1. Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfälische Wilhelms-Universität Münster, Hamm, Germany;
2. Department of Stereotactic Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfälische Wilhelms-Universität Münster, Hamm, Germany;
3. Department of Neurosurgery, Academic Hospital Cologne-Merheim, Witten-Herdecke University, Witten, Germany