[Epidemiology of multiple sclerosis and new diagnostic criteria].

Epidemiology of multiple sclerosis and new diagnostic criteria. There have been many advances in epidemiology and diagnosis of multiple sclerosis (MS) in the recent years. Prevalence and incidence data show that MS is more frequent than expected in France, with 100.000 people affected and 5 new cases each year per 100.000 inhabitants; survival is only slightly decreased. A better definition of MS has also been allowed by new diagnostic criteria in 2010, but also by a modernization of the clinical course classification and major improvements in the characterization of other disorders in the spectrum of MS, in particular neuromyelitis optica.