1. Department of Neurosurgery, University of Ulm, Ulm, Germany
2. Department of Pediatric Surgery, University of Ulm, Ulm, Germany
3. Department of Pediatrics, University of Ulm, Ulm, Germany
4. Department of Traumatology and Plastic Surgery, University of Ulm, Ulm, Germany
5. Department of Neurosurgery, Hospital Landshut, Landshut, Germany