1. Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, Mayo Clinic, Rochester, Minnesota, USA
2. Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
3. Division of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
4. Department of Otolaryngology/Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA