Enriching experiences may have a protective role in cognitive performance in multiple sclerosis (MS), reducing the effect that gray matter atrophy has on cognitive functions. These findings were presented at the 32nd Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in London, September 14-17, 2016.
The researchers, led by Maria Assunta Rocca, MD, PhD, of the Division of Neuroscience at Vita-Salute San Raffaele University in Milan, Italy, aimed to examine whether the cognitive reserve (CR) hypothesis – in which enriching experiences protect against cognitive decline and dementia – could predict cognitive decline as well as gray matter (GM) and white matter (WM) volume changes in MS patients. The role of CR in protecting against cognitive decline over time in patients with MS has remained unclear.
The researchers obtained 3D T1-weighted scans and Rao’s Brief Repeatable Battery from 54 patients with MS and 20 healthy controls at baseline and at 2 years (median 2.2 years) follow-up. To assess cognitive decline, the researchers calculated a reliable change index (RCI); education, intelligence quotient, and leisure activities were included in a cognitive reserve index (CRI) calculation. Regional GM atrophy was estimated with voxel-based-morphometry and longitudinal GM changes were examined using tensor-based morphometry analysis. To evaluate CRI’s effect on cognitive performance and GM changes, between group-comparisons (SPM12) and linear regression analysis (SPSS22) were performed, controlling for demographic, clinical, and structural MRI measures.
At baseline, the researchers found that a higher CRI predicted better information processing speed (IPS) (β=0.30, P =.02), verbal memory (β=0.43, P =.001; β=0.52, P <.001; β=0.29, P =.021), and fluency tests (β=0.51, P <.001).
Compared with healthy controls, MS patients had GM atrophy of the deep GM nuclei, fronto-temporal-parietal-occipital regions, and left (L) cerebellum. Controlling for atrophy within these regions, higher CRI predicted better performances at verbal memory (β=0.45, P =.001; β=0.52, P <.001; β=0.29, P =.021), attention (β=0.28, P =.002), IPS (β=0.29, P =.03), and verbal fluency (β=0.38, P =.003) functions.
The researchers found that an interaction between CRI and GM volume in the right (R) superior temporal gyrus, left lingual gyrus, and left cerebellum predicted better performances in IPS (β=0.30, P =.02), verbal fluency (β=0.39, P =.002), and attention (β=0.30, P =.01) tests, respectively. CRI also predicted GM volume in the bilateral lingual gyrus (L: β=0.37, P =.006; R: β=0.27, P =.05).
At follow-up, GM atrophy predicted cognitive decline in several fronto-temporal areas and in the left cerebellum. The researchers found no effect of CRI on cognitive and longitudinal structural changes.
“CR in MS patients has a protective role on cognitive performance, reducing the effect of GM atrophy on cognitive functions,” the authors concluded. However, “this protective role might lose his efficacy with the progression of disease.”
Disclosures: This study was partially funded by grants from FISM (FISM 2014/R/7 and FISM2013/S/1). See the abstract for a complete listing of all disclosures.
Rocca MA, Del Sette P, Riccitelli G, et al. Role of cognitive reserve on cognitive function and regional brain atrophy in multiple sclerosis: a two-year longitudinal study. Presented at: ECTRIMS 2016. September 14-17, 2016; London, UK. Poster 1033.