Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA.
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
Neurobiol Dis. 2023 Sep;185:106243. doi: 10.1016/j.nbd.2023.106243. Epub 2023 Jul 29.
Approximately one third of recently diagnosed Parkinson's disease (PD) patients experience cognitive decline. The nucleus basalis of Meynert (NBM) degenerates early in PD and is crucial for cognitive function. The two main NBM white matter pathways include a lateral and medial trajectory. However, research is needed to determine which pathway, if any, are associated with PD-related cognitive decline.
Thirty-seven PD patients with no mild cognitive impairment (MCI) were included in this study. Participants either developed MCI at 1-year follow up (PD MCI-Converters; n = 16) or did not (PD no-MCI; n = 21). Mean diffusivity (MD) and fractional anisotropy (FA) of the medial and lateral NBM tracts were extracted using probabilistic tractography. Between-group differences in MD and FA for each tract was compared using ANCOVA, controlling for age, sex, and disease duration. Control comparisons of the internal capsule MD and FA were also performed. Associations between baseline MD or FA and cognitive outcomes (working memory, psychomotor speed, delayed recall, and visuospatial function) were assessed using linear mixed models.
PD MCI-Converters had significantly greater MD and lower FA (p < .001) of both NBM tracts compared to PD no-MCI. No difference was found in the MD (p = .06) or FA (p = .31) of the control region. Trends were identified between: 1) lateral tract MD and FA with working memory decline; and 2) medial tract MD and reduced psychomotor speed.
Reduced integrity of the NBM tracts is evident in PD patients up to one year prior to the development of MCI. Thus, deterioration of the NBM tracts in PD may be an early marker of those at risk of cognitive decline.
大约三分之一的新诊断帕金森病（PD）患者经历认知能力下降。基底核梅内尔特（NBM）在 PD 中早期退化，对认知功能至关重要。NBM 的两条主要白质通路包括外侧和内侧轨迹。然而，需要研究确定哪条通路（如果有的话）与 PD 相关的认知能力下降有关。
本研究纳入了 37 名无轻度认知障碍（MCI）的 PD 患者。参与者在 1 年随访时要么发展为 MCI（PD MCI-转化者；n=16），要么没有（PD 无-MCI；n=21）。使用概率追踪法提取内侧和外侧 NBM 束的平均扩散系数（MD）和各向异性分数（FA）。使用协方差分析比较两组之间各束的 MD 和 FA 差异，控制年龄、性别和疾病持续时间。还对内侧囊 MD 和 FA 进行了对照组比较。使用线性混合模型评估基线 MD 或 FA 与认知结果（工作记忆、心理运动速度、延迟回忆和视觉空间功能）之间的关系。
与 PD 无-MCI 相比，PD MCI-转化者的两条 NBM 束的 MD 显著增加，FA 显著降低（p<0.001）。控制区域的 MD 无差异（p=0.06）或 FA 无差异（p=0.31）。发现了以下趋势：1）外侧束 MD 与工作记忆下降有关，FA 与工作记忆下降有关；2）内侧束 MD 与心理运动速度降低有关。
在 MCI 发生前一年，PD 患者的 NBM 束完整性明显降低。因此，PD 中 NBM 束的退化可能是认知能力下降风险增加的早期标志物。
