Abstract:
The neural network mediating successful response inhibition mainly includes right hemisphere activation of the pre-supplementary motor area, inferior frontal gyrus (IFG), subthalamic nucleus (STN), and caudate nucleus. However, the causal role of these regions in the inhibitory network is undefined. Five patients with Parkinson\'s disease were assessed prior to and after therapeutic thermal ablation of the right STN in two separate functional magnetic resonance imaging (fMRI) sessions while performing a stop-signal task. Initiation times were faster but motor inhibition with the left hand (contralateral to the lesion) was significantly impaired as evident in prolonged stop-signal reaction times. Reduced inhibition after right subthalamotomy was associated (during successful inhibition) with the recruitment of basal ganglia regions outside the established inhibitory network. They included the putamen and caudate together with the anterior cingulate cortex and IFG of the left hemisphere. Subsequent network connectivity analysis (with the seed over the nonlesioned left STN) revealed a new inhibitory network after right subthalamotomies. Our results highlight the causal role of the right STN in the neural network for motor inhibition and the possible basal ganglia mechanisms for compensation upon losing a key node of the inhibition network.
摘要:
介导成功反应抑制的神经网络主要包括补充前运动区的右半球激活,额下回(IFG),丘脑底核(STN),和尾状核.然而,这些区域在抑制网络中的因果作用尚不明确.在执行停止信号任务的同时,在两个单独的功能磁共振成像(fMRI)会话中,在右STN的治疗性热消融之前和之后评估了五名帕金森病患者。启动时间更快,但左手(病变的对侧)的运动抑制显着受损,这在延长的停止信号反应时间中很明显。右丘脑下切开术后抑制的减少(在成功抑制期间)与已建立的抑制网络之外的基底神经节区域的募集有关。它们包括壳核和尾状以及左半球的前扣带回皮质和IFG。随后的网络连接分析(种子在未受损的左STN上)揭示了右丘脑下切开术后的新抑制网络。我们的结果强调了右STN在运动抑制神经网络中的因果作用,以及在失去抑制网络的关键节点时可能的基底神经节机制进行补偿。