Neuromuscular transmission deficits in patients with CMT and ClC-1 inhibition in CMT animal models.

Objective: Charcot-Marie Tooth (CMT) is a hereditary neuropathy characterized by muscle weakness and fatigue with no approved therapies. Preclinical studies implicate neuromuscular junction (NMJ) transmission deficits in muscle dysfunction in CMT. This study aimed to evaluate NMJ function in patients with CMT types 1 and 2, and to determine whether enhancing NMJ transmission can improve muscle function in preclinical CMT models.

Behavior of jittering potential before and after impulse blockings: a preliminary study in myasthenia gravis.

Neuromuscular junction disorders lead to secession of bioelectrical activity transmission between motor nerve endings and muscle fibers. In diseases that are severe enough, impulse blockings are observed. This study aims to reveal the behavior of neuromuscular junction before and after impulse blockings.

Using jitter analysis with concentric needle electrodes to assess disease status and treatment responses in myasthenia gravis.

Objective: This study assesses the utility of jitter analysis with concentric needles to evaluate disease severity in myasthenia gravis (MG), correlate changes in jitter with clinical status as well as identify reasons for any discordance.

Methods: We performed a retrospective chart review of 82 MG patients and extracted data on demographics, MG subtype, antibody status, clinical scales, electrophysiology, and interventions at baseline and follow-up.

Results: Baseline MGII scores correlated with jitter (r = 0.

Application of Electrophysiological Techniques in Assessing of Neuromuscular Junction-Related Disorders.

This review aims to comprehensively summarize the application of electrophysiological methods, specifically repetitive nerve stimulation (RNS) and single fiber electromyography (SFEMG), in the diagnosis of neuromuscular junction (NMJ) disorders, including myasthenia gravis, Lambert-Eaton syndrome, and sarcopenia in the elderly. Both RNS and SFEMG have demonstrated high sensitivity and specificity in detecting NMJ abnormalities. RNS aids in distinguishing presynaptic from postsynaptic lesions, while SFEMG provides direct evidence of NMJ function by assessing single motor unit action potentials.

Diagnostic accuracy of voluntary and stimulated neuromuscular jitter studies in ocular myasthenia gravis.

Introduction/aims: There is a lack of studies comparing the accuracy of neuromuscular jitter analysis during voluntary activation (v-jitter study) versus axonal stimulation (s-jitter study). The study aimed to compare these two techniques in the same population of patients with suspected ocular myasthenia gravis (OMG).

Methods: Fourteen control subjects (mean age: 55.

Correlation of single-fiber electromyography studies and functional status in patients with amyotrophic lateral sclerosis.

Objective: Our aim was to examine the significance of single-fiber electromyography (SFEMG) in patients diagnosed with amyotrophic lateral sclerosis (ALS) and determine the best correlating parameter with SFEMG parameters and clinical scales across different muscles including facial muscles.

Methods: SFEMG examinations were conducted on the extensor digitorum (ED), frontalis, and orbicularis oculi muscles. Mean jitter, percentage of increased jitter, fiber density (FD), and impulse blocking percentage were compared to reference values and functional scales.

Concomitant Botulinum Toxin Injections for Neurogenic Detrusor Overactivity and Spasticity-A Retrospective Analysis of Practice and Safety.

As multiple indications for botulinum toxin injections (BTIs) can coexist for neurological patients, there are to date no description of concomitant injections (CIs) to treat both spasticity and neurogenic detrusor overactivity incontinence (NDOI) in patients with spinal cord injuries (SCIs) and multiple sclerosis (MS). We therefore identified patients followed at our institution by health data hub digging, using a specific procedure coding system in use in France, who have been treated at least once with detrusor and skeletal muscle BTIs within the same 1-month period, over the past 5 years (2017-2021). We analyzed 72 patients representing 319 CIs.

[Enhancing Neuromuscular Disease Diagnosis through Electrophysiology].

Electrophysiologic testing plays an important role in evaluating peripheral nerve, muscle, and neuromuscular junction diseases, aiding in diagnosis and treatment strategies by offering real-time assessment. Demyelination of peripheral nerves results in increased conduction delay, temporal dispersion, conduction block, and stimulation threshold. The localization or diffusion of these changes is crucial in understanding disease pathogenesis, necessitating stimulation at multiple points along nerve pathways.

Prevalences of Other Non-Thyroid Autoimmune Diseases and Factor Associated with Their Presence in Ocular Myasthenia Gravis.

Purpose: To report the prevalences of other non-thyroid autoimmune diseases and identify factors associated with their presence in ocular myasthenia gravis (OMG) subjects.

Subjects And Methods: A total of 208 subjects with OMG diagnosis were included. Demographic data, clinical characteristics, the ice-pack test, the acetylcholine receptor (AChR) antibody test, electrophysiology tests (single-fiber electromyography and repetitive nerve stimulation), the presence of thymoma, generalized myasthenia gravis conversion, and the presence of other non-thyroid autoimmune diseases (defined as the presence of at least one other non-thyroid autoimmune disease) were retrospectively reviewed.

Accuracy of Repetitive Ocular Vestibular-Evoked Myogenic Potentials to Diagnose Myasthenia Gravis in Patients With Ptosis or Diplopia.

Background And Objectives: We developed repetitive ocular vestibular-evoked myogenic potentials (roVEMP) as an electrophysiologic test that allows us to elicit the characteristic decrement of extraocular muscles in patients with ocular myasthenia gravis (OMG). Case-control studies demonstrated that roVEMP reliably differentiates patients with OMG from healthy controls. We now aimed to evaluate the diagnostic accuracy of roVEMP for OMG diagnosis in patients with ptosis and/or diplopia.

Concentric needle jitter analysis of the genioglossus muscle in patients with motor neuron disease.

Objectives: Difficulty relaxing the genioglossus muscle makes the evaluation of spontaneous activity problematic in patients with motor neuron disease (MND). We performed jitter analysis using conventional disposable concentric needle electrodes (CNEs) of the voluntarily activated genioglossus muscle in patients with and without MND to detect the denervation-reinnervation process.

Methods: CNE jitter analysis was performed at the genioglossus muscle in 21 MND(+) patients and 22 MND(-) subjects.

Stimulated Single Fiber Electromyography (SFEMG) for Assessing Neuromuscular Junction Transmission in Rodent Models.

As the final connection between the nervous system and muscle, transmission at the neuromuscular junction (NMJ) is crucial for normal motor function. Single fiber electromyography (SFEMG) is a clinically relevant and sensitive technique that measures single muscle fiber action potential responses during voluntary contractions or nerve stimulations to assess NMJ transmission. The assessment and quantification of NMJ transmission involves two parameters: jitter and blocking.

Myasthenia gravis-Pathophysiology, diagnosis, and treatment.

Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction of the neuromuscular junction resulting in skeletal muscle weakness. It is equally prevalent in males and females, but debuts at a younger age in females and at an older age in males. Ptosis, diplopia, facial bulbar weakness, and limb weakness are the most common symptoms.

Comparative effectiveness of azathioprine and mycophenolate mofetil for myasthenia gravis (PROMISE-MG): a prospective cohort study.

Background: Myasthenia gravis is an autoimmune disorder of the neuromuscular junction. Treatment typically includes symptomatic oral cholinesterase inhibitors, immunosuppression, and immunomodulation. In addition to corticosteroids, azathioprine and mycophenolate mofetil are the most frequently used immunosuppressants in North America.

Electrophysiological evaluation of the neuromuscular junction: a brief review.

The nerve terminal and muscle membrane compose the neuromuscular junction. After opening the voltage-gated calcium channels, action potentials from the motor axons provoke a cascade for the acetylcholine release from synaptic vesicles to the synaptic cleft, where it binds to its receptor at the muscle membrane for depolarization. Low amplitude compound muscle action potential typically presents in presynaptic disorders, increasing by more than 100% after a 10-second effort in the Lambert-Eaton myasthenic syndrome and less in botulism.

Investigation of Ongoing Denervation and Reinnervation in Amyotrophic Lateral Sclerosis by Using Concentric Needle Electrode with Single Fiber Electromyography Method.

Introduction: The aim of this study is to demonstrate the conduction disturbance at the neuromuscular junction in a cranial muscle by measuring jitter with a concentric needle (CN) electrode in the diagnosis of Amyotrophic Lateral Sclerosis (ALS) and to investigate the utility of evaluating the peak number as an ongoing reinnervation marker.

Method: Twelve patients diagnosed with ALS were included in this study. Single fiber electromyography (SFEMG) was performed using a CN electrode during the voluntary contraction of the right extensor digitorum communis (EDC) and left frontalis muscles.

The MuSK-BMP pathway regulates synaptic Nav1.4 localization and muscle excitability.

The neuromuscular junction (NMJ) is the linchpin of nerve-evoked muscle contraction. Broadly considered, the function of the NMJ is to transduce a nerve action potential into a muscle fiber action potential (MFAP). Efficient information transfer requires both cholinergic signaling, responsible for the generation of endplate potentials (EPPs), and excitation, the activation of postsynaptic voltage-gated sodium channels (Nav1.

Clinical features and outcomes of Myasthenia Gravis associated with COVID-19 vaccines: A systematic review and pooled analysis.

Backgrounds: Myasthenia Gravis (MG), a chronic neuromuscular junction disorder, emerged as one of the serious side effects of the Coronavirus Disease 2019 (COVID-19) vaccination. We aimed to summarize the findings of studies on the clinical features and outcomes of COVID-19 vaccination-associated MG.

Methods: We performed a systematic search on 3 databases, Medline, Embase, and Scopus, using the query "COVID-19 vaccine" and "Myasthenia Gravis.

Increased prevalence of mild myopathic changes in the post-COVID-19 duration.

Objective: There are reports of peripheral nerve and muscle involvement during or after coronavirus disease 2019 (COVID-19), even following a mild infection. Here, we aimed to analyze the objective findings regarding peripheral nerve, neuromuscular junction, and muscle function using electrophysiology in patients with a previous COVID-19 infection.

Methods: All consecutive patients with a history of COVID-19 were questioned for post-COVID-19 duration-related neurological complaints via Composite Autonomic Symptom Score-31 (COMPASS-31), modified Toronto Neuropathy score (mTORONTO), and Fatigue Severity Scale (FSS).

Quantitative electrodiagnosis of the motor unit.

Electromyography (EMG) focuses on assessment of the motor unit (MU), and a given muscle has several hundred MUs, each innervating hundreds of muscle fibers. Assessment is limited by the recording radius of electrodes, 1-2 fibers with single-fiber electrodes and 7-15 fibers with concentric or monopolar electrodes. Routine qualitative EMG studies rely on observing MUs in free-run mode and qualitatively estimating common metrics.

Sporadic late onset nemaline myopathy with concurrent dermatological symptoms responding to immunosuppressive treatment.

Background: Sporadic late onset nemaline myopathy is a rare, progressive muscle disease, presenting in adulthood, mainly affecting proximal limb and bulbar muscles. Muscle biopsies show characteristic nemaline rods. The putative mechanism is considered immune-related.

Neuromuscular junction transmission failure in aging and sarcopenia: The nexus of the neurological and muscular systems.

Sarcopenia, or age-related decline in muscle form and function, exerts high personal, societal, and economic burdens when untreated. Integrity and function of the neuromuscular junction (NMJ), as the nexus between the nervous and muscular systems, is critical for input and dependable neural control of muscle force generation. As such, the NMJ has long been a site of keen interest in the context of skeletal muscle function deficits during aging and in the context of sarcopenia.