid artery stenosis.