Park Kayne, Chilvers Matthew J, Low Trevor A, Dukelow Sean P, Scott Stephen H
Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
Brain Commun. 2023 Mar 20;5(2):fcad066. doi: 10.1093/braincomms/fcad066. eCollection 2023.
Visuospatial neglect is a disorder characterized by an impairment of attention, most commonly to the left side of space in individuals with stroke or injury to the right hemisphere. Clinical diagnosis is largely based on performance on pen and paper examinations that are unable to accurately measure the speed of processing environmental stimuli-important for interacting in our dynamic world. Numerous studies of impairment after visuospatial neglect demonstrate delayed reaction times when reaching to the left. However, little is known of the visuospatial impairment in other spatial directions and, further, the influence of the arm being assessed. In this study, we quantify the ability of a large cohort of 204 healthy control participants (females = 102) and 265 individuals with stroke (right hemisphere damage = 162, left hemisphere damage = 103; mean age 62) to generate goal-directed reaches. Participants used both their contralesional and ipsilesional arms to perform a centre-out visually guided reaching task in the horizontal plane. We found that the range of visuospatial impairment can vary dramatically across individuals with some individuals displaying reaction time impairments restricted to a relatively small portion of the workspace, whereas others displayed reaction time impairments in all spatial directions. Reaction time impairments were observed in individuals with right or left hemisphere lesions (48% and 30%, respectively). Directional impairments commonly rotated clockwise when reaching with the left versus the right arms. Impairment in all spatial directions was more prevalent in right than left hemisphere lesions (32% and 12%, respectively). Behavioral Inattention Test scores significantly correlated ( = -0.49, < 0.005) with reaction time impairments but a large portion of individuals not identified as having visuospatial neglect on the Behavioral Inattention Test still displayed reaction time impairments (35%). MRI and CT scans identified distinct white matter and cortical regions of damage for individuals with directional (insula, inferior frontal-occipital fasciculus and inferior longitudinal fasciculus) and general (superior and middle temporal gyri) visuospatial impairment. This study highlights the prevalence and diversity of visuospatial impairments that can occur following stroke.
视觉空间忽视是一种以注意力受损为特征的疾病，在中风或右半球损伤的个体中，最常见的是对空间左侧的注意力受损。临床诊断很大程度上基于纸笔测试的表现，而这些测试无法准确测量处理环境刺激的速度——这对在我们这个动态世界中进行互动很重要。众多关于视觉空间忽视后损伤的研究表明，向左伸手时反应时间会延迟。然而，对于其他空间方向的视觉空间损伤以及被评估手臂的影响，人们了解甚少。在本研究中，我们对204名健康对照参与者（女性 = 102名）和265名中风患者（右半球损伤 = 162名，左半球损伤 = 103名；平均年龄62岁）进行目标导向伸手动作的能力进行了量化。参与者使用对侧手臂和同侧手臂在水平面上执行中心向外的视觉引导伸手任务。我们发现，视觉空间损伤的范围在个体之间可能有很大差异，一些个体的反应时间损伤仅限于工作空间的相对较小部分，而另一些个体在所有空间方向上都有反应时间损伤。在右半球或左半球病变的个体中均观察到反应时间损伤（分别为48%和30%）。与右臂相比，用左臂伸手时，方向损伤通常顺时针旋转。在所有空间方向上的损伤在右半球病变中比左半球病变中更普遍（分别为32%和12%）。行为疏忽测试得分与反应时间损伤显著相关（ = -0.49， < 0.005），但在行为疏忽测试中未被确定为有视觉空间忽视的个体中，仍有很大一部分表现出反应时间损伤（35%）。MRI和CT扫描确定了有方向（岛叶、额枕下束和下纵束）和一般（颞上回和颞中回）视觉空间损伤的个体的不同白质和皮质损伤区域。这项研究强调了中风后可能出现的视觉空间损伤的普遍性和多样性。
