Deficits of anticipatory grip force control after damage to peripheral and central sensorimotor systems
Deficits of anticipatory grip force control after damage to peripheral and central sensorimotor systems
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DOI：
10.1016/j.humov.2004.10.005
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发表时间：
2004-11-01
影响因子：
2.1
通讯作者：
Nowak, DA
中科院分区：
文献类型：
--
作者：
Hermsdörfer, J;Hagl, E;Nowak, DA
健康的受试者经济地调整他们的握力以适应手持物体的重量。此外，平行握力调节可以预测手臂与被抓物体运动产生的惯性载荷。已经提出了内部前瞻性模型来预测自愿运动的后果。手指的麻醉损害了握力的经济性，但握力/负载耦合的前馈特性被保留。为了进一步分析感觉输入对内部前向模型的作用，并描述中枢神经系统损伤对预期握力控制的后果，我们测量了神经系统患者的握力行为。我们测试了一组不同程度的精细运动控制受损和感觉丧失的中风患者，一个病人与所有触觉和本体感受输入完全和永久性的分化，和一组肌萎缩侧索硬化症（ALS），专门损害运动系统，而不影响感觉模态的患者。握力增加是所有患者的常见结果。感觉缺陷是一个强大的，但不是唯一的预测受损的握力经济。尽管中风患者存在中枢感觉缺陷，但握力控制的前馈模式通常在中风患者中得到保留，但在外周感觉分化的患者和少数中风患者中受到严重干扰。中度前馈控制缺陷在ALS患者中也很明显。因此，内部前向模型的功能和握力产生的精度可能取决于感觉和运动结构的复杂解剖和功能网络及其在时间和空间上的相互作用。(C)2004 Elsevier B. V.保留所有权利。
Healthy subjects adjust their grip force economically to the weight of a hand-held object. In addition, inertial loads, which arise from arm movements with the grasped object, are anticipated by parallel grip force modulations. Internal forward models have been proposed to predict the consequences of voluntary movements. Anesthesia of the fingers impairs grip force economy but the feedforward character of the grip force/load coupling is preserved. To further analyze the role of sensory input for internal forward models and to characterize the consequences of central nervous system damage for anticipatory grip force control, we measured grip force behavior in neurological patients. We tested a group of stroke patients with varying degrees of impaired fine motor control and sensory loss, a single patient with complete and permanent differentation from all tactile and proprioceptive input, and a group of patients with amyotrophic lateral sclerosis (ALS) that exclusively impairs the motor system without affecting sensory modalities. Increased grip forces were a common finding in all patients. Sensory deficits were a strong but not the only predictor of impaired grip force economy. The feedforward mode of grip force control was typically preserved in the stroke patients despite their central sensory deficits, but was severely disturbed in the patient with peripheral sensory differentation and in a minority of stroke patients. Moderate deficits of feedforward control were also obvious in ALS patients. Thus, the function of the internal forward model and the precision of grip force production may depend on a complex anatomical and functional network of sensory and motor structures and their interaction in time and space. (C) 2004 Elsevier B.V. All rights reserved.