Introduction: Extensive forms of white matter hyperintensity (WMH) are a consequence of and indicative for advanced cerebral small vessel disease, and thus are reportedly associated with higher risks for stroke, dementia, and mortality. Our aim was to analyze impact of WMH on severity and outcome in patients with acute ischemic and hemorrhagic stroke using data from a nationwide stroke registration.
Methods: We studied patients hospitalized with acute stroke in 103 participating centers of the Japan Stroke Data Bank from 2001 to 2015. Deep WMH was evaluated with magnetic resonance imaging (MRI) and classified with Fazekas grade. We examined associations of WMH with National Institutes of Health Stroke Scale (NIHSS) on admission and poor outcome (modified Rankin Scale of 3 - 6) at discharge using multivariable models.
Results: We studied a total of 28,469 patients with MRI imformation. In patients with ischemic stroke (n = 24,591; women, 40%; and age, 72.5±12.1 years), median NIHSS was 4 (interquartile range [IQR] 2-9); and 10,073 (41%) had poor outcome. WMH grades of 0, 1, 2, and 3 were observed in 23%, 45%, 25%, and 6%, respectively. In multivariate analysis adjusted by age and sex, WMH grade was independently related to higher admission NIHSS (incidence rate ratio [IRR] of grade 3 versus 0, 1.33; 95% confidence interval [CI], 1.30-1.35, P for trend <0.001). In multivariate analysis adjusted by age, sex, and admission NIHSS, WMH grade was related to poor outcome (odds ratio [OR] of grade 3 versus 0, 3.08; 95% CI 2.63-3.60; P for trend <0.001). In patients with intracerebral hemorrhage (n = 3,878; women, 42%; and age, 66.9±14.2), median NIHSS was 10 (IQR 4-20); and 2,393 (62%) had poor outcome. WMH grade of 0, 1, 2 and 3 were observed in 28%, 43%, 22%, and 7%, respectively. In multivariate analysis adjusted by age and sex, WMH was independently related to higher NIHSS (IRR of grade 3 versus 0, 1.35; 95%CI, 1.30-1.40). In multivariate analysis adjusted by age, sex, and admission NIHSS, WMH grade was related to poor outcome (OR of grade 3 versus 0, 1.99; 95% CI 1.28-3.11; P for trend <0.001).
Conclusions: Extensive forms of WMH influenced on severity and outcome in both acute ischemic stroke and intracerebral hemorrhage in a nationwide hospital-based patient cohort.