1. Division of Neurosurgery, Department of Surgery, University of Malaya, Kuala Lumpur, Malaysia.
2. University Malaya Research Imaging Center, University of Malaya, Kuala Lumpur, Malaysia.
3. VA San Diego Healthcare System, San Diego, California.
4. Department of Psychiatry, University of California San Diego, San Diego, California.
5. Julius Center University Malaya, Department of Social and Preventive Medicine, University of Malaya, Kuala Lumpur, Malaysia.