Muscle & Nerve最新文献

Introduction/aims: Durable medical equipment (DME)-wheelchairs, non-invasive ventilation, gastrostomy tubes, and communication devices-provides vital support for individuals with amyotrophic lateral sclerosis (ALS). Here, we describe DME use in COURAGE-ALS evaluating reldesemtiv's efficacy and safety in ALS, to evaluate if DME use can be considered an endpoint of interest in ALS trials.

Methods: COURAGE-ALS, a multicentre, double-blind, randomized, placebo-controlled clinical trial was conducted at 83 sites in the United States, Canada, Europe, and Australia. Participants were randomized 2:1 to receive reldesemtiv or placebo for 24 weeks, followed by 24 weeks of active drug treatment. Exploratory outcomes included reasons for prescribing, extent of use, DME types, and regional differences.

Results: Among 482 participants, 166 (34.4%) were using at least one DME item at baseline. Among 276 participants completing study visits through Week 24, 130 (47.1%) initiated use of a total of 188 new DME items post-baseline through 24 weeks. Manual wheelchairs were most used at baseline (89 items) and initiated (47 items) during the trial. Both baseline DME use and initiating a new item were associated with lower ALS Functional Rating Scale-Revised scores and worse quality of life. The trial was terminated early due to futility. Treatment assignment did not impact DME use. Regional disparities were noted.

Discussion: This study shows that DME is commonly prescribed to ALS trial participants. Further understanding of geographic differences in DME access and their impact on clinical outcomes is warranted prior to including DME use as an endpoint in ALS trials.

Trial registration: ClinicalTrials.gov identifier: (NCT04944784).

Introduction/aims: Segmental zoster paresis (SZP) of the upper limb is a complication of herpes zoster (HZ), but the risk factors for onset and prognosis of SZP are still unknown. The aims of this study were to analyze the correlations between neural foraminal stenosis (NFS) and the incidence and prognosis of upper-limb SZP.

Methods: In this retrospective case-control study, 87 HZ inpatients with C5-T1 spinal nerves affected were reviewed and divided into a case group (n = 21) and a control group (n = 66) based on whether they had SZP. Logistic regression analysis was used to assess correlation between NFS and the incidence of upper-limb SZP. Within the case group, Cox regression analyses were used to evaluate the correlation between NFS and complete muscle strength recovery at 24 months.

Results: Univariate and multifactor logistic analysis revealed that the grade of NFS was an independent risk factor for the incidence of upper extremity SZP [mild NFS (aOR = 18, p < 0.05); moderate NFS (aOR = 30, p < 0.05); severe NFS (aOR = 90, p < 0.05)]. Univariate and multifactorial Cox regression analyses confirmed the grade of NFS (HR = 0.186, p < 0.05) and baseline muscle strength (HR = 23.015, p < 0.05) as independent prognostic factors affecting complete muscle strength recovery of upper-limb SZP.

Discussion: The grade of NFS is an independent risk factor for the occurrence and poor prognosis of SZP in patients with upper extremity HZ. The evaluation of NFS should be incorporated into the prognosis assessment and individualized treatment strategy development for patients with upper limb SZP. Prospective cohort studies with larger sample sizes are needed.

Introduction/aims: Accurate needle electromyography (EMG) of the short head of the biceps femoris (SHBF) is often important to localize nerve damage when proximal to the fibular head. Techniques have been proposed for accurate SHBF EMG; however, needle placement accuracy is low and with the risk of inadvertent needle placement into the long head (LHBF) potentially resulting in false localization and inappropriate operative management. This study aimed to define the optimal window for accurate SHBF needle EMG placement through ultrasound (US) investigation of the anatomical relationships of the SHBF, LHBF, and common fibular nerve (CFN) in the distal posterolateral thigh.

Methods: Forty lower limbs from 20 healthy adults were evaluated using US. Distances from the popliteal crease (PC) to the SHBF and LHBF myotendinous junctions and position of the CFN in the popliteal fossa were recorded. The "SHBF window" was defined as the region where the SHBF muscle body is present in the absence of the LHBF.

Results: The SHBF was located anterolateral to the LHBF tendon/muscle and the CFN medial to the SHBF in all limbs. The average distances from the PC to SHBF and LHBF muscles were 0.6 and 6.4 cm, respectively. The optimal "SHBF window" was identified to be 3-4 cm (2-3 fingerbreadths) proximal to the PC, anterolateral to the LHBF tendon in the distal thigh.

Discussion: SHBF examination within this optimized window results in increased accuracy of needle placement, aiding in the electrodiagnostic localization of fibular nerve lesions.

Introduction/aims: Health literacy (HL) can influence self-management and outcomes in chronic diseases, but it remains poorly characterized in the context of rare diseases, including myasthenia gravis (MG). This study aimed to explore general HL levels and specific HL domains and competencies in adults with MG and their associations with sociodemographic, clinical, and organizational factors.

Methods: A multicentre, observational, cross-sectional study was conducted between April and October 2024 in 22 neurology centres located in 11 regions of northern, central, and southern Italy. Eligible participants were adult patients (≥ 18 years) with a confirmed diagnosis of MG. Comparisons across patient groups were explored with non-parametric tests; multivariable linear models were used to estimate adjusted associations.

Results: A total of 113 participants were enrolled. The median HLS₁₉-Q12 total score was 58.3 (IQR: 41.7-75.0), indicating problematic HL. In adjusted models, higher education was significantly associated with lower appraisal competence (β = -11.1, 95% CI: -20.2, -2.0). Not meeting the Patient Acceptable Symptom State (PASS) was significantly associated with lower scores across multiple domains and competencies, while follow-up in centres with nurses specialized in MG was significantly associated with higher scores in access (β = 8.2, 95% CI: 0.9, 15.6), understanding (β = 10.8, 95% CI: 2.1, 19.4), application (β = 10.6, 95% CI: 2.6, 18.7), health care (β = 11.5, 95% CI: 2.9, 20.0), and health promotion (β = 11.9, 95% CI: 3.5, 20.2).

Discussion: Symptom-burdened patients and centres without specialized nursing support appear to be priority targets for HL-oriented interventions and organizational redesign.

Introduction/aims: Nerve ultrasound is becoming increasingly important for diagnosing and monitoring peripheral nerve disorders in children. This research seeks to determine reference values for ultrasound cross-sectional area (CSA) and elastography of peripheral nerves in healthy children from northern China.

Methods: A total of 150 healthy children aged 2-16 years were recruited. To make the results more intuitive and applicable, the CSA data were divided into five age groups and the elastography data into two. The CSA measurements included nerves of the cervical region (C5, C6, vagus), upper limb (median, ulnar, radial), and lower limb (sciatic, tibial, common peroneal, sural). Shear wave velocity (SWV) measurements were performed solely on the median nerve in the right forearm. t Tests and analysis of variance (ANOVA) were used to compare the data.

Results: The average CSA of all nerves increased with age, particularly in the sciatic, tibial, and common peroneal nerves. No sex-based differences were observed in nerve CSA, which increased with weight and height. Among groups categorized by weight and height, significant differences were noted in the larger nerves, with the exception of the vagus and sural nerves. The mean median nerve SWV in this cohort was 3.48 ± 0.62 m/s, with no significant variations attributable to sex, age, height, weight, or CSA.

Discussion: In children, nerve CSA as measured by ultrasound changes with age, height, and weight, while median nerve SWV values remain consistent despite these variations.

The human intestine harbors a dense community of commensal microbes that strongly shape humoral immune responses. While secretory immunoglobulin A (sIgA) has long been recognized as a key regulator of microbiota compartmentalization and intestinal homeostasis, recent studies have also highlighted important roles for secretory IgM and systemic IgG in host-microbiota interactions. In this review, we examine critical aspects of the antibody-microbiota interface, first showing the extent to which microbiota and factors influencing microbiota ecosystem such as diet shape sIgA repertoire and binding capacity. We further integrate insights from both murine and human studies to provide a comprehensive overview of how antibody-microbiota interactions are altered in autoimmune diseases and contribute both to the identification of microbial drivers of disease and to the development of new therapeutic approaches. It is noteworthy that myasthenia gravis (MG) patients have a unique microbial signature, different from other autoimmune diseases, suggesting that yet-to-be-identified gut bacteria might specifically drive the host's immune response toward MG. Finally, we discuss the mechanisms through which the microbiota may contribute to the initiation or perpetuation of dysregulated immune responses underlying autoimmunity. Given the presence of IgA autoantibodies in MG patients and the broad homology between the acetylcholine receptor and the microbial proteome, molecular mimicry and epitope spreading should be investigated as potential triggering mechanisms.

Introduction/aims: Sex-specific differences in myasthenia gravis (MG) are widely acknowledged, yet data on sex-based outcomes of MG treatment are scarce. In accordance with Sex and Gender Equity in Research guidelines, this post hoc analysis assessed potential sex-specific differences in treatment outcomes in acetylcholine receptor antibody-positive (AChR-Ab+) generalized (g)MG participants in the Phase 3 ADAPT trial (NCT03669588).

Methods: Participants received four once-weekly efgartigimod infusions (10 mg/kg) or placebo per cycle. Endpoints (primary: proportion of Myasthenia Gravis Activities of Daily Living (MG-ADL) responders (Cycle 1); secondary: proportion of Quantitative Myasthenia Gravis (QMG) and early (Cycle 1) MG-ADL responders, and time with clinically meaningful improvements in MG-ADL score; additional: quality of life outcomes, pharmacodynamics) were assessed according to sex.

Results: Females were younger (mean age: 42.9 vs. 54.8 years), more likely to have undergone thymectomy (65.1% [56/86] vs. 44.2% [19/43]), and had higher baseline QMG scores (16.3 vs. 14.3) compared with males. Efgartigimod demonstrated homogeneous effects between sexes, with no significant difference in proportions of MG-ADL (p = 0.7014), early (Cycle 1) MG-ADL (p = 1.00), or QMG responders (p = 0.1595). Improvements in quality-of-life assessments, rates of minimal symptom expression, and mean total immunoglobulin G reductions (Cycle 1) were greater with efgartigimod verso placebo in females and males. Efgartigimod was well tolerated, with similar safety profiles across sexes.

Discussion: In ADAPT, efgartigimod-treated female and male AChR-Ab+ gMG patients had similar efficacy and safety outcomes. These data provide valuable insight for clinicians, given the established sex differences in MG disease course and treatment responses.

Trial registration: The ADAPT trial is registered on ClinicalTrials.gov (NCT03669588).

Introduction/aims: Previous ultrasound (US)-based assessments of median nerve (MN) displacement within the carpal tunnel have shown inconsistent results due to methodological variability. Quantitative data on how different upper-limb movements affect MN displacement and shear strain at the wrist remain scarce. This study aimed to quantify MN longitudinal displacement and shear strain during finger, wrist, and elbow movements in healthy individuals to establish normative patterns of nerve gliding and deformation.

Methods: Twenty healthy subjects (13 females; mean age: 31.9 years, range: 27-36 years) were prospectively recruited. US videos captured MN motion during middle finger, wrist, and elbow movements. A custom robotic device ensured consistent wrist motion and forearm stability. Speckle-tracking software was used to analyze MN absolute longitudinal displacement, relative displacement to adjacent deep and superficial tissues, and normalized shear strain at both interfaces.

Results: Elbow motion resulted in significantly greater MN absolute displacement (3.8 ± 1.2 mm) and displacement relative to deep tissue (3.6 ± 1.2 mm), compared to finger or wrist motion. No significant differences were observed in MN displacement relative to superficial tissue across motions. Normalized shear strain at the deep interface was lowest during elbow motion (41.8 ± 16.6 mm^-1). Significant differences were found for wrist-to-elbow and finger-to-elbow motions, but not for finger-to-wrist motions.

Discussion: Presented findings highlight the importance of joint-specific contributions to MN motion and suggest that proximal joint movements, such as at the elbow, may promote more effective nerve excursion while minimizing shear strain. This knowledge may help refine nerve current mobilization approaches.

Introduction/aims: For recording the compound muscle action potential (CMAP) of the deltoid muscle, the reference electrode over the acromion (Ac) has been used to avoid contamination of responses from other arm muscles to the distal tendon (DT). A recent article recommended the sternum (St) as the reference electrode. In this study, we aimed to find the appropriate reference site for the deltoid CMAP.

Methods: Subjects were 12 healthy volunteers. The deltoid CMAP was recorded using Ac, St and DT references. CMAPs of the biceps brachii (BB) and triceps brachii (TB) were also recorded. In addition to stimulation at Erb's point, selective stimulations of the axillary, musculocutaneous, or radial nerve were attempted at the axilla.

Results: The deltoid CMAPs with Ac reference had similar shapes following Erb's point (proximal) stimulation and axillary plus radial (distal) stimulation at the axilla. In contrast, CMAP using St reference was considerably smaller following proximal than distal stimulation. This difference was derived from the Ac-St lead, to which proximal muscles such as pectoralis major are supposed to contribute only following the proximal stimulation. Such a contribution can be explained by the far-field potential (FFP) theory, which suggests that the Ac-St lead can record FFPs from muscles situated between the Ac and St electrodes.

Discussion: Consistency between proximal and distal stimulations is preferred for motor nerve conduction studies. We propose that Ac reference that enables selective recording from the deltoid muscle is the most appropriate way to record deltoid CMAP to date.

Introduction/aims: Digital nerve lacerations are common. Current methods employed to differentiate intact and transected digital nerves lack diagnostic accuracy. This may result in patients with intact nerves undergoing unnecessary surgery. The objective of the study was to determine the best diagnostic method for detecting true sensory nerve transections and to delineate the sensitivities and specificities of common sensory tests.

Methods: Patients aged 18-65 years with suspected complete digital nerve lacerations were recruited. Sensory testing including static two-point discrimination (s2PD), Semmes-Weinstein Monofilaments, and Quantitative Sensory Testing were used prior to surgical exposure to evaluate different categories of sensory nerve fibers. Likelihood ratios, sensitivity, and specificity of each test were compared to direct visualization intraoperatively. Receiver operating characteristic (ROC) curves were used to determine the area under the curve (AUC) for each test.

Results: Of the 60 patients recruited, 41 (68%) had complete digital nerve transections while 19 (32%) had intact nerves. Heat pain threshold testing showed the greatest AUC at 0.812 ± 0.067 with a sensitivity of 90% and specificity of 65% at a cutoff of 22.1 just noticeable difference (JND). However, combining s2PD (7 mm, 100% sensitivity, 32% specificity) and warm detection threshold (WDT) (25 JND, 100% sensitivity, 37% specificity) in a two-step algorithm achieved 100% sensitivity and increased the specificity to 58%.

Discussion: Implementing a two-step diagnostic algorithm combining s2PD and WDT can effectively diagnose complete digital nerve laceration with high sensitivity and improved specificity. These findings underscore the utility of both tests in accurately identifying complete digital nerve lacerations.