Impact of white matter hypodensities on outcome after intracerebral hemorrhage

White matter hypodensities (WMH), a surrogate of small vessel disease, associate with cognitive decline and stroke risk. The impact of WMH on functional outcome after intracerebral hemorrhage (ICH) has differed between studies. We aimed to examine factors associated with the severity of WMH in ICH, and whether there is an independent association between the extent of WMH and outcome. This was a prospective study of consented patients with non-traumatic primary ICH, admitted to the Helsinki University Hospital between May 2014 and December 2018. To evaluate the extent of the WMH, modified van Swieten score of the side contralateral to the ICH was obtained. Patients were grouped into 3 categories of the scores. We performed univariate and multivariable analyses to find out factors associated with the severity of WMH, and whether WMH associate with functional outcome and mortality up to 12 months, adjusted for the known major outcome predictors. In our cohort of 417 ICH patients, WMH severity associated with older age, female sex, admission National Institutes of Health Stroke Scale (NIHSS) points, and signs of previous ischemic stroke on CT. We found an independent association between WMH severity and poor functional outcome at 3 months (OR 1.72, 95% CI 1.27-2.33), and 1 year (OR 2.16, 95% CI 1.57-2.95), and mortality at 1 year (OR 1.91, 95% CI 1.29-2.85). In our ICH patients, vascular comorbidities and older age associated with the presence of WMH, which, in turn, strongly associated with poor functional outcome.