The relationship between disability and memory dysfunction in multiple sclerosis.

We examined the relationship between memory impairment and functional disability in multiple sclerosis. Tests of memory, sensorimotor ability, and functional capacity were administered to fifty-six subjects with chronic-progressive or remitting-relapsing MS. Sensorimotor impairment, functional disability, and chronicity predicted impairment on various measures of memory acquisition, while age and type of diagnosis did not. After accounting for the effects of initial acquisition, delayed-recall performance was weakly-associated with disability. We suggest that: (1) Functional disability is associated with memory loss in MS; (2) MS-forgetting is caused by defective acquisition, rather by a deficit in consolidation or storage; (3) Level of disease activity, rather than type of MS diagnosis, determines the degree of memory impairment; and (4) MS disability needs to be evaluated multidimensionally, to account for both neurologic and functional impairment.