1. a Department of Neurology, Keck School of Medicine , University of Southern California , Los Angeles, CA, USA
2. b Division of Geriatric Psychiatry , UCLA Semel Institute of Neuroscience and Human Behavior , Los Angeles, CA, USA
3. c Emory University/Atlanta VAMC , Decatur, GA, USA
4. d Department of Internal Medicine , University of California , Los Angeles, CA, USA