Needle Electromyography Research Articles

Alignment of magnetic sensing and clinical magnetomyography.

Neuromuscular diseases are a prevalent cause of prolonged and severe suffering for patients, and with the global population aging, it is increasingly becoming a pressing concern. To assess muscle activity in NMDs, clinicians and researchers typically use electromyography (EMG), which can be either non-invasive using surface EMG, or invasive through needle EMG. Surface EMG signals have a low spatial resolution, and while the needle EMG provides a higher resolution, it can be painful for the patients, with an additional risk of infection. The pain associated with the needle EMG can pose a risk for certain patient groups, such as children. For example, children with spinal muscular atrophy (type of NMD) require regular monitoring of treatment efficacy through needle EMG; however, due to the pain caused by the procedure, clinicians often rely on a clinical assessment rather than needle EMG. Magnetomyography (MMG), the magnetic counterpart of the EMG, measures muscle activity non-invasively using magnetic signals. With super-resolution capabilities, MMG has the potential to improve spatial resolution and, in the meantime, address the limitations of EMG. This article discusses the challenges in developing magnetic sensors for MMG, including sensor design and technology advancements that allow for more specific recordings, targeting of individual motor units, and reduction of magnetic noise. In addition, we cover the motor unit behavior and activation pattern, an overview of magnetic sensing technologies, and evaluations of wearable, non-invasive magnetic sensors for MMG.

Instrumental methods for assessing the state of the paravertebral lumbar muscles in patients with lumbosacral radiculopathy and nonspecific muscle-skeletal pain

Neurological examination plays the main role in diagnostic and management of radiculopathies. In addition, the instrumental methods could be used for diagnosis of the morphological and functional state of paraspinal muscles. Paraspinal muscles are symmetrical back muscles surrounding the spinal column and supporting it. Magnetic resonance imaging (MRI) as well as needle electromyography (EMG) and ultrasound are used for instrumental diagnosis of paraspinal muscles conditions. We provide the review on the current scope of studies on radiculopathies and non-specific back pain. MRI is the principle standard for radiculopathy diagnosis, but other methods such as muscle ultrasound and needle electromyography are also used here. MRI is characterized by a high cost, and it is impossible to carry it out if there are magnetic objects present in the patient’s body. EMG and ultrasound both are not sufficient enough to study the level of the fatty replacement of the paraspinal muscle, while this parameter is quite significant for measuring a radiculopathy outcome. Thus, we consider it rational to recommend using these methods in combination. Indications for the combined examination may be such complex cases as anatomical anomalies of spinal roots, atypical disease pattern.

N°377 – Are neuromuscular long-term COVID-19 complications chronic? A quantitative and single fiber electromyography follow-up study

N°377 – Are neuromuscular long-term COVID-19 complications chronic? A quantitative and single fiber electromyography follow-up study

Clinic-Electrophysiologic Correlations in Rehabilitation of Adult Patients with Traumatic Brachial Plexus Lesions

Nerve-transfer surgery is the treatment of choice for traumatic brachial plexus injuries (tBPIs). Combined electromyography (EMG) follow-ups and results obtained by transcranial magnetic stimulation (TMS) may provide useful follow-up of rehabilitation outcomes of elbow flexion in C5-C7 tBPIs. A total of 11 patients with complex tBPIs, operated by the Oberlin surgical technique, were assessed clinically (British Medical Research Council’s score—MRC) and by EMG + TMS after undergoing neuromuscular electrical stimulation and proprioceptive neuromuscular facilitation. Dynamometer quantitative muscle strength (DQMS) was also assessed for overall grip strength evaluation. Six patients continued rehabilitation three times a week, whereas five patients did not follow recommendations for continuous physical therapy (PT). All patients were assessed after 6 months as planned. Following a 6-month PT protocol, clinical improvements correlated with decreases of the Motor Evoked Potential (MEP) latency recorded at the first dorsal interosseous muscle, biceps brachii, and cortical level in the sublot group with continuous PT protocol compliance. We obtained significant amelioration of MEP latency and needle EMG signs of amelioration in these six patients. These cases also correlated to the MRC improvement in elbow flexion, as well as DQMS parameters. TMS parameters also mildly and inconstantly improved in the other five patients who limited themselves just to PT after surgery; however, there was no correlation with the EMG findings or MRC scaling. PT influences the cortical representation within the motor area of the upper limb when performed continuously. The electrical signals within the motor cortex promote the utility adherence to long-term PT protocols.

Diagnosis and Treatment of Cauda Equina Arachnoiditis, a Rare Manifestation of Tuberculosis Meningoencephalitis: A Case Report

Tuberculous meningoencephalitis (TM) is an acute, progressive form of tuberculosis (TB). The epidemiology, clinical signs, and diagnosis of TB are well established, but several atypical forms of tuberculous spinal arachnoiditis can be easily misdiagnosed. We report a rare case of TM with cauda equina arachnoiditis diagnosed by magnetic resonance imaging and an electrodiagnostic study. A 26-year-old otherwise healthy male patient experienced fever, headache, gait disturbance, and bladder and bowel incontinence. Needle electromyography (EMG) recordings were suggestive of bilateral diffuse lumbar and lumbosacral polyradiculopathy, and the pudendal sensory-evoked potential and bulbocavernosus reflex latencies were prolonged. Lumbar arachnoiditis is a rare clinical condition that warrants a heightened index of suspicion. It has diverse etiologies and symptoms, and it can lead to potentially serious and irreversible disorders. This case illustrates the usefulness of nerve conduction, EMG, and pudendal sensory-evoked potential and bulbocavernosus reflex latency studies in the diagnosis of cauda equina syndrome induced by TB arachnoiditis.

Comparison of the effects of dry needling technique and combination of different manual therapy techniques on electrophysiological and psychological status in patients with myofascial pain syndrome - randomized, controlled, single blind, a pilot study

Aims: Our aim was to compare the electrophysiological and psychometric properties of the effects of the dry needling technique, graston technique, and muscle energy technique in treating myofascial pain syndrome. Methods: The study included 21 patients diagnosed with myofascial pain syndrome (MPS) and an active trigger point in the upper trapezius muscle. The patients were randomly divided into three groups of 7 each. The first group received only exercise and dry needling technique (DNT), the second group received graston technique (GT), muscle energy technique (MET) and exercise, and the third group received only exercise. Evaluations were conducted before and after treatment. The trigger point detected with an algometer in the upper trapezius muscle was evaluated with needle electromyography (EMG). The study used the Beck Depression Inventory (BDI) to determine its effects on psychological state. Results: The change in EMG variable over time was significant in each treatment group (p<0.05). The improvement in EMG change was more pronounced in the DNT group compared to the other groups. There was also a significant decrease in BDI scores before and after treatment (p<0.05). Pairwise comparison analysis revealed an improvement in the BDI scores of all groups, except the control (exercise) group, after treatment, when compared to pre-treatment. Conclusion: During the trigger point needle EMG examination of all subjects in the study, we detected spontaneous muscle activity (SMA) in addition to entry activity. After treatment, we observed improvement in SMA. These results suggest that the applied techniques are effective in treating trigger points.The effectiveness of the applied techniques can be evaluated in terms of creating alternatives.

Vasculogenic Myoclonus of Peripheral Origin after Whiplash Injury: A Case Report

Based on the neuroanatomical origin of the electrical discharge, myoclonus could be classified in terms of its etiology as cortical, subcortical, spinal, or peripheral. A 29-year-old female patient experienced a continuous involuntary rhythmic twitching movement of the right elbow for 6 months. This myoclonus occurred immediately after a whiplash injury caused by a rear-end car accident. The patient had no radiological, clinical, or electrophysiological evidence for central nervous system origin. Concentric needle electromyography recordings of the right biceps, brachioradialis, and triceps muscles presented bursts of spontaneous rhythmic activity synchronous to the clinical myoclonus. Doppler ultrasound on the right arm revealed that the biceps and triceps contraction coincided with the vascular pulsation of the brachial artery and vein. This result suggested that myoclonus was caused by vascular stimulation, similar to the pathophysiology of hemifacial spasms. A whiplash injury around the neck or arm may have affected the vascular structures in the upper and middle trunks, resulting in vasculogenic myoclonus. Electromyography can be used to determine the classification and distribution of myoclonic jerks.

Correlation between Elbow Flexor Muscle Strength and Needle Electromyography Parameters after Musculocutaneous Nerve Injury.

To explore the changes of elbow flexor muscle strength after musculocutaneous nerve injury and its correlation with needle electromyography (nEMG) parameters. Thirty cases of elbow flexor weakness caused by unilateral brachial plexus injury (involving musculocutaneous nerve) were collected. The elbow flexor muscle strength was evaluated by manual muscle test (MMT) based on Lovett Scale. All subjects were divided into Group A (grade 1 and grade 2, 16 cases) and Group B (grade 3 and grade 4, 14 cases) according to their elbow flexor muscle strength of injured side. The biceps brachii of the injured side and the healthy side were examined by nEMG. The latency and amplitude of the compound muscle action potential (CMAP) were recorded. The type of recruitment response, the mean number of turns and the mean amplitude of recruitment potential were recorded when the subjects performed maximal voluntary contraction. The quantitative elbow flexor muscle strength was measured by portable microFET 2 Manual Muscle Tester. The percentage of residual elbow flexor muscle strength (the ratio of quantitative muscle strength of the injured side to the healthy side) was calculated. The differences of nEMG parameters, quantitative muscle strength and residual elbow flexor muscle strength between the two groups and between the injured side and the healthy side were compared. The correlation between elbow flexor manual muscle strength classification, quantitative muscle strength and nEMG parameters was analyzed. After musculocutaneous nerve injury, the percentage of residual elbow flexor muscle strength in Group B was 23.43% and that in Group A was 4.13%. Elbow flexor manual muscle strength classification was significantly correlated with the type of recruitment response, and the correlation coefficient was 0.886 (P<0.05). The quantitative elbow flexor muscle strength was correlated with the latency and amplitude of CMAP, the mean number of turns and the mean amplitude of recruitment potential, and the correlation coefficients were -0.528, 0.588, 0.465 and 0.426 (P<0.05), respectively. The percentage of residual elbow flexor muscle strength can be used as the basis of muscle strength classification, and the comprehensive application of nEMG parameters can be used to infer quantitative elbow flexor muscle strength.

A Case of Hydroxychloroquine-Induced Neuromyopathy Causing Severe Ventilatory Failure (P9-8.013)

<h3>Objective:</h3> We present a case of HCQ-induced neuromyopathy culminating in reversible respiratory failure. <h3>Background:</h3> Hydroxychloroquine (HCQ) induced neuromyopathy is a well-documented but rare side effect of HCQ. Here, we discuss a case of HCQ-induced neuromyopathy culminating in respiratory failure. There are few documented cases of fulminant respiratory failure requiring mechanical ventilation due to this severe neuromuscular complication of HCQ. <h3>Design/Methods:</h3> A 58-year-old female with systemic lupus erythematous on HCQ for 15 years presented with peripheral edema and acute respiratory failure requiring intubation. She was admitted to the cardiovascular ICU for acute heart failure workup. Neurology was involved to help consider neuromuscular etiologies given the slightly restrictive pattern of respiratory failure. On exam, she had facial weakness and MRC grade 4/5 throughout without clear proximal or distal pattern. Reflexes were 1+ throughout. Acetylcholine receptor antibodies, anti-muscle-specific kinase antibodies, and voltage gated calcium channel antibodies were normal. Creatine kinase and aldolase were slightly elevated at 228 U/L and 9.1 U/L respectively. Concentric needle electromyography of the left vastus lateralis demonstrated low amplitude motor units of increased complexity but without early recruitment. <h3>Results:</h3> Muscle biopsy demonstrated internal accumulation of lysosomal vacuoles and glycogen in many myofibers. Electron microscopy showed curvilinear bodies, a characteristic finding in HCQ-induced myopathy. Testing for other causes of lysosomal storage diseases, which can have similar histologic findings, was negative. HCQ was discontinued. Within weeks of discontinuing HCQ the patient was weaned from mechanical ventilation and was ambulating with a walker. <h3>Conclusions:</h3> Our case underscores the importance of a high clinical suspicion for HCQ toxicity in the setting of respiratory failure in patients with risk factors. Increased awareness of HCQ neuromuscular toxicity marked by muscle weakness with possible ventilatory failure may lead to early recognition and treatment of a reversible condition. Furthermore, thorough evaluation of a patient’s pharmacopeia, including longstanding, previously tolerated medications, is paramount. <b>Disclosure:</b> Dr. Juster-Switlyk has nothing to disclose. Dr. Crane has nothing to disclose. Joshua M Klonoski has nothing to disclose. The institution of Dr. Mahoney has received research support from Viela Bio.

Acquired Rippling Muscle Disease with Acetylcholine Receptor Antibodies (P1-8.008)

<h3>Objective:</h3> To report a case series of acquired rippling muscle disease (RMD) with acetylcholine receptor (AChR) antibodies. <h3>Background:</h3> Previous studies have demonstrated association of acquired RMD with autoimmune disorders, or less commonly with cancer. AChR antibodies are often observed in RMD in parallel with the presumed immune-mediated etiology of acquired RMD. Despite having AChR antibodies, acquired RMD patients may exhibit minimal or no manifestations of myasthenia gravis (MG). Treatment selection in these RMD patients may prove challenging. <h3>Design/Methods:</h3> All cases of acquired RMD seen at our institution since 2010 were identified by search of the electronic medical record. <h3>Results:</h3> Three patients with acquired RMD were identified. These were men with classic RMD symptoms beginning in the fourth to sixth decade. Two developed ocular MG after onset of RMD, while the third had no MG symptoms. None had other autoimmune disorders or malignancy. AChR-binding antibodies were detected in all three patients, and two had positive striational antibodies. None had thymoma. Creatine kinase was mildly elevated, and caveolin-3 genetic testing was negative in all three patients. Concentric needle electromyography showed electrical silence during spontaneous muscle contractions in 2 of 3 patients. The third patient exhibited decreased caveolin-3 and dystrophin sarcolemmal immunoreactivity on muscle biopsy. All patients received at least one immunosuppressive (IS) therapy. While MG symptoms responded to IS treatment, RMD symptoms were more refractory. Only one individual who received intravenous immunoglobulin (IVIg) experienced significant improvement in RMD symptoms. Symptomatic treatment for RMD yielded only minimal benefit. <h3>Conclusions:</h3> Acquired RMD is a rare disorder of muscular hyperexcitability, presumably related to an underlying immune-mediated phenomenon. Most cases of RMD/MG were heralded by RMD and may only exhibit minimal or no manifestations of MG despite AChR antibody positivity. IS therapies appear to be ineffective for RMD symptoms, although one patient had significant symptomatic benefit with IVIg. <b>Disclosure:</b> Dr. Wannarong has nothing to disclose. Dr. Gable has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Medscape, Web MD. Dr. Gable has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Pharmacy Times. Dr. Gable has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cowen. Dr. Gable has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Argenx. Dr. Gable has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Ultragenx. Dr. Gable has received personal compensation in the range of $5,000-$9,999 for serving as a Lecture series with Medscape. Dr. Juel has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Immunovant. Dr. Juel has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion. Dr. Juel has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Accordant Health Services. The institution of Dr. Juel has received research support from argenx. The institution of Dr. Juel has received research support from Alexion. The institution of Dr. Juel has received research support from Janssen. The institution of Dr. Juel has received research support from NIH Rare Diseases Network.

Axial Postural Abnormalities in Parkinsonism: Gaps in Predictors, Pathophysiology, and Management.

Axial Postural Abnormalities in Parkinsonism: Gaps in Predictors, Pathophysiology, and Management.

Wearable Electronics for Surface and Needle Electromyography Measurements

Because the electromyography (EMG) signal can reflect the potential of muscle contraction controlled by neural activities, it has aroused great interest from researchers. As a result, a number of studies have been conducted around EMG. EMG-based wearable electronics are used not only in the diagnosis of neurogenic or myogenic diseases but also in sports science, rehabilitation, augmented reality, and virtual reality. This article briefly introduces the development history and background of EMG technology, then focuses on the classification of EMG and its technical mechanisms and reviews representative EMG-based wearable electronics. Finally, the challenges and development trends of EMG-based wearable electronics are also discussed. Developing devices with high specificity, adaptability, and robustness remains challenging. It has become a trend to optimize EMG signals' classification, characterization and noise cancellation algorithms for future study by combining multiple technical means. Because of the various applications of wearable electronic devices based on EMG measurements, it will have promising prospects in many fields.

Evaluation of the relationship between clinical findings and F responses and diffusion tensor tractography in patients with amyotrophic lateral sclerosis

Purpose: The aim of this study is to show whether radiologically diffusion tractography imaging (DTI) and electrophysiologically F responses methods support clinical examination in Amyotrophic Lateral Sclerosis (ALS). It is to determine the relationships between these two methods.&#x0D; Materials and Methods: Patients with a definite diagnosis of ALS according to the Revised-El Escorial and Awaji criteria at any stage of the disease, who applied to the Electromyography (EMG) laboratory of the Neurology Clinic of Istanbul University Cerrahpaşa, Cerrahpaşa Medical Faculty, prospectively and cross-sectionally, were included in the study. The revised ALS functional rating scale (ALSFRS-R) was scored. Electrophysiological studies included routine nerve conduction studies, F responses and needle EMG. In radiological examinations, diffusion tractography imaging (DTI) maps were obtained in brain and cervical Magnetic Resonance Imaging (MRI) and diffusivity and fractional anisotropy (FA) values were compared. &#x0D; Results: The mean age of the 12 volunteer patients included in the study was 55.92±9.68 (43-72), and consisted of 4 female and 8 male individuals. The mean ALSFRS-R score was 35.75±7.86 (24-46). MRI was performed in 11 of the patients, spinal imaging could not be performed in one patient. The mean age of the 11 patients who were imaging was 56.4±9.8 years and the disease duration was 2.7±1.9 years. Low values of DTI-FA were found to be associated with poor respiratory and speech scores as assessed by linear regression analysis. Repeater F responses in the ulnar nerves were also associated with a high ALSFRS-R score.&#x0D; Conclusion: In our study, we observed that low values of DTI-FA were associated with poor respiratory and speech scores. Showing the correlation of low FA with a vital function such as respiration may indicate that this technique will be helpful in the prognosis and progression of the disease. The increase of repeater F responses in the ulnar nerves in those with high ALSFRS-R scores suggests that it is worth investigating whether ALS can be used in differentiating from other anterior horn diseases. The results of this study suggest that DTI-FA, which is an advanced radiological evaluation, and repeater F responses as an electrophysiological method may support early diagnosis in ALS.

Efficacy of transcutaneous electroneurostimulation in treatment of erectile dysfunction associated with Covid-19

Background: Many studies provide data on the development of erectile dysfunction in patients after COVID-19. In most cases, the authors associated this complication with depression. However, in rare cases, erectile dysfunction is organic in nature as a result of pudendal neuropathy. Materials and methods: We examined 29 patients with the development of sexual erectile dysfunction after COVID-19. In all patients, entrapment of the pudendal nerve was detected using pudendal evoked potentials and needle electromyography of pelvic floor. All patients underwent standard medical therapy for the treatment of sexual dysfunction after recovery from COVID-19. In addition to drug therapy, 9 patients underwent TENS of the pudendal nerve using monophasic square wave pulses with a frequency of 1 Hz and a duration of 100 μs with small amplitude below the threshold of sensory fibers (sham-TENS group). 10 patients underwent the same impulses with a frequency of 1 Hz and a duration of 100 μs with amplitude higher threshold level of sensory fibers (low-frequency TENS group), and 10 patients underwent TENS with frequency of 100 Hz and duration of 100 μs with amplitude higher threshold level of sensory fibers (high-frequency TENS group). International Index of Erectile Function questionnaire, QLS-H (Questions on Life Satisfaction), pudendal somatosensory evoked potentials, and needle electromyography of pelvic floor were used before and after treatment. Results: In patients after direct TENS of the pudendal nerve, erectile function improved in high-frequency TENS group and in low-frequency TENS group by 56 % and 27 % respectively. A remarkable increase in the quality of life satisfaction was noted by 95 % of patients after high-frequency TENS and by 35 % of patients after low-frequency TENS. There were no significant changes in erectile function and quality of life satisfaction in patients after sham stimulation. Partial recovery of latency and amplitudes of pudendal somatosensory evoked potentials N1 N2 was recorded in 6 patients only after high-frequency TENS. Conclusion: Direct high-frequency TENS of pudendal nerve is highly effective in treatment of erectile dysfunction associated with COVID-19. The high-frequency TENS proved 2 times more efficient than the low-frequency TENS. Notably, positive neurophysiological dynamics, determined using needle electromyography of the pelvic floor and pudendal somatosensory evoked potentials, was detected only against the background of high-frequency TENS.

Neurophysiological Effects of Electrical Stimulation on a Patient with Neurogenic Bowel Dysfunction and Cauda Equina Syndrome after Spinal Anesthesia: A Case Report

Neurogenic bowel dysfunction (NBD) is common in patients with cauda equina syndrome (CES). Previous studies have reported that electrical stimulation (ES) improves NBD but more neurophysiologic evidence is required. This case report describes a patient who experienced difficulty with defecation as a result of cauda equina syndrome (CES) that developed after a cesarean section performed 12 years ago under spinal anesthesia. The neurophysiological effects were assessed using the bulbocavernosus reflex (BCR) and electromyography (EMG). Two ES treatments, interferential current therapy and transcutaneous electrical stimulation, were used to stimulate the intestine and the external anal sphincter, respectively. The BCR results showed right-side delayed latency and no response on the left side. Needle EMG revealed abnormal spontaneous activities of the bilateral bulbocavernosus (BC) muscles. Electrodiagnostic testing revealed chronic bilateral sacral polyradiculopathy, compatible with CES. After treatment, the patient reported an improved perianal sensation, less strain and time for defecation than before, and satisfaction with her bowel condition. At the follow-up electrodiagnosis, the BCR latency was normal on the right side-needle EMG revealed reductions in the abnormal spontaneous activities of both BC muscles and re-innervation of the right BC muscle. Electrodiagnostic testing can offer insight into the neurophysiological effects of ES, which can help in understanding the mechanism of action and optimizing the therapy for patients with NBD.

Myotonic Dystrophy Type 1 - An Atypical Presentation Having Symmetric Parkinsonism and Early Proximal Muscle Involvement.

Myotonic Dystrophy Type 1 - An Atypical Presentation Having Symmetric Parkinsonism and Early Proximal Muscle Involvement.

Neuromuscular junction involvement in inherited motor neuropathies: genetic heterogeneity and effect of oral salbutamol treatment

ObjectivesInherited defects of the neuromuscular junction (NMJ) comprise an increasingly diverse range of diseases. Several recently identified genes highlight the overlap between peripheral neuropathies and congenital myasthenic syndromes (CMS). The beta-2 adrenergic receptor agonist salbutamol has been shown to provide symptomatic benefit in CMS, while improving structural defects at the NMJ. Based on these findings, we identified cases of motor neuropathy with NMJ dysfunction and assessed the effect of salbutamol on motor function.MethodsCases of motor neuropathy with significant NMJ dysfunction, were identified using repetitive nerve stimulation and single fibre electromyography. Oral salbutamol was administered for 12 months. Repeat neurophysiological and clinical assessments were undertaken at baseline, 6 months and 12 months.ResultsSignificant defects of neuromuscular transmission were identified in 15 patients harbouring a range of genetic defects, including mutations in GARS1, DNM2, SYT2 and DYNC1H. No clear benefit on motor function was seen following the administration of 12 months of oral salbutamol; however, there was a significant improvement in patient reported fatigue. In addition, no clear effect on neurophysiological parameters was seen in patients treated with salbutamol. Side-effects due to off-target beta-adrenergic effects were significant in the patient cohort.ConclusionThese results highlight the involvement of the NMJ in several subtypes of motor neuropathies, including subtypes of neuropathy due to deficits in mitochondrial fusion-fission, synaptic vesicle transport, calcium channels and tRNA synthetases. Whether the NMJ dysfunction is simply due to muscle reinnervation or a pathology unrelated to denervation is unknown. The involvement of the NMJ may represent a novel therapeutic target in these conditions. However, treatment regimens will need to be more targeted for patients with primary inherited defects of neuromuscular transmission.

Combination of sporadic inclusion body myositis and primary Sjögren’s syndrome: clinical case and review of literature

The article presents a review of the literature and a clinical observation of a patient with long-term anamnesis of primary Sjögren's syndrome (SS) in combination with sporadic inclusion body myositis (sIBM). The diagnosis of SS was confirmed in accordance with the Russian diagnostic criteria for SS 2001, as well as with the ACR 2012 and ACR/EULAR 2016 criteria. The diagnosis of sIBM was established on the basis of a characteristic clinical picture: the development of the disease in a woman after 50 years of age with slowly progressive asymmetric muscle weakness and a typical distribution, a moderate increase in the level of creatine phosphokinase (&lt;10 norms for the entire observation period), the presence of a generalized primary muscle process according to needle electromyography, a typical picture of muscle involvement according to magnetic resonance imaging, and the ineffectiveness of high doses of glucocorticoids. The absence of histological confirmation does not contradict the diagnosis, since morphological examination of muscles in patients with a typical course of the disease fails to detect characteristic signs of sIBM in 20% of cases.Currently, there is no effective pathogenetic therapy for sIBM. Understanding the mechanisms of sIBM development will allow to develop effective methods of its treatment.

Features of repetitive nerve stimulation and nerve conduction studies in patients with amyotrophic lateral sclerosis

AbstractBackgroundPrecise diagnosis of amyotrophic lateral sclerosis (ALS) and differential diagnosis between ALS and other diseases are important. For ALS diagnosis, not only needle electromyography but also decremental responses to repetitive nerve stimulation (RNS) and a decreased abductor pollicis brevis (APB)/abductor digiti minimi (ADM) amplitude ratio in nerve conduction studies (NCS) are useful. We should know the incidence of decrement in RNS responses and the decreased amplitude ratio in NCS in ALS patients with upper limb symptoms.AimsTo evaluate the findings of both tests in ALS patients with and without upper limb symptoms.MethodsWe selected consecutive ALS patients at our hospital from September 2016 to December 2020 who underwent RNS and NCS. RNS was performed on at least one of the following five muscles: APB, ADM, trapezius, deltoid, and/or frontalis.ResultsForty‐seven patients were included in this study. The rate of abnormal examination results was 70% for RNS responses, 49% for NCS, and 78% for at least one of the two tests in patients with upper limb symptoms at the time of RNS; by contrast, the rate was 30% for RNS responses, 20% for NCS, and 40% for at least one test in patients without upper limb symptoms at the time of RNS. RNS abnormalities were more often observed in patients with upper limb symptoms than in those without upper limb symptoms at the time of RNS (p = 0.030).ConclusionUpper limb symptoms at the time of RNS may reflect the rate of abnormal RNS responses in ALS.

Not myopathic, but autonomic changes in patients with long-COVID syndrome: a case series

IntroductionNeurological sequelae following SARS-CoV-2 infection still represent a serious concern both for neurologists and neuroscientists. In our paper, we investigated pain, myalgia, and fatigue as symptoms in long-COVID patients with an electrophysiological approach, comprising the evaluation of sympathetic skin responses (SSRs) and quantitative electromyography (qEMG).Materials and methodsTwelve patients were enrolled (mean age, 47.7 ± 11.6 years), referred to our attention because of myalgia, pain, or muscle cramps, which persisted about 6 months after the diagnosis of SARS-CoV-2 infection. They underwent conventional electroneurography (ENG), needle electromyography (EMG), and SSRs; moreover, qEMG was performed by sampling at least 20 motor unit potentials (20–30 MUPs) during weak voluntary contraction in deltoid and tibialis anterior muscles. The mean duration, amplitude, and percentage of polyphasic potentials were assessed and compared with healthy and age-matched volunteers.ResultsENG did not disclose significant changes compared to healthy subjects; needle EMG did not reveal denervation activity. In addition, qEMG showed MUPs similar to those recorded in healthy volunteers in terms of polyphasia (deltoid: p = 0.24; TA: p = 0.35), MUP area (deltoid: p = 0.45; TA: p = 0.44), mean duration (deltoid: p = 0.06; TA: p = 0.45), and amplitude (deltoid: p = 0.27; TA: p = 0.63). SSRs were not recordable from lower limbs in seven patients (58%) and from the upper ones in three of them (25%).ConclusionOur data suggest an involvement of the autonomic system, with a focus on cholinergic efferent sympathetic activity, without any evidence of myopathic changes.