Currently, no reliable predictors of cognitive impairment in Parkinson’s disease exist. We hypothesized that microstructural changes at grey matter T₁-weighted MRI and diffusion tensor imaging in the cholinergic system nuclei and associated limbic pathways underlie cognitive impairment in Parkinson’s disease. We performed a cross-sectional comparison between patients with Parkinson’s disease with and without cognitive impairment. We also performed a longitudinal 36-month follow-up study of cognitively intact Parkinson’s disease patients, comparing patients who remained cognitively intact to those who developed cognitive impairment. Patients with Parkinson’s disease with cognitive impairment showed lower grey matter volume and increased mean diffusivity in the nucleus basalis of Meynert, compared to patients with Parkinson’s disease without cognitive impairment. These results were confirmed both with region of interest and voxel-based analyses, and after partial volume correction. Lower grey matter volume and increased mean diffusivity in the nucleus basalis of Meynert was predictive for developing cognitive impairment in cognitively intact patients with Parkinson’s disease, independent of other clinical and non-clinical markers of the disease. Structural and microstructural alterations in entorhinal cortex, amygdala, hippocampus, insula, and thalamus were not predictive for developing cognitive impairment in Parkinson’s disease. Our findings provide evidence that degeneration of the nucleus basalis of Meynert precedes and predicts the onset of cognitive impairment, and might be used in a clinical setting as a reliable biomarker to stratify patients at higher risk of cognitive decline.

中文翻译：

---

Meynert 变性的基底核先于并预测帕金森病的认知障碍


目前，尚无帕金森病认知障碍的可靠预测因素。我们假设胆碱能系统核和相关边缘通路中灰质 T ₁加权 MRI 和弥散张量成像的微观结构变化是帕金森病认知障碍的基础。我们对患有和不患有认知障碍的帕金森病患者进行了横断面比较。我们还对认知功能完好的帕金森病患者进行了一项为期 36 个月的纵向随访研究，将认知功能完好的患者与出现认知障碍的患者进行了比较。与无认知障碍的帕金森病患者相比，患有认知障碍的帕金森病患者的 Meynert 基底核灰质体积较低，平均扩散率增加。这些结果通过感兴趣区域和基于体素的分析以及部分体积校正后得到证实。迈纳特基底核灰质体积降低和平均扩散率增加可预测认知功能完好的帕金森病患者出现认知障碍，独立于该疾病的其他临床和非临床标志物。内嗅皮层、杏仁核、海马、岛叶和丘脑的结构和微观结构改变并不能预测帕金森病认知障碍的发生。我们的研究结果提供了证据，表明 Meynert 基底核的变性先于并预测认知障碍的发生，并且可能在临床环境中用作可靠的生物标志物，以对认知能力下降较高风险的患者进行分层。