Hoogkamer Wouter, Bruijn Sjoerd M, Sunaert Stefan, Swinnen Stephan P, Van Calenbergh Frank, Duysens Jacques
Movement Control and Neuroplasticity Research Group, Department of Kinesiology, KU Leuven, Belgium.
Movement Control and Neuroplasticity Research Group, Department of Kinesiology, KU Leuven, Belgium; Department of Orthopedics, First Affiliated Hospital of Fujian Medical University, PR China; MOVE Research Institute, VU University Amsterdam, The Netherlands.
Gait Posture. 2015 Feb;41(2):592-6. doi: 10.1016/j.gaitpost.2015.01.004. Epub 2015 Jan 10.
The evident ataxic characteristics of gait in patients with cerebellar damage suggest that the cerebellum plays an important role in the neural control of gait. Ataxic features, such as increased gait variability and increased step width, are often related to gait stability. However, the link between these measures and gait stability is not straightforward. Therefore, to gain more insights into relations between gait stability, gait variability and gait ataxia, we quantified gait stability using the short-term maximum Lyapunov exponent. This is a more valid measure of gait stability, derived from dynamical systems theory. Eighteen patients with focal cerebellar lesions after tumor resection walked on an instrumented treadmill at 1.0m/s for 3min. The patients displayed relatively mild functional deficits (ICARS=6.9±6.4, range 0-20) and had a lower overground walking speed as compared to healthy controls (1.12m/s versus 1.31m/s). During treadmill walking, the short-term maximum Lyapunov exponent was higher in cerebellar patients, indicating reduced gait stability. Furthermore, step width was increased in the patient group while other spatio-temporal gait parameters were similar. Patients with the largest lesions in the vermis displayed the least stable gait pattern. These observations imply that the short-term maximum Lyapunov exponent is a sensitive measure of gait deficits in mildly ataxic cerebellar patients.
小脑损伤患者明显的共济失调步态特征表明，小脑在步态的神经控制中起着重要作用。共济失调特征，如步态变异性增加和步幅增宽，通常与步态稳定性有关。然而，这些指标与步态稳定性之间的联系并不直接。因此，为了更深入了解步态稳定性、步态变异性和步态共济失调之间的关系，我们使用短期最大李雅普诺夫指数来量化步态稳定性。这是一种从动力系统理论推导出来的更有效的步态稳定性测量方法。18例肿瘤切除术后局灶性小脑病变患者在装有仪器的跑步机上以1.0m/s的速度行走3分钟。与健康对照组相比，这些患者表现出相对较轻的功能缺陷（国际小脑共济失调评级量表评分为6.9±6.4，范围为0 - 20）且地面行走速度较低（分别为1.12m/s和1.31m/s）。在跑步机行走过程中，小脑病变患者的短期最大李雅普诺夫指数较高，表明步态稳定性降低。此外，患者组的步幅增宽，而其他时空步态参数相似。蚓部病变最大的患者表现出最不稳定的步态模式。这些观察结果表明，短期最大李雅普诺夫指数是轻度共济失调小脑患者步态缺陷的敏感指标。
