Samsung Medical Center, Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, Korea.
J Alzheimers Dis. 2013;35(4):813-21. doi: 10.3233/JAD-121927.
Patients with early-onset Alzheimer's disease (EOAD) may differ from those with late-onset Alzheimer's disease (LOAD) in cognitive impairment profiles and clinical course. Postmortem studies also reported that EOAD has a greater pathologic burden than LOAD. We examined the effects of age at onset on the burden and distribution of amyloid plaques in patients with AD, using a statistical parametric mapping (SPM) and regions of interest (ROIs) analyses of the Pittsburgh compound B (PiB)-PET.
We initially recruited 72 patients with AD who had completed the [11C] PiB-PET scan, but four patients were excluded due to familial AD or incomplete MRI data. Of the 68 patients, 61 were classified as PiB-positive (PiB+) and seven as PiB-negative (PiB-) using the measured global PiB uptake ratio values. Of the 61 patients with PiB+ AD, in order to maximize the effect of onset age, we excluded 20 patients in their 60 s. Thus among the remaining 41 patients, the amyloid deposition of only 17 patients with EOAD (age onset <60 years) and 24 patients with LOAD (onset age ≥70 years) were compared.
There were no significant differences in the global mean PiB index between EOAD and LOAD patients, whereas SPM and ROIs analyses showed that those with EOAD retained higher levels of PiB in the bilateral basal ganglia, bilateral thalamus, left superior temporal cortex, and left cuneus compared to those with LOAD.
Our findings demonstrated that EOAD patients differed from those with LOAD in the topography of amyloid deposition, which may partly account for the findings from previous studies that extrapyramidal symptoms and frontal dysfunction are more common in EOAD than in LOAD patients.
早发性阿尔茨海默病（EOAD）患者的认知障碍模式和临床病程可能与晚发性阿尔茨海默病（LOAD）患者不同。尸检研究还报告称，EOAD 的病理负担比 LOAD 更大。我们使用匹兹堡化合物 B（PiB）-PET 的统计参数映射（SPM）和感兴趣区域（ROI）分析，检查了发病年龄对 AD 患者淀粉样斑块负担和分布的影响。
我们最初招募了 72 名完成 [11C]PiB-PET 扫描的 AD 患者，但由于家族性 AD 或不完整的 MRI 数据，有 4 名患者被排除在外。在 68 名患者中，根据测量的全局 PiB 摄取比值，61 名患者被归类为 PiB+（PiB+），7 名患者为 PiB-（PiB-）。在 61 名 PiB+AD 患者中，为了最大限度地发挥发病年龄的作用，我们排除了 20 名 60 多岁的患者。因此，在其余的 41 名患者中，仅比较了 17 名 EOAD（发病年龄<60 岁）和 24 名 LOAD（发病年龄≥70 岁）患者的淀粉样蛋白沉积。
EOAD 和 LOAD 患者之间的全球平均 PiB 指数没有显著差异，而 SPM 和 ROI 分析显示，与 LOAD 患者相比，EOAD 患者双侧基底节、双侧丘脑、左颞上回和左楔前叶保留了更高水平的 PiB。
我们的研究结果表明，EOAD 患者与 LOAD 患者在淀粉样蛋白沉积的分布上存在差异，这可能部分解释了之前的研究结果，即锥体外系症状和额叶功能障碍在 EOAD 患者中比在 LOAD 患者中更为常见。
