DWI-Positive Lesions in Patients With Acute Intracerebral Hemorrhage: Associations With Cerebral Small Vessel Disease and Clinical Outcome.

BACKGROUND AND

OBJECTIVES

Diffusion-weighted imaging (DWI)-positive lesions are increasingly recognized as markers of cerebral small vessel disease (cSVD) in acute intracerebral hemorrhage (ICH), but their underlying mechanisms, clinical-radiologic associations, and prognostic significance remain uncertain. We therefore aimed to determine their prevalence, anatomical distribution, and associations with baseline clinical-radiologic features and 6-month functional outcome assessed by the modified Rankin Scale (mRS).

METHODS

In this prospective cohort study, we analyzed consecutive patients with ICH included in the Stroke Investigation Group in North and Central London registry. We assessed the presence and anatomical distribution of DWI-positive lesions on acute MRI, as well as other cSVD markers rated according to the STandards for ReportIng Vascular changes on nEuroimaging criteria. The primary outcome was disability at 6 months assessed using the mRS. We investigated associations between DWI-positive lesions, clinical-radiologic features, and poor 6-month functional outcome (mRS ≥3) using adjusted multivariable logistic regression.

RESULTS

We included 342 patients (median age 67 years [interquartile range (IQR) 55-78]; 142 (41.5%) women; 138 (40.3%) lobar ICH; median cSVD burden 2 [IQR 1-3]). Overall, 74 patients (21.6%) had DWI-positive lesions, most commonly in lobar regions (33 [44.6%]). Patients with cerebral amyloid angiopathy (CAA) more frequently had strictly lobar DWI-positive lesions compared with those without (78.6% vs 36.7%); strictly deep DWI-positive lesions were exclusively observed in the non-CAA group (25.0% vs 0%). Compared with patients without DWI-positive lesions, those with DWI-positive lesions more frequently had severe white matter hyperintensities (WMH; Fazekas ≥2: 81.1% vs 64.2%, p < 0.001), higher cerebral microbleed (CMB) burden (median = 3 vs 1, p = 0.034), and larger ICH volume (median = 14 mL vs 7 mL, p = 0.0006). In adjusted analyses, DWI-positive lesions were independently associated with severe WMH (odds ratio [OR] 3.37, 95% CI 2.72-6.89), ICH volume ≥30 mL (OR 2.29, 95% CI 1.76-3.42), CMBs (OR 1.61, 95% CI 1.21-2.93), and poor functional outcome at 6 months (OR 2.16, 95% CI 1.67-3.48).

DISCUSSION: DWI-positive lesions are common after acute ICH and are independently associated with cSVD and poor functional outcome, supporting their role as a prognostic biomarker. Their anatomical distribution differs according to the underlying cSVD subtype.