School of Physical and Occupational Therapy, McGill University, 3654 Promenade Sir-William-Osler, Montreal, Quebec, H3G 1Y5, Canada.
Feil-Oberfeld Research Centre, Jewish Rehabilitation Hospital, Laval, Quebec, Canada.
J Neuroeng Rehabil. 2018 Apr 23;15(1):34. doi: 10.1186/s12984-018-0374-y.
Unilateral spatial neglect (USN), a highly prevalent and disabling post-stroke impairment, has been shown to affect the recovery of locomotor and navigation skills needed for community mobility. We recently found that USN alters goal-directed locomotion in conditions of different cognitive/perceptual demands. However, sensorimotor post-stroke dysfunction (e.g. decreased walking speed) could have influenced the results. Analogous to a previously used goal-directed locomotor paradigm, a seated, joystick-driven navigation experiment, minimizing locomotor demands, was employed in individuals with and without post-stroke USN (USN+ and USN-, respectively) and healthy controls (HC).
Participants (n = 15 per group) performed a seated, joystick-driven navigation and detection time task to targets 7 m away at 0°, ±15°/30° in actual (visually-guided), remembered (memory-guided) and shifting (visually-guided with representational updating component) conditions while immersed in a 3D virtual reality environment.
Greater end-point mediolateral errors to left-sided targets (remembered and shifting conditions) and overall lengthier onsets in reorientation strategy (shifting condition) were found for USN+ vs. USN- and vs. HC (p < 0.05). USN+ individuals mostly overshot left targets (- 15°/- 30°). Greater delays in detection time for target locations across the visual spectrum (left, middle and right) were found in USN+ vs. USN- and HC groups (p < 0.05).
USN-related attentional-perceptual deficits alter navigation abilities in memory-guided and shifting conditions, independently of post-stroke locomotor deficits. Lateralized and non-lateralized deficits in object detection are found. The employed paradigm could be considered in the design and development of sensitive and functional assessment methods for neglect; thereby addressing the drawbacks of currently used traditional paper-and-pencil tools.
单侧空间忽略（USN）是一种高发病率和致残性的中风后障碍，已被证明会影响社区活动所需的运动和导航技能的恢复。我们最近发现，USN 改变了在不同认知/感知需求条件下的目标导向运动。然而，中风后的感觉运动功能障碍（例如，步行速度降低）可能会影响结果。类似于以前使用的目标导向运动范式，采用了一种坐姿、操纵杆驱动的导航实验，最大限度地减少了运动需求，用于有和没有中风后 USN（USN+和 USN-，分别）的个体和健康对照组（HC）。
参与者（每组 15 人）在 3D 虚拟现实环境中，执行坐姿、操纵杆驱动的导航和检测时间任务，以 7 米远的 0°、±15°/30°的目标为目标，处于实际（视觉引导）、记忆（记忆引导）和转移（视觉引导，具有代表性更新组件）条件下。
与 USN-和 HC 相比，USN+在左目标（记忆和转移条件）的终点左右偏差更大，重新定向策略的起始时间更长（转移条件）（p<0.05）。USN+ 个体大多向左目标（-15°/-30°）偏航。在 USN+中，目标位置的检测时间延迟更大，横跨整个视觉范围（左、中、右）（p<0.05）。
USN 相关的注意力感知缺陷改变了记忆引导和转移条件下的导航能力，与中风后的运动缺陷无关。发现了对物体检测的侧化和非侧化缺陷。所采用的范式可用于设计和开发忽略的敏感和功能性评估方法；从而解决当前使用的传统纸笔工具的缺点。
