1. The Stanford Neurosurgical Training and Innovation Center, Stanford University, Palo Alto, California
2. Neurosurgery Unit, Ferrara University Hospital, Department of Morphology Surgery and Experimental Medicine, Ferrara, Italy
3. Department of Neurosurgery, Hospital Clínico Universitario de Valencia, Valencia, Spain
4. Microneurosurgery Laboratory, Department of Anatomy and Human Embriology, University of Valencia, Valencia, Spain
5. College of Medicine and Science, Mayo Clinic, Jacksonville, Florida
6. Department of Neurological Surgery, Stanford University, Palo Alto, California