Inclusion Criteria:  (1) Diagnosis of multiple sclerosis (MS) according to 2017 McDonald criteria. (2) Age >=18 years.  (3) Treatment with Teriflunomide for at least 6 months/or 4 to 18 months after the last course treatment with Alemtuzumab/or untreated.  (4) Signed written informed consent.  Exclusion Criteria:  (1) Cognitive decline that precludes understanding the study procedures.