Kemppainen Nina, Joutsa Juho, Johansson Jarkko, Scheinin Noora M, Någren Kjell, Rokka Johanna, Parkkola Riitta, Rinne Juha O
Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.
J Alzheimers Dis. 2015;48(1):123-33. doi: 10.3233/JAD-150190.
The aim of this longitudinal positron emission tomography (PET) study was to evaluate the interrelationship between brain metabolism and amyloid accumulation during the disease process from mild cognitive impairment (MCI) to Alzheimer's disease (AD). Nine MCI patients, who converted to AD between two and five years, and nine healthy subjects underwent [11C]PIB and [18F]FDG PET scans at baseline and at 5 years. [11C]PIB uptake was clearly higher in MCI patients at baseline compared to controls and spread extensively to the cerebral cortex during the conversion to AD. [18F]FDG uptake was reduced especially in the temporal-parietal regions in MCI compared to controls at baseline, and widely over the cortex at the 5-year follow-up. The reduction in metabolism during the follow-up was significant in the posterior brain regions. In addition, brain amyloid load was positively associated with metabolism in posterior brain regions in MCI, but not after conversion to AD. The results suggest that there are interactions between brain amyloid accumulation and metabolism during the AD process, including a possible compensatory upregulation of posterior brain metabolism in the early phase.
这项纵向正电子发射断层扫描（PET）研究的目的是评估从轻度认知障碍（MCI）到阿尔茨海默病（AD）的疾病过程中脑代谢与淀粉样蛋白积累之间的相互关系。9名在两到五年内转化为AD的MCI患者和9名健康受试者在基线期和5年时接受了[11C]PIB和[18F]FDG PET扫描。与对照组相比，MCI患者在基线期的[11C]PIB摄取明显更高，并且在转化为AD的过程中广泛扩散至大脑皮层。与对照组相比，MCI患者在基线期时[18F]FDG摄取尤其在颞顶叶区域减少，而在5年随访时则广泛分布于整个皮层。随访期间后脑区域的代谢降低显著。此外，MCI患者后脑区域的脑淀粉样蛋白负荷与代谢呈正相关，但转化为AD后则不然。结果表明，在AD过程中脑淀粉样蛋白积累与代谢之间存在相互作用，包括早期阶段后脑代谢可能的代偿性上调。
