Cognitive dysfunction and change in multiple sclerosis

A cross‐sectional study of 60 multiple sclerosis outpatients assessed neuropsychological variables in relation to age, duration of disease, and degree of disability. The test battery included subtests of the WAIS (Vocabulary, Similarities, and Digit Span); the Raven matrices; and memory tests (Wechsler Paired Associates, Benton Visual Retention). Results showed that cognitive functioning of MS patients varies considerably. There is a general mild decline that affects reasoning and memory as the disease progresses. These deficits are usually not sufficient to impair occupational or social functioning. In addition, there is spotty deterioration in certain cognitive functions for some patients (17%). Only a small subsample (6.7%), however, showed global deterioration significant enough to be highlighted by an Index of Dementia that was developed for this investigation.