School of Psychology, University of Ottawa, Faculty of Social Sciences, 136 Jean Jacques Lussier, Vanier Hall, Ottawa, Ontario, Canada K1N 6N5.
Brain Cogn. 2012 Oct;80(1):53-63. doi: 10.1016/j.bandc.2012.03.009. Epub 2012 May 23.
Limb apraxia is a neurological disorder characterized by an inability to pantomime and/or imitate gestures. It is more commonly observed after left hemisphere damage (LHD), but has also been reported after right hemisphere damage (RHD). The Conceptual-Production Systems model (Roy, 1996) suggests that three systems are involved in the control of purposeful movements: the conceptual, the production and the sensory/perceptual system. Depending on which system is damaged different patterns of apraxia are expressed. To determine the apraxia pattern, pantomime, delayed, and concurrent imitation tasks need to be administered, as well as conceptual tasks assessing one's knowledge of actions. Based on the model, eight patterns of apraxia should emerge. The purpose of this study is to determine whether these patterns are in fact observed in stroke patients and examine their frequency. If the performance of most stroke patients falls into one of the patterns, then we would have strong support for the conceptual-production model. Stroke (34 LHD and 39 RHD) patients and 27 age- and education-matched healthy controls participated in the study. Participants were assessed in four task modalities: pantomime, delayed imitation, concurrent imitation and conceptual knowledge (two tasks were used: tool naming by action and action identification). Patients were categorized as impaired on a task if they scored 2 SD below the mean performance of the controls for gesture production tasks, or below a cut-off score on the conceptual tasks. They were then classified into patterns depending on their performance on the four task modalities. Most patients (86%) fell into one of seven patterns originally predicted from the Conceptual-Production Systems model. The two most common patterns were deficits in pantomime and imitation with preserved gesture recognition and conduction apraxia (selective deficit in imitation). Four new patterns emerged, but mostly single cases of these were found. Overall, the study provides strong support for the Conceptual-Production Systems model.
肢体失用症是一种神经系统障碍，其特征是无法进行模仿和/或手势模仿。它更常见于左半球损伤（LHD）后，但也有报道称右半球损伤（RHD）后也会发生。概念-产生系统模型（Roy，1996）表明，有三个系统参与了有目的运动的控制：概念、产生和感觉/知觉系统。根据哪个系统受损，会表现出不同的失用症模式。为了确定失用症模式，需要进行模仿、延迟和同时模仿任务以及评估动作知识的概念任务。根据该模型，应该会出现八种失用症模式。本研究的目的是确定这些模式是否实际上在中风患者中观察到，并检查它们的频率。如果大多数中风患者的表现都属于其中一种模式，那么我们将为概念-产生模型提供强有力的支持。该研究纳入了 34 名左侧大脑半球损伤（LHD）和 39 名右侧大脑半球损伤（RHD）中风患者和 27 名年龄和教育程度匹配的健康对照者。参与者在四种任务模式下进行评估：模仿、延迟模仿、同时模仿和概念知识（使用两项任务：通过动作命名工具和动作识别）。如果患者在手势生成任务中的得分低于对照组平均值的 2 个标准差，或者在概念任务中低于截断分数，则认为他们在某项任务中存在障碍。然后根据他们在四个任务模式中的表现将他们分类为不同的模式。最初从概念-产生系统模型预测的七种模式中，大多数患者（86%）符合其中一种模式。最常见的两种模式是模仿和模仿障碍，而手势识别和传导性失用保留（模仿选择性缺陷）。还出现了四个新的模式，但大多数情况下仅发现了这些模式中的单个案例。总体而言，该研究为概念-产生系统模型提供了强有力的支持。
