<Original> Comparison with regional glucose metabolism, amyloid deposition and tau deposition between dementia with Lewy bodies and Alzheimer disease brains

[Abstract] Purpose: Although some dementia with Lewy bodies (DLB) patients have Alzheimer disease (AD) pathology, there are no reports comparing AD and DLB by amyloid PET and tau PET in the same patient. The aim of this study was to investigate the regional difference of metabolic reduction, amyloid deposition and tau deposition between DLB and AD brain. Methods: Five consecutive subjects with DLB and five age and Mini-mental state examination score matched AD patients, who underwent both fluoro-2-deoxyglucose (FDG)-PET, Pittsburgh compound B (PiB)-amyloid PET and THK5351 (THK)-tau PET, were included in this study. Voxel-based statistical analysis was performed with Statistical Parametric Mapping for comparison with FDG, amyloid and tau accumulation between the DLB and AD brains. Results: FDG PET demonstrated that occipital metabolism in DLB group was significantly lower than that in AD group. PiB PET demonstrated that in the AD group the anterior to posterior cingulate cortices, supplementary motor area, and thalamic amyloid depositions were significantly higher than those in the DLB group. THK PET demonstrated that in the AD group the posterior cingulate cortices, posterior internal capsules, thalamic and peri-brainstem regions tau depositions were significantly higher than those in the DLB group. Conclusions: In the DLB brain, it is suggested that decreased regional glucose metabolism is unrelated to amyloid and tau depositions, and the amyloid and tau depositions in the cingulate gyri and thalamic regions in the AD brain are higher than those in DLB brain.