[1] Univ Edinburgh, Sch Med, Med Stat Unit, Edinburgh EH8 9AG, Midlothian, Scotland
[2] So Gen Hosp, Inst Neurol Sci, Univ Dept Neurosurg, Glasgow G51 4TF, Lanark, Scotland
[3] Hosp Pellegrin, Dept Neurosurg, Bordeaux, France
[4] Gen Infirm, Dept Anaesthet, Leeds LS1 3EX, W Yorkshire, England
[5] Southampton Gen Hosp, Dept Clin Neurosci, Southampton SO9 4XY, Hants, England
[6] Univ Cologne, Neurochirurg Klin, Cologne, Germany
[7] CHU Poitiers, Serv Neurochirurg, Poitiers, France
[8] Univ Rotterdam Hosp, Dept Neurosurg, Rotterdam, Netherlands
[9] Univ Helsinki, Cent Hosp, Dept Neurosurg, Helsinki, Finland
[10] Akademiska Hosp, Dept Neurosurg, Uppsala, Sweden
[11] Osped Gen Provinciale M Bufalini, Div Neurochirurg, Cesena, Italy
[12] IRCCS, Terapia Intens Neurochirurg Serv Anestesia & Rian, Osped Maggiore Policlin, Milan, Italy
[13] Univ Med Sch, Dept Neurosurg, Lublin, Poland
[14] Humboldt Univ, Dept Neurosurg, Virchow Klinkum, Fak Med, Berlin, Germany