The present study is an opportunity to assess grey matter damage at the earliest phase of Multiple Sclerosis (MS) allowing to a better understanding of its origins and its impact and disease severity. This study is a preliminary longitudinal study to precisely depict the kinetic of grey matter damage and the links with disease aggravation. Thirty MS patients without time and spatial dissemination criteria (only one symptomatic MRI lesion detected) but with oligoclonal bands detected on cerebro spinal fluid analysis will be included for a monocentric transversal MRI study at 7T to assess grey matter injury. Clinical and neuropsychological assessments will be performed in the population the same day of a multi-parametric MRI. A longitudinal clinical and MRI follow up will be performed during 2 years.

The present study is an opportunity to assess grey matter damage at the earliest phase of MS allowing to a better understanding of its origins and its impact and disease severity. This study is a preliminary longitudinal study to precisely depict the kinetic of grey matter damage and the links with disease aggravation. Thirty MS patients without time and spatial dissemination criteria (only one symptomatic MRI lesion detected) but with oligoclonal bands detected on cerebro spinal fluid analysis will be included for a monocentric transversal MRI study at 7T to assess grey matter injury. Clinical and neuropsychological assessments will be performed in the population the same day of a multi-parametric MRI. A longitudinal clinical and MRI follow up will be performed during 2 years.

Inclusion Criteria:

• First presumed inflammatory demyelinating event in the central nervous system involving either the optic nerve, the spinal cord, a brain hemisphere, or the brainstem without spatial and time dissemination criteria
• Oligoclonal bands on CSF analysis
• Age between 18 and 45
• No previous history of neurological symptoms suggestive of demyelination
• No steroids in the month before MRI
• First MRI within six months after the first clinical episode

Exclusion Criteria:

• Possible alternative diagnoses
• Previous history of neurological or psychiatric disease
• Previous administration of immunosuppressive drugs
• Pregnancy
• Patient unable to give his consent for the study or patient under tutorship