1. Neurosurgical Service, Massachusetts General Hospital, Boston;
2. Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts; and
3. Stritch School of Medicine,
4. Department of Neurological Surgery, and
5. Department of Otolaryngology-Head and Neck Surgery, Loyola Center for Cranial Base Surgery, Loyola University Chicago, Loyola University Medical Center, Maywood, Illinois