Clinical and Striatal Dopamine Transporter Predictors of β-Amyloid in Dementia With Lewy Bodies

Abstract

Objective: To investigate the relationship between β-amyloid (Aβ) deposition and striatal dopamine depletion, cognitive functions, and neuropsychiatric symptoms in dementia with Lewy bodies (DLB).

Methods: We consecutively recruited 51 patients with DLB who had undergone a neuropsychological test, Neuropsychiatric Inventory assessment, brain MRI, N-(3-[18F]fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) PET, and 18F-florbetaben PET within 6 months. The patients were divided into Aβ-negative (DLB-Aβ-, n = 20) and Aβ-positive (DLB-Aβ+, n = 31) groups according to the brain amyloid plaque load score. We performed comparative analyses of dopamine transporter (DAT) activity, neuropsychological profile, and neuropsychiatric symptoms between the 2 groups.

Results: Compared to the DLB-Aβ- group, the DLB-Aβ+ group had a younger age at diagnosis (p = 0.017), poorer performance in attention (p = 0.028) and visuospatial (p = 0.006) functions, and higher proportion of anxiety (p = 0.006) and total neuropsychiatric burden (p = 0.013). Those in the DLB-Aβ+ group also had lower DAT activity in the anterior putamen (p = 0.015) and ventral striatum (p = 0.006) regardless of age, sex, and years of education. In addition, lower DAT activity in the ventral striatum was significantly associated with anxiety and total neuropsychiatric burden in DLB.

Conclusions: This study demonstrated that Aβ deposition in DLB is associated with diagnosis at a younger age, higher cognitive and neuropsychiatric burden, and decreased DAT activity, suggesting that evaluation of clinical features and DAT activity can predict the presence of Aβ in DLB.