Muscle & Nerve最新文献

Introduction/aims: T2 magnetic resonance imaging (MRI) mapping has been applied to carpal tunnel syndrome (CTS) for quantitative assessment of the median nerve. However, quantitative changes in the median nerve before and after surgery using T2 MRI mapping remain unclear. We aimed to investigate whether pathological changes could be identified by pre- and postoperative T2 MRI mapping of the median nerve in CTS patients after open carpal tunnel release.

Methods: This was a prospective study that measured median nerve T2 and cross-sectional area (CSA) values at the distal carpal tunnel, hamate bone, proximal carpal tunnel, and forearm levels pre- and postoperatively. Associations between T2, CSA, and nerve conduction latency were also evaluated.

Results: A total of 36 patients with CTS (mean age, 64.5 ± 11.7 years) who underwent surgery were studied. The mean preoperative T2 values significantly decreased from 56.3 to 46.9 ms at the proximal carpal tunnel levels (p = .001), and from 52.4 to 48.7 ms at the hamate levels postoperatively (p = .04). Although there was a moderate association between preoperative T2 values at the distal carpal tunnel levels and distal motor latency values (r = -.46), other T2 values at all four carpal tunnel levels were not significantly associated with CSA or nerve conduction latency pre- or postoperatively.

Discussion: T2 MRI mapping of the carpal tunnel suggested a decrease in nerve edema after surgery. T2 MRI mapping provides quantitative information on the median nerve before and after surgery.

Total supported abduction, or TSA, is a position for ultrasound evaluations and guided interventions of the upper extremity. It provides optimal access to the medial arm through the volar wrist and palmar hand for diagnostic evaluations of the median and ulnar nerves as well as procedures including injections for carpal tunnel syndrome, ulnar neuropathy at the elbow, and stenosing tenosynovitis. It enables ease of both ipsilateral and bilateral evaluations/interventions without the need for significant positional changes by the patient or physician. Incorporation of TSA may enhance clinical efficiency by reducing the amount of time, materials, and space required to provide such services.

Introduction/aims: Magnetic resonance imaging (MRI) findings in peroneal neuropathy are not well documented and the prognostic value of imaging remains uncertain. Upper limits of cross-sectional area (CSA) on ultrasound (US) have been established, but uncertainty regarding generalizability remains. We aimed to describe MRI findings of the peroneal nerve in patients and healthy controls and to compare these results to US findings and clinical characteristics.

Methods: We prospectively included patients with foot drop and electrodiagnostically confirmed peroneal neuropathy, and performed clinical follow-up, US and MRI of both peroneal nerves. We compared MRI findings to healthy controls. Two radiologists evaluated MRI features in an exploratory analysis after images were anonymized and randomized.

Results: Twenty-two patients and 38 healthy controls were included. Whereas significant increased MRI CSA values were documented in patients (mean CSA 20 mm² vs. 13 mm² in healthy controls), intra- and interobserver variability was substantial (variability of, respectively, 7 and 9 mm² around the mean in 95% of repeated measurements). A pathological T2 hyperintense signal of the nerve was found in 52.6% of patients (50% interobserver agreement). Increased CSA measurements (MRI/US), pathological T2 hyperintensity of the nerve and muscle edema were not predictive for recovery.

Discussion: Imaging is recommended in all patients with peroneal neuropathy to exclude compressive intrinsic and extrinsic masses but we do not advise routine MRI for diagnosis or prediction of outcome in patients with peroneal neuropathy due to high observer variability. Further studies should aim at reducing MRI observer variability potentially by semi-automation.

Introduction/aims: The impact of treatment expectations on active treatment outcomes has not been specifically investigated in neuromuscular disorders. We thus explored in myasthenia gravis (MG) the contribution of patients' pre-treatment expectations combined with an immunosuppressant drug on treatment outcomes.

Methods: This pilot correlational study involved 17 patients with generalized MG, scheduled to start immunosuppressant azathioprine. At baseline, a healthcare professional administered: (i) the Stanford Expectations of Treatment Scale; (ii) a structured checklist paper form asking patients which side-effects they expected to develop after starting azathioprine, coupled with a standardized framing of statements. Quantitative Myasthenia Gravis (QMG) score and daily dose of concomitant drugs were assessed by neurologists as clinical outcomes. Clinical outcomes and side-effects were re-assessed at 3 and 6 months, and clinical outcomes were monitored at 18 months.

Results: Clinically significant improvement in the QMG scores was achieved at 3 or 6 months. The level of state anxiety appeared to act as moderator of pre-treatment negative expectations (strong, positive, indicative correlation, rs = .733, p = .001). The latter were, in turn, associated with the fulfillment of side-effects that patients expected to develop with the new treatment (moderate, positive, indicative correlation, rs = .699, p = .002). No significant correlation emerged between positive and negative expectations.

Discussion: Our findings show a very quick clinical response and also suggest that patients' expectations and anxiety contributed to treatment outcomes, highlighting the importance of promoting safety messages and education strategies around newly introduced treatments. Future goals include evaluating a larger cohort that includes a matched control group.

Introduction/aims: The care burden of people living with amyotrophic lateral sclerosis (pALS) increases with disease progression. This study aimed to investigate the home care status and preparedness of care partners of pALS (cALS) in Korea.

Methods: An online survey was conducted with family care partners of patients diagnosed with ALS for over 1 year in 2022. The data collected included care time, depression evaluated using the patient health questionnaire-9 (PHQ-9), preparedness for caregiving scale (PCS), and caregiver competence scale (CCS). Results were compared based on whether the pALS underwent a tracheostomy or not.

Results: Ninety-eight cALS of 98 pALS participated in the study, of whom 59 pALS had undergone tracheostomy. Among the cALS, 60.2% were spouses, and 34.7% were children. The cALS took care of the patients for 13 (8-20) hours/day (median, interquartile range [IQR]) on weekdays and 15 (10-24) h/day on weekends. Among the cALS, 91.8% were depressed, and 28.6% had severe depression. The median (IQR) PCS and CCS scores were low (11/32 (8-15) and 8/20 (8-11), respectively), and both were lower in those caring for patients without than with tracheostomy (p < .001 and p < .02, respectively). Most cALS (77.6%) wished to continue caring for their pALS at home.

Discussion: Family care partners of pALS spend more than half of each day caring for patients and are often depressed. Most cALS preferred providing care at home, but felt ill-prepared. Designing home-based medical care is necessary for pALS to thrive at home.

Introduction/aims: Using a set of process-of-care quality measures for electrodiagnostic testing in suspected carpal tunnel syndrome (CTS), the research team previously documented large variations in electrodiagnostic testing practices and adherence to quality measures. This study sought to enhance the applicability and validity of the quality measures by integrating acceptable variations in testing practices.

Methods: We recruited 13 expert electrodiagnostic medicine specialists from five specialty societies. The experts iteratively refined five quality measures, and then rated the validity of the refined quality measures (1-9 scale). During this process, the experts reviewed data on adherence to existing quality measures and variations in electrodiagnostic testing practices, and considered recently published quality measures from the American Association of Neuromuscular and Electrodiagnostic Medicine.

Results: Three quality measures (electrodiagnostic testing before surgery for CTS, temperature assessment during electrodiagnostic testing, and electrodiagnostic criteria for severe median neuropathy) underwent few refinements and were rated valid (medians 8-9). Two measures (essential components of electrodiagnosis, criteria for interpreting electrodiagnostic tests as median neuropathy) were judged valid (medians 8) after revisions. For these measures, experts' ratings on the recommended components of sensory or mixed nerve conduction studies varied: agreement among the experts about the use of sensory peak latency was greater than for onset latency or sensory velocity.

Discussion: This study produced quality measures that provide minimum standards for electrodiagnostic testing for suspected CTS that are more comprehensive and nuanced than prior versions. Future work can assess the feasibility, reliability, and validity of these refined measures in diverse physician practices.

Introduction/aims: The precise relationship between molecular mimicry and tissue-specific autoimmunity is unknown. Major histocompatibility complex (MHC) class II antigen presenting cell-CD4+ T-cell receptor complex interactions are necessary for adaptive immunity. This study aimed to determine the role of endoneurial endothelial cell MHC class II in autoimmune polyneuropathy.

Methods: Cryopreserved Guillain-Barré syndrome (GBS) patient sural nerve biopsies and sciatic nerves from the severe murine experimental autoimmune neuritis (sm-EAN) GBS model were studied. Cultured conditional ready MHC Class II antigen A-alpha chain (H2-Aa) embryonic stem cells were used to generate H2-Aa^flox/+ C57BL/6 mice. Mice were backcrossed and intercrossed to the SJL background to generate H2-Aa^flox/flox SJL mice, bred with hemizygous Tamoxifen-inducible von Willebrand factor Cre recombinase (vWF-iCre/+) SJL mice to generate H2-Aa^flox/flox; vWF-iCre/+ mice to study microvascular endothelial cell adaptive immune responses. Sm-EAN was induced in Tamoxifen-treated H2-Aa^flox/flox; vWF-iCre/+, H2-Aa^flox/flox; +/+, H2-Aa^+/+; vWF-iCre/+ and untreated H2-Aa^flox/flox; vWF-iCre/+ adult female SJL mice. Neurobehavioral, electrophysiological and histopathological assessments were performed at predefined time points.

Results: Endoneurial endothelial cell MHC class II expression was observed in normal and inflamed human and mouse peripheral nerves. Tamoxifen-treated H2-Aa^flox/flox; vWF-iCre/+ mice were resistant to sm-EAN despite extensive MHC class II expression in lymphoid and non-lymphoid tissues.

Discussion: A conditional MHC class II knockout mouse to study cell- and time-dependent adaptive immune responses in vivo was developed. Initial studies show microvascular endothelial cell MHC class II expression is necessary for peripheral nerve specific autoimmunity, as advocated by human in vitro adaptive immunity and ex vivo transplant rejection studies.

Introduction/aims: Conventional F wave analysis involves a relatively uniform physiological environment induced by supramaximal stimulations. The F wave characteristics in a dynamic physiological condition, however, are rarely investigated. This study aimed to improve understanding of F wave properties in the more dynamic process by introducing a novel method to analyze F waves based on the compound muscle action potential (CMAP) scan technique.

Methods: Twenty four healthy subjects participated in the study. The CMAP scan was applied to record muscle responses in the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles, respectively. F wave characteristics including mean F wave amplitude and latency (F-M latency), persistence and activating threshold were quantified.

Results: An average of 200 F waves per muscle were obtained from the CMAP scan recording. Weak to moderate correlations between F wave amplitude and stimulating intensity were observed in most of the APB (19 muscles; r = 0.33 ± 0.14, all p < .05) and ADM (23 muscles, r = 0.46 ± 0.16, all p < .05) muscles. Significantly longer mean F latency and lower activating F-threshold were found in the ADM muscles (F-M latency: APB: 25.43 ± 2.39 ms, ADM: 26.15 ± 2.32 ms, p < .05; F-threshold: APB: 7.68 ± 8.96% CMAP, ADM: 2.35 ± 2.42% CMAP, p < .05).

Discussion: This study introduces new features of F waves using the CMAP scan technique and identifies differences of F wave characteristics between the hand muscles. The CMAP scan based F waves analysis can be combined with the motor unit number estimation to assess functional alterations in motor neurons in neurological disorders.

Introduction/aims: Fatigue is a common and debilitating symptom encountered in the neuromuscular clinic. The 7-item Fatigue Severity Scale (FSS-7) is a Rasch-modified assessment validated in inflammatory neuropathies but not across a typical neuromuscular patient population. The aim of this study was to validate this measure in neuromuscular disorders and to compare between patient sex, age and diagnoses.

Methods: The modified FSS-7 was mailed to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis and descriptive statistics were performed on the Rasch converted data.

Results: The mFSS-7 met the Rasch model expectations with an overall Chi-square probability of 0.4918, a strict unidimensional scale free from differential item functioning (DIF) that satisfied the model with substantial test-retest reliability using Lin's concordance correlation coefficient 0.71 (95% CI 0.63-0.77). A 15.7% ceiling effect was observed in this patient cohort. Post hoc analysis did not show any significant difference in fatigue between sex, age or neuromuscular diagnoses.

Discussion: The self-completed Rasch mFSS-7 showed acceptable test-retest reliability across patients with varied disorders under follow-up in a specialist neuromuscular clinic. The ceiling effect constrains its use for those with the most severe fatigue. Future considerations could include assessment of the benefits of clinical interventions, particularly multidisciplinary team input or dedicated fatigue clinics.