This study tested the cognitive reserve (CR) hypothesis in the model of MS by assessing the interactions among CR, brain atrophy and cognitive efficiency in patients with RRMS.
The researchers calculated a Cognitive Reserve Index (CRI) including education, premorbid leisure activities and IQ. Brain atrophy was assessed through MR quantitative parameters of normalized total brain volume and normalized cortical volume. Cognitive function was assessed using Rao’s Brief Repeatable Battery.
The study included 52 patients with RRMS evaluated at baseline and 35 of them were reassessed after 1.6 years' follow-up period. The researchers found that higher CR at baseline predicted better performance on most of the Brief Repeatable Battery tests, independent of brain atrophy and clinical and demographic characteristics. An interaction between CRI and normalized cortical volume predicted better cognitive performance on tasks of verbal memory and attention/information processing speed. At follow-up, progressing cortical atrophy and older age were the only predictors of deteriorating cognitive performance. Therefore, these findings suggest that higher CR in individuals with MS may mediate between cognitive performance and brain pathology. CR-related compensation may, however, fail with progression of damage and the time window of opportunity for therapeutic approaches aimed at intellectual enhancement most likely lies in the earliest stages of the disease.
Authors: Amato MP, Razzolini L, Goretti B
Source: Neurology. 2013 Apr 10. [Epub ahead of print]
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