1. Department of Otorhinolaryngology—Head and Neck Surgery Mayo Clinic Rochester Minnesota USA
2. Department of Quantitative Health Sciences Rochester Minnesota USA
3. Department of Otolaryngology and Neurological Surgery University of Pittsburgh School of Medicine Pittsburgh Pennsylvania USA
4. Department of Neurosurgery Medical College of Wisconsin Milwaukee Wisconsin USA
5. Department of Neurological Surgery Oregon Health & Science University Portland Oregon USA
6. Department of Otolaryngology—Head and Neck Surgery Oregon Health & Science University Portland Oregon USA
7. Department of Neurosurgery CHU de Québec—Université Laval Quebec City Quebec Canada
8. Department of Otorhinolaryngology CHU de Québec—Université Laval Quebec City Quebec Canada
9. Department of Neurologic Surgery Mayo Clinic Rochester Minnesota USA