1. Harvard Medical School Boston Massachusetts 02115 USA
2. Ann Romney Center for Neurologic Disease Harvard Medical School Boston Massachusetts 02115 USA
3. Massachusetts General Hospital Biostatistics Center Boston Massachusetts USA
4. Department on Nutrition Harvard T.H. Chan School of Public Health Boston Massachusetts USA
5. Departments of Medicine, Biomedicine and Clinical Research Neurologic Clinic and Policlinic University Hospital Basel University of Basel Basel Switzerland
6. Department of Clinical Research Clinical Trial Unit University Hospital Basel University of Basel Basel Switzerland
7. Department of Neurology Partners Multiple Sclerosis Center Brigham and Women's Hospital Boston Massachusetts USA