Occipital Amyloid Deposition Is Associated with Rapid Cognitive Decline in the Alzheimer's Disease Continuum.

ABSTRACT

BACKGROUND: Clinical significance of additional occipital amyloid-ß (Aß) plaques in Alzheimer's disease (AD) remains unclear. OBJECTIVE: In this study, we investigated the effect of regional Aß deposition on cognition in patients on the AD continuum, especially in the occipital region. METHODS: We retrospectively reviewed the medical record of 208 patients with AD across the cognitive continuum (non-dementia and dementia). Multivariable linear regression analyses were performed to determine the effect of regional Aß deposition on cognitive function. A linear mixed model was used to assess the effect of regional deposition on longitudinal changes in Mini-Mental State Examination (MMSE) scores. Additionally, the patients were dichotomized according to the occipital-to-global Aß deposition ratio (ratio ≤1, Aß-OCC- group; ratio >1, Aß-OCC+ group), and the same statistical analyses were applied for between-group comparisons. RESULTS: Regional Aß burden itself was not associated with baseline cognitive function. In terms of Aß-OCC group effect, the Aß-OCC+ group exhibited a poorer cognitive performance on language function compared to the Aß-OCC- group. High Aß retention in each region was associated with a rapid decline in MMSE scores, only in the dementia subgroup. Additionally, Aß-OCC+ individuals exhibited a faster annual decline in MMSE scores than Aß-OCC- individuals in the non-dementia subgroup (ß= -0.77, standard error [SE] = 0.31, p = 0.013). CONCLUSION: The present study demonstrated that additional occipital Aß deposition was associated with poor baseline language function and rapid cognitive deterioration in patients on the AD continuum.