[1] Nottingham Univ Hosp NHS Trust, QMC, Ctr Spinal Studies & Surg, Nottingham, England
[2] Charles Univ Prague, Fac Med 1, Dept Neurosurg & Neurooncol, Prague, Czech Republic
[3] Mil Univ Hosp Prague, Prague, Czech Republic
[4] Charles Univ Prague, Fac Med 3, Dept Anesthesiol & Crit Care Med, Prague, Czech Republic