Haaland K Y, Harrington D L, Knight R T
Psychology and Research Services, Veterans Affairs Medical Center and University of New Mexico, Albuquerque, 87108, USA.
Brain. 1999 Jun;122 ( Pt 6):1169-82. doi: 10.1093/brain/122.6.1169.
Ideomotor limb apraxia is a classic neurological disorder manifesting as a breakdown in co-ordinated limb control with spatiotemporal deficits. We employed kinematic analyses of simple aiming movements in left hemisphere-damaged patients with and without limb apraxia and a normal control group to examine preprogramming and response implementation deficits in apraxia. Damage to the frontal and parietal lobes was more common in apraxics, but neither frontal nor parietal damage was associated with different arm movement deficits. Limb apraxia was associated with intact preprogramming but impaired response implementation. The response implementation deficits were characterized by spatial but not temporal deficits, consistent with decoupling of spatial and temporal features of movement in limb apraxia. While the apraxics' accuracy was normal when visual feedback was available, it was impaired when visual feedback of either target location or hand position was unavailable. This finding suggests that ideomotor limb apraxia is associated with disruption of the neural representations for the extrapersonal (spatial location) and intrapersonal (hand position) features of movement. The non-apraxic group's normal kinematic performance demonstrates that the deficits demonstrated in the apraxic group are not simply a reflection of left hemisphere damage per se.
观念运动性肢体失用症是一种典型的神经障碍，表现为肢体协调控制功能障碍以及时空缺陷。我们对患有和未患有肢体失用症的左半球损伤患者以及正常对照组进行简单瞄准动作的运动学分析，以研究失用症中的预编程和反应执行缺陷。额叶和顶叶损伤在失用症患者中更为常见，但额叶和顶叶损伤均与不同的手臂运动缺陷无关。肢体失用症与完整的预编程但受损的反应执行有关。反应执行缺陷的特征是空间缺陷而非时间缺陷，这与肢体失用症中运动的空间和时间特征解耦一致。当有视觉反馈时，失用症患者的准确性正常，但当目标位置或手部位置的视觉反馈不可用时，准确性会受损。这一发现表明，观念运动性肢体失用症与运动的体外（空间位置）和体内（手部位置）特征的神经表征破坏有关。非失用症组的正常运动学表现表明，失用症组所表现出的缺陷并非仅仅是左半球损伤本身的反映。
