[1] Toronto Western Hosp, Div Neurosurg, Spinal Program, Krembi Neurosci Ctr, Toronto, ON M5T 2S8, Canada
[2] Univ Toronto, Dept Surg, Div Neurosurg, Toronto, ON, Canada
[3] Univ Hlth Network, Dept Pathol, Div Neuropathol, Toronto, ON, Canada
[4] Toronto Western Hosp, Univ Hlth Network, Toronto Western Res Inst, Toronto, ON M5T 2S8, Canada
[5] Univ Western Ontario, Dept Phys Med & Rehabil, London, ON, Canada