Clinically isolated demyelinating syndromes (CIS) can evolve into multiple sclerosis (MS). Cognitive deficiencies could occur at this early stage and concern mainly information processing speed (IPS) and their mechanisms are not fully understood. Diffusion Tensor Imaging (DTI) can help in the understanding of these mechanisms.

This is a prospective cohort, observational, longitudinal, monocentric study. This study will include 60 patients with CIS followed for 1 year and 60 healthy subjects.

Inclusion Criteria:

• Patients:

  • Men and Women
  • ≥16 years
  • Fluent French speaker
  • Clinically isolated neurological syndrome (CIS) compatible with a demyelinating inflammatory episode within the central nervous system, potentially beginning multiple sclerosis (MS) whatever the mode of presentation
  • Between 60 and 180 days from the onset
  • At least two clinically silent lesions on their T2-weighted brain or spinal MRI scan with a size of at least 3 mm, at least one of which being cerebral, ovoid, or periventricular
  • Having a medical insurance
  • Free and informed consent signed

• Controls:

  • Men and Women
  • ≥18 years
  • Fluent French speaker
  • Having a medical insurance
  • Free and informed consent signed

Exclusion Criteria:

• Patients:

  • Prior documented neurological episode suggestive of MS.
  • Other ongoing neurological diseases.
  • Known chronic systemic diseases as judged by the investigator (for instance: lupus, Gougerot-Sjögren, sarcoidosis, sclerodermia, Crohn disease,…).
  • Other causes (trauma, tumor, radiotherapy, infections, vascular diseases, neuromyelitis optica).
  • Current dependence on alcohol or drugs.
  • Dosage change, stop or start of hypnotic or anxiolytic or antidepressive treatment less than 15 days
  • MRI contra-indications.
  • Steroid treatment less than one month (be taken orally or by infusion) at the dosage of 500mg daily.

• Controls:

  • Known chronic psychiatric or neurologic diseases which could interfere with neuropsychological testing, not taking into account stable and mild depressive syndrome
  • Known chronic systemic diseases as judged by the investigator (for instance: lupus, Gougerot-Sjögren, sarcoidosis, scleroderma, Crohn disease…).
  • MS familial history
  • Current dependence on alcohol or drugs
  • Known cognitive impairment
  • Prior neuropsychological testing with the same tests less than one year
  • Dosage change, stop or start of hypnotic or anxiolytic or antidepressive treatment less than 2 months
  • Steroid treatment less than one month (be taken orally or by infusion) at the dosage of 500mg daily.
  • MRI contra-indications
  • Steroid treatment less than one month (be taken orally or by infusion) at the dosage of 500mg daily.