Faculty of Health Sciences, Department of Psychology, University of Tromsø, The Arctic University of Norway, Tromsø, Norway.
Department of Radiology and Nuclear Medicine, University Hospital of North Norway, Tromsø, Norway.
Exp Gerontol. 2019 Dec;128:110744. doi: 10.1016/j.exger.2019.110744. Epub 2019 Oct 18.
To date the neural mechanisms behind gait perturbations caused by dual-task paradigms are still unknown. Therefore, the present study examined white matter correlates of gait perturbations caused by a dichotic listening task where spontaneous (free focus of attention) and lateralized attentional control (voluntary attention directed to right or left-ear) were tested. Fifty-nine right-handed, healthy older adults (59-88 years) were evaluated during single-task walking and three dual-task conditions. Dual-task costs were calculated for mean (DTCM) and coefficients of variation (DTCCoV) in gait speed, step length, stride length and step width. Volume, fractional anisotropy and mean diffusivity were estimated using global probabilistic tractography for the 18 major brain tracts and correlated with the DTCs. Data demonstrated that DTCs on gait speed and step length significantly correlated with white matter integrity and volume in various tracts. Perturbations on gait speed caused by spontaneous attention were related to frontal circuitry integrity including corpus callosum, while perturbations on gait speed and step length produced by voluntary lateralized attention were associated to tracts subserving visuomotor integration and frontal function.
迄今为止,双任务范式引起的步态紊乱的神经机制仍不清楚。因此,本研究检测了双任务条件下的分散注意任务(自由注意焦点和单侧注意控制[右耳或左耳定向注意])引起的步态紊乱的大脑白质相关物。59 名右利手健康老年人(59-88 岁)在单任务行走和三种双任务条件下接受评估。步态速度、步长、步幅和步宽的平均(DTCM)和变异系数(DTCCoV)计算双重任务成本。使用全脑概率追踪法估计 18 条主要脑束的体积、各向异性分数和平均扩散系数,并与 DTC 相关。数据表明,步态速度和步长的 DTC 与各脑束的白质完整性和体积显著相关。自发注意引起的步态速度紊乱与包括胼胝体在内的额皮质电路完整性有关,而自愿单侧注意引起的步态速度和步长紊乱与支持视动整合和额叶功能的脑束有关。