Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
Wicking Dementia Research and Education Centre, University of Tasmania, Tasmania, Australia.
Gait Posture. 2020 Oct;82:174-180. doi: 10.1016/j.gaitpost.2020.08.113. Epub 2020 Aug 18.
BACKGROUND & AIMS: Dual-task walking is an emerging marker of cognitive impairment. However, there is uncertainty regarding which dual-task test and measure to use. The aims of this study were to determine the association between three different dual-tasks and 1) global cognition and 2) individual cognitive domains.
Participants (n = 91) were adults aged between 56-83 years (mean 68.8, SD 6.7). Under single- and dual-task, gait speed was obtained using a computerized mat. For the dual-task there were three conditions: 1) reciting alternate letters of the alphabet (DT-alpha); 2) counting backwards in 3 s (DT-counting); and 3) recalling words from a shopping list (DT-recall). Dual-task interference in gait and cognition were calculated as: (dual task-single task)/single task×100 and summed to obtain total interference. The cognitive domains of executive function, processing speed, working memory, verbal fluency, visuospatial function and verbal memory (recall and recognition) were assessed using a battery of neuropsychological tests. Raw test scores were subjected to principal component analysis to derive a global cognition score. Partial correlations were used to determine the strength of associations between single- and dual-task measures and cognitive scores, adjusting for age, sex and education.
The strongest significant associations for each cognitive outcome variable were between greater total interference under DT-alpha and lower global cognition (r = 0.25), working memory (r = 0.28) and verbal memory [recognition] (r = 0.21), greater gait interference under DT-alpha and slower processing speed (r = 0.43) and single-task gait speed and verbal fluency (r = 0.23). Associations between dual-task measures and cognition were generally weaker under the DT-counting and DT-recall.
Calculating total and gait interference during DT-alpha may be the most useful in order to identify adults with poorer cognition.
双重任务行走是认知障碍的一个新兴标志物。然而，对于使用哪种双重任务测试和测量方法仍存在不确定性。本研究的目的是确定三种不同的双重任务与 1）整体认知和 2）个体认知领域之间的关联。
参与者（n=91）为年龄在 56-83 岁之间的成年人（平均 68.8，标准差 6.7）。在单任务和双重任务下，使用计算机化垫子获得步态速度。对于双重任务，有三种情况：1）背诵字母表中的交替字母（DT-alpha）；2）以 3 秒为间隔倒数（DT-counting）；3）从购物清单中回忆单词（DT-recall）。步态和认知的双重任务干扰通过以下公式计算：（双重任务-单任务）/单任务×100，并求和得到总干扰。使用一系列神经心理学测试评估执行功能、处理速度、工作记忆、词语流畅性、视空间功能和言语记忆（回忆和识别）的认知域。原始测试分数通过主成分分析得出整体认知分数。偏相关用于确定单任务和双重任务测量值与认知分数之间的关联强度，调整年龄、性别和教育因素。
对于每个认知结果变量，最强的显著关联是在 DT-alpha 下总干扰增加与整体认知（r=0.25）、工作记忆（r=0.28）和言语记忆[识别]（r=0.21）降低相关，在 DT-alpha 下步态干扰增加与处理速度较慢（r=0.43）和单任务步态速度与词语流畅性（r=0.23）相关。在 DT-counting 和 DT-recall 下，双重任务测量值与认知之间的关联通常较弱。
在 DT-alpha 期间计算总干扰和步态干扰可能最有助于识别认知较差的成年人。
