Background/objective: Dawson’s fingers have been traditionally associated with multiple sclerosis. However, this imaging biomarker has also been linked to white matter hyperintensities related to cerebral small vessel disease. In the latter, Dawson’s fingers could represent damage of small venules in subjects with severe small vessel disease and could theoretically be associated with cognitive decline. In this study, we aimed to assess the association between Dawson’s fingers and cognitive performance in a population of older adults.
Methods: Population-based study conducted in individuals aged 60 years or older, residing in three rural villages of coastal Ecuador (Atahualpa, El Tambo and Prosperidad). Of 712 older adults identified by means of a door-to-door survey, 590 underwent a brain MRI. Of them, 575 also had the Montreal Cognitive Assessment (MoCA). We selected the 157 individuals with moderate-to-severe white matter hyperintensities to assess the presence of Dawson’s fingers. The independent association between Dawson’s fingers and cognitive performance (as the dependent variable) was assessed by means of a linear regression model, after adjusting for demographics, cardiovascular risk factors, and the other biomarkers of cerebral small vessel disease.
Results: Of 157 individuals with moderate-to-severe White matter hyperintensities, 17 (11%) had Dawson’s fingers on MRI. The mean MoCA score in subjects with Dawson’s fingers was 14.5±6.4 points and that of those without this neuroimaging biomarker was 17.3±6.2 points. The association between Dawson’s fingers and the MoCA score was marginal in univariate models (p=0.082), but it completely vanished in a multivariate linear regression model adjusted for relevant covariates (β:-0.31; 95% C.I.: -3.23 – 2.60; p=0.833). A mediation model disclosed that 83.5% of the effect of Dawson’s finger on cognitive performance was mediated by age.
Conclusion: Dawson’s fingers are not independently associated with cognitive performance in individuals with cerebral small vessel disease. Most of the effect of this association is mediated by age.
