SUBJECTS
Patients with Alzheimer disease were diagnosed using National Institute of Neurological and Communication Disorders and Stroke—Alzheimer's Disease and Related Disoders Association criteria14 by 2 board certified neurologists in a memory disorders clinic at a tertiary care university medical center. Patients with AD were subdivided into mild (n = 11) and moderate (n = 9) AD subgroups according to published criteria, with mild AD defined as a Mini-Mental State Examination (MMSE)9 score greater than 20, and moderate AD defined as an MMSE score between 10 and 20.4 One AD patient with an MMSE score of 8 was included in the moderate group based on the diagnostic consensus of the treating neurologists. Controls were recruited from community advertisements. Controls had MMSE scores equal to or greater than 1 SD below the mean for their age and education. Informant reports for controls verified no cognitive impairment history. Participants were screened for medications and medical and psychiatric conditions that might affect cognition. Informed consent was obtained from all subjects and from AD caregivers as part of this institutional review board–approved research.