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Introduction/aims: Ultra high-frequency ultrasound (UHFUS) has been demonstrated to allow easy visualization and quantification of median and digital nerve fascicles; however, there is a lack of normative data for other upper limb nerves. The purpose of this study was to use UHFUS to establish normative reference values and ranges for fascicle count and density within selected upper extremity nerves., Methods: Twenty-one healthy volunteers underwent sonographic examination of the ulnar, superficial branch of the radial, and radial nerves on one upper limb using UHFUS with a 48 MHz linear transducer. The number of fascicles in each peripheral nerve and fascicle density were assessed., Results: The mean fascicle number and fascicle density for each of the measured nerves was ulnar nerve at the wrist 11.7 and 2.0, ulnar nerve at the elbow 9.2 and 1.1, superficial branch of the radial nerve 7.3 and 2.5, and radial nerve at the spiral groove 4.2 and 0.8. A single significant association was observed between CSA and fascicle number in the ulnar nerve at the wrist (p = .023, r = 0.66). Neither fascicle number nor density could be predicted by age, sex, height, weight, or body mass index., Discussion: UHFUS may help to establish a baseline of normative data on upper limb nerves that are not frequently biopsied due to their mixed motor and sensory functions and has the potential for increased understanding of nerve fascicular anatomy to improve diagnostic accuracy of focal nerve lesions, particularly those with selective fascicular involvement., (© 2024 Wiley Periodicals LLC.)

Introduction/aims: Ultrahigh-frequency ultrasound (UHFUS) allows improved visualization and higher resolution images of nerve fascicles than standard high-frequency ultrasound. Dynamic UHFUS may detect the presence of fascicular entwinement, the recently described sonographic phenomenon of pathologic fascicular rotation seen in neuralgic amyotrophy. This pilot study aims to establish normative reference values and degrees of fascicular rotation for the proximal portions of commonly involved upper limb nerves in healthy controls using UHFUS., Methods: Twenty healthy participants underwent sonographic examination of the median, musculocutaneous, and radial nerves on both upper limbs using UHFUS with a 48 MHz linear transducer. A single rater assessed the degree of fascicular rotation in each peripheral nerve., Results: Fascicular rotation appears to occur in the proximal portion of each of these nerves. The mean degree of fascicular rotation for each of the measured nerves was median 94.5°, musculocutaneous 97.9°, and radial 50.9°. The maximum observed fascicular rotation in each nerve was 180°. Age, sex, height, weight, body mass index, and race did not predict degree of fascicular rotation (all p > .103). A single-factor ANOVA test showed the degree of fascicular rotation differed in median, musculocutaneous, and radial nerves (F = 4.748, p = .011)., Discussion: UHFUS allows quantification of fascicular rotation in healthy controls in the median, musculocutaneous, and radial nerves, and provides normative data. The data from this pilot study may serve as control data for future comparative studies in conditions where fascicular rotation occurs, such as neuralgic amyotrophy., (© 2024 Wiley Periodicals LLC.)

The 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., Competing Interests: None declared., (Thieme. All rights reserved.)

Background/ Aim: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting upper and lower motor neurons, causing progressive atrophy of muscles, hypertonia, and paralysis. This study aimed to evaluate the current evidence and effectiveness of ultrasound in investigating nerve cross-sectional area (CSA) of peripheral nerves, vagus and cervical roots in those with ALS compared with healthy controls and to pool the CSA measurements., Methods: A systematic search was conducted on Cochrane, Clarivate Web of Science, PubMed, Scopus, and Embase for the mesh terms nerve, ultrasonography, and amyotrophic lateral sclerosis. A quality assessment was performed using the New-Ottawa scale. In addition, a double-arm meta-analysis using Review Manager 5 software version 5.4 was performed., Results: From the seventeen studies included in this review, the overall mean difference showed that individuals with ALS had a significantly smaller CSA in comparison to healthy controls for median, ulnar, C6 root, and phrenic nerves. However, no significant difference in the CSA was found in radial, vagal, sural, and tibial nerves., Discussion: This study confirmed results of some of the included studies regards the anatomic sites, where nerve atrophy in ALS could be detected to potentially support the diagnosis of ALS. However, we recommend further large, prospective studies to assess the diagnostic value of these anatomical sites for the diagnosis of ALS., Conclusions: Our findings confirmed specific anatomic sites to differentiate ALS patients from healthy controls through ultrasound. However, these findings cannot be used to confirm the ALS diagnosis, but rather assist in differentiating it from other diagnoses., Trial Registration: Retrospectively registered on July 30th 2024 in PROSPERO (PROSPERO (york.ac.uk)) with ID574702., (© 2024. The Author(s).)

Carpal tunnel syndrome (CTS) is the most prevalent focal mononeuropathy worldwide and is traditionally diagnosed based on clinical history, examination, and nerve conduction studies. Surgical release is the gold standard in cases where conservative management fails; however, it is prudent to obtain imaging before planning such intervention. We present the case of a 47-year-old woman who presented with typical symptoms of CTS, which was confirmed with nerve conduction studies and was being considered for carpal tunnel release surgery. Her history and laboratory studies revealed rheumatoid arthritis and subsequent ultrasonography showed swelling of the median nerve just proximal to the transverse carpal ligament at the level of pronator quadratus muscle. The possibility of a nerve sheath tumour or tenosynovitis with edematous fascicles of the median nerve was considered, and a decision was taken to give a short course of prednisolone 1 mg/kg, to which she clinically responded and the repeat ultrasonography showed near complete resolution of the focal nerve enlargement. This case emphasizes the role of point-of-care neuromuscular ultrasound (NMUS) in identifying the underlying cause of CTS and validates NMUS as a powerful tool in reaching a comprehensive diagnosis in entrapment neuropathies and it should be incorporated into the routine protocol of diagnosis of these disorders., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Roy et al.)

Neuromuscular ultrasound is a painless, radiation-free, high-resolution imaging technique for assessing the peripheral nervous system. It can accurately depict changes in the nerves and muscles of individuals with neuromuscular conditions, and it is therefore a robust diagnostic tool for the assessment of individuals with polyneuropathies. This review will outline the typical ultrasonographic changes found in a wide variety of polyneuropathies. In general, demyelinating conditions result in greater nerve enlargement than axonal conditions, and acquired conditions result in more patchy nerve enlargement compared to diffuse nerve enlargement in hereditary conditions. This review is data-driven, but more nuanced anecdotal findings are also described. The overall goal of this paper is to provide clinicians with an accessible review of the ultrasonographic approaches and findings in a wide variety of polyneuropathies., (© 2024 American Institute of Ultrasound in Medicine.)

Introduction/aims: While ultrasound assessment of cross-sectional area and echogenicity has gained popularity as a biomarker for various neuropathies, there is a scarcity of data regarding fascicle count and density in neuropathies or even healthy controls. The aim of this study was to determine whether fascicles within select lower limb nerves (common fibular, superficial fibular, and sural nerves) can be counted in healthy individuals using ultrahigh-frequency ultrasound (UHFUS)., Methods: Twenty healthy volunteers underwent sonographic examination of the common fibular, superficial fibular, and sural nerves on each lower limb using UHFUS with a 48 MHz linear transducer. Fascicle counts and density in each examined nerve were determined by a single rater., Results: The mean fascicle number for each of the measured nerves included the following: common fibular nerve 9.85 (SD 2.29), superficial fibular nerve 5.35 (SD 1.59), and sural nerve 6.73 (SD 1.91). Multivariate linear regression analysis revealed a significant association between cross-sectional area and fascicle count for all three nerves. In addition, there was a significant association seen in the common fibular nerve between fascicle density and height, weight, and body mass index. Age and sex did not predict fascicle count or density (all p > .13)., Discussion: UHFUS enabled the identification and counting of fascicles and fascicle density in the common fibular, superficial fibular, and sural nerves. Knowledge about normal values and normal peripheral nerve architecture is needed in order to further understand and identify pathological changes that may occur within each nerve in different disease states., (© 2024 Wiley Periodicals LLC.)

Objective: To assess the role of serum neurofilament light chain (NfL) levels in individuals with diabetic polyneuropathy (DPN) compared with controls, as well as to highlight the different sonographic changes in DPN and determine if NfL correlates with sonographic, clinical, and functional parameters., Methods: Diabetic individuals with signs or symptoms consistent with peripheral nerve involvement were recruited. They were evaluated by examination, functional neuropathy severity scores, laboratory assessments (including NfL), nerve conduction studies (NCS), and ultrasound. Ultrasound was performed of the bilateral median, ulnar, tibial, fibular, sural, and vagus nerves, and cervical roots 5 and 6. Results were compared with age, sex, and body mass index matched healthy controls., Results: A total of 320 nerves from 20 patients and 480 nerves from 30 controls were evaluated. NfL was significantly elevated in those with diabetes with a mean and standard deviation of 6.95 ± 2.95 pg/mL in the diabetic group and 2.83 ± 0.77 pg/mL in controls (P < .001). Nerve cross-sectional area and serum NfL levels correlated significantly with clinical and functional parameters and with each other (P < .05)., Conclusion: Individuals with DPN have significantly higher NfL levels than healthy controls, and NfL levels correlate with ultrasonographic parameters. These findings may be useful for the diagnosis, prognosis, and disease monitoring of those with DPN, though further exploration is needed., (© 2023 American Institute of Ultrasound in Medicine.)

Background and Objectives: Most published studies on the clinical utility of genetic testing for neuromuscular diseases (NMDs) focus on disease-specific cohorts and/or involve multiple centers. The aim of this study was to examine the clinical utility and diagnostic yield of genetic testing at a single, large neuromuscular center. Unlike previous studies, this study is unique in that it includes a broad array of patients at a single, large neuromuscular center, providing real-world data that may assist both neuromuscular specialists as well as general neurologists in decision-making regarding the need for genetic testing in patients with suspected NMDs., Methods: Genetic testing results were reviewed for all patients who underwent testing through a single genetic testing company for NMDs in this single laboratory at a large neuromuscular center from 2015 to 2020. Retrospective chart reviews were performed to determine whether genetic testing results conferred a specific NMD diagnosis, including cases where a variant of uncertain significance (VUS) was identified., Results: Genetic testing was pursued for 192 patients. A positive result, defined as a pathogenic mutation, a VUS, or both, was found in 77.1%. A definitive diagnosis was conferred in 35.9%. The most common testing indication was suspected neuropathy (53.3%), and the indication with the highest diagnostic yield was suspected myopathy (48.7%)., Discussion: This study provides further evidence of the clinical utility of genetic testing for NMDs in a real-world setting with over one-third of patients tested receiving a definitive diagnosis. Over time, genetic testing will continue to become increasingly accessible, cost-effective, and sensitive, which will lead to even more utilization., Competing Interests: The authors report no relevant disclosures. Full disclosure form information provided by the authors is available with the full text of this article at Neurology.org/cp., (© 2024 American Academy of Neurology.)

Introduction/aims: In 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., Methods: Institutional 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., Results: Fourteen 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., Discussion: These results suggest that most patients are satisfied when switching from nusinersen to risdiplam, with the method of delivery being a primary factor., (© 2023 Wiley Periodicals LLC.)

Objectives: To explore neurofilament light chain (NfL) levels in leprotic neuropathy compared to controls, and to determine if the changes correlate with ultrasonographic nerve findings., Methods: Individuals with leprosy with signs or symptoms suggestive of peripheral nerve involvement were recruited. They were evaluated by clinical examination, functional scores, laboratory assessments (including NfL), nerve conduction studies (NCS), and ultrasound. Ultrasound was conducted in bilateral median, ulnar, tibial, fibular, sural, and vagus nerves as well as cervical roots 5 and 6. Results were compared to age, sex, and body mass index matched healthy controls., Results: A total of 320 nerves from 20 patients and 480 nerves from 30 controls were evaluated. NfL was significantly elevated in those with leprosy with a mean and standard deviation of 7.50 + 2.83 compared with 3.42 + 1.18 in controls (P < .001). Ultrasound showed focal enlargement of the nerves, particularly at entrapment sites. Additionally, there were noticeable changes in neural Doppler signal, echogenicity, and epineural thickness among the measured nerve sites. NfL levels in those with leprosy correlated closely with nerve cross-sectional area at all sites (P < .05). Functional and clinical assessment scores correlated with NfL and sonographic cross-sectional area as well (P ≤ .05)., Conclusions: NfL is elevated in leprotic neuropathy. Ultrasound showed specific morphological changes in individuals with leprosy, and nerve enlargement correlated with NfL levels. Thus, both modalities may be useful for the diagnosis, prognosis, and disease monitoring in those with leprotic neuropathy, and further investigations are warranted., (© 2023 American Institute of Ultrasound in Medicine.)

The diagnosis of leprosy neuropathies has been traditionally based on clinical findings and electrodiagnostic studies, but ultrasound has emerged as a new tool for use in clinical practice. We conducted a literature search on the subject and developed a pragmatic ultrasound scanning protocol for patients with confirmed or suspected leprosy neuropathy. We suggest scanning the ulnar, median, superficial radial, common fibular and sural nerves at specific sites and assessing cross-sectional area, vascularity, and epineural thickness. Our protocol is potentially useful in differentiating leprosy neuropathies from other demyelinating neuropathies, but its applicability and accuracy must be evaluated in different centers., (© 2023 Wiley Periodicals LLC.)

Neuromuscular ultrasound has become an integral part of the diagnostic workup of neuromuscular disorders at many centers. Despite its growing utility, uniform standard scanning techniques do not currently exist. Scanning approaches for similar diseases vary in the literature creating heterogeneity in the studies as reported in several meta-analysis. Moreover, neuromuscular ultrasound experts including the group in this study have different views with regards to technical aspects, scanning protocols, and the parameters that should be assessed. Establishing standardized neuromuscular scanning protocols is essential for the development of the subspeciality to ensure uniform clinical and research practices. Therefore, we aimed to recommend consensus-based standardized scanning techniques and protocols for common neuromuscular disorders using the Delphi approach. A panel of 17 experts participated in the study, which consisted of three consecutive electronic surveys. The first survey included voting on six scanning protocols addressing the general scanning technique and five common categories of suspected neuromuscular disorders. The subsequent surveys focused on refining the protocols and voting on new steps, rephrased statements, or areas of non-agreement. A high degree of consensus was achieved on the general neuromuscular ultrasound scanning technique and the scanning protocols for focal mononeuropathies, brachial plexopathies, polyneuropathies, amyotophic lateral sclerosis, and muscle diseases. In this study, a group of neuromuscular ultrasound experts developed six consensus-based neuromuscular ultrasound scanning protocols that may serve as references for clinicians and researchers. The standardized protocols could also aid in achieving high-quality uniform neuromuscular ultrasound practices., (© 2023 Wiley Periodicals LLC.)

Neuromuscular ultrasound (NMUS) is a valuable tool in establishing a diagnosis of carpal tunnel syndrome (CTS) and can be particularly helpful in patients with clinical CTS but normal nerve conduction studies (NCSs). This case involves the uncommon presentation of enlarged median nerves on NMUS with normal NCS in a patient with breast cancer who developed chemotherapy-induced peripheral neuropathy and CTS after taxane treatment. This case demonstrates that CTS should not be excluded based on electrodiagnostic studies alone, and comorbid CTS should be considered in patients receiving neurotoxic chemotherapy, even in the setting of normal NCS., (© 2023 American Academy of Neurology.)

Purpose: Previous ultrasonographic studies of individuals with chronic inflammatory demyelinating polyneuropathy (CIDP) have shown nerve enlargement at several sites. This prospective study compares only the bilateral median and ulnar nerves of individuals with CIDP with reference values to determine the clinical usefulness of this focused approach as a diagnostic tool., Methods: The cross-sectional area, echogenicity, and vascularity of the bilateral median and ulnar nerves of 25 subjects with CIDP were measured using ultrasound. Nineteen had typical CIDP based on the European Federation of Neurological Societies and the Peripheral Nerve Society guidelines, whereas six had atypical CIDP and were diagnosed based on clinical impression., Results: Focal nerve enlargement was found in at least one segment in all subjects. Subjects with typical CIDP had larger cross-sectional areas compared with subjects with atypical CIDP., Conclusion: A focused ultrasound study, involving only the median and ulnar nerves, is sensitive for the detection of nerve enlargement in CIDP. Measuring the cross-sectional area of the median and ulnar nerves is clinically feasible and may help establish the diagnosis of CIDP., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 by the American Clinical Neurophysiology Society.)

Introduction/aims: Nerve ultrasound is useful in the diagnosis and follow-up of peripheral nerve disorders in children. The aim of this study was to explore and analyze the current literature on nerve cross-sectional area (CSA) in healthy children, with the goal of presenting reference values and discussing their implications., Methods: We performed a systematic review and meta-analysis of studies that reported ultrasound measurements of the upper or lower limb nerves in healthy children through a search of Web of Science, PubMed, Embase, and Scopus., Results: Sixteen studies with measurements of 10 nerves covering a total of 5149 nerves measured in 823 healthy children (445 boys and 378 girls) were included. Mean nerve CSA increased with age in the median nerve at the middle and lower third of the upper arm, mid-forearm, and distal wrist crease, the ulnar nerve at the middle third of the upper arm and elbow, the radial nerve at the spiral groove, and the tibial nerve at the popliteal fossa. Growth charts for nerve CSA for different age groups were developed., Discussion: This meta-analysis provides robust reference values for nerve CSA at different sites in children, and this can inform clinical practice and assist in identifying nerve enlargement. Moreover, it identifies the strength and quality of the current published data. We recommend future studies divide their samples into smaller age subgroups and standardize the anatomic site of measurement., (© 2022 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)

Introduction/aims: We have previously reported that online neuromuscular ultrasound courses are feasible and were found to be useful by most survey respondents. However, our previous report lacked objective assessment of the educational value of the courses. Therefore, we aimed in this study to evaluate the learning outcomes of online neuromuscular ultrasound courses., Methods: Each of the basic and advanced courses featured one pre- and two post-course online knowledge tests. The percentage of corrected answers and the participants' scores in the three tests were calculated and compared., Results: A total of 153 out of 277 course participants answered the course test. The mean percentage of correct answers were significantly higher in the second and first post-course tests compared to the pre-course test (Basic course test: 80.2 ± 14.8%, 75.5 ± 15.9%, 64.3 ± 19.1%, respectively; Advanced course test: 80.9 ± 20.1, 78.9 ± 15.2%, 69.5 ± 20.2%, respectively). The mean scores of the participants in the basic course test significantly improved in the first and second post-course tests (from 66.6% to 77.5% and from 67.2% to 80.2%, respectively) whereas those of the participants in the advanced course test significantly improved in the first post-course test only (from 76.3% to 85.4%)., Discussion: This report demonstrates the capability of online neuromuscular ultrasound courses, particularly the basic-level courses, to enhance knowledge. This information can further help integrate virtual neuromuscular ultrasound teaching as a standard complementary educational format together with supervised in-person or remote hands-on training., (© 2022 Wiley Periodicals LLC.)

Neuralgic amyotrophy (NA), also referred to as idiopathic brachial plexitis and Parsonage-Turner syndrome, is a peripheral nerve disorder characterized by acute severe shoulder pain followed by progressive upper limb weakness and muscle atrophy. While NA is incompletely understood and often difficult to diagnose, early recognition may prevent unnecessary tests and interventions and, in some situations, allow for prompt treatment, which can potentially minimize adverse long-term sequalae. High-resolution ultrasound (HRUS) has become a valuable tool in the diagnosis and evaluation of NA. Pathologic HRUS findings can be grouped into four categories: nerve swelling, swelling with incomplete constriction, swelling with complete constriction, and fascicular entwinement, which may represent a continuum of pathologic processes. Certain ultrasound findings may help predict the likelihood of spontaneous recovery with conservative management versus the need for surgical intervention. We recommend relying heavily on history and physical examination to determine which nerves are clinically affected and should therefore be assessed by HRUS. The nerves most frequently affected by NA are the suprascapular, long thoracic, median and anterior interosseous nerve (AIN) branch, radial and posterior interosseous nerve (PIN) branch, axillary, spinal accessory, and musculocutaneous. When distal upper limb nerves are affected (AIN, PIN, superficial radial nerve), the lesion is almost always located in their respective fascicles within the parent nerve, proximal to its branching point. The purpose of this review is to describe a reproducible, standardized, ultrasonographic approach for evaluating suspected NA, and to share reliable techniques and clinical considerations when imaging commonly affected nerves., (© 2022 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)

Introduction: Ultrasound is emerging as a useful tool for the evaluation of immune-mediated neuropathies because it can provide high-resolution anatomic information to complement electrodiagnostic data. Nerve enlargements are commonly found in chronic inflammatory demyelinating polyneuropathy (CIDP), and their presence likely useful in diagnosis, particularly if multifocal., Methods: In this study, the authors undertook a retrospective chart review to identify ultrasound findings in patients with CIDP previously studied in a single busy neurodiagnostic laboratory., Results: Of the 50 cases identified from 2000 to 2017, individuals with a confirmed diagnosis of CIDP (21 cases) were more likely to have multiple sites of enlargement, as well as more pronounced nerve enlargement, than patients who were subsequently found to have an alternate cause of neuropathy (22 cases). The presence of any moderately enlarged nerve segment predicted definite CIDP with sensitivity of 81% and specificity 77%., Conclusion: This study demonstrates that ultrasound can be of diagnostic utility in patients with suspected CIDP, even when conducted in a nonstandardized real-world setting., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Expert consensus was sought to guide clinicians on the use of electrodiagnostic tests (EDX) and neuromuscular ultrasound (NMUS) in the investigation of suspected carpal tunnel syndrome (CTS). Consensus was achieved using the Delphi method via three consecutive anonymised surveys of 15 experts and was defined as rating agreement ≥ 80%. The panel agreed that combining EDX and NMUS is more informative than using each modality alone. NMUS adds value in patients with clinically suspected CTS with non-localizing or normal EDX, atypical EDX, failed CTS surgery, polyneuropathy, and CTS suspected to be secondary to structural pathology. The median nerve cross-sectional area should be measured at the site of maximal nerve enlargement, and the nerve should be scanned from mid-forearm to the palm. The group also identified those situations where the wrist-to-forearm area ratio and longitudinal scans of the median nerve should also be obtained. EDX should always be performed to quantify CTS severity and in individuals over age 70. This document is an initial step to guide clinicians on the combined investigation of CTS using EDX and NMUS, to be updated regularly with the emergence of new research., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Introduction/aims: The purpose of this literature review is to develop an evidence-based guideline for the use of neuromuscular ultrasound in the diagnosis of ulnar neuropathy at the elbow (UNE). The proposed research question was: "In patients with suspected UNE, does ulnar nerve enlargement as measured with ultrasound accurately identify those patients with UNE?", Methods: A systematic review and meta-analysis was performed, and studies were classified according to American Academy of Neurology criteria for rating articles for diagnostic accuracy., Results: Based on Class I evidence in four studies, it is probable that neuromuscular ultrasound measurement of the ulnar nerve at the elbow, either of diameter or cross-sectional area (CSA), is accurate for the diagnosis of UNE., Recommendation: For patients with symptoms and signs suggestive of ulnar neuropathy, clinicians should offer ultrasonographic measurement of ulnar nerve cross-sectional area or diameter to confirm the diagnosis and localize the site of compression (Level B)., (Copyright © 2021 by the American Association of Neuromuscular & Electrodiagnostic Medicine, Inc. All rights reserved.)

Abstract: Accurate assessment of neuromuscular disorders is critical to facilitate timely treatment and achieve the best outcomes. Historically, electrodiagnostic studies have filled this role, but recently, neuromuscular ultrasound is being used in the electrodiagnostic laboratory. This review discusses the uses of neuromuscular ultrasound in the electrodiagnostic laboratory that have strong evidence, emphasizing those that could be adopted in a typical electrodiagnostic laboratory with a reasonable level of equipment and training. The evidence currently supports using neuromuscular ultrasound to diagnose carpal tunnel syndrome and ulnar neuropathies at the elbow and as a supplementary test when electrodiagnostic studies are suspected to be falsely negative or in axonal nonlocalizing lesions. Neuromuscular ultrasound can identify the causes of focal mononeuropathies, which can change treatment in specific cases. It is sensitive at identifying fasciculations and providing complementary evidence of autoimmune demyelinating polyneuropathies. It is particularly helpful in assessing nerves after trauma. Neuromuscular ultrasound is likely to prove even more useful in the electrodiagnostic laboratory as the technology continues to advance., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction/aims: Hands-on supervised training is essential for learning diagnostic ultrasound. Unfortunately, the coronavirus disease 2019 (COVID-19) pandemic led to suspension of in-person training courses. As a result, many hands-on training courses were converted into virtual courses during the pandemic. Several reports regarding virtual ultrasound courses exist, but none has addressed virtual neuromuscular ultrasound courses, their design, or participants' views of this form of training. Therefore, the aims of this study were: (1) to determine the feasibility of conducting virtual neuromuscular ultrasound courses during the COVID-19 pandemic; and (2) to report the positive and negative aspects of the courses through the analyses of the responses of post-course surveys., Methods: Two virtual neuromuscular ultrasound courses, basic and intermediate level, were conducted by the Egyptian Neuromuscular Ultrasound society during August 2020. Post-course, the attendees were directed to an electronic survey that consisted of eight questions. Ninety-three responses (23.8%) were obtained from the survey of the basic course and 156 responses (44.4%) were obtained from the survey of the intermediate course., Results: Ninety-eight percent of the respondents to basic course surveys, and 100% of the respondents to the intermediate course survey found the courses useful or very useful., Discussion: This report demonstrates the utility of virtual neuromuscular ultrasound courses for those participants willing to respond to a survey and describes a proposed design for such courses. Although hands-on supervised ultrasound training is ideal, virtual courses can be useful alternatives to in-person training when in-person interaction is restricted., (© 2021 Wiley Periodicals LLC.)

Purpose: Electrodiagnostic testing is often critical for the diagnosis of neuromuscular disease, but it can be challenging in the pediatric population because of poor tolerance. This study evaluates an ultrasound-first approach as a means of reducing the number of electrodiagnostic tests (nerves stimulated and muscles sampled) in the pediatric population., Methods: A retrospective analysis of 21 pediatric patients who underwent ultrasound before electrodiagnostic testing as part of a quality-improvement project was conducted and compared with an age-matched control group of 84 patients., Results: The ultrasound-first group underwent significantly fewer muscle samplings (P = 0.0002) and overall number of electrodiagnostic tests (P = 0.0010) than the control group. The ultrasound-first group also underwent fewer nerve stimulations, which approached statistical significance (P = 0.0600)., Conclusions: Using ultrasound first in the electrodiagnostic laboratory in pediatric patients could reduce the number of electrodiagnostic tests needed to arrive at a diagnosis., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Introduction/aims: There are currently three medications approved for spinal muscular atrophy (SMA), but the use of these medications in combination has not been well described., Methods: This is a retrospective report of four cases of SMA treated with dual onasemnogene and risdiplam therapy at our institution., Results: Following onasemnogene therapy, all four patients experienced a perceived plateau of therapeutic benefit, at which time daily risdiplam was started. Transient fatigue and weakness was seen in two patients following risdiplam initiation, but this resolved within 1 mo. One patient was hospitalized with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and post-viral pneumonia, weeks following risdiplam initiation. No other adverse effects related to onasemnogene and risdiplam combination therapy were identified and all patients experienced objective and subjective improvement., Discussion: Combination therapy with onasemnogene and risdiplam in patients with SMA appears to be well-tolerated. Further large prospective trials are needed to determine whether dual therapy is more efficacious than monotherapy, and to identify rare adverse events that may occur with the use of combination therapy., (© 2021 Wiley Periodicals LLC.)

Spinal muscular atrophy (SMA) is an inherited lower motor neuron disease. SMA occurs secondary to alterations in the survival motor neuron 1 gene (SMN1), which is the main driver of SMN protein production. The severity of the disease is determined by the number of copies of the SMN2 gene, which is a homolog to SMN1 but not as efficient in protein production. Three medications have recently been approved for the treatment of SMA. Nusinersen is an intrathecal antisense oligonucleotide that alters SMN2 pre-mRNA, onasemnogene abeparvovec-xioi is an intravenous SMN1 gene replacement therapy, and risdiplam is an oral small molecule splicing modifier of SMN2. No head-to-head studies have been conducted comparing these medications, so selection of one of these medications for an individual with SMA can be challenging. In this article we outline the efficacy, safety, and other pertinent factors to consider when selecting a therapy for an individual with SMA. The age of the individual and comorbidities, such as liver or kidney disease, help guide treatment choices. All three of these medications are efficacious, and early initiation is critical for obtaining the best outcomes., (© 2021 by the American Association of Neuromuscular & Electrodiagnostic Medicine. All rights reserved.)

The addition of ultrasound (US) to electrodiagnostic (EDX) tests can significantly enhance the accuracy of testing for ulnar neuropathy at the elbow (UNE). We aimed to obtain expert consensus to guide clinicians on the combined use of EDX and US in UNE investigation. Consensus was achieved using the Delphi method. Two consecutive anonymised questionnaires were submitted to 15 experts, who were asked to choose their level of agreement with each statement. Consensus was pre-defined as ≥ 80% rating agreement. The experts concluded that all investigations of UNE should include both nerve conduction studies and US. There was consensus that US should include cross-sectional area measurement and assessment of nerve mobility at the elbow, and that the entire ulnar nerve should be imaged. This study defined expert opinion on the 'core' techniques that should be used routinely in the UNE investigation using EDX and US. Areas with lack of consensus highlighted some controversial issues in the current use of these diagnostic modalities and the need for future research. This document is an initial step to guide clinicians on the combined investigation of UNE using EDX and US, to be regularly updated as new research emerges., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: To describe rapid implementation of telehealth during the COVID-19 pandemic and assess for disparities in video visit implementation in the Appalachian region of the United States., Methods: A retrospective cohort of consecutive patients seen in the first 4 weeks of telehealth implementation was identified from the Neurology Ambulatory Practice at a large academic medical center. Telehealth visits defaulted to video, and when unable, phone-only visits were scheduled. Patients were divided into 2 groups based on the telehealth visit type: video or phone only. Clinical variables were collected from the electronic medical record including age, sex, race, insurance status, indication for visit, and rural-urban status. Barriers to scheduling video visits were collected at the time of scheduling. Patient satisfaction was obtained by structured postvisit telephone call., Results: Of 1,011 telehealth patient visits, 44% were video and 56% phone only. Patients who completed a video visit were younger (39.7 vs 48.4 years, p < 0.001), more likely to be female (63% vs 55%, p < 0.007), be White or Caucasian ( p = 0.024), and not have Medicare or Medicaid insurance ( p < 0.001). The most common barrier to scheduling video visits was technology limitations (46%). Although patients from rural and urban communities were equally likely to be scheduled for video visits, patients from rural communities were more likely to consider future telehealth visits (55% vs 42%, p = 0.05)., Conclusion: Rapid implementation of ambulatory telemedicine defaulting to video visits successfully expanded video telehealth. Emerging disparities were revealed, as older, male, Black patients with Medicare or Medicaid insurance were less likely to complete video visits., (© 2020 American Academy of Neurology.)

One barrier to widespread adoption of neuromuscular ultrasound by clinical neurophysiologists is concern over how to identify and manage non-neuromuscular findings. This review addresses this concern by describing the sonographic appearance of a variety of commonly observed pathologies and anatomic variants in dermal, subcutaneous, bony, glandular, lymphatic, vascular, and other superficial tissues. Additionally, it outlines techniques to ensure proper clinical and ultrasound evaluation of unexpected or uncommon findings. Finally, it highlights strategies to manage unexpected findings, including how to best communicate findings to patients and referring clinicians to avoid unnecessary testing and ensure appropriate follow-up. Ultrasound extends the ability of the neuromuscular sonographer-clinician to contribute to patient care., (© 2020 Wiley Periodicals LLC.)

Interleukin-6 (IL6) expression increases in atrophying muscles and lung tissue during compromised function. Considering ALS patients undergo these same pathological changes, IL6 levels may be relevant for prognostication and treatment. The amount of soluble IL6 receptor, dictated by the IL6R 358 Ala variant, and local tissue environment in which IL6 signaling occurs is known to influence the ultimate effects of IL6 in multiple diseases. In this longitudinal study, we show that serum IL6 levels negatively correlate both with the patient's functional status as measured by the overall ALSFRS-R and subscores, and with respiratory function as measured by the percent predicted FVC (ppFVC). The correlations are only present in the two-thirds of patients who carry the IL6R 358 Ala variant that mediates pro-inflammatory transsignaling in the cases of ALSFRS-R limb and respiratory subscores and ppFVC. These results suggest that some observed associations between IL6 and ALS are driven by the subset of patients carrying the IL6R 358 Ala variant and thus that any IL6-targeted therapeutic approaches may be more advantageous when aimed at this group. Specifically, with relation to respiratory decline, these patients may benefit from closer respiratory follow-up and early initiation of noninvasive ventilation.

Neuromuscular ultrasound is a rapidly evolving specialty with direct application for patient care. Competency assessment is an essential standard needed to ensure quality for practitioners, particularly for those newly acquiring skills with the technique. Our aim was to survey experts' opinions regarding physician competency assessment of neuromuscular ultrasound and to identify minimal competency of knowledge and skills. The opinions of 18 experts were obtained through the Delphi method using two consecutive electronic surveys. A high degree of consensus was achieved on items regarding framework and the conduct of neuromuscular ultrasound assessment and the knowledge and skills that a candidate needs to attain minimal competency in neuromuscular ultrasound. In this study, a group of neuromuscular ultrasound experts developed a general framework for neuromuscular ultrasound competency assessment and recommended testable areas of knowledge and skills suitable for establishing minimal competency., (© 2020 Wiley Periodicals LLC.)

There is currently a shortage of neurologists in the United States. Multiple efforts are underway to increase the strength of the neurology workforce. One potential approach is early exposure to neurology research and clinical care to pique interest and promote the specialty as a career choice. This study details the rewarding experience of working with undergraduate students, both in clinical research and clinical care. The logistics, benefits to students, and positive aspects for neurologists are outlined. Examples provided by undergraduate students who have participated in neurology research and clinical care are presented. The ultimate goals of this work are to encourage and inspire academic neurologists to involve undergraduate students in research and clinical care, to facilitate this process by outlining the steps needed to make this pairing successful, and to ultimately promote a pathway to build the neurology pipeline., (© 2020 American Academy of Neurology.)

Background and Purpose: Mycobacterium leprae complex affects peripheral nerves, causing nerve enlargement. This proof-of-concept pilot study was conducted to determine if a small hand-held ultrasound device can accurately identify nerve involvement in individuals with leprosy., Methods: Peripheral nerve ultrasound was conducted of the bilateral median (wrist, forearm, elbow, and mid-humerus), ulnar (wrist, forearm, elbow, 4 cm proximal to the elbow, and mid-humerus), C5 root, and greater auricular nerves with a standard ultrasound device (15 Mhz) and a hand-held ultrasound device (5 MHz). Nerve cross-sectional areas were compared using the two devices., Results: Eight individuals with leprosy were examined. Strong correlation was found between the standard and hand-held ultrasound devices (r = .76, P < .001). A certain amount of variability between ultrasound devices may occur for multiple reasons., Conclusion: A hand-held ultrasound device can readily identify nerve enlargement in individuals with leprosy. This type of device may assist in the diagnosis of leprosy in areas with limited healthcare resources because of the portability and low-cost nature of such devices., (© 2020 American Society of Neuroimaging.)

The diagnosis and evaluation of neuromuscular disorders traditionally involves electrodiagnostic (EDx) testing, including nerve conduction studies (NCSs) and electromyography (EMG). These tools can cause pain and discomfort, an important consideration when performed on children. Neuromuscular ultrasound is noninvasive, cost-effective, and increasingly utilized for the detection of neuromuscular pathology. Studies investigating the performance and clinical implementation of ultrasound have primarily been performed in adult populations. Ultrasound in children has the potential to guide EDx testing and ultimately improve diagnostic efficiency and accuracy. This review aims to describe key features of neuromuscular ultrasound in the pediatric population based on the available studies, including our own institutional experience.

Background: The most common neuromuscular ultrasound abnormality in carpal tunnel syndrome is enlargement of the median nerve near the distal wrist crease, but sometimes the median nerve enlarges in the palm, just distal to the transverse carpal ligament. This study was conducted to devise a protocol for measuring the median nerve in the palm and to generate reference values for nerve cross-sectional area at this site., Methods: A systematic protocol was developed, 30 healthy individuals underwent ultrasound of the median nerve in the palm bilaterally, and cross-sectional area was recorded., Results: The mean cross-sectional area of the median nerve at the palm was between 11.4 mm 2 (95% confidence interval [CI] [10.4,12.4]) and 11.6 mm 2 (95%CI [10.6,12.6])., Conclusions: The median nerve can be measured just distal to the hook of the hamate in the palm, and the mean cross-sectional area at this site is slightly larger than it is at the distal wrist crease., (© 2020 Wiley Periodicals LLC.)

We systematically identified and reviewed 29 studies of peripheral nerve ultrasound or magnetic resonance imaging (MRN) in amyotrophic lateral sclerosis (ALS). The majority of the ultrasound studies reported smaller nerves and nerve roots in ALS compared to healthy controls, but there was a large overlap of the cross-sectional nerve area between ALS and controls. Most of the MRN studies confirmed nerve abnormalities demonstrating slight T2 hyperintensities and, sometimes, mild enlargement of more proximal nerve segments (plexus, roots) in ALS. The size of the proximal nerve segments, i.e. nerve roots, is thus somewhat incongruent between nerve ultrasound and MRN in ALS. Peripheral nerve ultrasound has the potential to differentiate between ALS and multifocal motor neuropathy (MMN) in that patients with MMN have significantly larger nerves. Conversely, there is an overlap of MRN abnormalities in ALS and MMN, restricting the techniques' utility in the clinical setting. A subgroup of patients with ALS seems to reveal a sonographic nerve pattern suggesting peripheral nerve inflammation. In the future, combined imaging with nerve ultrasound and MRN assessing parameters such as blood flow or textural markers may aid in the understanding of the deep nerve microstructure down to the fascicle level, and thus, in the classification of the nerve state as more degenerative or more inflammatory in ALS. This systematic review provides evidence that nerve imaging abnormalities are common in ALS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background: The treatment of spinal muscular atrophy (SMA) with nusinersen requires intrathecal medication administration, which can be challenging in individuals with complicated spines. This retrospective case series reviews the nusinersen treatment experience at one academic medical center with children and adults with SMA and complicated spines., Methods: Twenty medical records of individuals receiving nusinersen were reviewed and administration methods summarized and assessed., Results: Ten children and 10 adults were treated, and 55% had complicated spines. In total, 163 treatments were given, 91 in those with complicated spines. In the complicated spines, 74% of treatments were done by means of fluoroscopic lumbar puncture, 22% by means of intrathecal Ommaya reservoir, 3% by means of palpation, and < 1% by means of computed tomography-guided transforaminal approach., Conclusions: A large majority of individuals with complicated spines can receive intrathecal nusinersen using fluoroscopic guidance in the lumbar region. Other delivery methods are available but less frequently used., (© 2020 Wiley Periodicals, Inc.)

Background: Our study aim was to evaluate neuromuscular ultrasound (NMUS) for the assessment of taxane chemotherapy-induced peripheral neuropathy (CIPN), the dose-limiting toxicity of this agent., Methods: This cross-sectional study of breast cancer patients with taxane CIPN measured nerve cross-sectional area (CSA) by NMUS and compared with healthy historical controls. Correlations were determined between CSA and symptom scale, nerve conduction studies, and intraepidermal nerve fiber density (IENFD)., Results: A total of 20 participants reported moderate CIPN symptoms at a median of 3.8 months following the last taxane dose. Sural nerve CSA was 1.2 mm 2 smaller than healthy controls (P ≤ .01). Older age and time since taxane were associated with smaller sural nerve CSA. For each 1 mm 2 decrease in sural nerve CSA, distal IENFD decreased by 2.1 nerve/mm (R 2 0.30; P = .04)., Conclusions: These data support a sensory predominant taxane neuropathy or neuronopathy and warrant future research on longitudinal NMUS assessment of CIPN., (© 2020 Wiley Periodicals, Inc.)

Neuromuscular ultrasound (NMUS) is a diagnostic technique that is now commonly used to complement electrodiagnostic studies when evaluating for suspected peripheral nerve pathology. The use of NMUS has been described in focal mononeuropathies, polyneuropathies, and motor neuron disease. This article provides a general overview of NMUS for the evaluation of peripheral neuropathies based on clinical practice guidelines, primary literature, and expert opinion. The characteristic changes detected by NMUS are described in focal mononeuropathies (including entrapment and other causes), polyneuropathies (including demyelinating and axonal processes), and motor neuron disease., Competing Interests: Drs. Baute Penry and Cartwright have no conflicts of interest., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)