Longitudinal Study in Clinically Isolated Syndrome (CIS) Patients Treated With Interferon Beta

Inclusion Criteria: * Patients older than 18 years, * Patients with CIS and temporo spatial dissemination for less than one year * Patient without prior immunomodulatory treatment * Patient informed of CIS diagnosis and MS according to McDonald criteria, * Patients with EDSS inferior or egal to 5,5 * Patients usually french-reader and with MMS \>24 * Patients informed of study protocol * Patients agree to sign informed consent * Patients with affiliation number from social French département. Exclusion Criteria: * Secondary progressive MS * Patient with acute relapse * Patient already treated with IFN * corticosteroids less than 15 days * Patient with severe dépressive disorders * Patient already included in clinical study * Patient \< 18 years * Patient with known contra indications for beta interféron * Every reason with can provoke an interruption of the study, regarding a patient empechment * Contre indications for MRI or other tests required in the study * pregnancy or lactation * patient Under juridic protection