Multiple sclerosis (MS) is the most common acquired neurological disease leading to disability in young adults. MS often leads to the development of a physical and/or cognitive impairment that disables patients in their daily lives. Early use of disease modifying treatments for patients at risk of developing disability is therefore essential.

However, disability progression is very heterogeneous between patients and currently impossible to predict at the individual level. Thus, numerous studies, particularly epidemiological and imaging studies, have identified prognostic factors for the development of disability such as age, gender, number of relapses during the first years of the disease, existence of a residual disability after a first relapse, number of gadolinium-enhancing lesions on initial MRI, early brainstem and spinal cord lesions. However, these different factors only explain incompletely the progression of the physical or cognitive disability in MS patients. In particular, some components of MS pathophysiology, more related to the progressive development of disability, such as axonal degeneration or the existence of chronic inflammation of the central nervous system (CNS) are usually not measured by these biomarkers.

In this research project, the investigators will test promising biomarkers, focused on these components of the disease, on a large cohort of patients in a multicenter setting, in order to evaluate their added value to predict disability progression, in comparison with more classical biomarkers such as clinical characteristics, and brain and spinal cord lesion load.

In particular, the investigators will test:

• Imaging biomarkers extracted from brain and spinal cord MP2RAGE, brain and spinal cord QSM, brain and spinal cord relaxometry, brain diffusion and spinal cord magnetization transfer sequences
• Biomarkers extracted from optical coherence tomography (OCT)
• Biological biomarkers (serum neurofilament-light chain (NFL) and Glial Fibrillary Acidic Protein (GFAP))

For MS patients:

• Inclusion Criteria:

  • The patient must be already included in the OFSEP High Definition cohort (NCT03603457).
  • The patient must have given his informed and signed consent for the inclusion in the VHD cohort.
  • The patient must be insured or beneficiary of a health insurance plan.

• Exclusion Criteria:

  • The patient is under judicial protection.
  • The patient refuses to sign the consent.
  • It is impossible to correctly inform the patient (Inability to understand the study, language problem).
  • The patient has experienced a relapse in the previous 3 months.
  • The patient is pregnant or breast-feeding (MRI contraindicated).
  • Patient with MRI contra-indications (patient with a pacemaker, ferromagnetic vascular clip, infusion pump, neurostimulator, cochlear implants or in whom there is a suspicion of a metallic foreign body).
  • The patient has a severe psychiatric illness
  • The patient has severe chronic alcoholism

For healthy subjects:

• Inclusion Criteria:

  • The healthy subject must be older than 18 years
  • The healthy subject must have given his informed and signed consent for the inclusion in the VHD cohort.
  • The healthy subject must be insured or beneficiary of a health insurance plan.

• Exclusion Criteria:

  • The healthy subject is under judicial protection.
  • It is impossible to correctly inform the healthy subject (Inability to understand the study, language problem).
  • The healthy subject is pregnant or breast-feeding (MRI contraindicated).
  • The healthy subject has MRI contra-indications (a pacemaker, ferromagnetic vascular clip, infusion pump, neurostimulator, cochlear implants or in whom there is a suspicion of a metallic foreign body).
  • The healthy subject has a history of disease that may affect the central nervous system.
  • The healthy subject has a family history of MS.

In order to ensure the inclusion of patients with different MS phenotypes representative of the general MS patients population in the VHD cohort, the investigators will aim to respect the inclusion percentages of at least 10% of patients with primary progressive MS and at least 15% of patients with secondary progressive MS.