[1] Iran Univ Med Sci, Physiol Res Ctr, Fac Med, Tehran, Iran
[2] Iran Univ Med Sci, Colorectal Res Ctr, Tehran, Iran
[3] Kurdistan Univ Med Sci, Liver & Digest Res Ctr, Sanandaj, Iran
[4] Univ Tehran Med Sci, Dept Med, Tehran, Iran
[5] Univ Nottingham, Inst Mental Hlth, Cochrane Schizophrenia Grp, Nottingham, England
[6] Thomas Jefferson Univ, Dept Orthoped & Neurosurg, Rothman Inst, Philadelphia, PA 19107 USA
[7] Thomas Jefferson Univ, Dept Neurosurg, Philadelphia, PA 19107 USA
[8] Univ Hlth Network, Krembil Res Inst, Div Genet & Dev, Toronto, ON, Canada
[9] Univ Hlth Network, Toronto Western Hosp, Div Neurosurg, Toronto, ON, Canada
[10] Univ Toronto, Dept Surg, Toronto, ON, Canada
[11] Univ Toronto, Spine Program, Toronto, ON, Canada
[12] Univ Tehran Med Sci, Sch Publ Hlth, Dept Epidemiol & Biostat, Poursina Ave, Tehran, Iran
[13] Univ Tehran Med Sci, Sina Trauma & Surg Res Ctr, Tehran, Iran
[14] Univ Tehran Med Sci, Neurosci Inst, Imam Khomeini Hosp, Brain & Spinal Injuries Res Ctr BASIR, Tehran, Iran