Department of Neurology, Massachusetts General Hospital, Boston, USA.
Neurology. 2013 Jan 1;80(1):85-91. doi: 10.1212/WNL.0b013e31827b1a07. Epub 2012 Dec 12.
To determine whether amyloid burden, as indexed by Pittsburgh compound B (PiB) retention, identifies patients with Parkinson disease with mild cognitive impairment (PD-MCI) compared to those with normal cognition (PD-nl). A related aim is to determine whether amyloid burden predicts cognitive decline in a cohort of subjects with PD without dementia.
In this prospective cohort study, we examined 46 subjects with PD without dementia, of whom 35 had normal cognition and 11 met criteria for PD-MCI at study baseline. All subjects underwent standardized neurologic and neuropsychological examinations and PiB PET at baseline, and clinical examinations were conducted annually for up to 5 years.
At baseline, precuneus PiB retention did not distinguish PD-MCI from PD-nl. Subjects with PD-MCI declined more rapidly than PD-nl subjects on cognitive tests of memory, executive function, and activation retrieval. Of the 35 PD-nl subjects, 8 progressed to PD-MCI and 1 to dementia; of the 11 PD-MCI subjects, 5 converted to dementia. Both higher PiB retention and a diagnosis of PD-MCI predicted a greater hazard of conversion to a more severe diagnosis. Baseline PiB retention predicted worsening in executive function over time. The APOE ε4 allele also related to worsening in executive function, as well as visuospatial function, activation retrieval, and performance on the Mini-Mental State Examination. In contrast to its relation to cognitive decline, PiB retention did not affect progression of motor impairment.
At baseline measurements, amyloid burden does not distinguish between cognitively impaired and unimpaired subjects with PD without dementia, but our data suggest that amyloid contributes to cognitive, but not motor, decline over time.
确定匹兹堡化合物 B（PiB）保留指数所代表的淀粉样蛋白负担是否可将帕金森病伴轻度认知障碍（PD-MCI）患者与认知正常（PD-nl）患者区分开来。相关目的是确定淀粉样蛋白负担是否可预测无痴呆帕金森病患者队列的认知下降。
在这项前瞻性队列研究中，我们检查了 46 名无痴呆的帕金森病患者，其中 35 名认知正常，11 名符合 PD-MCI 的标准。所有患者在基线时接受了标准化的神经学和神经心理学检查以及 PiB PET，并且在长达 5 年的时间内每年进行临床检查。
在基线时，扣带回后部的 PiB 保留并不能区分 PD-MCI 与 PD-nl。与 PD-nl 患者相比，PD-MCI 患者在记忆、执行功能和激活检索的认知测试中下降更快。在 35 名 PD-nl 患者中，有 8 名进展为 PD-MCI，1 名进展为痴呆；在 11 名 PD-MCI 患者中，有 5 名进展为痴呆。较高的 PiB 保留和 PD-MCI 的诊断均预测向更严重的诊断转变的风险更大。基线 PiB 保留可预测执行功能随时间的恶化。APOE ε4 等位基因也与执行功能以及视空间功能、激活检索和简易精神状态检查的表现恶化有关。与认知下降相反，PiB 保留不会影响运动功能的进展。
在基线测量中，淀粉样蛋白负担不能区分无痴呆的帕金森病患者中认知受损和未受损的患者，但我们的数据表明，淀粉样蛋白随时间推移会导致认知而非运动功能下降。
