1. Department of Otolaryngology-Head and Neck Surgery; University California; San Francisco, San Francisco California U.S.A
2. Department of Neurological Surgery; University California; San Francisco, San Francisco California U.S.A
3. Skull Base and Cerebrovascular Laboratory; University California; San Francisco, San Francisco California U.S.A
4. Center for Minimally Invasive Skull Base Surgery; University California; San Francisco, San Francisco California U.S.A