1. Department of Medicine, Faculty of Health, Witten/Herdecke University, 58448 Witten, Germany
2. Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany
3. Department of Neurosurgery, St. Marien-Hospital, Academic Hospital of the Hannover Medical School, 49076 Osnabrueck, Germany
4. Department of Neurosurgery, University Hospital Muenster, 48149 Muenster, Germany
5. Institute of Neuropathology, University Hospital Muenster, 48149 Muenster, Germany
6. Department of Neurosurgery, Academic Hospital Koeln-Merheim, Witten/Herdecke University, 51109 Koeln, Germany