Department of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Mov Disord. 2024 Jan;39(1):130-140. doi: 10.1002/mds.29661. Epub 2023 Nov 27.
Multiple system atrophy (MSA) clinically manifests with either predominant nigrostriatal or cerebellopontine degeneration. This corresponds to two different phenotypes, one with predominant Parkinson's symptoms (MSA-P [multiple system atrophy-parkinsonian subtype]) and one with predominant cerebellar deficits (MSA-C [multiple system atrophy-cerebellar subtype]). Both nigrostriatal and cerebellar degeneration can lead to impaired dexterity, which is a frequent cause of disability in MSA.
The aim was to disentangle the contribution of nigrostriatal and cerebellar degeneration to impaired dexterity in both subtypes of MSA.
We thus investigated nigrostriatal and cerebellopontine integrity using diffusion microstructure imaging in 47 patients with MSA-P and 17 patients with MSA-C compared to 31 healthy controls (HC). Dexterity was assessed using the 9-Hole Peg Board (9HPB) performance.
Nigrostriatal degeneration, represented by the loss of cells and neurites, leading to a larger free-fluid compartment, was present in MSA-P and MSA-C when compared to HCs. Whereas no intergroup differences were observed between the MSAs in the substantia nigra, MSA-P showed more pronounced putaminal degeneration than MSA-C. In contrast, a cerebellopontine axonal degeneration was observed in MSA-P and MSA-C, with stronger effects in MSA-C. Interestingly, the degeneration of cerebellopontine fibers is associated with impaired dexterity in both subtypes, whereas no association was observed with nigrostriatal degeneration.
Cerebellar dysfunction contributes to impaired dexterity not only in MSA-C but also in MSA-P and may be a promising biomarker for disease staging. In contrast, no significant association was observed with nigrostriatal dysfunction. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
多系统萎缩（MSA）在临床上表现为黑质纹状体或脑桥小脑变性为主。这对应于两种不同的表型，一种以帕金森症状为主（MSA-P[多系统萎缩-帕金森亚型]），另一种以小脑缺陷为主（MSA-C[多系统萎缩-小脑亚型]）。黑质纹状体和小脑变性均可导致动作灵活性受损，这是 MSA 患者致残的常见原因。
旨在厘清 MSA 两种亚型中黑质纹状体和小脑变性对动作灵活性受损的影响。
因此，我们使用扩散微观结构成像技术，对 47 例 MSA-P 患者和 17 例 MSA-C 患者以及 31 名健康对照者（HC）进行了黑质纹状体和脑桥小脑完整性研究。使用 9 孔钉板（9HPB）测试评估动作灵活性。
黑质纹状体变性，表现为细胞和神经突的丢失，导致更大的自由液腔，在 MSA-P 和 MSA-C 中与 HC 相比均存在。虽然在黑质中，MSA-P 和 MSA-C 之间没有组间差异，但 MSA-P 显示出比 MSA-C 更明显的壳核变性。相反，在 MSA-P 和 MSA-C 中观察到脑桥小脑轴突变性，在 MSA-C 中更为明显。有趣的是，小脑浦肯野纤维的变性与两种亚型的动作灵活性受损有关，而与黑质纹状体变性无关。
小脑功能障碍不仅在 MSA-C 中，而且在 MSA-P 中都与动作灵活性受损有关，可能是疾病分期的一个有前途的生物标志物。相比之下，与黑质纹状体功能障碍没有显著关联。
