Alphonsa Sushma, Wuebbles Ryan, Jones Takako, Pavilionis Phil, Murray Nicholas
Department of Pharmacology, School of Medicine, University of Nevada, Reno, 89557, USA.
Department of Kinesiology, School of Public Health, University of Nevada, Reno, 89557, USA.
J Clin Transl Res. 2022 Mar 19;8(2):166-175. eCollection 2022 Apr 29.
Facioscapulohumeral muscular dystrophy (FSHD) is a rare genetic muscle disorder leading to progressive muscle loss over time. Research indicates that this progressive muscular atrophy can negatively impact spatio-temporal gait characteristics, but this is not always the case during early-onset or mild cases of the disease. In addition, the performance of a secondary task during overground walking may elucidate greater deficits in spatio-temporal characteristics of gait. However, such dual task effects on FSHD gait have not been studied thus far.
The current study aimed to (a) quantify changes in spatio-temporal gait parameters in individuals with FSHD using the Tekscan Strideway gait mat system, (b) measure the dual task (DT) effects on cadence and gait velocity during single task (ST) and DT overground walking in FSHD and healthy controls and (c) investigate the correlation between the gait parameters and the methylation status in FSHD.
Nine FSHD (M±SD=52.78±14.69 years) and nine nearly matched healthy controls (M±SD=50.11±16.18 years) performed five ST and five DT walking in a pseudo-randomized order. The DT included a serial 7's subtraction task from a random number between 50 and 100. Dependent variables: Cadence (steps/min) and gait velocity (cm/sec) were obtained from Tekscan Strideway (30 Hz, Boston, MA).
The pairwise comparison indicated that cadence was significantly different for both ST (<0.004) and DT (<0.02) where FSHD showed lower cadence compared to controls. Gait velocity was also significantly lower for FSHD during ST (<0.004) and DT (<0.008). Multilevel modeling (MLM) approach revealed a group by task interaction for cadence (<0.05) and gait velocity (<0.001). The interaction showed a significant difference between ST and DT in controls for cadence and gait velocity. However, there was no difference between ST and DT in FSHD. Finally, a comparison of methylation percentage versus gait parameters revealed a significant negative correlation coefficient for cadence but not for gait velocity.
These results indicate specific pairwise differences in both ST and DT walking, observed in the gait parameters as decreased cadence and gait velocity during ST and DT. In addition, the MLM showed that controls exhibited the DT cost as expected but FSHD did not for cadence and gait velocity.
ST appears to be sufficiently challenging in FSHD and results in overall declines in spatio-temporal characteristics of gait. Further research is needed to test this paradigm with early-onset or mild cases to track disease progression and its effects on ambulation.
面肩肱型肌营养不良症（FSHD）是一种罕见的遗传性肌肉疾病，随着时间的推移会导致进行性肌肉萎缩。研究表明，这种进行性肌肉萎缩会对时空步态特征产生负面影响，但在疾病的早发型或轻症病例中情况并非总是如此。此外，在地面行走时执行次要任务可能会揭示步态时空特征方面更大的缺陷。然而，迄今为止尚未研究这种双重任务对FSHD步态的影响。
本研究旨在（a）使用Tekscan Strideway步态垫系统量化FSHD患者时空步态参数的变化，（b）测量FSHD患者和健康对照在单任务（ST）和双重任务（DT）地面行走期间双重任务（DT）对步频和步态速度的影响，以及（c）研究FSHD患者步态参数与甲基化状态之间的相关性。
9名FSHD患者（平均年龄±标准差=52.78±14.69岁）和9名年龄匹配的健康对照（平均年龄±标准差=50.11±16.18岁）以伪随机顺序进行5次ST行走和5次DT行走。DT包括从50到100之间的随机数中连续减去7的任务。因变量：步频（步/分钟）和步态速度（厘米/秒）通过Tekscan Strideway（30Hz，马萨诸塞州波士顿）获得。
成对比较表明，ST（<0.004）和DT（<0.02）时步频均存在显著差异，FSHD患者的步频低于对照组。FSHD患者在ST（<0.004）和DT（<0.008）期间的步态速度也显著较低。多水平建模（MLM）方法显示，步频（<0.05）和步态速度（<0.001）存在任务与组的交互作用。该交互作用表明，对照组在ST和DT时步频和步态速度存在显著差异。然而，FSHD患者的ST和DT之间没有差异。最后，甲基化百分比与步态参数的比较显示，步频存在显著负相关系数，而步态速度不存在。
这些结果表明，在ST和DT行走中，步态参数存在特定的成对差异，表现为ST和DT期间步频和步态速度降低。此外，MLM显示，对照组表现出预期的DT成本，但FSHD患者在步频和步态速度方面没有。
ST对FSHD患者似乎具有足够的挑战性，并导致步态时空特征全面下降。需要进一步研究以在早发型或轻症病例中测试该模式，以追踪疾病进展及其对行走的影响。
