1. Departments of Neurological Surgery, University of Pittsburgh, Pennsylvania;
2. Yokohama Rosai Hospital, Yokohama;
3. Osaka City General Hospital, Osaka;
4. University of Virginia, Charlottesville, Virginia;
5. Katsuta Hospital Mito GammaHouse, Hitachinaka;
6. Barrow Neurological Institute, Phoenix, Arizona;
7. Kitanihon Hospital, Gosen;
8. Tsukiji Neurological Clinic, Tokyo;
9. Saitama Gamma Knife Center, Saitama;
10. Mominoki Hospital, Kochi;
11. Asanogawa General Hospital, Kanazawa;
12. University of Kentucky, Lexington, Kentucky;
13. Steel Memorial Yawata Hospital, Kitakyushyu;
14. Nagatomi Neurosurgical Hospital, Oita;
15. Hoag Hospital, Newport Beach, California;
16. Southern Tohoku Hospital, Koriyama;
17. Université de Sherbrooke, Centre de Recherche Clinique Étienne-LeBel, Sherbrooke, Quebec, Canada; and
18. NTT Kanto Hospital, Tokyo;
19. Chiba Cardiovascular Center, Ichihara, Japan;
20. New York University Langone Medical Center, New York, New York