Gaßner Heiko, Marxreiter Franz, Steib Simon, Kohl Zacharias, Schlachetzki Johannes C M, Adler Werner, Eskofier Bjoern M, Pfeifer Klaus, Winkler Jürgen, Klucken Jochen
Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Institute for Sport Science and Sport, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Front Neurol. 2017 Oct 26;8:550. doi: 10.3389/fneur.2017.00550. eCollection 2017.
Cognitive and gait deficits are common symptoms in Parkinson's disease (PD). Motor-cognitive dual tasks (DTs) are used to explore the interplay between gait and cognition. However, it is unclear if DT gait performance is indicative for cognitive impairment. Therefore, the aim of this study was to investigate if cognitive deficits are reflected by DT costs of spatiotemporal gait parameters.
Cognitive function, single task (ST) and DT gait performance were investigated in 67 PD patients. Cognition was assessed by the Montreal Cognitive Assessment (MoCA) followed by a standardized, sensor-based gait test and the identical gait test while subtracting serial 3's. Cognitive impairment was defined by a MoCA score <26. DT costs in gait parameters [(DT - ST)/ST × 100] were calculated as a measure of DT effect on gait. Correlation analysis was used to evaluate the association between MoCA performance and gait parameters. In a linear regression model, DT gait costs and clinical confounders (age, gender, disease duration, motor impairment, medication, and depression) were correlated to cognitive performance. In a subgroup analysis, we compared matched groups of cognitively impaired and unimpaired PD patients regarding differences in ST, DT, and DT gait costs.
Correlation analysis revealed weak correlations between MoCA score and DT costs of gait parameters (/ ≤ 0.3). DT costs of stride length, swing time variability, and maximum toe clearance (|/| > 0.2) were included in a regression analysis. The parameters only explain 8% of the cognitive variance. In combination with clinical confounders, regression analysis showed that these gait parameters explained 30% of MoCA performance. Group comparison revealed strong DT effects within both groups (large effect sizes), but significant between-group effects in DT gait costs were not observed.
These findings suggest that DT gait performance is not indicative for cognitive impairment in PD. DT effects on gait parameters were substantial in cognitively impaired and unimpaired patients, thereby potentially overlaying the effect of cognitive impairment on DT gait costs. Limits of the MoCA in detecting motor-function specific cognitive performance or variable individual response to the DT as influencing factors cannot be excluded. Therefore, DT gait parameters as marker for cognitive performance should be carefully interpreted in the clinical context.
认知和步态缺陷是帕金森病（PD）的常见症状。运动-认知双重任务（DTs）用于探究步态与认知之间的相互作用。然而，尚不清楚双重任务步态表现是否可指示认知障碍。因此，本研究的目的是调查时空步态参数的双重任务成本是否反映认知缺陷。
对67例帕金森病患者的认知功能、单任务（ST）和双重任务步态表现进行了研究。通过蒙特利尔认知评估（MoCA）评估认知，随后进行标准化的基于传感器的步态测试以及在倒数3的同时进行相同的步态测试。认知障碍定义为MoCA评分<26。计算步态参数的双重任务成本[（DT - ST）/ ST×100]，作为双重任务对步态影响的指标。采用相关性分析评估MoCA表现与步态参数之间的关联。在一个线性回归模型中，双重任务步态成本和临床混杂因素（年龄、性别、疾病持续时间、运动障碍、药物治疗和抑郁）与认知表现相关。在亚组分析中，我们比较了认知受损和未受损帕金森病患者匹配组在单任务、双重任务和双重任务步态成本方面的差异。
相关性分析显示MoCA评分与步态参数的双重任务成本之间存在弱相关性（/≤0.3）。步长、摆动时间变异性和最大足尖间隙的双重任务成本（|/|>0.2）纳入回归分析。这些参数仅解释了8%的认知方差。结合临床混杂因素，回归分析表明这些步态参数解释了30%的MoCA表现。组间比较显示两组内双重任务效应均较强（效应量较大），但未观察到双重任务步态成本的显著组间效应。
这些发现表明双重任务步态表现不能指示帕金森病患者的认知障碍。双重任务对步态参数的影响在认知受损和未受损患者中均很显著，从而可能掩盖了认知障碍对双重任务步态成本的影响。不能排除MoCA在检测运动功能特定认知表现或个体对双重任务的可变反应作为影响因素方面的局限性。因此，在临床背景下应谨慎解释将双重任务步态参数作为认知表现标志物的结果。
