不同频率rTMS对脑卒中后中-重度运动性失语患者语言功能恢复的影响及机制

目的 探讨不同频率重复经颅磁刺激（rTMS）对恢复期脑卒中后中-重度运动性失语患者语言功能恢复的影响及机制。方法 纳入恢复期脑卒中后中-重度运动性失语患者30例,将其分为对照组、低频组（1 Hz rTMS）和高频组（10 Hz rTMS）各10例,3组均进行常规语言训练;低频、高频组予右侧额下回三角部相应频率rTMS治疗后再进行常规语言训练。采用中文版西方失语症成套检验（WAB）及任务态功能磁共振成像（fMRI）检测治疗前后语言水平差异以及脑区激活、激活体素指数（AVI）变化。结果 治疗后,3组患者的听理解、复述、失语商（AQ）值较治疗前改善（P均< 0.05）,且低频、高频组的自发言语、命名得分也较治疗前改善（P均< 0.05）;与对照组比较,低频组复述、命名、AQ值改善更明显（P均< 0.05）,高频组自发言语、听理解、命名、AQ值改善更明显（P均< 0.05）;与低频组比较,高频组自发言语、听理解改善更明显（P均< 0.05）。治疗后,3组患者AVI结果提示语言偏侧化半球均由治疗前的右侧转为左侧;fMRI结果显示双侧大脑半球均存在激活升高、降低的语言相关感兴趣区（ROI）、非感兴趣区,但以左侧大脑半球参与语言感知、语义理解和表达的ROI激活升高为主;低频组左侧大脑半球AVI增加（P < 0.05）,右侧额下回三角部受抑制后未出现左侧额下回三角部激活升高;高频组治疗后双侧大脑半球AVI均升高（P均< 0.05）,双侧额下回三角部等语言相关ROI激活升高。结论 低频、高频rTMS均有利于改善脑卒中后中-重度运动性失语患者语言功能,高频rTMS的效果优于低频rTMS。低频rTMS通过增加高效语言功能区的激活,优化失语患者语言功能重组模式;高频rTMS增强了右侧大脑半球的代偿作用,同时在促进左侧大脑半球激活重组中发挥了作用。

Effect and mechanism of rTMS with different frequencies on speech function recovery in patients with moderate to severe motor aphasia after stroke

Objective To evaluate the effect and mechanism of different frequencies of repetitive transcranial magnetic stimulation （rTMS） on speech function recovery in patients with moderate to severe motor aphasia after stroke. Methods Thirty patients with moderate to severe motor aphasia after stroke were recruited in this study and divided into the control group, 1 Hz rTMS （low-frequency rTMS, LF-rTMS） group and 10 Hz rTMS （high-frequency rTMS, HF-rTMS） group, 10 cases in each group. All patients received regular language training. Patients in the LF-rTMS and HF-rTMS groups received rTMS treatment at the corresponding frequency of the right inferior frontal gyrus triangle, followed by regular language training. The Chinese version of Western Aphasia Battery （WAB） and task state fMRI were performed before and after corresponding treatment to compare the differences in language level and the changes in brain region activation and activation voxel indices （AVI）. Results All patients showed significant improvement in auditory comprehension, repetition, aphasia quotients （AQ） after treatment （all P < 0.05）. Moreover, spontaneous speech and naming were significantly improved in both LF-rTMS and HF-rTMS groups （all P < 0.05）. Compared with the control group, repetition, naming and AQ were remarkably improved in the LF-rTMS group （all P < 0.05）, whereas spontaneous speech, auditory comprehension, naming and AQ were significantly improved in the HF-rTMS group （all P < 0.05）. Compared with the LF-rTMS group, the improvement in spontaneous speech and auditory comprehension in the HF-rTMS group was more significant （both P < 0.05）. The hemispheric dominance was shifted from the right to the left hemisphere after treatment in all three groups. fMRI showed either increased or decreased activation among both language-related regions of interest （ROI） and non-ROI after treatment, whereas the ROIs related to language perception and semantic comprehension and expression in the left hemisphere were the most activated. In the LF-rTMS group, the AVI was significantly increased in the left hemisphere （P < 0.05）. The left pars triangularis failed to show increased activation after suppressing the homologous region. In the HF-rTMS group, the AVI was significantly increasedin bilateral hemispheres （both P < 0.05）. The language-related ROI activation was increased in bilateral pars triangularis. Conclusions Both LF-rTMS and HF-rTMS can facilitate the speech function recovery in patients with moderate to severe motor aphasia after stroke, and the HF-rTMS seem to be more effective compared to LF-rTMS. LF-rTMS can optimize the language organization through greater activation of high-efficiency language function area in patients with post-stroke aphasia. HF-rTMS can enhance the compensatory effect of the right hemisphere and play a role in facilitating the reconstruction of language performance in the left hemisphere.