1 From the Department of Neurology (Y.X.), Duke Clinical Research Institute, Duke University Medical Center, Durham, NC; and UCSF Neurology (W.C.), Memory and Aging Center, San Francisco, CA. ying.xian@duke.edu.
2 From the Department of Neurology (Y.X.), Duke Clinical Research Institute, Duke University Medical Center, Durham, NC; and UCSF Neurology (W.C.), Memory and Aging Center, San Francisco, CA.