Evaluation of Brain Atrophy in CIS Patients on Avonex

Inclusion Criteria: * MRI findings must reveal at least 2 hyperintense lesions on T2-WI or FLAIR images at first clinical onset * CSF examination should confirm oligoclonal bands (examination must be done in an internationally approved lab and the CSF taken before the treatment of attack starts) * Age 18 - 55 years * Effective contraception in female patients of childbearing potential * Kurtzke EDSS ≤ 3.5 at baseline * Willingness to accept the plan of the study and compliance with the study * Time from the beginning of first symptoms of CIS to baseline visit should not exceed 4 months (baseline MRI and baseline visit will be organized first 28 days after last steroid administration) * CIS attack is treated by at least 3g of methylprednisolone without taper * In case of severe attack 1 g of cyclophosphamide does not disqualify the patient from the study if first MRI and CSF examination was done before treatment administered * No active major organ disease especially of hepatic or thyroid origin Exclusion Criteria: * The clinical diagnosis of MS is definite (the second attack occurs before the baseline visit) * Age less than 18 or more than 55 * Non-effective contraception method or pregnancy planning * Active major organ disease, especially hepatic or endocrinologic * Cooperation of the subject cannot be ensured * Kurtzke EDSS higher than 3.5 at baseline