Using a fixel-based analysis (FBA), we assessed the fiber-specific white matter (WM) alterations in nonmedicated patients with early-stage Parkinson’s disease (PD) with tremor-dominant (TD; n = 53; mean age, 61.7 ± 8.7 years) and postural instability and gait disorder (PIGD; n = 27; mean age, 57.8 ± 8.1 years) motor subtypes and age- and sex-matched healthy controls (HC; n = 43; mean age, 61.6 ± 9.2 years) from Parkinson’s Progression Markers Initiative dataset. FBA revealed significantly increased macrostructural fiber cross section and a combination of fiber density and cross section metrics within the corticospinal tract in patients with TD-PD compared with HC. Nonetheless, no significant changes in FBA-derived metrics were found in patients with PIGD-PD compared with HC or patients with TD-PD. Our results may provide evidence of WM neural compensation mechanisms in patients with TD-PD marked by increases in fiber bundle size and the ability to relay information between brain regions.

使用基于 fixel 的分析 (FBA)，我们评估了非药物治疗的早期帕金森病 (PD) 患者的纤维特异性白质 (WM) 变化，这些患者以震颤为主 (TD；n  = 53；平均年龄，61.7 ± 8.7 岁）和姿势不稳和步态障碍（PIGD；n  = 27；平均年龄，57.8 ± 8.1 岁）运动亚型和年龄和性别匹配的健康对照（HC；n = 43; 平均年龄，61.6 ± 9.2 岁）来自帕金森病进展标记倡议数据集。FBA 显示与 HC 相比，TD-PD 患者的皮质脊髓束的宏观结构纤维横截面显着增加，纤维密度和横截面指标的组合显着增加。尽管如此，与 HC 或 TD-PD 患者相比，PIGD-PD 患者的 FBA 衍生指标没有显着变化。我们的研究结果可能为 TD-PD 患者的 WM 神经补偿机制提供证据，其特征是纤维束大小的增加和大脑区域之间传递信息的能力。