PIXCIS

Treatment tested

• Analysis of cerebral MRI with automatic segmentation software

Other measures (3)

Identical to those of the study D-Lay-MS: NCT01817166: Inclusion Criteria: * The patient must have given his/her informed and signed consent * The patient must be insured or beneficiary of a health insurance plan * The patient is available for 24 months of follow-up * The patient has had a classic CIS with the past 90 days * Reference cerebro-medullary MRI scheduled within the 90 days after the beginning of symptoms * With MRI (cerebro ± medullary) showing demyelination according to spatial spread criteria by Swanton (2006): * At least 1 lesion in at least 2 of the 4 following territories: (1) Peri-ventricular; (2) Juxta-cortical; (3) Sub-tentorial; (4) Medullary * No other suspected pathology * Vitamin D level in blood less than 100 nmol / l at the pre-inclusion visit * Women of childbearing potential must use very effective contraception for the duration of the study. A very effective contraceptive method is defined as a method resulting in a low failure rate (that is to say less than 1% per year) when used consistently and correctly, such as implants, injectables, combined oral contraceptives, IUDs, sexual abstinence, or partner with a vasectomy. Randomisation stratification criteria: • The patient can also also meet the temporal dissemination criteria defined according to McDonald criteria 2010 (Polman et al., 2011), because this condition is currently not sufficient for prescribing a background treatment: Simultaneous presence of at least one asymptomatic lesion taking on contrast and at least one asymptomatic lesion not taking on contrast after injection of gadolinium Exclusion Criteria: * The patient is participating in another study other than D-Lay-MS: NCT01817166 (this criteria does not apply to the POLAR study (RCB 2011-A01269-32); patients included in this study may simultaneously participate in the POLAR study) * The patient is in an exclusion period determined by a previous study * The patient is under judicial protection, under tutorship or curatorship * The patient refuses to sign the consent * It is impossible to correctly inform the patient * The patient is pregnant, parturient, or breastfeeding * Major medical or psychiatric illness that, according to the investigator, would result in the patient running an unnecessary risk or that could affect compliance with the study protocol * Vitamin D insufficiency linked to currently active digestive or more general diseases (celiac disease, inflammatory bowel disease, intestinal bypass, short bowel syndrome, cirrhosis, nephrotic syndrome, hyperthyroidism, rickets, hypoparathyroidism, cancer, granulomatous diseases and lymphomas) * Moderate or severe renal insufficiency (creatinine clearance less than 60 ml / min) * Epilepsy not adequately controlled by treatment * Any illness requiring chronic treatment with corticosteroids * Patient with osteoporosis or history of osteopenia * Pathology requiring calcium intakes greater than 1 gram per day * Current or past history of hypercalcemia * Medications that affect the metabolism of vitamin D other than corticosteroids; e.g. anticonvulsants [phenobarbital, primidone, phenytoin] rifampicin, isoniazid, ketoconazole, 5-FU and leucovorin, thiazide diuretics. * Situations accompanied by increased vulnerability to hypercalcemia, e.g. arrhythmia or known heart disease, treatment with digitalis, and subjects with nephrolithiasis. * Contraindications to vitamin D3 as mentioned in the documentation for UVEDOSE * Known hypersensitivity to gadolinium and / or known inability to undergo an MRI (pacemaker, osteosynthesis material, intraocular metal splinter, etc ....). * The subject is participating in an interventional study, or is in a period of exclusion determined by a previous study * The subject refuses to sign the consent * It is impossible to give the subject informed information * The patient is under safeguard of justice or state guardianship

Using an automatic software tool, Pixyl.Neuro, to conduct a retrospective analysis (detection of lesions + segmentation of images + tracking over time) of cerebral MRI images acquired during a prospective study of patients presenting with clinically isolated syndrome, and comparing the results against manual analysis.