Department of Neurology, China-Japan Union Hospital of Jilin University, Xiantai street 126, Changchun, 130033, Jilin Province, China.
J Neural Transm (Vienna). 2021 Feb;128(2):171-179. doi: 10.1007/s00702-020-02295-8. Epub 2021 Feb 9.
Neuromelanin (NM) is a dark pigment that mainly exists in neurons of the substantia nigra pars compacta (SNc). In Parkinson disease (PD) patients, NM concentration decreases gradually with degeneration and necrosis of dopamine neurons, suggesting potential use as a PD biomarker. We aimed to evaluate associations between NM concentration in in vivo SN and PD progression and different motor subtypes using NM magnetic resonance imaging (NM-MRI). Fifty-four patients with idiopathic PD were enrolled. Patients were divided into groups by subtypes with different clinical symptoms: tremor dominant (TD) group and postural instability and gait difficulty (PIGD) group. Fifteen healthy age-matched volunteers were enrolled as controls. All subjects underwent clinical assessment and NM-MRI examination. PD patients showed significantly decreased contrast-to-noise ratio (CNR) values in medial and lateral SN (P < 0.05) compared to controls. CNR values in lateral SN region decreased linearly with PD progression (P = 0.001). PIGD patients showed significant decreases in CNR mean values in lateral SN compared to TD patients (P = 0.004). Diagnostic accuracy of using lateral substantia nigra (SN) in TD and PIGD groups was 79% (sensitivity 76.5%, specificity 78.6%). NM concentration in PD patients decreases gradually during disease progression and differs significantly between PD subtypes. NM may be a reliable biomarker for PD severity and subtype identification.
神经黑色素（NM）是一种深褐色的色素，主要存在于致密部黑质神经元中。在帕金森病（PD）患者中，随着多巴胺神经元的变性和坏死，NM 浓度逐渐降低，提示其可能作为 PD 的生物标志物。本研究旨在使用 NM 磁共振成像（NM-MRI）评估体内 SN 中 NM 浓度与 PD 进展和不同运动亚型之间的关系。纳入 54 例特发性 PD 患者。根据不同的临床症状将患者分为震颤为主型（TD）组和姿势不稳及步态困难型（PIGD）组。纳入 15 名年龄匹配的健康志愿者作为对照组。所有受试者均接受临床评估和 NM-MRI 检查。与对照组相比，PD 患者的中脑 SN 内侧和外侧的对比噪声比（CNR）值显著降低（P<0.05）。外侧 SN 区域的 CNR 值随 PD 进展呈线性下降（P=0.001）。与 TD 患者相比，PIGD 患者的外侧 SN 中 CNR 平均值显著降低（P=0.004）。TD 和 PIGD 组中使用外侧 SN 的诊断准确率为 79%（灵敏度 76.5%，特异性 78.6%）。PD 患者的 NM 浓度在疾病进展过程中逐渐降低，且在不同的 PD 亚型之间存在显著差异。NM 可能是 PD 严重程度和亚型识别的可靠生物标志物。
