A novel assessment of abdominal pseudohernia after thoracolumbar vertebral compression fractures using surface electromyography and ultrasonography: A case report

Rationale:An abdominal pseudohernia is a protrusion of the abdominal wall that there is no actual muscular disruption. This report presents a case in which abdominal muscle activities were accurately and quantitatively measured using ultrasonography (US) and surface electromyography in a patient with abdominal pseudohernia.Patient concerns:A 62-year-old man presented with a marked protrusion on the left abdomen with increasing abdominal pressure.Diagnoses:First, the thickness of the abdominal muscle was measured with US while the patient constantly blew the positive expiratory pressure device. When the force was applied to the abdomen, the mean thickness of the muscle layer on the lesion site was found to be thinner. Second, the activities of the abdominal muscles were measured using surface electromyography by attaching electrodes to 8 channels at the same time. When the same pressure was applied on both sides of the abdomen, more recruitment occurred to compensate for muscle weakness at the lesion site. Through the previous 2 tests, the decrease in muscle activity in the lesion area could be quantitatively evaluated. Third, the denervation of the muscle was confirmed using US-guided needle electromyography.Interventions:The patient in this case was wearing an abdominal binder. In addition, he had been training his abdominal muscles through McGill exercise and breathing exercises such as with a positive expiratory pressure device.Outcomes:The patient was able to understand his symptoms. A follow-up test will be performed to see if there is any improvement.Lessons:By using these outstanding assessment methods, proper diagnosis and rehabilitation treatment strategies can be developed.     

Subtypes of anhedonia and facial electromyography response to negative affective pictures in non-psychiatric adults

Introduction. Flat/constricted affect and anhedonia are symptoms found in several psychiatric disorders such as depression and schizophrenia. However, there are very few studies on the relationships between specific anhedonia subtypes and objectively assessed flat affect, and it appears that none of the existing studies examined potential moderation by sex.

Methods. Forty-seven undergraduate students (60% male) completed self-report questionnaires assessing three subtypes of anhedonia – non-social consummatory (CON) and anticipatory (ANT) anhedonia, and overall social anhedonia. Participants viewed 15 pictures (5 neutral and 10 negative) from the International Affective Picture System, whereas facial muscle reaction was recorded using electromyography (EMG).

Results. Male participants reporting a greater level of overall social or non-social CON anhedonia showed a greater EMG activity increase in the corrugator supercilii muscle to negative (vs. neutral) pictures. In females, the relationship was only found with social anhedonia and was opposite in direction, as increased social anhedonia related to less EMG activity change in the corrugator muscle.

Conclusions. The relationship between anhedonia and flat affect varied as a function of sex and anhedonia subtype. These findings may help explain discrepancies in the sparse existing literature examining this relationship in psychiatric populations and have implications for assessment and treatment of these symptoms across psychiatric disorders.     

髂腰肌针极肌电图在诊断多发性肌炎中的应用价值

 目的 探讨髂腰肌肌电图在诊断多发性肌炎中的应用价值。方法 回顾性收集2018-01至2019-02于首都医科大学附属北京天坛医院就诊并确诊为多发性肌炎的28例患者(多发性肌炎组)的临床资料,以及年龄、性别相匹配的健康人20名(对照组),就其髂腰肌、股四头肌、三角肌肌电图自发电位和小力收缩运动单位电位(motor unit action potential, MUAP)进行分析。结果 对照组髂腰肌未检测出自发电位,多发性肌炎组髂腰肌自发电位阳性率为57.14%(16/28),显著高于对照组(P<0.001);另外其MUAP波幅显著低于对照组[(424.20±82.41)μV vs. (593.93±65.49 )μV,P<0.001],MUAP时限也显著短于对照组[(9.73±2.05)vs. (11.26±0.42) ms,P<0.01]。在肌肉病患者中,股四头肌自发电位阳性率为35.71%(10/28),三角肌自发电位阳性率为25.00%(7/28),三角肌自发电位显著低于髂腰肌(P<0.05)。结论 髂腰肌在多发性肌炎患者中有明显的肌源性损害的表现,可为临床提供更加敏感、客观的诊断依据。     

Change in Electromyographic Activity of Wrist Extensor by Cylindrical Brace

Purpose

To verify the effect of a newly-developed cylindrical type forearm brace, which was designed to give focal counterforce perpendicularly on the muscle belly of the wrist extensor.

Materials and Methods

The dominant hands of 24 (12 males, 12 females) healthy subjects were tested. Two types of forearm braces (focal cylindrical type and broad pneumatic type) were examined. The braces were applied at the extensor carpi radialis brevis, 5 to 7 cm distal to the lateral epicondyle. Two surface electrodes were attached to the proximal and distal parts of the brace. By quantitative electromyography, the mean amplitudes of voluntary extensor carpi radialis brevis contraction before and after applying each brace were recorded and analyzed.

Results

The mean amplitudes of the focal cylindrical brace and broad pneumatic brace were reduced significantly compared to no brace (p<0.05), with a larger reduction for the cylindrical brace than the pneumatic brace (p<0.05). There was no significant difference between the proximal and distal mean amplitudes with each brace.

Conclusion

A cylindrical type brace decreased electromyographic activity in the wrist extensor more effectively than did the pneumatic type brace.     

Nerve stimulator for regional anaesthesia procedures with automatic interactive closed-loop control

Abstract

Peripheral nerve stimulators have widespread among anaesthesiologists and remain a popular technique. However, in commercial devices, the user has to manually adjust stimulus intensity. Thus, the aim of this study is to propose a method that allows automating the current intensity control. An earlier nerve stimulator prototype was modified to add an accelerometer and an sEMG module. The choice of these two sensors is aimed at the possibility of observing the mechanical and electrical responses of the muscle contraction evoked by the stimulation. The tests were performed in two steps. The first step was to observe how the sensors behave during stimulation and muscle contraction. The second step was to implement a control algorithm and to validate the automation technique. Comparing the two methods, no significant differences were found on procedure time (manual: 12.5?±?2.3; automatic: 11.6?±?1.9; ρ?=0.380) and blockade latency time (manual: 11.6?±?1.1; automatic: 11.9?±?1.2; ρ?=0.524). Comparing needle-nerve distance in manual or automatic mode, no significant differences were found for 1.0?mA, 0.8?mA, 0.5?mA and 0.3?mA. We conclude that the technique for automating the current intensity update, using accelerometer and/or electromyography, is satisfactory. Furthermore, we conclude that the use of the accelerometer alone is sufficient for detection of muscle contraction.     

Chronic fatigue syndrome: Abnormally fast muscle fiber conduction in the membranes of motor units at low static force load

ObjectiveChronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of – especially muscular –fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities.MethodsFemales with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured.ResultsThe CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed.ConclusionOur results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance.SignificanceThese findings help to detangle the underlying mechanisms of CFS.     

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。     

Prominent fatigue in spinal muscular atrophy and spinal and bulbar muscular atrophy: Evidence of activity-dependent conduction block

ObjectivesTo clarify whether patients with spinal muscular atrophy (SMA) or spinal and bulbar muscular atrophy (SBMA) suffer disabling muscle fatigue, and whether activity-dependent conduction block (ADCB) contributes to their fatigue. ADCB is usually caused by reduced safety factor for impulse transmission in demyelinating diseases, whereas markedly increased axonal branching associated with collateral sprouting may reduce the safety factor in chronic lower motor neuron disorders.MethodsWe assessed the fatigue severity scale (FSS) in 22 patients with SMA/SBMA, and in 100 disease controls (multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy (CIDP), and axonal neuropathy). We then performed stimulated-single fibre electromyography (s-SFEMG) in the extensor digitorum communis (EDC) muscle of 21 SMA/SBMA patients, 6 CIDP patients, and 10 normal subjects.ResultsThe FSS score was the highest in SMA/SBMA patients [4.9 ± 1.1 (mean ± SD)], with 81% of them complaining of disabling fatigue, compared with normal controls (3.5 ± 1.0), whereas patients with multiple sclerosis (4.3 ± 1.6), myasthenia gravis (4.0 ± 1.6) or CIDP (4.3 ± 1.4) also showed higher FSS score. When 2000 stimuli were delivered at 20 Hz in s-SFEMG, conduction block of single motor axons developed in 46% of patients with SMA/SBMA, and 40% of CIDP patients, but in none of the normal controls.ConclusionSMA/SBMA patients frequently suffer from disabling fatigue presumably caused by ADCB induced by voluntary activity.SignificanceADCB could be the mechanism for muscle fatigue in chronic lower motor neuron diseases.