Effect of age at onset on cortical thickness and cognition in posterior cortical atrophy

• Published in: Neurobiology of aging Vol. 44; pp. 108 - 113
• Main Authors: Suárez-González, Aida, Lehmann, Manja, Shakespeare, Timothy J, Yong, Keir X.X, Paterson, Ross W, Slattery, Catherine F, Foulkes, Alexander J.M, Rabinovici, Gil D, Gil Néciga, Eulogio, Roldán-Lora, Florinda, Schott, Jonathan M, Fox, Nick C, Crutch, Sebastian J
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2016
• Subjects: Age at onset; Age of Onset; Aged; Aging - pathology; Aging - psychology; Alzheimer Disease - pathology; Alzheimer Disease - psychology; Atrophy; Atypical Alzheimer disease; Cerebral Cortex - pathology; Cognition; Cortical thickness; Female; Humans; Internal Medicine; Male; Middle Aged; Neuroimaging; Neurology; Neuropsychological Tests; Posterior cortical atrophy; Neuroimaging; Age at onset; Cortical thickness; Posterior cortical atrophy; Atypical Alzheimer disease
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2016.04.012

Abstract Age at onset (AAO) has been shown to influence the phenotype of Alzheimer’s disease (AD) but how it affects atypical presentations of AD remains unknown. Posterior cortical atrophy (PCA) is the most common form of atypical AD. In this study we aimed to investigate the effect of AAO on cortical thickness and cognitive function in 98 PCA patients. We used Freesurfer (v5.3.0) to compared cortical thickness with AAO both as a continuous variable, and by dichotomising the groups based on median age (58 years). In both the continuous and dichotomised analyses, we found a pattern suggestive of thinner cortex in precuneus and parietal areas in earlier-onset PCA, and lower cortical thickness in anterior cingulate and prefrontal cortex in later-onset PCA. These cortical thickness differences between PCA subgroups were consistent with earlier-onset PCA patients performing worse on cognitive tests involving parietal functions. Our results provide a suggestion that AAO may not only affect the clinico-anatomical characteristics in AD but may also affect atrophy patterns and cognition within atypical AD phenotypes.