[1] Paracelsus Med Univ, Christian Doppler Klin, Dept Neurosurg, Mullner Hauptstr 48, A-5020 Salzburg, Austria
[2] Paracelsus Med Univ, Univ Hosp, Dept Pediat Surg, Salzburg, Austria
[3] Paracelsus Med Univ, Doctoral Degree Program Med Sci, Strubergasse 21, A-5020 Salzburg, Austria
[4] Paracelsus Med Univ, Dept Oral & Maxillofacial Surg, Salzburg, Austria
[5] Univ Hosp Leipzig, Dept Neurosurg, Dept Pediat Surg, Liebigstr 20a, D-04103 Leipzig, Germany