ABSTRACT NUMBER: ESOC2026A2057 NORM-REFERENCED SMALL VESSEL DISEASE MRI-SCORES AND ITS ASSOCIATION WITH COGNITION IN PATIENTS WITH VASCULAR COGNITIVE IMPAIRMENT

Abstract Background and aims Age and sex norm-referenced small vessel disease (SVD) MRI-scores may provide a more precise and individualized interpretation of SVD burden. We recently created such reference data from the population-based Rotterdam Study. Here, we assessed the distribution of norm-referenced SVD burden and its association with cognitive functioning in patients with possible vascular cognitive impairment, and compared these findings with conventional clinical metrics. Methods We included 857 TRACE-VCI memory clinic patients with vascular injury on MRI. White matter hyperintensity (WMH) volumes were converted to norm-referenced percentiles. Lacune and microbleed counts were expressed as Number Needed to Scan (NNS=1/lesion-count probability). We analyzed cross-sectional and longitudinal associations with cognitive domain z-scores and Clinical Dementia Rating (CDR) using unadjusted regression models. Analyses were repeated with conventional SVD metrics adjusted for age and sex. Results Mean age was 67.7 years (54% men). In TRACE-VCI, 30.2% had WMH-percentiles >90th. High lacune burden (NNS ≥21) was observed in 15% of TRACE-VCI patients compared to 3% in the Rotterdam Study; for microbleeds this was 23% versus 6%. Higher WMH-percentiles were significantly associated with worse cognitive performance cross-sectionally across domains (all p<0.001) and with increased CDR (OR=1.26, 95%CI 1.13-1.40). No significant longitudinal associations were observed. Lacune and microbleed NNS-scores showed no associations with cognition. Norm-referenced SVD-scores showed similar associations with cognition as conventional WMH-volumes and outperformed Fazekas-scores. Conclusions Norm-referenced MRI-scores enable clinicians to determine the individual patient’s SVD burden according to age and sex. These scores retain their intrinsic association with cognition and are at least as informative as conventional metrics. Conflict of interest The author(s) declare(s) that there is no conflict of interest.