1 Sultan Qaboos University, Muscat, Sultanate of Oman.
2 College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman.
3 Department of Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada; Neurosurgery Department, Khoula hospital, Muscat, Sultanate of Oman. Electronic address: tariq.al-saadi@mail.mcgill.ca.