1. Department of Physical Medicine and Rehabilitation; University of Pennsylvania; 1800 Lombard Street, First Floor Philadelphia Pennsylvania 19146 USA
2. Department of Neurology, Rutgers; the State University of New Jersey, Robert Wood Johnson Medical School; New Brunswick New Jersey USA
3. Department of Physical Medicine and Rehabilitation, College of Osteopathic Medicine; Michigan State University; East Lansing Michigan USA
4. Department of Physical Medicine and Rehabilitation; Indiana University; Indianapolis Indiana USA
5. Department of Physical Medicine and Rehabilitation; Medical College of Wisconsin; Milwaukee Wisconsin USA
6. Department of Neurology; Mayo Clinic; Scottsdale Arizona USA
7. Qinqunxx Institute; Rosharon Texas USA
8. Department of Neurology; Stanford University; Stanford California USA