Filtering and analyzing normal and abnormal electromyogram signals

<p><span>The electromyogram (EMG) is an important measurement to assess the health of muscles and the nerve cells that control them. The appearance of noise in electromyography (EMG) signals may unquestionably minimize the efficiency of the analysis of the signal. The denoising techniques are inevitable for minimizing noise affecting the EMG signals; these methods are Complete Ensemble Empirical Mode Decompositions with Adaptive Noise (CEEMDAN) and the Ensemble Empirical Mode Decomposition (EEMD). After that, we analyze these signals by time-frequency techniques as Adaptive Optimal Kernel (AOK) and Choi-Williams. Firstly, the obtained results illustrate the effectiveness of the CEEMDAN that permits reducing noise that interferes with normal and abnormal EMG signals with higher resolution than other techniques used as EEMD. Secondly, they show that the AOK technique is adapted to the detection and classification of these types of normal and abnormal EMG signals by the good localization of the Motor Unit Action Potentials (MUAPs) in the time-frequency plan. This paper shows the efficiency of the combination of the AOK and CEEMDAN techniques in analyzing the EMG signals. </span></p>

An ultrasonographic and electromyographic evaluation of jumping stump possibly due to a neuroma in a patient with transradial amputation: A case report

BACKGROUND AND OBJECTIVE: Jumping stump is an uncommon movement disorder characterized by involuntary movements and severe neuropathic pain in the stump. The pathophysiology and etiology of this phenomenon have not yet been clearly elucidated, and unfortunately, no proven treatment with successful recovery exists. This report aims to describe a severe painful jumping stump, possibly due to neuromas, in a traumatic transradial amputee. MATERIALS AND METHOD: We performed ultrasound examination of the painful stump depicted neuroma. Electromyographic evaluation of the stump revealed arrhythmic motor unit action potentials (MUAPs) with normal duration and amplitude; other movement disorders, such as myokymia and fasciculations, were excluded. Ultrasound should be preferred to magnetic resonance imaging (MRI) for evaluation of stumps in patients with painful stump because MRI may not be helpful due to motion artefacts. The involuntary movements ceased after surgical excision of the neuroma following failure of conservative treatments. CONCLUSION: This report confirms that neuromas are clearly associated with jumping stump. Ultrasonographic and electromyographic assessments are necessary to reveal the features of this pathology for treatment planning.

Diaphragm quantitative electromyography in difficult-to-treat asthmatic patients

ABSTRACT Quantitative electromyography is an important tool to evaluate myopathies, and some difficult-to-treat asthmatic patients may have a subclinical corticosteroid myopathic process, using only inhaled corticosteroid, according to some studies. In this report, diaphragm quantitative electromyography was used to evaluate asthmatic difficult-to-treat patients, comparing them with a control group. Significant differences were obtained in amplitude, duration and size index of motor unit action potentials, with lower parameters in the asthmatic patients, which may indicate a myopathic process.

Case 20

Inflammatory myopathies are a group of disorders characterized by necrotizing myopathies with inflammatory infiltrates. Dermatomyositis, polymyositis, and inclusion body myositis are the classical types although other overlapping disorders are now more commonly diagnosed, including necrotizing autoimmune myopathy and the anti-synthetase syndrome. This case presents a typical patient with polymyositis and outlines the clinical and pathological findings of the various inflammatory myopathies. It highlights the differential diagnosis as well as the differences and similarities among the autoimmune inflammatory myopathies. A detailed discussion of the needle electromyography findings in the various myopathies is included: Myopathies are classified into those with or without fibrillations, with or without myotonic discharges, and with or without changes in the morphology of the motor unit action potentials.

Primary muscle diseases

This chapter on primary muscle diseases explains how analysis of compound muscle action potential (CMAP) amplitude, abnormal spontaneous activity on needle electromyography (EMG), and motor unit action potentials (MUAP) characteristics may be used to give an indication of pathophysiological processes, and goes on to describe the combination and distribution of abnormalities that may be expected in the more commonly encountered myopathies. The conditions considered in detail are inflammatory myopathy (including myositis), critical illness myopathy, disorders with myotonia, inherited myopathy (including muscular dystrophy), and endocrine, metabolic and toxic disorders. Each of these has a characteristic combination of CMAP, spontaneous EMG, and MUAP findings, but the systematic approach to clinical neurophysiology as a way of understanding muscle pathophysiology can be used to investigate the myriad of rare myopathies that may be encountered in clinical practice.