Impacts of cerebral small vessel disease on global and domain‐specific cognition

Abstract Background The 2021 Alzheimer’s Association International Conference press release forecasted global dementia cases to triple by 2050, due to the major contribution of increases in vascular risk factors. The Global Vascular Risk Score (GVRS) was developed to predict vascular events using a point‐based index for risk factor variables, though has demonstrated to be a significant predictor of global and domain‐specific cognitive performance in a multi‐ethnic cohort (Rundek, T. et al. Global Vascular Risk Score and CAIDE Dementia Risk Score Predict Cognitive Function in the Northern Manhattan Study. J Alzheimers Dis 73 , 1221‐1231 (2020)). However, more than half of the variance in global and domain‐specific cognitive performance is still unexplained by GVRS variables. We sought to explain additional variance in cognitive performance by addition of MRI biomarkers of cerebral small vessel disease to the GVRS model. Method We included 1290 subjects from the multiethnic Northern Manhattan Study population (age 64+/‐8 years, 40% women, 66% Hispanic, 17% non‐Hispanic Black, 15% non‐Hispanic White, education 10+/‐5 years). Multivariate linear regression models were employed to assess the added value of the cerebral small vessel disease MRI measures (white matter hyperintensity volume, silent brain infarcts, cerebral microbleeds, and perivascular spaces) beyond GVRS variables in explaining more variance in global and domain‐specific (episodic memory, executive function, semantic memory, and processing speed) cognitive performance. The explained variance (R 2 ) of the GVRS model was compared to the proposed model with added imaging markers to determine their predictive performance. Statistical significance was determined using F‐statistic difference test between the models. Result The explained variance (R 2 ) and F‐statistic for models of global and domain‐specific cognition are in the table. Addition of MRI measures significantly improved the model for global cognition (F(4, 1108) = 2.68, p < 0.05) and domain‐specific cognitive performance models of episodic memory (F(4, 1096) = 3.34, p < 0.01) and processing speed (F(4, 1096) = 2.40, p < 0.05). Conclusion MRI measures of cerebral small vessel disease explain more variance in global cognition, episodic memory, and processing speed than GVRS factors alone. However, most of the variance in cognitive performance remains unexplained.