Little is known about old MS patients. In a previous work, systematic search in Bordeaux, Strasbourg and Dijon university hospital regional MS center databases European Database for Multiple Sclerosis (EDMUS) retrieved 2% of 75 years old or older Multiple Sclerosis (MS) patients in the 3 databases. Data analysis showed that MS may switch off in the very old patients with mild progression and very few relapses. The project is to continue this preliminary work and extend it with a systematic study of MS in the elderly.

The scientific aims: To add new insights into long lasting MS natural history in the growing population of elderly patients with MS.

75 to 77 years old MS patients whose disease began at 65 years old or earlier will be retrieved from the "Observatoire français de la sclérose en plaques" (OFSEP) which includes more than 50 000 MS patients in France. Accuracy of these patients' data from 65 to 75 years old will be thereafter checked and completed in 3 French MS centers: Lyon, Rennes and Bordeaux, participating to this database directly from the patients' clinical files. From these 3 MS centers around 150 MS patients from 75 to 77 years old are expected to be analysed on site.

The data wich will be retrieved for these patients are: irreversible disability status scale progression, relapses, Magnetic Resonance Imaging (MRI) data, CSF data, Lublin classification of type of MS, McDonald 2005 and 2010 criteria, date and age at beginning of progression, characteristics and modality of relapses and clinical impairment at the beginning of the disease, treatments used, treatment failures and side effects, co morbidity, Barthel index, EuroQol-5D (EQ-5D), cognitive impairment (SDMT test), social life data and socio economic data. To the investigator's knowledge this will be the first systematic description of very old MS patients with data on long term natural history of MS and characteristics in this population of elderly MS patients.

Inclusion Criteria:

• Patients with McDonald 2001, 2005 or 2010 criteria of multiple sclerosis 75 to 77 years old MS patients at the time of inclusion
• Patients whose beginning of MS was before 65 years old or 65 years old
• Patients who signed OFSEP 's consent

Exclusion Criteria:

• Patients whose clinical data cannot be entered or for whom too much clinical data are missing
• Alive patients older than 77 years or younger than 75 years the day of the inclusion in the study
• Patients died before 65 years old

75 to 77 years old MS patients whose disease began at 65 years old or earlier will be retrieved from the "Observatoire français de la sclérose en plaques" which includes more than 50 000 MS patients in France.