Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, Kapittelweg 29, 6500 HB Nijmegen, Netherlands.
Neuropsychologia. 2010 May;48(6):1782-8. doi: 10.1016/j.neuropsychologia.2010.02.029. Epub 2010 Mar 4.
Conversion paralysis (CP) is a frequent and impairing psychiatric disorder, affecting voluntary motor function. Yet, we have previously shown that the motor system of CP patients with a unilateral conversion paresis is recruited to a similar degree during imagined movements of the affected and unaffected limb. In contrast, imagery of movements with the affected limb results in larger prefrontal activation. It remains unclear how this hand-specific increased prefrontal activity relates to the reduced responsiveness of motor and somatosensory areas, a consistent and important feature of CP patients. In the current study, we investigated changes in the inter-regional coupling between prefrontal cortex (PFC) and sensorimotor regions when CP patients imagined movements involving either the affected or the unaffected hand. We found that there were distinct connectivity patterns for different parts of the PFC. While ventromedial PFC was not functionally connected to the motor system, we observed strong functional coupling between the dorsolateral PFC and various sensorimotor areas. Furthermore, this coupling was modulated by whether patients imagined movements of their affected or unaffected hand. Together, these results suggest that the reduced motor responsitivity observed in CP may be linked to altered dorsolateral prefrontal-motor connectivity.
转换性瘫痪（CP）是一种常见且使人虚弱的精神障碍，影响自愿运动功能。然而，我们之前已经表明，单侧转换性瘫痪患者的运动系统在想象受影响和未受影响肢体的运动时被同等程度地招募。相比之下，想象受影响肢体的运动则会导致前额叶更大的激活。目前尚不清楚这种手部特异性的前额叶活动增加与运动和体感区域反应性降低有何关系，而这是 CP 患者的一个一致且重要的特征。在当前的研究中，我们研究了当 CP 患者想象涉及受影响或未受影响的手的运动时，前额叶皮层（PFC）和感觉运动区域之间的区域间耦合的变化。我们发现，PFC 的不同部分存在明显的连接模式。虽然腹内侧 PFC 与运动系统没有功能连接，但我们观察到背外侧 PFC 与各种感觉运动区域之间存在强烈的功能耦合。此外，这种耦合受患者想象受影响或未受影响的手的运动的影响。总的来说，这些结果表明，CP 中观察到的运动反应性降低可能与背外侧前额叶-运动连接的改变有关。
