Affiliations: Department of Neurology, Oita University, Faculty of Medicine, Yufu, Oita, Japan
Correspondence:
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Correspondence to: Noriyuki Kimura, MD, PhD, Department of Neurology, Oita University, Faculty of Medicine, Idaigaoka 1-1, Hasama, Yufu, Oita 879-5593, Japan. Tel.: +81 97 586 5814; Fax: +81 97 586 6502; E-mail: noriyuki@oita-u.ac.jp
Abstract: Background:The differences in positron emission tomography (PET) imaging among older adults with mild cognitive impairment (MCI), according to the recruitment source, remain unclear. Objective:To investigate the differences in brain amyloid deposition and cortical glucose metabolism according to recruitment source among older adults with MCI. Methods:Participants in the clinic-based MCI cohort, who were referred to Oita University Hospital for cognitive decline, consisted of 90 adults with MCI. The community-based MCI cohort, which participated in a prospective cohort study, consisted of 118 adults with MCI. Participants underwent cognitive function evaluation, 11C-Pittsburgh compound B (PiB)-PET, and 18F-fluorodeoxyglucose (FDG)-PET. The prevalence of amyloid positivity and mean PiB and FDG uptake values were compared between the cohorts. Moreover, a voxel-by-voxel group study was performed to determine the areas with significant differences between the clinic- and community-based MCI cohorts. Results:The prevalence of amyloid positivity and mean PiB uptake value in the clinic-based MCI cohort were significantly higher than those in the community-based MCI cohort (p < 0.001 and p < 0.001, respectively). The mean FDG uptake value in the clinic-based MCI cohort was significantly lower than that in the community-based MCI cohort (p < 0.001). SPM 8 analysis showed significantly increased PiB uptake in the precuneus and parietotemporal lobe and significantly decreased FDG uptake in the posterior cingulate in the clinic-based MCI cohort compared to the community-based MCI cohort. Conclusion:The prevalence and severity of amyloid pathology in older adults with MCI varied depending on the recruitment source.
