Multiple sclerosis with very late onset.

Multiple sclerosis (MS) can present clinically after age 59, but only rarely. In a large MS population (N = 2,019), 0.6% of patients had their first symptom at age 60 or older. Of this group, six had clinically definite MS, two had laboratory-supported definite MS, and four had clinically probable MS. The onset at this age was characteristically a slow deterioration of motor function. Most (10 of 12) of these very late-onset patients had a progressive course of disease from onset.