Brain acetylcholinesterase changes in dementia with Lewy Bodies and Parkinson\u27s disease with dementia demonstrated by PET

Objectives: To investigate alterations of brain cholinergic function in patients with Dementia with Lewy Bodies (DLB) and Parkinson\u27s Disease with Dementia (PDD) by measurements of brain acethylcholinesterase (AChE) activity in vivo. Methods: Participants were 10 patients with DLB (mean age: 75+/-4 years; male/female: 5/5; MMSE: 19+/-5), 10 patients with PDD (mean age: 75+/-4 years; male/female: 4/6; MMSE: 18+/-6), 9 patients with PD (mean age: 66+/-6 years; male/female: 6/3; MMSE: 28+/-2) and age-matched 27 healthy controls (mean age: 64+-10years; male/female: 14/13; MMSE: 29+-1). We performed N-[11C]-methyl-4-piperidyl acetate (MP4A) PET scan for 40 minutes with arterial blood sampling, and the regional brain AChE activities were estimated in the three-compartment model. Brain AChE activities were compared between DLB group and healthy control group by voxel-based analysis using the two sample t-test in statistical parametric mapping 2 (SPM), and .mean AChE activities of the cerebral cortex were also compared. Same statistical analyses were performed between PDD and controls, and between PD and controls. Results: The mean AChE activity of the cerebral cortex was significantly lower in the DLB(%reduction:29.4%) and PDD(-24.4%) groups compared with the PD(-11.5%) group and the healthy control group(ANOVA, p<0.01:DLBvsPD, DLBvsNC, PDDvsNC, p<0.05:PDDvsPD respectively). The SPM showed that regional AChE activities were significantly lower in almost all cortical areas in the DLB and PDD groups (FWE corrected p