1. Department of Neurosurgery, Taipei Veterans General Hospital, Taipei, Taiwan
2. School of Medicine, National Yang-Ming University, Taipei, Taiwan
3. Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA
4. Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
5. Department of Neurosurgery, University of Miami, Coral Gables, FL, USA