Affiliations: [a] Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [b] Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands | [c] Department of Radiology, Image Analysis Center and Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands | [d] Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
Correspondence:
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Correspondence to: Annelies E. van der Vlies, Department of Neurology and Alzheimer Center, VU University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands. Tel.: +31 20 4440816; Fax: +31 20 4448529; E-mail: ae.vdvlies@vumc.nl.
Abstract: Aim: To assess the associations of global atrophy and white matter hyperintensities (WMH) with neuropsychological function in early and late onset Alzheimer's disease (AD). Methods: We included 107 patients with sporadic AD (21 early onset and 86 late onset) from our memory clinic. Tests for (working) memory, language, executive function, mental speed, and attention were administered. Global atrophy and global and lobar WMH were measured using 1 Tesla MRI. Linear regression analyses with terms for MRI measures, neuropsychological test results, age, gender, education, and the interaction between separate brain measures and age of onset were performed. Results: Global atrophy was associated with more severely impaired global cognition, working memory, mental speed, and executive function (p < 0.05). Significant interactions between global atrophy and age at onset showed that these associations were mostly attributable to patients with early onset AD. By contrast, an association between global atrophy and memory was found, which was specifically attributable to late onset AD patients. No associations between global WMH and cognitive function were found. Subsequently we analyzed regional WMH and found that temporal WMH was associated with impaired memory, and frontal WMH was associated with slower mental speed. Conclusion: Cortical atrophy, a key feature of AD, is linked to a wide range of cognitive functions, specifically in early onset AD patients. For WMH, there were no interactions with age at onset, but we found specific associations between temporal WMH and memory and frontal WMH and mental speed.
Keywords: Age of onset, Alzheimer's disease, cognition, magnetic resonance imaging
