1. Department of Neurological Surgery, Wexner Medical Center, The Ohio State University College of Medicine, Columbus, Ohio
2. Department of Neurological Surgery, Aswan University, Aswan, Egypt
3. Department of Neurological Surgery, Ain Shams University, Cairo, Egypt
4. Department of Otolaryngology-Head and Neck Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio