1. Division of Neurosurgery, University of the Philippines-Philippine General Hospital, Manila, Philippines;
2. Section of Neurosurgery, Department of Surgery, Northern Mindanao Medical Center, Cagayan de Oro City, Misamis Oriental, Philippines;
3. Department of Internal Medicine, Mariano Marcos Memorial Hospital & Medical Center, Batac City, Ilocos Norte, Philippines;
4. Department of Neurosciences, Section of Adult Neurology, Makati Medical Center, Makati, Philippines