Limb apraxia, a disorder of skilled action not consequent on primary motor or sensory deficits, has traditionally been defined according to errors patients make on neuropsychological tasks. Previous models of the disorder have failed to provide a unified account of patients deficits, due to heterogeneity in the patients and tasks used. In this study we implemented principal component analysis (PCA) to elucidate core factors of the disorder in a cohort of 41 unselected left hemisphere chronic stroke patients who were tested on a comprehensive and validated apraxia screen. Three principal components were identified: posture selection, semantic control and multi-demand sequencing. These were submitted to a lesion symptom mapping (VBCM) analysis in a subset of 24 patients, controlled for lesion volume, age and time post-stroke. Although the first component revealed no significant structural correlates, the second and third components were related to regions in the ventro-dorsal and ventral and dorsal pathways, respectively. These results challenge the previously reported distinction between ideomotor and ideational deficits and highlight a significant role of common cognitive functions in the disorder, which include action selection, semantic retrieval, sequencing and response inhibition. Further research using this technique would help elucidate the cognitive processes underlying limb apraxia and their relationship with other cognitive disorders.

中文翻译：

---

慢性左半球卒中患者实践缺陷背后的特征因素

传统上根据患者在神经心理学任务上犯的错误来定义肢体性失用症，这是一种由于原发性运动或感觉不足而导致的熟练动作障碍。由于患者和所用任务的异质性，该疾病的先前模型未能提供患者缺陷的统一说明。在这项研究中，我们实施了主成分分析（PCA），以阐明41名未经选择的左半球慢性卒中患者队列中的疾病核心因素，这些患者在全面且经过验证的失用症筛查中进行了测试。确定了三个主要组成部分：姿势选择，语义控制和多需求排序。将这些患者接受了24例患者的病变症状图谱（VBCM）分析，控制了病变量，中风后的年龄和时间。尽管第一成分没有显着的结构相关性，但是第二成分和第三成分分别与腹背和腹侧和背侧通路中的区域相关。这些结果挑战了先前报道的意识运动和概念缺陷之间的区别，并突显了常见认知功能在疾病中的重要作用，包括行动选择，语义检索，排序和反应抑制。使用该技术的进一步研究将有助于阐明肢体失用症的潜在认知过程及其与其他认知障碍的关系。这些结果挑战了先前报道的意识运动和概念缺陷之间的区别，并突显了常见认知功能在疾病中的重要作用，包括行动选择，语义检索，排序和反应抑制。使用该技术的进一步研究将有助于阐明肢体失用症的潜在认知过程及其与其他认知障碍的关系。这些结果挑战了先前报道的意识运动和概念缺陷之间的区别，并突显了常见认知功能在疾病中的重要作用，包括行动选择，语义检索，排序和反应抑制。使用该技术的进一步研究将有助于阐明肢体失用症的潜在认知过程及其与其他认知障碍的关系。