Total Small Vessel Disease Score in Neurologically Healthy Japanese Adults in the Kashima Scan Study

Abstract

Objective We explored the association between the total small vessel disease (SVD) score obtained with magnetic resonance imaging and risk factors and outcomes in the Japanese population. Methods The presence of SVD features, including lacunes, cerebral microbleeds, white matter changes, and basal ganglia perivascular spaces on MRI, was summed to obtain a "total SVD score" (range 0-4). Ordinal and multinomial logistic regression analyses were performed to investigate the association of higher total SVD scores with vascular risk factors, the Mini-Mental State Examination (MMSE) score, and cerebral atrophy. Results We included 1,451 neurologically healthy adults (mean age, 57.1 years; 47% male). A multivariate ordinal logistic regression analysis showed that the total SVD score was associated with aging, hypertension, blood pressure (BP), diabetes mellitus, MMSE score, and deep cerebral atrophy, but the equal slopes assumption between scores did not hold. A multivariate multinomial logistic regression analysis (total SVD score 0=reference) showed that aging, hypertension, and BP were positively associated with scores of 1, 2, or ≥3. These effects, presented as odds ratios (ORs), increased as the score increased and were strongest with a score of ≥3 [aging (per 10-year increment), OR 4.00, 95% confidence interval (CI) 2.47-6.46; hypertension, OR 5.68, 95% CI 2.52-12.80; systolic BP (per standard deviation increase), OR 1.96, 95% CI 1.41-2.74, respectively]. Diabetes mellitus and deep cerebral atrophy tended to be associated with the SVD scores. The MMSE score showed no consistent associations. Conclusion The total SVD score may be a promising tool for indexing SVD, even in the Japanese population.

Keywords: cerebral atrophy; cerebral small vessel disease; cognitive impairment; diabetes mellitus; hypertension.

Figure 1.

Prevalence of SVD findings contributing to each total SVD score, and the total SVD score by age group. (A) The graph shows the prevalence of each SVD finding for each total SVD score. Blue represents subjects with lacunes, orange represents subjects with CMBs, green represents subjects with moderate to severe PVH or WMH (including subjects with PVH grade 3 and/or WMH grade 2 or more), and purple represents subjects with moderate to severe BG-PVS. (B) The graph shows the prevalence of each total SVD score by age group (p<0.001, χ² test). Blue represents subjects with a score of 1, red represents subjects with a score of 2, and green represents subjects with a score of ≥3. BG: basal ganglia, CMBs: cerebral microbleeds, PVH: periventricular hyperintensity, PVS: perivascular spaces, SVD: small vessel disease, WMH: white matter hyperintensity

Figure 2.

Representative graphs of the results of a multinomial logistic regression analysis. The graphs show odds ratios (squares), 95% confidence intervals (bars), and p values. BP: blood pressure, MMSE: Mini-Mental State Examination, SD: standard deviation, SVD: small vessel disease (A) adjusted for sex, hypertension, and diabetes mellitus; (B) and (C) adjusted for age, sex, and diabetes mellitus; (D) adjusted for age, sex, and hypertension; (E) and (F) adjusted for age, sex, hypertension, and diabetes mellitus.