1. Division of Physical Medicine & Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
2. Rehabilitation Research Program, GF Strong Rehab Centre, Vancouver, British Columbia, Canada
3. Neurosurgery, Massachusetts General Hospital, Neurosurgery, Harvard Medical School, Boston
4. Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Boston
5. Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts