Allali Gilles, Kressig Reto W, Assal Frédéric, Herrmann François R, Dubost Véronique, Beauchet Olivier
Department of Rehabilitation and Geriatrics, Geneva University Hospitals, Geneva, Switzerland.
Gait Posture. 2007 Oct;26(4):572-6. doi: 10.1016/j.gaitpost.2006.12.011. Epub 2007 Mar 6.
Gait disorders caused by dementia have been associated with frontal lobe dysfunction. Dual-tasking is used to explore the involvement of cortical level in gait control. It has been shown that dual-task induced gait changes that could be related to (1) the efficiency of executive function, (2) the level of difficulty involved in the walking-associated task, or (3) the articulo-motor components comprised in the walking-associated task. A better understanding of dual-task related changes in demented subjects with frontal lobe dysfunction could help us to clarify the role of the frontal lobe in motor gait control.
To assess and compare the effects of two mental arithmetic tasks involving similar articulo-motor components but different level of difficulty on the mean values and coefficient of variation (CV) of stride time among demented older adults with impaired executive function.
The mean values and coefficients of variation of stride time were measured using a GAITRite-System among 16 demented older adults with impaired executive function while walking with and without forward counting (FC) and backward counting (BC).
The mean values and CV of stride time were significantly higher under both dual-task conditions than during a simple walking task (p<0.05). The change in CV of stride time during BC was significantly higher when compared with the change during FC (p=0.015), whereas the change in mean value was not significant (p=0.056). There was no difference between the dual-task and single task condition as far the number of enumerated figures were concerned (p=0.678 for FC and p=0.069 for BC), but significantly fewer figures were enumerated while BC compared with FC (p<0.001).
BC provoked more changes in gait parameters than FC with major modification in gait variability related to an inappropriate focusing of attention. These findings suggest that the CV may be a suitable criterion for the assessment of gait control.
痴呆所致步态障碍与额叶功能障碍有关。双任务法用于探究皮质水平在步态控制中的作用。研究表明，双任务诱发的步态变化可能与以下因素有关：（1）执行功能的效率；（2）与行走相关任务的难度水平；（3）与行走相关任务中包含的关节运动成分。更好地理解额叶功能障碍的痴呆患者中与双任务相关的变化，有助于我们阐明额叶在运动步态控制中的作用。
评估并比较两项涉及相似关节运动成分但难度水平不同的心算任务，对执行功能受损的老年痴呆患者步幅时间平均值及变异系数（CV）的影响。
使用GAITRite系统，测量16名执行功能受损的老年痴呆患者在向前计数（FC）和向后计数（BC）时及无计数行走时的步幅时间平均值和变异系数。
两种双任务条件下的步幅时间平均值和CV均显著高于简单行走任务时（p<0.05）。与FC时相比，BC时步幅时间CV的变化显著更高（p=0.015），而平均值的变化不显著（p=0.056）。就计数数字的数量而言，双任务和单任务条件之间没有差异（FC时p=0.678，BC时p=0.069），但BC时计数的数字明显少于FC时（p<0.001）。
与注意力不适当集中相关的步态变异性主要改变方面，BC比FC引发更多的步态参数变化。这些发现表明，CV可能是评估步态控制的合适标准。
