Behavioural and neurophysiological markers reveal differential sensitivity to homeostatic interactions between centrally and peripherally applied passive stimulation

Repetitive transcranial magnetic stimulation (rTMS) is an effective tool for inducing functional plastic changes in the brain. rTMS can also potentiate the effects of other interventions such as tactile coactivation, a form of repetitive stimulation, when both are applied simultaneously. In this study, we investigated the interaction of these techniques in affecting tactile acuity and cortical excitability, measured with somatosensory evoked potentials after paired median nerve stimulation. We first applied a session of 5‐Hz rTMS, followed by a session of tactile repetitive stimulation, consisting of intermittent high‐frequency tactile stimulation (iHFS) to a group of 15 healthy volunteers (“rTMS + iHFS” group). In a second group (“rTMS w/o iHFS”), rTMS was applied without iHFS, with a third assessment performed after a similar wait period. In the rTMS w/o iHFS group, the 5‐Hz rTMS induced an increase in cortical excitability that continued to build for at least 25 min after stimulation, with the effect on excitability after the wait period being inversely correlated to the baseline state. In the rTMS + iHFS group, the second intervention prevented the continued increase in excitability after rTMS. In contrast to the effect on cortical excitability, rTMS produced an improvement in tactile acuity that remained stable until the last assessment, independent of the presence or absence of iHFS. Our results show that these methods can interact homeostatically when used consecutively, and suggest that different measures of cortical plasticity are differentially susceptible to homeostatic interactions.     

When emulation becomes reciprocity

It is well known that perceiving another''s body movements activates corresponding motor representations in an observer''s brain. It is nevertheless true that in many situations simply imitating another''s actions would not be an effective or appropriate response, as successful interaction often requires complementary rather than emulative movements. At what point does the automatic tendency to mirror another''s actions become the inclination to carry out appropriate, complementary movements? In the present study, single-pulse transcranial magnetic stimulation (TMS) was used to explore corticospinal excitability in participants observing action sequences evoking imitative or complementary movements. TMS was delivered at five time points corresponding to different moments in time when key kinematic landmarks characterizing an observed action occurred. A variation in motor evoked potentials (MEPs) confirmed that the motor system flexibly shifts from imitative to complementary action tendencies. That shift appears to take place very precociously in time. Observers are attuned to advance movement information and can use it to anticipate a future course of action and to prepare for an appropriate, complementary action. Altogether, these findings represent a step forward in research concerning social action-perception coupling mechanisms providing important data to better understand the role of predictive simulation in social contexts.     

Challenges in comparing the acute cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) vs. electroconvulsive therapy (ECT) in major depression: A systematic review

The present study aimed to systematically compare the cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and electroconvulsive therapy (ECT) in head-to-head studies with major depression (MDD) patients. A systematic literature search identified six studies with 219 MDD patients that were too heterogeneous to reliably detect meaningful differences in acute cognitive outcomes after ECT vs. HF-rTMS. Cognitive effects of brain stimulation vary depending on the timeframe and methods of assessment, stimulation parameters, and maintenance treatment. Thus, acute and longer-term differences in cognitive outcomes both need to be investigated at precisely defined timeframes and with similar instruments assessing comparable functions.     

经颅超声对我国帕金森病患者的诊断价值:Meta分析

目的 采用Meta分析的方法,评价我国经颅超声（TCS）对帕金森病（PD）患者的诊断价值。方法 检索建库至2017年11月间PubMed、Cochrone图书馆、CNKI和中国生物医学文献数据库中有关TCS诊断国人PD的文献,以诊断性试验准确性评价工具（QUADAS）评价纳入文献的质量,并采用Meta-disc 1.4软件进行数据分析,计算我国TCS诊断PD患者的汇总敏感度、特异度、阳性似然比、阴性似然比和诊断比值比,并绘制汇总受试者工作特征（SROC）曲线。结果 共纳入15篇文献,中文12篇,英文3篇,我国TCS诊断PD的敏感度范围为0.62~0.93,特异度范围为0.50~0.94。纳入研究存在异质性,采用随机效应模型进行分析。我国TCS诊断的汇总敏感度、特异度、阳性似然比、阴性似然比和诊断比值比及其95% CI分别为0.78（0.76,0.81）、0.85（0.83,0.88）、5.46（4.01,7.44）、0.22（0.17,0.29）和27.15（16.96,43.46）,SROC曲线下面积为0.904 9,Q指数为0.836 5。结论 在我国,TCS诊断PD具有一定价值,可作为辅助检查手段。     

应用定量脑电图探讨低频重复经颅磁刺激干预亚急性期运动性失语症机制的研究

目的:通过观察定量脑电图(QEEG)在低频重复经颅磁刺激(r TMS)干预亚急性期运动性失语患者前后的变化,进一步探讨其机制。方法:将30例脑卒中后亚急性期运动性失语患者随机分为r TMS组与假刺激组各15例。两组患者均给予常规药物治疗及言语训练,r TMS组在右侧大脑半球Broca镜像区给予低频r TMS治疗,连续治疗3周。最终两组各脱落2例。于治疗前和治疗3周后(治疗后)行定量脑电图检查,比较各个频段上(δ+θ)/(α+β)值的差异,并采用西方失语成套测验(WAB)评定治疗前后的言语功能。结果:治疗后,两组患者在FP1、F3、F7、T3、C3频段(δ+θ)/(α+β)值下降,差异有显著性意义(P0.01);r TMS组在F3频段(δ+θ)/(α+β)值下降较假刺激组明显,差异有显著性意义(P0.01);r TMS组治疗前后自发言语、复述、命名以及失语商(AQ)分的差值较假刺激组大,差异有显著性意义(P0.05);相关分析显示r TMS组在FP1、F3、F7、T3、C3频段上,治疗前后的(δ+θ)/(α+β)差值与AQ差值呈负相关,差异有显著性意义(P0.05)。结论:低频r TMS刺激右侧大脑半球Broca镜像区能改善亚急性期运动性失语患者的言语功能,定量脑电图的变化提示了低频r TMS能促进左侧大脑皮质神经电活动变化。     

低频重复经颅磁刺激联合肌电生物反馈疗法对脑卒中患者上肢功能的临床研究

目的:观察低频重复经颅磁刺激(rTMS)联合肌电生物反馈(EMGBFT)治疗脑卒中患者上肢痉挛及其运动功能的临床疗效。方法:脑卒中伴上肢痉挛患者45名,随机分为3组(A、B、C),每组患者各15名。3组患者均给予常规康复治疗,B组另外给予EMGBFT治疗,C组另外给予低频rTMS联合EMGBFT治疗。3组患者均于治疗前、治疗4周后和第8周随访时进行改良Ashworth分级、表面肌电图(sEMG)、上肢Fugl-Meyer评定法(UFMA)以及改良Barthel指数(MBI)进行评估。结果:治疗4周时,3组患者改良Ashworth分级、sEMG、UFMA和MBI较治疗前差异有统计学意义(P0.05),C组的评估指标与其余2组比较差异均有统计学意义(P0.05)。第8周随访时A组患者各项评估指标较第4周时差异有统计学意义(P0.05),其余2组患者变化无统计学差异。结论:低频重复经颅磁刺激联合肌电生物反馈治疗可以有效缓解脑卒中患者上肢痉挛,提高上肢功能。     

间歇性θ短阵脉冲刺激对脑卒中后运动功能障碍的影响

目的:探索间歇性θ短阵脉冲刺激(iTBS)对脑卒中后运动功能障碍的影响。方法:招募我院住院治疗的脑卒中后恢复期(1—6个月)严重上肢运动功能障碍患者,随机分为iTBS组和假刺激组。每位患者接受2周共10次对患侧M1的iTBS或假刺激干预。干预前、干预结束后第二天和1个月随访时分别对受试者进行上肢Fugl-Meyer评分、运动功能状态量表(MSS)、Barthel指数(BI)的评定和静息运动阈值(RMT)的测定。干预和评定均由经过专业培训后的专人完成。除干预实施者外,患者和所有涉及的研究人员均不知晓分组情况。结果:共有16例患者(每组各8例)完成了这项前瞻性、单中心、单盲、随机、假刺激对照的探索性临床试验。所有受试者均能够耐受iTBS或假刺激。干预前后和随访时两组间上肢Fugl-Meyer评分、MSS、BI评分和健侧RMT的组间差异均无显著性意义(P0.05)。两组干预后和1个月随访时的各项量表得分均明显高于干预前(P0.01),但干预后和随访时的健侧RMT与基线相比无明显改变(P0.05)。所有受试者干预前后和随访时均无法引出患侧第一骨间背侧肌(FDI)的运动诱发电位(MEP)。结论:对于脑卒中后恢复期的严重上肢运动功能障碍的患者,在常规治疗的基础上额外增加iTBS刺激可能并不能在短时期内促进其运动功能的恢复。     

重复经颅磁刺激对卒中后大鼠的学习记忆功能和海马区胰岛素样生长因子-1表达的影响

目的:研究重复经颅磁刺激(rTMS)对卒中后大鼠的学习记忆功能和海马区胰岛素样生长因子1(IGF-1)表达的影响。方法:取成年健康雄性Wistar大鼠18只,采用线栓法建立永久性大脑中动脉闭塞大鼠模型,采用低频rTMS对实验组大鼠进行干预治疗,应用免疫荧光技术检测大鼠海马区IGF-1表达变化,应用Morris水迷宫检测大鼠空间学习记忆水平。结果:IGF-1的表达方面,海马区的平均光密度值PMCAO组显著低于PMCAO+rTMS组和sham组(P0.01),PMCAO+rTMS组和sham组相比平均光密度值无显著性差异。空间学习记忆方面,在1—5天定位航行实验中,PMCAO+rTMS组和sham组大鼠的上台潜伏期显著缩短,而PMCAO组上台潜伏期的缩短趋势不如前两组显著(P0.05),在第6天空间探索实验中PMCAO+rTMS组和sham组大鼠的第一次找到平台位置的时间少于PMCAO组(P0.05),并且在60s内穿台次数多于PMCAO组(P0.01)。结论:低频rTMS治疗对于卒中后大鼠在学习和记忆功能的康复具有一定的临床意义,低频rTMS治疗能够在一定程度上维持大脑IGF-1的水平。     

高压氧联合重复经颅磁刺激治疗脑梗死患者认知功能的疗效观察

目的:观察高压氧(HBO)联合重复经颅磁刺激(rTMS)治疗对脑梗死后患者认知功能的改善情况。方法:采用随机数字表法随机将90例脑梗死患者分为治疗组和对照组,每组45例。两组患者均给予常规治疗(常规药物治疗及认知功能训练),对照组患者在常规治疗基础上给予rTMS治疗,治疗组患者在常规治疗基础上给予HBO和rTMS联合治疗。两组患者均于治疗前和治疗4周后分别采用蒙特利尔认知评估量表(MoCA)进行认知功能评估,同时检测事件相关电位(P300)潜伏期及波幅改善情况。结果:治疗前两组患者的MoCA评分及P300潜伏期及波幅组间差异均无显著性意义(P0.05);治疗后,两组患者MoCA评分较组内治疗前均明显改善(P0.05),除语言项目外,治疗组的MoCA评分显著高于对照组,差异具有显著性意义(P0.05)。两组治疗后P300潜伏期及波幅均显著优于对照组水平,差异均具有显著性意义(P0.05)。结论:HBO联合rTMS治疗比单独r TMS治疗脑梗死患者的认知障碍效果更显著,该疗法值得临床推广。