Meiling, James B.

ABSTRACTIntroduction/AimsNeuromuscular ultrasound (NMUS), initially performed by physicians, is increasingly performed by technicians in many electrodiagnostic (EDX) laboratories for certain studies under physician supervision. The aims of this study were to determine: (1) the reproducibility of nonphysician sonographers' assessments of the median nerve and (2) the need for ongoing training to maintain the reproducibility and reliability of median nerve ultrasound assessments.MethodsThe median nerve was examined sonographically in a healthy volunteer by 12 nonphysicians on 3 separate occasions: Day 1 and then 2 weeks (Day 2) and 4 months (Day 3) later. Cross‐sectional area (CSA) and wrist‐to‐forearm ratios (WFRs) were calculated each time. Sonographers were retrained prior to Day 2. Reproducibility and reliability were determined using coefficients of variation calculated for each characteristic for each day and each nonphysician sonographer, comparing performance across the 3 time points.ResultsThere was overall less variation for each characteristic (wrist CSA, forearm CSA, and WFR) on Day 2 compared to Day 1 (coefficients of variation 3.0%, 5.4%, and 5.7% vs. 8.8%, 15.5%, and 11.3%, respectively), both when viewed at the group and individual levels, indicating an improvement in reproducibility and reliability after the retraining session. The improvement was similar for Day 3.DiscussionThis study demonstrates the need for training and subsequent retraining sessions to ensure the reproducibility and reliability of NMUS measurements in the median nerve.

AbstractThe classification of peripheral neuropathies has traditionally been based on etiology, electrodiagnostic findings, or histopathologic features. With the advent of modern imaging, they now can also be characterized based on their varied distribution of imaging findings. We describe the major morphologic patterns of these changes, which include homogeneous enlargement; homogeneous thinning; focal, multifocal, and segmental enlargement; and focal thinning and beading (multifocal thinning). Representative disorders in each of these categories are discussed, along with examples of the more complex imaging manifestations of neuralgic amyotrophy, nerve transection, and hereditary amyloidosis. An appreciation of the diverse morphologic manifestations of neuropathy can help neuromuscular clinicians conduct appropriate imaging studies with ultrasound and, when needed, order suitable investigations with magnetic resonance neurography.

Abstract Introduction/Aims Point‐of‐care ultrasound of the diaphragm is highly sensitive and specific in the detection of neuromuscular diaphragmatic dysfunction. In some patients with neuromuscular diaphragmatic dysfunction, paradoxical thinning of the diaphragm during inspiration is observed on ultrasound; however, its frequency, electrodiagnostic associations, and prognostic significance remain uncertain. Methods Medical records of patients presenting to two electrodiagnostic laboratories (Mayo Clinic, Rochester, Minnesota and University of Alberta, Edmonton, Alberta) from January 1, 2022 to December 31, 2022, for evaluation of suspected neuromuscular respiratory failure, were reviewed. Results 214 patients were referred and 19 patients excluded due to incomplete information. Of 195 patients (384 hemidiaphragms), 104 had phrenic neuropathy, 12 had myopathy, and 79 had no evidence of neuromuscular disease affecting the diaphragm. Paradoxical thinning occurred in 31 (27%) patients with neuromuscular diaphragmatic dysfunction and was unilateral in 30, the majority (83%) having normal contralateral ultrasound. Phrenic nerve conduction studies and diaphragm electromyography results did not distinguish patients with paradoxical thinning versus without. Most patients (71%) with paradoxical thinning required non‐invasive ventilation (NIV), including 16 with unilateral paradoxical thinning. Paradoxical thinning and BMI ≥30 kg/m 2 were risk factors for requiring NIV in multivariable logistic regression analysis, with odds ratios of 2.887 (95% CI:1.166, 7.151) and 2.561 (95% CI: 1.186, 5.532), respectively. Discussion Paradoxical thinning of the diaphragm occurs in patients with prominent neuromuscular diaphragmatic dysfunction, most commonly from phrenic neuropathy, and is a significant risk factor for requiring NIV. Unilateral paradoxical thinning is sufficient for needing NIV. BMI ≥30 kg/m 2 additionally increases risk of requiring NIV in patients with neuromuscular diaphragmatic dysfunction.

AbstractIntroduction/AimsIn 2016, nusinersen became the first disease‐modifying medication approved by the U.S. Food and Drug Administration (FDA) for spinal muscular atrophy (SMA). With the later availability of risdiplam in 2020, individuals now have the option of switching from nusinersen to risdiplam. Limited published data exist to inform this decision. This study aims to evaluate the perceptions and experiences of adult participants and parents of minor participants who previously received nusinersen and switched to risdiplam for the treatment of SMA.MethodsInstitutional Review Board (IRB) approval was obtained from the Wake Forest IRB prior to the initiation of this study. A cross‐sectional, observational study, with qualitative and quantitative data gathered via questionnaire and medical record review, was performed. Inclusion criteria included (1) prior diagnosis of SMA, (2) previous treatment with nusinersen, and (3) change to treatment with risdiplam. No participants were excluded based on age.ResultsFourteen participants—eight adults and six children—were enrolled in the study. Respondents noted improvements in physical function with each medication. Overall, respondents reported worse satisfaction with the method of delivery of the intrathecally delivered nusinersen compared to the orally‐delivered risdiplam, but no respondent reported negative overall satisfaction with either medication. A majority (78.6%) of respondents reported that switching from nusinersen to risdiplam was the correct decision.DiscussionThese results suggest that most patients are satisfied when switching from nusinersen to risdiplam, with the method of delivery being a primary factor.