1. Department of General Medicine, Ibaraki Prefectural Central Hospital
2. Department of Neurosurgery, Ibaraki Prefectural Central Hospital
3. Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukuba
4. Department of Otolaryngology, Ibaraki Prefectural Central Hospital
5. Department of Neurology, Ibaraki Prefectural Central Hospital
6. Department of Neurosurgery, National Hospital Organization, Mito Medical Center
7. Department of Radiology, Ibaraki Prefectural Central Hospital