Moss Rehabilitation Research Institute, Elkins Park, PA, USA.
Moss Rehabilitation Research Institute, Elkins Park, PA, USA; Department of Psychology, Drexel University, Philadelphia, PA, USA.
Neuropsychologia. 2022 Jun 6;170:108210. doi: 10.1016/j.neuropsychologia.2022.108210. Epub 2022 Mar 11.
Influential theories of skilled action posit that distinct cognitive mechanisms and neuroanatomic substrates support meaningless gesture imitation and tool use pantomiming, and poor performance on these tasks are hallmarks of limb apraxia. Yet prior research has primarily investigated brain-behavior relations at the group level; thus, it is unclear whether we can identify individuals with isolated impairments in meaningless gesture imitation or tool use pantomiming whose performance is associated with a distinct neuroanatomic lesion profile. The goal of this study was to test the hypothesis that individuals with disproportionately worse performance in meaningless gesture imitation would exhibit cortical damage and white matter disconnection in left fronto-parietal brain regions, whereas individuals with disproportionately worse performance in tool use pantomiming would exhibit cortical damage and white matter disconnection in left temporo-parietal brain regions. Fifty-eight participants who experienced a left cerebrovascular accident took part in a meaningless gesture imitation task, a tool use pantomiming task, and a T1 structural MRI. Two participants were identified who had relatively small lesions and disproportionate impairments on one task relative to the other, as well as below-control-level performance on one task and not the other. Using these criteria, one participant was disproportionately impaired at meaningless gesture imitation, and the other participant was disproportionately impaired at pantomiming tool use. Graph theoretic analysis of each participant's structural disconnectome demonstrated that disproportionately worse meaningless gesture imitation performance was associated with disconnection among the left inferior parietal lobule, the left superior parietal lobule, and the left middle and superior frontal gyri, whereas disproportionately worse tool use pantomiming performance was associated with disconnection between left temporal and parietal regions. Our results demonstrate that relatively focal lesions to specific portions of the Tool Use Network can be associated with distinct limb apraxia subtypes.
熟练动作的影响理论假设，不同的认知机制和神经解剖学基础支持无意义的手势模仿和工具使用模仿，而这些任务表现不佳是肢体运动障碍的标志。然而，先前的研究主要在群体水平上研究了大脑-行为关系；因此，我们不清楚是否可以识别出那些在无意义的手势模仿或工具使用模仿方面存在孤立障碍的个体，其表现与特定的神经解剖损伤模式相关。本研究的目的是检验以下假设：在无意义的手势模仿中表现明显较差的个体，其左额顶叶大脑区域会出现皮质损伤和白质中断；而在工具使用模仿中表现明显较差的个体，其左颞顶叶大脑区域会出现皮质损伤和白质中断。58 名经历过左侧脑血管意外的参与者参与了无意义的手势模仿任务、工具使用模仿任务和 T1 结构 MRI。确定了两名参与者，他们在一项任务中的相对较小的损伤和不成比例的障碍，以及在一项任务中的表现低于控制水平而在另一项任务中没有。使用这些标准，一名参与者在无意义的手势模仿方面表现出不成比例的障碍，另一名参与者在模仿工具使用方面表现出不成比例的障碍。对每位参与者的结构分离图进行的图论分析表明，无意义的手势模仿表现明显较差与左顶下小叶、左顶上小叶以及左中、上额回之间的连接中断有关，而工具使用模仿表现明显较差与左颞区和顶区之间的连接中断有关。我们的结果表明，特定的工具使用网络的相对局灶性损伤可能与不同的肢体运动障碍亚型有关。
