Disruption of brain circuits is one of the core mechanisms of Parkinson’s disease (PD). Understanding structural connection alterations in PD is important for effective treatment. However, due to methodological limitations, most studies were unable to account for confounding factors such as crossing fibers and were unable to identify damages to specific fiber tracts. In the present study, we aimed to demonstrate tract-specific white matter structural changes in PD patients and their relationship with clinical symptoms. Ninety-eight PD patients, divided into early (ES) and middle stage (MS) groups, and 76 healthy controls (HCs) underwent brain magnetic resonance imaging scans and clinical assessments. Fixel-based analysis was used to investigate fiber tract alterations in PD patients. Compared to HCs, the PD patients showed decreased fiber density (FD) in the corpus callosum (CC), increased FD in the cortical spinal tract (CST), and increased fiber-bundle cross-section (FC, log-transformed: log-FC) in the superior cerebellar peduncle (SCP). Analysis of variance (ANOVA) revealed significant differences in FD in the CST and log-FC in the SCP among the three groups. Post-hoc analysis revealed that the mean FD values of the CST were higher in ES and MS patient groups compared to HCs, and the mean log-FC values of the SCP were higher in ES and MS patient groups compared to HCs. Additionally, the FD values of the CC in PD patients were negatively correlated with the Unified Parkinson’s Disease Rating Scale part-III (UPDRS-III) scores (r = -0.257, p = 0.032), Hamilton Depression Rating Scale 17 Items (HAMD-17) scores (r = -0.230, p = 0.033), and Hamilton Anxiety Scale (HAMA) scores (r = -0.248, p = 0.032). Moreover, log-FC values of the SCP (r = 0.274, p = 0.028) and FD values of the CST (r = 0.384, p < 0.001) were positively correlated with the UPDRS-III scores. We concluded that PD patients had both decreased and increased white matter integrity within specific fiber bundles. Additionally, these white matter alterations were different across disease stages, suggesting the occurrence of complex pathological and compensatory changes during the development of PD.

脑回路中断是帕金森氏病（PD）的核心机制之一。了解PD中的结构连接改变对于有效治疗很重要。但是，由于方法的局限性，大多数研究无法解释混杂因素，例如交叉纤维，也无法确定对特定纤维束的损害。在本研究中，我们旨在证明PD患者的特定于管道的白质结构变化及其与临床症状的关系。分为早期（ES）和中期（MS）组的98名PD患者以及76名健康对照（HCs）进行了脑磁共振成像扫描和临床评估。基于Fixel的分析用于研究PD患者的纤维束改变。与HC相比，PD患者的call体（CC）纤维密度（FD）降低，皮质脊髓（CST）FD升高，纤维束横截面（FC，log-transformed：log-FC）增加上小脑梗（SCP）。方差分析（ANOVA）显示，三组之间CST的FD和SCP的log-FC显着不同。事后分析显示，与HC相比，ES和MS患者组中CST的平均FD值更高，而ES和MS患者组中SCP的平均log-FC值更高。此外，PD患者CC的FD值与帕金森病综合评分量表（III）（UPDRS-III）得分呈负相关（并在上小脑梗（SCP）中增加了纤维束横截面（FC，log-transformed：log-FC）。方差分析（ANOVA）显示，三组之间CST的FD和SCP的log-FC显着不同。事后分析显示，与HC相比，ES和MS患者组中CST的平均FD值更高，而ES和MS患者组中SCP的平均log-FC值更高。此外，PD患者CC的FD值与帕金森病综合评分量表（III）（UPDRS-III）得分呈负相关（并在上小脑梗（SCP）中增加了纤维束横截面（FC，log-transformed：log-FC）。方差分析（ANOVA）显示，三组之间CST的FD和SCP的log-FC显着不同。事后分析显示，与HC相比，ES和MS患者组中CST的平均FD值更高，而ES和MS患者组中SCP的平均log-FC值更高。此外，PD患者CC的FD值与帕金森病综合评分量表（III）（UPDRS-III）得分呈负相关（事后分析显示，与HC相比，ES和MS患者组中CST的平均FD值更高，而ES和MS患者组中SCP的平均log-FC值更高。此外，PD患者CC的FD值与帕金森病综合评分量表（III）（UPDRS-III）得分呈负相关（事后分析显示，与HC相比，ES和MS患者组中CST的平均FD值更高，而ES和MS患者组中SCP的平均log-FC值更高。此外，PD患者CC的FD值与帕金森病综合评分量表（III）（UPDRS-III）得分呈负相关（r  = -0.257，p  = 0.032），汉密尔顿抑郁量表17个项目（HAMD-17）得分（r  = -0.230，p  = 0.033），汉密尔顿焦虑量表（HAMA）得分（r  = -0.248，p  = 0.032） ）。此外，SCP的log-FC值（r  = 0.274，p  = 0.028）和CST的FD值（r = 0.384，p <0.001）与UPDRS-III得分呈正相关。我们得出的结论是，PD患者在特定纤维束内白质完整性降低且升高。此外，这些白质变化在疾病各个阶段均不同，这表明在PD发生过程中会发生复杂的病理和代偿性变化。