Social interaction is impaired in schizophrenia, including the use of hand gestures, which is linked to poor social perception and outcome. Brain imaging suggests reduced neural activity in a left-lateralized frontoparietal network during gesture preparation; therefore, gesturing might be improved through facilitation of left hemispheric brain areas or via disruption of interhemispheric inhibition from the right homolog. This study tested whether repetitive transcranial magnetic stimulation (rTMS) protocols would improve gesture performance in schizophrenia. This randomized, placebo-controlled, double-blind, crossover trial applied 3 different protocols of rTMS separated by 48 h. Twenty right-handed schizophrenia patients and 20 matched healthy controls received facilitatory intermittent theta burst stimulation (iTBS) over the left inferior frontal gyrus (IFG), inhibitory continuous theta burst stimulation (cTBS) over right inferior parietal lobe (IPL), and placebo over left IPL in randomized order. Primary outcome was change in the test of upper limb apraxia (TULIA), rated from video recordings of hand gesture performance. Secondary outcome was change in manual dexterity using the coin rotation task. Participants improved on both tasks following rTMS compared with baseline. Only patients improved gesture performance following right IPL cTBS compared with placebo (P = .013). The results of the coin rotation parallel those of the TULIA, with improvements following right IPL cTBS in patients (P = .001). Single sessions of cTBS on the right IPL substantially improved both gesture performance accuracy and manual dexterity. The findings point toward an inhibition of interhemispheric rivalry as a potential mechanism of action.

中文翻译：

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单次经颅磁刺激改善了精神分裂症的手势缺陷。

精神分裂症的社交互动会受到影响，包括使用手势会导致不良的社会认知和结果。脑部成像提示手势准备过程中左前额叶额叶网络中的神经活动减少；因此，可以通过促进左半球大脑区域或通过破坏右同系物对半球之间的抑制来改善手势。这项研究测试了重复性经颅磁刺激（rTMS）协议是否会改善精神分裂症的手势表现。这项随机，安慰剂对照，双盲，交叉试验应用了3种不同的rTMS方案，间隔48小时。20例右手型精神分裂症患者和20名相匹配的健康对照组在左下额额回（IFG）上接受了促进性间断theta爆裂刺激（iTBS），在右下顶叶（IPL）上进行了抑制性连续theta爆裂刺激（cTBS），并接受了安慰剂以随机顺序离开IPL。主要结果是上肢失用症测试（TULIA）的变化，根据手势表现的视频记录进行了评估。次要结果是使用硬币旋转任务改变手巧程度。与基线相比，参加rTMS的参与者在两项任务上均得到了改善。与安慰剂相比，只有患者在正确的IPL cTBS后改善了手势表现（P = 0.013）。硬币旋转的结果与TULIA的结果平行，在患者进行正确的IPL cTBS后有所改善（P = .001）。在正确的IPL上进行一次cTBS会话可以显着提高手势性能准确性和手动灵活性。研究结果表明，抑制半球竞争是一种潜在的作用机制。