Higher education moderates the effect of T2 lesion load and third ventricle width on cognition in multiple sclerosis

Abstract

Background: Previous work suggested greater intellectual enrichment might moderate the negative impact of brain atrophy on cognition. This awaits confirmation in independent cohorts including investigation of the role of T2-lesion load (T2-LL), which is another important determinant of cognition in MS. We here thus aimed to test this cognitive reserve hypothesis by investigating whether educational attainment (EA) moderates the negative effects of both brain atrophy and T2-LL on cognitive function in a large sample of MS patients.

Methods: 137 patients participated in the study. Cognition was assessed by the "Brief Repeatable Battery of Neuropsychological Tests." T2-LL, normalized brain volume (global volume loss) and third ventricle width (regional volume loss) served as MRI markers.

Results: Both T2-LL and atrophy predicted worse cognition, with a stronger effect of T2-LL. Higher EA (as assessed by years of education) also predicted better cognition. Interactions showed that the negative effects of T2-LL and regional brain atrophy were moderated by EA.

Conclusions: In a cohort with different stages of MS, higher EA attenuated the negative effects of white matter lesion burden and third ventricle width (suggestive of thalamic atrophy) on cognitive performance. Actively enhancing cognitive reserve might thus be a means to reduce or prevent cognitive problems in MS in parallel to disease modifying drugs.

Figure 1. Correlation of lesion load/third ventricle width with cognition for high and low education.

Correlation for low education (25^th percentile: ≤11 years of education; blue triangles) r = −0.52; p<0.05/r = 0.33; p<0.05 (N = 27) vs. correlation for high education (75^th percentile: ≥14 years of education) r = −0.37; p<0.05/r = 0.12; ns (N = 36), including fit of linear regression lines.