磁刺激对脊髓前角细胞兴奋性的影响

背景：F波是末梢神经接受最大电刺激,从肌肉诱发出来的后期合成活动电位之一,是脊髓运动神经元突触后电位的反映,对F波的研究已经被作为衡量脊髓运动神经元兴奋性的一种手段.但F波具有低波幅和出现不稳定的特点,如何使F波的出现更加稳定和明显且又不影响F波的最短潜伏期是神经电生理研究的方向.目的：了解枕骨粗隆处磁刺激对F波的影响,更进一步了解人类中枢神经系统对脊髓前角运动细胞兴奋性的影响.设计：自身对照实验.单位：广西医科大学第一附属医院神经内科,日本熊本机能医院.对象：选择2000-03/2001-03日本熊本机能医院的工作人员13名,男6名,女7名,年龄20～54岁,均排除神经系统疾病史,体内无植入金属体.方法：枕骨粗隆上或稍低处使用8字形磁刺激头进行磁刺激,右腕关节尺神经上进行电刺激,在右手的第一骨间肌记录肌电活动,每一个受试者均分别记录磁刺激前、磁刺激后间隔30,50,100和300 ms时电刺激的F波,每一个实验条件下记录10个F波.主要观察指标：①M波的波幅.②F波平均波幅与M波波幅比.③F波最大波幅与M波波幅比.④F波最小潜伏期.⑤F波平均持续时间.⑥F波出现频率（F 波波幅≥0.05 mV）.结果：13名健康自愿者的实验数据均进入结果分析.磁-电刺激间隔50 ms时F波平均持续时间出现极显著性延长[（8.39&;#177;1.59）,（6.75&;#177;1.62）ms,P＜0.001];F平均/M波幅出现极显著性升高[1.73&;#177;1.20,0.87&;#177;0.78,P＜0.001];F最大/M波幅出现显著性升高[4.07&;#177;2.59,2.19&;#177;1.76,P＜0.05];F波出现频率出现极显著性升高[（80.77&;#177;22.89）,（61.82&;#177;23.16）%,P＜0.001];在磁-电刺激间隔100 ms亦出现显著性升高（P＜0.05）.在整个实验过程中,任何实验条件下都没有观察到F波最短潜伏期有显著性改变（P＞0.05）.结论：枕骨粗隆处磁刺激明显改变了脊髓前角细胞兴奋性,表现为当枕骨粗隆处施行的磁刺激和腕关节处尺神经电刺激间隔一定的时间时,F波波幅增高,时程延长.同时还发现无论在任何实验条件下,F波最短潜伏期都没有明显的变化.     

磁刺激对脊髓前角细胞兴奋性的影响

背景F波是末梢神经接受最大电刺激,从肌肉诱发出来的后期合成活动电位之一,是脊髓运动神经元突触后电位的反映,对F波的研究已经被作为衡量脊髓运动神经元兴奋性的一种手段.但F波具有低波幅和出现不稳定的特点,如何使F波的出现更加稳定和明显且又不影响F波的最短潜伏期是神经电生理研究的方向.目的了解枕骨粗隆处磁刺激对F波的影响,更进一步了解人类中枢神经系统对脊髓前角运动细胞兴奋性的影响.设计自身对照实验.单位广西医科大学第一附属医院神经内科,日本熊本机能医院.对象选择2000-03/2001-03日本熊本机能医院的工作人员13名,男6名,女7名,年龄20～54岁,均排除神经系统疾病史,体内无植入金属体.方法枕骨粗隆上或稍低处使用8字形磁刺激头进行磁刺激,右腕关节尺神经上进行电刺激,在右手的第一骨间肌记录肌电活动,每一个受试者均分别记录磁刺激前、磁刺激后间隔30,50,100和300 ms时电刺激的F波,每一个实验条件下记录10个F波.主要观察指标①M波的波幅.②F波平均波幅与M波波幅比.③F波最大波幅与M波波幅比.④F波最小潜伏期.⑤F波平均持续时间.⑥F波出现频率(F 波波幅≥0.05 mV).结果13名健康自愿者的实验数据均进入结果分析.磁-电刺激间隔50 ms时F波平均持续时间出现极显著性延长[(8.39±1.59),(6.75±1.62)ms,P＜0.001];F平均/M波幅出现极显著性升高[1.73±1.20,0.87±0.78,P＜0.001];F最大/M波幅出现显著性升高[4.07±2.59,2.19±1.76,P＜0.05];F波出现频率出现极显著性升高[(80.77±22.89),(61.82±23.16)%,P＜0.001];在磁-电刺激间隔100 ms亦出现显著性升高(P＜0.05).在整个实验过程中,任何实验条件下都没有观察到F波最短潜伏期有显著性改变(P＞0.05).结论枕骨粗隆处磁刺激明显改变了脊髓前角细胞兴奋性,表现为当枕骨粗隆处施行的磁刺激和腕关节处尺神经电刺激间隔一定的时间时,F波波幅增高,时程延长.同时还发现无论在任何实验条件下,F波最短潜伏期都没有明显的变化.     

Manual therapy directed at the knee or lumbopelvic region does not influence quadriceps spinal reflex excitability

Manual therapies, directed to the knee and lumbopelvic region, have demonstrated the ability to improve neuromuscular quadriceps function in individuals with knee pathology. It remains unknown if manual therapies may alter impaired spinal reflex excitability, thus identifying a potential mechanism in which manual therapy may improve neuromuscular function following knee injury.AimTo determine the effect of local and distant mobilisation/manipulation interventions on quadriceps spinal reflex excitability.MethodsSeventy-five individuals with a history of knee joint injury and current quadriceps inhibition volunteered for this study. Participants were randomised to one of five intervention groups: lumbopelvic manipulation (grade V), lumbopelvic manipulation positioning (no thrust), grade IV patellar mobilisation, grade I patellar mobilisation, and control (no treatment). Changes in spinal reflex excitability were quantified by assessing the Hoffmann reflex (H-reflex), presynaptic, and postsynaptic excitability. A hierarchical linear-mixed model for repeated measures was performed to compare changes in outcome variables between groups over time (pre, post 0, 30, 60, 90 min).ResultsThere were no significant differences in H-reflex, presynaptic, or postsynaptic excitability between groups across time.ConclusionsManual therapies directed to the knee or lumbopelvic region did not acutely change quadriceps spinal reflex excitability. Although manual therapies may improve impairments and functional outcomes the underlying mechanism does not appear to be related to changes in spinal reflex excitability.     

运动神经元病及运动神经元病综合征

目的探讨运动神经元病综合征(MNDS)的病因、发病机制、诊断。方法回顾性分析90例运动神经元病(MND)及MNDS的临床特点和诊疗过程。结果MND38例(42.4%),对症及支持治疗,总有效率21.4%;MNDS52例(57.8%),病因为主治疗,总有效率61.5%。两者疗效差异显著(P<0.01)。结论明确MNDS的病因,对治疗及预后极为重要。     

Motor imagery muscle contraction strength influences spinal motor neuron excitability and cardiac sympathetic nerve activity

[Purpose] The aim of this study was to investigate the changes in spinal motor neuron excitability and autonomic nervous system activity during motor imagery of isometric thenar muscle activity at 10% and 50% maximal voluntary contraction (MVC). [Methods] The F-waves and low frequency/high frequency (LF/HF) ratio were recorded at rest, during motor imagery, and post-trial. For motor imagery trials, subjects were instructed to imagine thenar muscle activity at 10% and 50% MVC while holding the sensor of a pinch meter for 5 min. [Results] The F-waves and LF/HF ratio during motor imagery at 50% MVC were significantly increased compared with those at rest, whereas those during motor imagery at 10% MVC were not significantly different from those at rest. The relative values of the F/M amplitude ratio during motor imagery at 50% MVC were significantly higher than those at 10% MVC. The relative values of persistence and the LF/HF ratio during motor imagery were similar during motor imagery at the two muscle contraction strengths. [Conclusion] Motor imagery can increase the spinal motor neuron excitability and cardiac sympathetic nerve activity. Motor imagery at 50% MVC may be more effective than motor imagery at 10% MVC.Key words: Motor imagery, F-wave, Autonomic nervous system activity     

短时程非强直性低频超强神经电刺激对脑卒中患者脊髓运动神经元兴奋性的影响

目的:研究非强直性低频超强神经电刺激对脊髓运动神经元兴奋性的影响,为完善脑卒中后外周神经电刺激治疗参数提供参考.方法:分别比较脑卒中患者和健康人群在0.5Hz低频F波检测中最初5次和最终5次超强刺激下F波次数,潜伏期和F波幅/M波幅(F/M)的变化情况.F波检测通过刺激腓骨头下腓总神经完成,记录肌肉为胫骨前肌和腓骨肌....     

Nutrition and dietary supplements in motor neuron disease

Compromised nutrition leading to weight loss is a common and significant problem in the amyotrophic lateral sclerosis (ALS) patient population. The benefit of aggressive and early nutritional therapy can profoundly influence the disease course, quality of life, and survival. This article reviews the role of nutrition, both as sustenance and treatment for patients who have ALS. Self-medication with dietary supplements has become increasingly popular within this patient population. Despite their popularity, the efficacy of these compounds has been largely unsupported by formal clinical trials. Available data will be highlighted to provide a basis upon which to advise patients requesting guidance.     

Amyotrophic lateral sclerosis and other motor neuron diseases

The anterior horn cell diseases, with the exception of polio, are progressive degenerative diseases of the motor neurons. These disorders include SMA types I to III in children and familial and sporadic ALS and its variants (PMA, PLS, and PBP), Kennedy's disease, and SMA type IV in adults. The electrodiagnostic study is a crucial step in the diagnostic process for all of these disorders. In general, motor NCS may be normal or reveal low CMAP amplitudes with relatively normal conduction velocities. Sensory NCS, except in the case of Kennedy's disease, are normal. The NEE is notable for the often abundant presence of abnormal spontaneous activity, including fibrillation potentials and positive sharp waves, fasciculation potentials, and complex repetitive discharges. Motor unit morphology is abnormal, with polyphasic motor units and large amplitude and duration MUAPs when the disease is slowly progressive. Recruitment in affected muscles is reduced with abnormally rapidly firing motor units. To diagnose a widespread disorder of the motor neurons, abnormalities must be present in multiple muscles with different nerve root and peripheral nerve innervation in multiple limbs. The Lambert Criteria and the El Escorial Criteria are the two most widely accepted sets of electrodiagnostic criteria for ALS. The electrodiagnostic diagnosis must be supported by appropriate history and physical examination findings and the exclusion, via neuroimaging and laboratory testing, of other diseases that may mimic a generalized disorder of the motor neurons.     

Androgen receptor function in motor neuron survival and degeneration

Polyglutamine repeat expansion in the androgen receptor is responsible for the motor neuron degeneration in X-linked spinal and bulbar muscular atrophy (SBMA; Kennedy's disease). This mutation, like the other polyglutamine repeat expansions, has proven to be toxic itself by a gain-of-function effect; however, a growing body of evidence indicates that loss of androgen receptor normal function simultaneously contributes to SBMA disease pathology, and, conversely, that normal androgen receptor signaling mediates important trophic effects upon motor neurons. This review considers the trophic requirements of motor neurons, focusing upon the role of known neurotrophic factors in motor neuron disease natural history, and the interactions of androgen receptor signaling pathways with motor neuron disease pathogenesis and progression. A thorough understanding of androgen receptor signaling in motor neurons should provide important inroads toward the development of effective treatments for a variety of devastating motor neuron diseases.     

The effect of transcutaneous electrical stimulation on spinal motor neuron excitability in people without known neuromuscular diseases: the roles of stimulus intensity and location

BACKGROUND AND PURPOSE: The Hoffmann reflex (H-reflex) is widely acknowledged as an indirect indicator of spinal motor neuron excitability. The purpose of this study was to determine whether transcutaneous electrical stimulation (TES), applied over the dorsiflexors or plantar flexors of the ankle, would alter the soleus muscle's H-reflex. Attention was focused on the roles of stimulus intensity and location. SUBJECTS: Thirty-two volunteers without known neuromuscular diseases (17 women [53%]; mean years of age=27, SD=7.3, range=21-48) were studied. METHODS: Subjects were randomly assigned to 1 of 4 groups, and TES was administered for 15 minutes. Stimulation site and intensity varied according to group assignment. H-reflexes were recorded before and for 10 minutes after TES. RESULTS: H-reflex amplitudes increased following TES at sensory threshold, whereas H-reflex amplitudes did not change following TES at 1.5 times motor threshold. The site of stimulation did not influence the resulting H-reflexes. DISCUSSION AND CONCLUSION: Low-intensity TES increases H-reflex amplitudes (and presumably the excitability of spinal motor neurons to Ia afferent input) in subjects without known neuromuscular diseases. High-intensity TES had little influence on H-reflex amplitudes.     

大鼠延髓呼吸性神经元向脊髓膈运动神经元投射的实验观察

目的观察大鼠延髓呼吸性神经元向脊髓膈运动神经元的直接投射。方法 2 5只Wistar大鼠分为 3组 :脊髓定位组(5只 )、延髓投射组 (15只 )和对照组 (5只 )。运用辣根过氧化物酶 (HRP)逆追踪法 ,于脊髓定位组膈神经干注入HRP ,确定膈运动神经元在脊髓中的位置 ,然后延髓投射组于逆行性标记细胞位置 ,对照组于脊髓后角分别注入HRP ,观察延髓呼吸性神经元的标记情况。结果在脊髓定位组的注射同侧观察到 ,C3 —C5节段的前角中间部出现逆行性标记细胞 ,为典型的前角运动神经元。在延髓投射组观察到 ,逆行性标识神经元出现在延髓疑后核和面后核的腹内侧部。对照组在上述位置未见标识神经元。结论大鼠膈运动神经元位于C3 -C5节段 ,其投射神经元主要分布在以延髓疑后核和面后核区为主轴的一个长的细胞柱上     

变频相位干涉电场刺激对运动皮层兴奋性及运动学习表现的影响

摘要目的：探究变频相位干涉电场刺激（temporal interference electrical fields stimulation, TI）对健康成年人运动皮层兴奋性及运动学习能力的影响,为TI刺激的应用提供依据。方法：采用随机交叉双盲设计,研究对象为健康成年人。试验1：20例受试者完成经颅磁刺激（transcranial magnetic stimulation,TMS）测试,评估刺激前后皮层兴奋性指标的改变,包括运动诱发电位（motor evoked potential, MEP）、静息运动阈值（resting motor threshold, RMT）、短时距皮层内抑制（short-interval intracortical inhibition, SICI）、皮质内促通（intracortical facilitation, ICF）。试验2：16例受试者完成随机反应时任务（random reaction time task, RRTT）和序列反应时任务（serial reaction time task, SRTT）,测试指标包括平均反应时（reaction time, RT）、第一内隐学习（first implicit learning, FIL）、第二内隐学习（second implicit learning, SIL）。通过双因素重复测量方差分析评价TI刺激对受试者运动皮层兴奋性及运动学习能力的影响。结果：试验1：刺激条件和时间对MEP（F=28.787,P<0.001,ηP2=0.602）和RMT（F=23.524,P<0.001,ηP2=0.580）具有显著交互作用,而SICI和ICF无显著交互效应。试验2：与假刺激相比,TI刺激后SRTT中的FIL有显著提升（F=4.601,P=0.049,ηP2=0.235）,而RRTT任务则无显著交互效应。结论：变频TI刺激可以显著增加初级运动皮层的兴奋性,这种调控效应可能有助于促进健康成年人运动学习表现。     

速度对膝关节屈肌和伸肌等速离心收缩力矩的影响

目的确定运动速度对离心收缩测试的影响,为进一步深入研究提供客观依据。方法对20例健康人膝关节进行等速离心收缩测试,用统计学方法观察不同速度下膝关节屈肌和伸肌峰力矩、相对峰力矩和屈肌/伸肌比值的变化。结果速度对膝关节屈肌和伸肌峰力矩和相对峰力矩影响显著,对屈/伸比值的影响不显著。结论离心等速测试和训练过程中,必须考虑速度的因素。     

髌股疼痛综合征患者股四头肌失衡程度评估及其与Q角的相关分析

目的:利用表面肌电图对髌股疼痛综合征(PFPS)患者股四头肌失衡程度进行评估,并对其与Q角的关系进行分析.方法:PFPS病例组及正常对照组各30人,分别进行Q角测量,同时在双足半蹲动作时检测股外侧肌(VL)及股内斜肌(VMO)表面肌电图(sEMG),分析股内、外侧肌时域指标,对Q角与VL/VMO肌电比值进行相关分析.结果:病例组VL、VMP时域指标ZCR、RMS、IEMG差异有统计学意义(P＜0.05),且VL较VMO高.Q角与VL/VMO肌电比值之间进行线性相关分析,Pearson相关系数为0.149(P＞ 0.05).结论:PFPS患者VL运动单位募集数量、活化程度要高于VMO.股四头肌失衡程度与Q角大小无明显相关.     

Gene therapy for amyotrophic lateral sclerosis and other motor neuron diseases

There are several incurable diseases of motor neuron degeneration, including amyotrophic lateral sclerosis (ALS), primary lateral sclerosis, hereditary spastic hemiplegia, spinal muscular atrophy, and bulbospinal atrophy. Advances in gene transfer techniques coupled with new insights into molecular pathology have opened promising avenues for gene therapy aimed at halting disease progression. Nonviral preparations and recombinant adenoviruses, adeno-associated viruses, herpesviruses, and lentiviruses may ultimately transduce sufficient numbers of cerebral, brainstem, and spinal cord neurons for therapeutic applications. This could be accomplished by direct injection, transduction of lower motor neurons via retrograde transport after intramuscular injection, or cell-based therapies. Studies using transgenic mice expressing mutant superoxide dismutase 1 (SOD1), a model for one form of ALS, established that several proteins were neuroprotective, including calbindin, bcl-2, and growth factors. These same molecules promoted neuronal survival in other injury models, suggesting general applicability to all forms of ALS. Potentially correctable genetic lesions have also been identified for hereditary spastic hemiplegia, bulbospinal atrophy, and spinal muscular atrophy. Finally, it may be possible to repopulate lost corticospinal and lower motor neurons by transplanting stem cells or stimulating native progenitor populations. The challenge ahead is to translate these basic science breakthroughs into workable clinical practice.