1. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
2. Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
3. Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Charlestown, MA, USA
4. Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA
5. Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
6. Centers for Rehab Services, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
7. Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA