1. Department of Neurosurgery, Osaka Neurological Institute
2. Department of Otorhinolaryngology, Kochi Medical School, Kochi University
3. Department of Neurosurgery, Hospital de Transplantes Euryclides de Jesus Zerbini
4. Divison of Neurological Surgery, Hospital das Clínicas, University of São Paulo School of Medicine
5. Department of Neurosurgery, Osaka University Graduate School of Medicine