Department of Radiology, Affiliated Hospital of Guizhou Medical University, Guiyang, 550004, China.
General Practice Center and Department of Radiology, The Seventh Affiliated Hospital, Southern Medical University, Foshan, 528200, China.
Sci Rep. 2023 Aug 30;13(1):14241. doi: 10.1038/s41598-023-41569-5.
Few comparative studies have assessed metabolic brain changes in cognitive impairment among neurodegenerative disorders, and the posterior cingulate cortex (PCC) is a metabolically active brain region with high involvement in multiple cognitive processes. Therefore, in this study, metabolic abnormalities of the PCC were compared in patients with mild cognitive impairment (MCI) due to Parkinson's disease (PD) or Alzheimer's disease (AD), as examined by proton magnetic resonance spectroscopy (H-MRS). Thirty-eight patients with idiopathic PD, including 20 with mild cognitive impairment (PDMCI) and 18 with normal cognitive function (PDN), 18 patients with probable mild cognitive impairment (ADMCI), and 25 healthy elderly controls (HCs) were recruited and underwent PCC H-MRS scans. Compared with HCs, patients with PDMCI exhibited significantly reduced concentrations of N-acetyl aspartate (NAA), total NAA (tNAA), choline (Cho), glutathione (GSH), glutamate + glutamine (Glx) and total creatine (tCr), while ADMCI cases exhibited significantly elevated levels of myo-inositol (Ins) and Ins/tCr ratio, as well as reduced NAA/Ins ratio. No significant metabolic changes were detected in PDN subjects. Compared with ADMCI, reduced NAA, Ins and tCr concentrations were detected in PDMCI. Besides, ROC curve analysis revealed that tCr concentration could differentiate PDMCI from PDN with an AUC of 0.71, and NAA/Ins ratio could differentiate patients with MCI from controls with normal cognitive function with an AUC of 0.74. Patients with PDMCI and ADMCI exhibited distinct PCC metabolic H-MRS profiles. The findings suggested cognitively normal PD patients with low NAA and tCr in the PCC might be at risk of preclinical PDMCI, and Ins and/or NAA/MI ratio in the PCC should be reconsidered a possible biomarker of preclinical MCI in clinical practice. So, comparing PCC's H-MRS profiles of cognitive impairment among neurodegenerative illnesses may provide useful information for better defining the disease process and elucidate possible treatment mechanisms.
这项研究采用质子磁共振波谱（H-MRS）比较了帕金森病（PD）或阿尔茨海默病（AD）所致轻度认知障碍（MCI）患者、特发性 PD 患者（包括 20 例轻度认知障碍伴 PD[PDMCI]和 18 例认知功能正常伴 PD[PDNC]）和可能的轻度认知障碍（ADMCI）患者及 25 例健康老年人（HC）的后扣带回（PCC）代谢异常。与 HC 相比，PDMCI 患者 PCC 的 N-乙酰天冬氨酸（NAA）、总 N-乙酰天冬氨酸（tNAA）、胆碱（Cho）、谷胱甘肽（GSH）、谷氨酸+谷氨酰胺（Glx）和总肌酸（tCr）浓度明显降低，而 ADMCI 患者的肌醇（Ins）和 Ins/tCr 比值升高，NAA/Ins 比值降低。PDNC 患者未发现代谢变化。与 ADMCI 相比，PDMCI 患者的 NAA、Ins 和 tCr 浓度降低。此外，ROC 曲线分析显示 tCr 浓度可区分 PDMCI 与 PDN，曲线下面积（AUC）为 0.71，NAA/Ins 比值可区分 MCI 患者与认知功能正常的对照组，AUC 为 0.74。PDMCI 和 ADMCI 患者的 PCC 代谢 H-MRS 谱不同。研究结果表明，PCC 中 NAA 和 tCr 水平低的认知正常 PD 患者可能有发生亚临床 PDMCI 的风险，Ins 和/或 NAA/Ins 比值可能是临床实践中 MCI 亚临床患者的一个可能的生物标志物。因此，比较神经退行性疾病认知障碍患者的 PCC H-MRS 谱可能为更好地定义疾病过程和阐明可能的治疗机制提供有用信息。
