Prospective study of multiple sclerosis with early onset.

Fifty-four subjects (36 females and 18 males) affected by clinically definite multiple sclerosis (MS) and with onset of the disease at 15 years of age or before were prospectively studied in five Italian MS centres. Female/male ratio was 4.7 in subjects with age > or = 12 years, suggesting a role of hormonal changes in triggering MS onset The mean follow-up duration was 10.9+/-5.6 years. The functional systems more frequently involved at onset were the pyramidal and brainstem (both in 28% of cases). The onset was monosymptomatic in 31 subjects (57%). The course was relapsing-remitting in 39 subjects (72%) and relapsing-progressive in 15 (28%). Disability was assessed by the Expanded Disability Status Scale (EDSS): the mean score after 8 years of follow up was 3.5 (+/-2.5). The score was <4 in 68% of cases, between 4 and 6 in 8% of cases, >6 in 24% of cases. Disability after 8 years was highly predicted by disability in the first year (p=0.008). There was a tendency to a worse prognosis in relation to the number of relapses in the first 2 years (p=0.08). The outcome was not influenced by the characteristics of symptoms at onset age and gender.