Clinical characteristics and long term prognosis in early onset multiple sclerosis.

The clinical features, disease course and long term prognosis of early onset multiple sclerosis (EOMS) are variable. A preponderance of female sex, a high incidence of visual and brainstem symptoms at onset and a relapsing-remitting disease course with slower progression rate all have been considered relatively frequent in this subgroup of MS patients. Unfortunately, follow-up in previous studies has usually been limited to less than 10 years, precluding general statements on the long term evolution and prognosis in EOMS. In this retrospective study of EOMS with a substantially longer follow-up of 20.8 years, clinical characteristics, disease course and long term prognosis are described in 49 EOMS patients. In a representative subgroup of 28 patients disability was scored using Kurtzke's Functional System (FS) and Expanded Disability Status Scale (EDSS). The mean period of follow- up for these patients was 28.7 years. The present study confirms that several specific clinical characteristics can be identified in EOMS patients, such as a mainly relapsing-remitting disease onset and frequent presentation with brainstem- cerebellar dysfunction (28.6 %), pyramidal symptoms (18.4 %) and optic neuritis (14.3%). However, after a long period of follow-up the overall disease course and prognosis do not seem to differ from that in adult onset MS. By consequence a young age at onset in MS cannot be considered a favourable prognostic factor.