IRCCS Centro Neurolesi Bonino Pulejo, via Palermo, SS 113, Ctr. Casazza, 98124, Messina, Italy.
Stomatodental Center, Messina, Italy.
J Neuroeng Rehabil. 2019 Sep 18;16(1):116. doi: 10.1186/s12984-019-0590-0.
A proper rehabilitation program targeting gait is mandatory to maintain the quality of life of patients with Myotonic dystrophy type 1 (DM1). Assuming that gait and balance impairment simply depend on the degree of muscle weakness is potentially misleading. In fact, the involvement of the Central Nervous System (CNS) in DM1 pathophysiology calls into account the deterioration of muscle coordination in gait impairment. Our study aimed at demonstrating the presence and role of muscle connectivity deterioration in patients with DM1 by a CNS perspective by investigating signal synergies using a time-frequency spectral coherence and multivariate analyses on lower limb muscles while walking upright. Further, we sought at determining whether muscle networks were abnormal secondarily to the muscle impairment or primarily to CNS damage (as DM1 is a multi-system disorder also involving the CNS). In other words, muscle network deterioration may depend on a weakening in signal synergies (that express the neural drive to muscles deduced from surface electromyography data).
Such an innovative approach to estimate muscle networks and signal synergies was carried out in seven patients with DM1 and ten healthy controls (HC).
Patients with DM1 showed a commingling of low and high frequencies among muscle at both within- and between-limbs level, a weak direct neural coupling concerning inter-limb coordination, a modest network segregation, high integrative network properties, and an impoverishment in the available signal synergies, as compared to HCs. These network abnormalities were independent from muscle weakness and myotonia.
Our results suggest that gait impairment in patients with DM1 depends also on a muscle network deterioration that is secondary to signal synergy deterioration (related to CNS impairment). This suggests that muscle network deterioration may be a primary trait of DM1 rather than a maladaptive mechanism to muscle degeneration. This information may be useful concerning the implementation of proper rehabilitative strategies in patients with DM1. It will be indeed necessary not only addressing muscle weakness but also gait-related muscle connectivity to improve functional ambulation in such patients.
针对步态的适当康复计划对于维持 1 型肌强直性营养不良（DM1）患者的生活质量是强制性的。假设步态和平衡障碍仅仅取决于肌肉无力的程度，这可能会产生误导。事实上，中枢神经系统（CNS）在 DM1 病理生理学中的参与考虑到了步态障碍中肌肉协调性的恶化。我们的研究旨在通过从 CNS 的角度证明 DM1 患者存在并研究肌肉连接恶化的作用，通过调查下肢肌肉在直立行走时的信号协同作用使用时频谱相干性和多变量分析。此外，我们试图确定肌肉网络是否是继发于肌肉损伤还是主要继发于中枢神经系统损伤（因为 DM1 是一种多系统疾病，也涉及中枢神经系统）。换句话说，肌肉网络的恶化可能取决于信号协同作用的减弱（这表达了从表面肌电图数据推断出的肌肉的神经驱动）。
在 7 名 DM1 患者和 10 名健康对照组（HC）中进行了这种估计肌肉网络和信号协同作用的创新方法。
与 HC 相比，DM1 患者在四肢内和四肢间水平上均显示出肌肉中低频和高频的混合，涉及肢体间协调的直接神经耦合较弱，网络分离程度适度，网络集成特性较高，以及可用信号协同作用的减少。这些网络异常与肌肉无力和肌强直无关。
我们的结果表明，DM1 患者的步态障碍也取决于肌肉网络的恶化，这是信号协同作用恶化的结果（与中枢神经系统损伤有关）。这表明肌肉网络的恶化可能是 DM1 的主要特征，而不是肌肉退化的适应不良机制。这些信息对于在 DM1 患者中实施适当的康复策略可能是有用的。不仅要解决肌肉无力问题，还要解决与步态相关的肌肉连接问题，以改善此类患者的功能性步行能力。
