Epub: Schwartz et al. Cognitive reserve and symptom experience in multiple sclerosis: A buffer to disability progression over time? Arch Phys Med Rehabil. 2013 May 28.
OBJECTIVE: To investigate the possible buffering effect of cognitive reserve on symptom experience for MS disease course. Enhanced cognitive reserve is associated with better health and well-being in MS. Passive cognitive reserve reflects developed capacity, whereas active cognitive reserve reflects current enrichment activities.
DESIGN: Secondary analysis of longitudinal data (n=859) from the North American Research Committee on MS (NARCOMS) Registry.
RESULTS: High-active reserve MSers had lesser symptom burden than low active MSers independent of passive reserve (p<0.01). Cognitive reserve was associated with course of disease, such that high-active MSers were over-represented among relapsing-remitting MSers, and under-represented among MSers with progressive disease. Longitudinal modeling revealed that a significant interaction of active reserve and time in mobility, fatigue, and overall disability in the whole sample (p<0.05 in all comparisons). Among MSers whose disability trajectories changed over time, active cognitive reserve was associated with less deterioration (p<0.001). Passive cognitive reserve evidenced no effect in the longitudinal analyses. Active cognitive reserve scores across disability groups had a similar range but comprised different items, indicating that patients maintain active cognitive reserve with different activities as the disease progresses.
CONCLUSION: These findings suggest that active cognitive reserve is a buffer for functional limitation across disability groupings. Cognitive reserve may provide an alternative lens for thinking about MS course of disease, providing a longer “runway” until disability accrual through cortical remodeling. Loss of cognitive reserve may explain the onset of progressive disease in MS.