Multiple Sclerosis (MS) is a chronic immune-mediated inflammatory disease with a broad diversity of symptoms and fluctuating progression patterns. Clinical assessments are challenging and are continually reviewed and enhanced. Optimal multiple sclerosis care depends on early detection of disease progression. The Digital self-Assessment for Multiple sclerosis (DAM) mobile program was developed by Ad Scientiam in order to create a robust and clinically validated remote monitoring platform for MS patients and clinicians. The correlation between DAM version 0 (the first iteration of DAMS) and Multiple Sclerosis Functional Composite (MSFC) has been clinically evaluated in a preliminary study in 30 subjects. DAM version 0 and MFSC global scores were correlated. However, the cognition test had a poor reproducibility and clinicians expressed the wish to measure a walking range rather than a walking speed. Even though vision is the main sense impacting all other tests, particularly when interacting with a mobile, visual tests are rarely performed in real life. A new version of DAM version 0, DAMS, was therefore developed with the addition of the Sloan Low Contrast Letter Acuity Test (SLCLAT), the replacement of the walking speed test with a walking distance test and the Paced Auditory Serial Addition Test (PASAT) by a new version of the cognitive test which resembles the Symbol Digit Modalities Test (SDMT).

The hypothesis is that systematic and prospective multi-dimensional data collection of MS disabilities through the DAMS mobile application will refine the quality and accuracy of both clinicians and patients' knowledge of the disease progression and will ultimately improve the current care of patients.

To test this assumption, the statistician will analyze:

1. The global diagnostic performance of DAMS with (DAMS 4 tests) and without (DAMS 3 tests) the low contrast vision test versus standard MS scales
2. The test-retest reliability of DAMS' scores at a 15 day interval

Inclusion Criteria:

MS patients:

• subjects: 18 Years to 60 Years
• with a confirmed and documented MS diagnosis, per the 2010 Revised McDonald criteria
• with or without MS maintenance and/or symptomatic treatment, if MS maintenance and/or symptomatic treatment: stable for the past 6 months before enrolment (Centrally acting antalgics, antidepressant or neuroleptic treatment are authorized but shall not be modified in the past 2 months before enrolment)
• with an EDSS [0;7] in the past 6 months before enrolment
• with an EDSS [0;7] in the past 6 months before enrolment
• with no evidence of EDSS score change since the last measure available
• with no evidence of relapse in the past 6 months before enrolment
• enrolled in or benefiting of a Social Security program
• who have read the information sheet and signed the informed consent form

Healthy volunteers:

• subjects: 18 Years to 60 Years
• with no evidence of walk limitation (as per clinician's judgment) nor walking aid
• no personal and familial history of inflammatory disease (e.g. rheumatoid arthritis) or multiple sclerosis
• matched to the sociodemographic characteristics of MS patients sample (age, sex, height, weight, education)
• enrolled in or benefiting of a Social Security program
• who have read the information sheet and signed the informed consent form

Non-Inclusion Criteria:

MS patients and Healthy volunteers:

• Participants wearing pacemakers, implantable defibrillators, or hearing aids
• Inability to use their right hand for the Coordination test (MCT)
• Evidence of neurologic or psychiatric disorder other than MS, including but not limited to major head trauma, seizures or systemic medical diseases that are likely to affect cognitive functioning
• Evolutive rheumatology disease
• Any vision (ex. short-sightedness (-6; +6); congenital dyschromatopsia and glaucoma) or hearing conditions that could influence the performing of the tests
• Omission of the usual visual and/or walking aids if it's usually needed
• Acute asthenia (score>7 on a visual analogic scale)
• Systemic corticosteroid treatment in the past 30 days before enrolment
• Intramuscular botulinic toxin injection in the past 4 months before enrolment
• Change in centrally acting antalgic, antidepressant or neuroleptic treatment in the past 2 months before enrolment
• Rehabilitation in the past 6 months before enrolment
• Pregnant and nursing women - Person under guardianship or curatorship
• Bedridden patients or patients with a daily activity of less than 2 hours per day
• Inability to use a mobile application
• Current drugs or/and alcohol abuse that could influence performance on the tests (clinician's judgment)
• Participation to another study Healthy volunteers who will not match the sociodemographic characteristics of MS patients will not be included in the study.

Exclusion Criteria:

• Patient experiencing a relapse once enrolled in the study
• Patient with a maintenance and symptomatic MS treatment modification
• Use of centrally acting antalgics, antidepressant or neuroleptic once enrolled in the study
• Substance or/and alcohol abuse that could influence performance on the tests between inclusion and follow-up visits (clinician's judgement)
• Omission or change in the usual visual and/or walking aids
• Acute asthenia (score>7 on a visual analogic scale) at the follow-up visit.