Diffusion-weighted imaging–positive lesions may be associated with greater cerebral small vessel disease burden and worse functional outcomes at 6 months among patients with acute intracerebral hemorrhage, according to a prospective cohort study.

Investigators analyzed 342 consecutive adult patients with imaging-confirmed intracerebral hemorrhage (ICH) enrolled in the Stroke Investigation Group in North and Central London registry from January 2017 to January 2020. Eligible patients underwent diagnostic-quality magnetic resonance imaging (MRI) within 90 days of emergency admission. Patients without diagnostic-quality MRI, with isolated intraventricular or subarachnoid hemorrhage, or with secondary causes of ICH were excluded.

MRI was performed a median of 4 days following acute ICH. The investigators identified diffusion-weighted imaging (DWI)-positive lesions outside a 1-cm perimeter surrounding the hematoma and excluded those at the hematoma margin considered likely to represent ICH-related acute tissue injury.

The primary outcome was functional disability at 6 months, assessed using the modified Rankin Scale. Scores of 0 to 2 represented functional independence, whereas scores of 3 to 6 represented dependence or mortality. Multivariable logistic regression was used to identify factors independently associated with DWI-positive lesions and poor 6-month functional outcome. Variable selection was performed using the Least Absolute Shrinkage and Selection Operator method, while age, sex, and stroke severity were retained in final models regardless of statistical significance.

DWI-positive lesions were identified in 22% (n = 74) of patients, 53% (n = 39) of whom had white matter lesions and 45% (n = 33) of whom had strictly lobar lesions. Severe white matter hyperintensities occurred in 81% of patients with DWI-positive lesions vs. 64% without them. Median ICH volume was 14 mL vs. 7 mL, and median cerebral microbleed burden was 3 vs. 1.

In adjusted analyses, previous stroke or transient ischemic attack, ICH volume of at least 30 mL, severe white matter hyperintensities, and at least 5 cerebral microbleeds were independently associated with DWI-positive lesions.

Among patients with DWI-positive lesions, strictly lobar lesions occurred in 79% of those with cerebral amyloid angiopathy (CAA) vs. 37% of those without CAA, and strictly deep lesions occurred in 25% of those without CAA vs. 0% of those with CAA. The investigators cautioned that the CAA/DWI-positive subgroup was small and characterized the finding as hypothesis generating.

Six-month follow-up data were available for 332 patients. DWI-positive lesions were independently associated with about twice the odds of dependence or mortality. In unadjusted analyses, recurrent stroke occurred in 20% of patients with DWI-positive lesions vs. 6% without them, ischemic stroke occurred in 7% vs. 3%, and recurrent ICH occurred in 14% vs. 3%, respectively. Mortality was 14% vs. 5%, but the difference was not statistically significant.

The investigators noted that excluded patients were older; had higher rates of atrial fibrillation, heart failure, and moderate stroke severity; had longer hospital stays; and were more fragile and had a worse prognosis, which may have introduced selection bias and limited generalizability to patients with less severe ICH. Detailed data on hyperacute blood pressure–lowering therapy were unavailable, limiting the investigators’ ability to assess its potential impact on outcomes.

“Our findings of a high prevalence of DWI-positive lesions, which show strong associations with all MRI markers of [cerebral small vessel disease] and the total [cerebral small vessel disease] burden, suggest that incidental DWI-positive lesions are most likely due to the underlying vasculopathy,” wrote lead study author Martina Locatelli, of the Stroke Research Centre in the Department of Translational Neuroscience and Stroke at the UCL Queen Square Institute of Neurology, and colleagues.

The study was funded by the National Institute for Health and Care Research University College London Hospitals Biomedical Research Centre. The study authors reported no conflicts of interest.

Source: Neurology