Early Cognitive Impairment in Multiple Sclerosis
Condition: Multiple Sclerosis; Cognitive Impairment
MeSH terms: Multiple Sclerosis; Sclerosis; Cognitive Dysfunction
Study type: Observational

Summary: 
      Cognitive impairment is one of the symptoms of Multiple Sclerosis (MS), and it may occur
      during the first years of the disease. It usually affects attention, information processing
      speed and short term memory. To date, the mechanisms of this specific symptom remain unclear
      (local or global inflammation, neurodegenerative processes).

      Magnetic Resonance Imaging (MRI) can be useful to understand the pathophysiology of cognitive
      impairment in MS. The investigators will combine conventional and non conventional MRI
      sequences to determine the respective role of white matter and grey matter injury and the
      cortical reorganization of neuronal networks.
    

Detailed description: 
      Cognitive impairment in Multiple Sclerosis (MS) occurs in 50% of patients and has a major
      social impact. There is no clear correlation between cognitive dysfunction and disease
      duration and recent studies have pointed out that it may affects patients at the very early
      stages of the disease especially in tasks involving sustained attention, processing speed,
      working memory and executive function.

      Recent imaging and pathology studies have shown that MS affects white matter as well as grey
      matter. Unlike white matter lesion burden or distribution, grey matter atrophy has often been
      linked to cognitive impairment. Microscopic injury of Normally Appearing White Matter (NAWM)
      explored by non conventional MRI sequences has also been shown to be involved in
      pathophysiology of cognitive disorders.

      Nevertheless mechanisms of cognitive impairment remain unclear. The relationship between
      cortical injury and diffuse white matter tracts damage and their respective contribution to
      cognitive dysfunction affecting patients during the first years of the disease is still under
      investigation.

      This study aims at investigating structural and functional correlates of early cognitive
      impairment using multimodal MRI.

      Relapsing Remitting MS (RRMS) patients with disease duration of less than 5 years will be
      included. Patients with and without cognitive impairment will be compared to healthy
      controls. All subjects will perform a clinical and neuropsychological evaluation before the
      MRI examination.

      We will combine new available MRI techniques using a 3 Tesla magnet in order to evaluate
      precisely cortical and white matter tracts lesions in patients with cognitive MS. These
      techniques will include :

        -  3D T1 sequences to study cortical atrophy using VBM.

        -  Diffusion tensor imaging fibre tracking to study selected white matter tracts that may
           be involved in cognitive disorders, such as the thalamus-cortical or the
           striatum-cortical tracts connecting sub-cortical structures to the prefrontal cortex.

        -  Functional MRI sequences during a working memory task and during the resting state in
           order to describe functional networks and their possible reorganization in patients with
           or without cognitive impairment.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        -  Relapsing remitting Multiple Sclerosis patients

          -  Age: 18-40 years

          -  Evolving between 3 and 5 years

          -  EDSS<5
      
Keywords: Multiple sclerosis; Cognitive impairment