1. Mandell Center for Multiple Sclerosis, Mount Sinai Rehabilitation Hospital, Trinity Health Of New England, Hartford, Connecticut, USA
2. Department of Rehabilitative Medicine, Frank H. Netter MD School of Medicine at Quinnipiac University, North Haven, Connecticut, USA
3. Department of Medical Sciences, Frank H. Netter MD School of Medicine at Quinnipiac University, North Haven, Connecticut, USA
4. Department of Neurology, University of Connecticut School of Medicine, Farmington, Connecticut, USA
5. Multiple Sclerosis Center for Excellence West, Veterans Affairs, Seattle, Washington, USA
6. Rehabilitation Care Service, VA Puget Sound Health Care System, Seattle, Washington, USA
7. Department of Rehabilitative Medicine, University of Washington, Seattle, Washington, USA
8. Department of Epidemiology, University of Washington, Seattle, Washington, USA
9. Department of Family Medicine, University of Connecticut Health Center, Farmington, Connecticut, USA
10. Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, Connecticut, USA