1 Division of Neurosurgery, Philippine General Hospital, and Department of Anatomy, College of Medicine, University of the Philippines Manila, Manila, Philippines. Electronic address: rebaticulon@up.edu.ph.
2 Division of Neurosurgery, National University Hospital Singapore, Singapore.
3 Division of Pediatric Neurosurgery, Hasan Sadikin Hospital/Padjadjaran University, Bandung, West Java, Indonesia.
4 Department of Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
5 Division of Neurosurgery, Department of Surgery, Queen Sirikit National Institute of Child Health, Bangkok, Thailand.