The proportion of patients with multiple sclerosis (MS) who develop symptoms before 16 years of age has been variously estimated at between 0.4% and 10.5%. There have been few studies of the course of childhood-onset MS and how it may differ from adult-onset disease. Now data from the European Database for Multiple Sclerosis (EDMUS) network of adult neurology departments (Christel Renoux and colleagues. New England Journal of Medicine 2007;356:2603–13) have clarified the natural history of MS beginning in childhood.

Thirteen adult neurology departments in France and Belgium provided data on 394 patients with MS of childhood (age 16 …