喉肌电图与喉肌诱发电位对甲状腺手术所致声带麻痹的评价

目的 :探讨喉肌电图 (LEMG)和喉体感诱发电位 (LSEP)对甲状腺手术所致声带麻痹的评估价值。方法 :对病程不同的 32例甲状腺手术所致单侧声带麻痹患者进行LEMG和LSEP检测并分析与临床预后的关系。结果 :不论是 2～ 6个月声带运动恢复组 ,还是未恢复组 ,LEMG和LSEP两种检查结果(波幅分别 6 5 .2± 2 2 .9μV和 4 4 .0± 2 8.2 μV)之间有高度一致性即其间差异无显著意义。不论是LEMG或是LSEP检查 ,2～ 6个月声带恢复组与未恢复组两组 (波幅分别 5 5 .4± 12 .7μV和 15 .4±15 .6 μV)之间差异有显著性意义。全部患者LSEP潜伏期明显延长 ,波幅降低 ,与对照组比较差异有显著意义。LEMG提示失神经电位增多。预后越好则LSEP和LEMG波幅越高。结论 :LSEP和LEMG检测有一致性 ,均可评估喉返神经损伤程度 ,对预测喉返神经损伤所致声带麻痹的预后有一定价值。     

基于经验模态分解-小波包变换的表面肌电信号手势识别

为了提高表面肌电信号（sEMG）手部运动识别的正确率,比较常规的sEMG预处理和特征提取方法,提出一种基于经验模态分解（EMD）和小波包变换（WPT）的sEMG手势识别模型。首先,使用EMD方法将sEMG进行平稳化,得到一系列的固有模态函数。其次,求取各个固有模态函数与原始信号的相关性,选取相关性较高的前4个分量作为有效分量。然后,采用Db3小波函数进行WPT,提取小波包系数中的平均能量、平均绝对值、最大值、均方根和方差等特征。分别采用线性判别分析和支持向量机对12种手部运动进行模式识别。结果表明基于EMD和WPT的sEMG手势识别正确率比直接提取小波包系数中的特征识别正确率高。     

膝骨关节炎患者肌电标准化方法的信度研究

目的 评估标准等长收缩(standard isometric contraction, SIC)与最大随意等长收缩(maximum voluntary isometric contraction, MVIC)应用于膝骨关节炎(knee osteoarthritis, KOA)患者肌电标准化的重测信度。方法 采用无线肌电测试系统收集KOA患者患侧腿在慢跑、SIC测试和MVIC测试时臀大肌、半腱肌、股直肌、股外侧肌、胫骨前肌、外侧腓肠肌和比目鱼肌的肌电数据。使用组内相关系数和95%置信区间评估重测信度。结果 KOA患者执行SIC测试时7块肌肉的重测信度均较好,执行MVIC测试时5块肌肉重测信度一般,2块肌肉重测信度较好,7块肌肉在SIC测试中的重测信度均高于MVIC测试;KOA患者慢跑时7块肌肉经SIC标准化后的重测信度均高于经MVIC标准化的重测信度,且股直肌经SIC标准化后的重测信度显著高于经MVIC标准化的重测信度。结论 对于KOA患者,SIC是一种比MVIC更为可靠的表面肌电标准化方案,具有较好的临床推广潜力。     

A study of uterine inertia on the spontaneous of labor using uterine electromyography

ObjectiveThe purpose of this study is to analyze uterine electromyography burst patterns in patients with spontaneous labor and patients with uterine inertia.Materials and methodsUterine electromyography was recorded using 4 silver/silver chloride electrodes placed periumbilical. Thirty women in the spontaneous labor were enrolled. Uterine electromyography was also recorded from patients with uterine inertia before and after oxytocin treatment. EMG bursts were characterized by analysis of multiple variables including burst frequency, duration, root mean squared, amplitude, and total power.ResultsThere were significant reductions (P < .01) in all EMG burst characteristics. In addition, uterine electromyography parameters were all increased after oxytocin treatment and were comparable (P > .05) to patients in spontaneous labor.ConclusionsUterine electromyography can be used effectively to distinguish patients progressing with spontaneous labor from patients that develop uterine inertia. Uterine inertia is characterized by reduced EMG activity and failure of cervical dilation. Uterine electromyography is a quantitative, non-invasive assessment tool that contributes to the diagnosis, evaluation and management of patients with spontaneous labor and uterine inertia.     

常运动对大学生Wingate无氧运动能力的影响

目的为研究有规律的运动对大学生无氧运动能力的影响,采用Wingate功率自行车测试比较常运动和久坐大学生的无氧做功能力,并用表面肌电信号分析下肢主要肌群无氧疲劳特征。方法募集38名男大学生,分为常运动和久坐大学生两组,每组各19名。常运动组的质控标准是每周每次运动超过30min、每周运动次数≥4次;0~3次则为久坐组。采用日本COMBI公司PowerMax Ⅶ功率自行车进行Wingate无氧功率测试,比较两组学生最大功率输出(peak power output,PP)、平均功率(mean power output,MP)和无氧疲劳指数(anaerobic fatigue index,AFI)的差异。同时采集了Wingate运动过程中下肢股直肌、股外侧肌、股内侧肌和股二头肌的表面肌电信号,利用自主构建的非线性小波对表面肌电信号的强度和平均功率频率(mean power frequency,MPF)进行分析,检测肌肉纤维的募集与肌肉无氧疲劳状况。结果常运动大学生功率自行车PP和MP显著高于久坐大学生(P0.05),AFI明显小于久坐大学生。肌电信号MPF随着疲劳的产生而持续下降,常运动组的下降趋势比久坐组显著。肌电信号的强度两组也呈现不同的趋势。结论常运动组大学生的无氧运动能力显著高于久坐组。无氧运动能力与快肌纤维密切相关,结合功率输出和肌电信号分析,大学生进行有规律的运动对于增加快肌纤维的比例和面积,并进一步增加肌肉的爆发力和速度有积极的影响。     

A novel electrodiagnostic assessment of the laryngeal closure reflex

Introduction: We describe a novel, clinically applicable conduction study of the laryngeal nerves. Methods: Seventeen normal volunteer subjects were included. Activation of the sensory territory of the superior laryngeal nerve was performed by administration of low level brief electrical stimuli. The laryngeal closure reflex (LCR) evoked by this stimulus was recorded by needle electrodes. Mean minimal latencies were calculated for each response, and proposed values for the upper limit of normal were determined. Results: Uniform, consistent early ipsilateral responses and late bilateral responses, which exhibit greater variation in latency and morphology, were recorded. Significant side‐to‐side differences in latencies were observed, consistent with the length discrepancy between right and left recurrent laryngeal nerves. Conclusions: This technique yields clear, quantifiable data regarding neurologic integrity of laryngeal function, heretofore unobtainable in the clinical setting. This study may yield clinically relevant information regarding severity and prognosis in patients with laryngeal neuropathic injury. Muscle Nerve 47:432‐436, 2013     

Age‐associated changes in muscle activity during isometric contraction

Introduction: We investigated the effect of age on the complexity of muscle activity and the variance in the force of isometric contraction. Methods: Surface electromyography (sEMG) from biceps brachii muscle and force of contraction were recorded from 96 subjects (20–70 years of age) during isometric contractions. Results: There was a reduction in the complexity of sEMG associated with aging. The relationship of age and complexity was approximated using a bilinear fit, with the average knee point at 45 years. There was an age‐associated increase in the coefficient of variation (CoV) of the force of muscle contraction, and this increase was correlated with the decrease in complexity of sEMG (r² = 0.76). Conclusions: There was an age‐associated increase in CoV and also a reduction in the complexity of sEMG. The correlation between these 2 factors can be explained based on the age‐associated increase in motor unit density. Muscle Nerve 47: 545–549, 2013     

Spasticity,weakness, force variability,and sustained spontaneous motor unit discharges of resting spastic–paretic biceps brachii muscles in chronic stroke

Introduction: The purpose of our study was to examine relations among spasticity, weakness, force variability, and sustained spontaneous motor unit discharges in spastic–paretic biceps brachii muscles in chronic stroke. Methods: Ten chronic stroke subjects produced submaximal isometric elbow flexion force on impaired and non‐impaired sides. Intramuscular EMG (iEMG) was recorded from biceps and triceps brachii muscles. Results: We observed sustained spontaneous motor unit discharges in resting biceps on iEMG. Spontaneous discharges increased after voluntary activation only on the impaired side. The impaired side had greater matching errors and greater fluctuations in isometric force. Spontaneous discharges were not related functionally to spasticity, force variability, or weakness. However, greater strength on the impaired side correlated with less force variability. Conclusion: Weakness rather than spasticity is a main factor interfering with voluntary force control in paretic–spastic biceps brachii muscles in chronic stroke. Muscle Nerve, 2013     

Spontaneous electromyographic activity of the tongue in amyotrophic lateral sclerosis

Introduction: Detection of denervation in muscles in the craniobulbar area is important to assure widespread lower motor neuron involvement in the diagnosis of amyotrophic lateral sclerosis (ALS). The value of spontaneous activity analysis in needle electromyography (EMG) of the tongue has been questioned in the recent literature. Methods: Spontaneous activity in the tongue and sternocleidomastoid (SCM) muscles was reviewed retrospectively in 17 ALS patients. Results: Needle EMG showed spontaneous activity in the tongue in 14 of 17 patients (82%) and in 6 patients of 17 (35%) in SCM. Spontaneous EMG activity in the tongue was found in patients with and without bulbar symptoms. Conclusions: Needle EMG is a valuable method for assessing clinical and subclinical involvement of the tongue in patients with bulbar and limb onset ALS. Adequate relaxation of the tongue is a prerequisite for proper spontaneous activity recording. Muscle Nerve, 48: 296–298, 2013     

Electrical impedance myography in the diagnosis of radiculopathy

Introduction: We sought to determine whether electrical impedance myography (EIM) could serve as a diagnostic procedure for evaluation of radiculopathy. Methods: Twenty‐seven patients with clinically and radiologically diagnosed cervical or lumbosacral radiculopathy who met a “gold standard” definition underwent EIM and standard needle electromyography (EMG) of multiple upper or lower extremity muscles. Results: EIM reactance values revealed consistent reductions in the radiculopathy‐affected myotomal muscles as compared with those on the unaffected side; the degree of asymmetry was associated strongly with the degree of EMG abnormality (P < 0.001). EIM had a sensitivity of 64.5% and a specificity of 77.0%; in comparison, EMG had a sensitivity of 79.7% but a specificity of 69.7%. Conclusions: These findings support the potential for EIM to serve as a new non‐invasive tool to assist in diagnosis of radiculopathy; however, further refinement of the technique is needed for this specific application. Muscle Nerve 48:800–805, 2013