非受累侧半球高频经颅磁刺激改善脑卒中后中重度上肢偏瘫的作用及运动皮质重组特征分析

关键词：脑卒中  上肢  偏瘫  运动功能  重复经颅磁刺激  功能性近红外光谱

Keywords:stroke  upper limb  hemiplegia  motor function  repetitive transcranial magnetic stimulation  functional near-infrared spectroscopy

摘要：

      摘要 目的：比较新型高频重复经颅磁刺激（rTMS）和常规低频rTMS干预非受累侧半球对脑卒中后中重度偏瘫上肢运动功能的影响，采用功能性近红外光谱（fNIRS）分析大脑运动皮质功能重组的特征。 方法：将20例脑卒中中重度上肢偏瘫患者（Fugl-Meyer上肢近端部分评分<26分）随机分为rTMS高频组和低频组。在常规药物治疗和康复训练基础上，高频组对非受累侧前运动皮质背侧（cPMd）进行5Hz的rTMS兴奋，低频组对非受累侧初级运动皮质（cM1）进行常规1Hz的rTMS抑制。于治疗前、治疗20天后，对两组患者采用Fugl-Meyer上肢运动功能评定量表（FMA-UE）进行疗效评价，并用fNIRS检测两侧大脑运动皮质的氧合血红蛋白（HbO2）浓度变化，探讨初级运动皮质（M1）、前运动皮质（PMC）及辅助运动区（SMA）的激活及功能连接变化情况。 结果：①上肢运动功能：与治疗前相比，治疗后两组FMA-UE评分均显著提高（P<0.05）；高频组FMA-UE总分显著高于低频组（P<0.05），且FMA-UE近端部分评分增加尤为显著（P<0.01）。②HbO2浓度的改变：治疗后高频组非受累侧M1、PMC及患侧M1显著增高（P<0.05）；低频组患侧M1显著增高（P<0.05）、非受累侧M1显著降低（P<0.05）；高频组非受累侧PMC显著高于低频组（P<0.05）。③偏侧化指数（LI）的改变：低频组经治疗后大脑运动皮质的LI较前显著性增加（P<0.01）；高频组经治疗后LI也增加，但差异无显著意义（P>0.05）。④静息态功能连接变化：治疗后高频组的非受累侧PMC-M1功能连接显著增加（P<0.05）、非受累侧M1-患侧M1的功能连接显著降低（P<0.05）。低频组治疗前后比较，非受累侧PMC-M1、患侧M1-PMC及患侧M1-SMA的功能连接有差异，但差异无显著意义（P>0.05）。 结论：对脑卒中后中重度上肢偏瘫患者的cPMd进行高频rTMS改善上肢运动功能的效果优于常规的cM1的低频抑制。可能与这种新型调控方法更有利于激活非受累侧PMC和M1的皮质兴奋性，加强非受累侧半球内、两半球间及皮质-皮质下环路的功能连接，从而促进偏瘫上肢尤其是近端的运动功能恢复有关。

Abstract:

      Abstract Objective： To compare the effects of novel high frequency repetitive transcranial magnetic stimulation （rTMS） and standard low frequency rTMS to contralesional hemisphere on the motor function of moderate-severe hemiplegic upper limbs after stroke and to analyze the characteristics of motor cortex reorganization using functional near-infrared spectroscopy （fNIRS）. Method： Twenty stroke patients with moderate-severe hemiplegic upper limbs （proximal upper extremity Fugl-Meyer scale less than 26） were randomly divided into high-frequency rTMS （HF-rTMS） and low-frequency rTMS （LF-rTMS） groups. In addition to conventional drug treatment and rehabilitation training， patients in HF-rTMS group received 5 Hz rTMS （excitation） to contralesional dorsal premotor cortex（cPMd） while patients in LF-rTMS group received 1Hz rTMS （inhibition） to contralesional primary motor cortex（M1）， respectively. The evaluation was performed before and after the 20th day of the treatment. The Fugl-Meyer assessment scaleupper extremity（FMA-UE） was used to measure upper limb motor function. The changes of oxyhemoglobin （HbO2） concentration and resting-state functional connectivity （FC） changes of the primary motor cortex （M1）， premotor cortex （PMC） and supplementary motor area （SMA） were analyzed by fNIRS. Result：①Changes in upper extremity motor function： FMA-UE scores improved in both groups after treatment（P<0.05）； the total FMA-UE scores of patients in the HF-rTMS group were higher than those in the LF-rTMS group（P<0.05）. In addition, the scores of FMA-UEproximal increased more significantly（P<0.01）. ②Changes in the HbO2 concentration in motor cortical areas： after treatment， the HbO2 in M1 and PMC of contralesional side and in M1 of ipsilesional side increased in HF-rTMS group（P<0.05）； the HbO2 in ipsilesional M1 increased and HbO2 in contralesinoal M1 decreased in LF-rTMS group（P<0.05）. ③Changes in the lateralization index（LI）： after treatment， the LI of the motor cortex increased significantly in LF-rTMS（P<0.01）， and the LI of the motor cortex in HF-rTMS group also increased， but the difference was not significant（P>0.05）. ④Changes in resting-state FC： in HF-rTMS group， FC between contralesional PMC and M1 increased（P<0.05） while FC between contralesional PMC and lesional M1 decreased（P<0.05）. In LF-rTMS group， FC between contralesional PMC and M1， lesional PMC and M1， lesional SMA and M1 all changed without statistical significance（P>0.05）. Conclusion： The effect of high-frequency rTMS excitation to contralesional dorsal premotor cortex in patients with moderate-severe upper limb hemiplegia after stroke is better than that of conventional low-frequency inhibition to contralesional M1 in improving upper limb motor functions. It may be related to the fact that this novel neuromodulation method is more beneficial to activate the cortical excitability of contralesional PMC and M1， strengthen the functional connections in contralesional hemisphere， between two hemispheres and cortical-subcortical circuits， so as to promote the motor function recovery of the hemiplegic upper limb， especially the proximal of upper limb for stroke patients.