Neuropsychological test performance as a function of the duration of MS-related symptomatology.

Thirty-six patients with definite diagnoses of multiple sclerosis received an extensive battery of neuropsychological tests. The MS patients were grouped in triads, and the members of each triad were matched on the basis of their sex, age at time of experiencing their first MS-related symptom, and education. One member of each triad was assigned to each of three experimental groups on the basis of the number of years they had complained of MS-related symptoms (i.e., one to five, six to ten, or greater than ten years). Data analyses yielded a limited number of significant findings. Differences on measures of verbal intelligence and reading skills were suggested as more probably reflecting a tendency for the "older" MS patients to have had more formal education, than being a true consequence of the disease process. Only a measure of simple tactile perception skills significantly delineated the experimental groups in a manner consistent with clinical observation of MS deterioration.