title: Family History of Alzheimer's Disease is Associated with Impaired Perceptual Discrimination of Novel Objects.
abstract: Early detection may be the key to developing therapies that will combat Alzheimer's disease (AD). It has been consistently demonstrated that one of the main pathologies of AD, tau, is present in the brain decades before a clinical diagnosis. Tau pathology follows a stereotypical route through the medial temporal lobe beginning in the entorhinal and perirhinal cortices. If early pathology leads to very subtle changes in behavior, it may be possible to detect these changes in subjects years before a clinical diagnosis can currently be made. We aimed to discover if cognitively normal middle-aged adults (40-60 years old) at increased risk for AD due to family history would have impaired performance on a cognitive task known to challenge the perirhinal cortex. Using an oddity detection task, we found that subjects with a family history of AD had lowered accuracy without demonstrating differences in rate of acquisition. There were no differences between subjects' medial temporal lobe volume or cortical thickness, indicating that the changes in behavior were not due to significant atrophy. These results demonstrate that subtle changes in perceptual processing are detectable years before a typical diagnosis even when there are no differences detectable in structural imaging data. Anatomically-targeted cognitive testing may be useful in identifying subjects in the earliest stages of AD.
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Mason
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Erin P
authors.initials: EP
authors.lastname: Hussey
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Molitor
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Philip C
authors.initials: PC
authors.lastname: Ko
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.|Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA.|Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Manus J
authors.initials: MJ
authors.lastname: Donahue
authors.affiliation: Department of Neurosurgery, University of Louisville, Louisville, KY, USA.
authors.forename: Brandon A
authors.initials: BA
authors.lastname: Ally
mesh_terms: D000328:Adult; D000544:Alzheimer Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000235:genetics; D002540:Cerebral Cortex / Q000000981:diagnostic imaging; D004192:Discrimination, Psychological / Q000502:physiology*; D005192:Family Health; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000235:genetics; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology*; D017603:Signal Detection, Psychological
keywords: Alzheimer’s disease; cognition; early diagnosis; neuroimaging; risk; visual perception