Early onset multiple sclerosis. Clinical study of 12 pathologically proven cases

Among 70 pathologically proven MS cases, we found 12 cases with onset before 25. Only females were affected. There was no positive familial history of MS. In every case the diagnosis was considered during life. Mean duration of the disease was 29.1 +/- 12.5 years. This was significantly longer (p less than 0.001) than in the control group (58 pathologically proven cases with onset after 25). There were no acute courses. Progressive courses (1 case) and remittent courses (5 cases) were less frequent than in the control group (p less than 0.001 and p less than 0.01, respectively). The frequency of remittent-progressive courses (6 cases) was similar in both groups. The length of remittent-progressive courses (30.2 +/- 16.2) and remittent courses (28.6 +/- 9.7) was longer than that of control group (p less than 0.001). The symptomatology of onset was similar in both groups and had no predictive value for prognosis. The overall frequency of signs and symptoms was not statistically different in both groups. For each sign, the percentage of affected patients, throughout the course of the disease, was always smaller in early onset MS than in control group, except for optic neuritis which was as frequent in both groups. However, this was statistically significant only for ocular motricity and nystagmus.