Neuromuscular ultrasound in leprosy: A scanning protocol.

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.

Intron mutations and early transcription termination in Duchenne and Becker muscular dystrophy.

DMD pathogenic variants for Duchenne and Becker muscular dystrophy are detectable with high sensitivity by standard clinical exome analyses of genomic DNA. However, up to 7% of DMD mutations are deep intronic and analysis of muscle-derived RNA is an important diagnostic step for patients who have negative genomic testing but abnormal dystrophin expression in muscle. In this study, muscle biopsies were evaluated from 19 patients with clinical features of a dystrophinopathy, but negative clinical DMD mutation analysis. Reverse transcription-polymerase chain reaction or high-throughput RNA sequencing methods identified 19 mutations with one of three pathogenic pseudoexon types: deep intronic point mutations, deletions or insertions, and translocations. In association with point mutations creating intronic splice acceptor sites, we observed the first examples of DMD pseudo 3'-terminal exon mutations causing high efficiency transcription termination within introns. This connection between splicing and premature transcription termination is reminiscent of U1 snRNP-mediating telescripting in sustaining RNA polymerase II elongation across large genes, such as DMD. We propose a novel classification of three distinct types of mutations identifiable by muscle RNA analysis, each of which differ in potential treatment approaches. Recognition and appropriate characterization may lead to therapies directed toward full-length dystrophin expression for some patients.

Effect of Different Corticosteroid Dosing Regimens on Clinical Outcomes in Boys With Duchenne Muscular Dystrophy: A Randomized Clinical Trial.

Importance: Corticosteroids improve strength and function in boys with Duchenne muscular dystrophy. However, there is uncertainty regarding the optimum regimen and dosage. Objective: To compare efficacy and adverse effects of the 3 most frequently prescribed corticosteroid regimens in boys with Duchenne muscular dystrophy. Design, Setting, and Participants: Double-blind, parallel-group randomized clinical trial including 196 boys aged 4 to 7 years with Duchenne muscular dystrophy who had not previously been treated with corticosteroids; enrollment occurred between January 30, 2013, and September 17, 2016, at 32 clinic sites in 5 countries. The boys were assessed for 3 years (last participant visit on October 16, 2019). Interventions: Participants were randomized to daily prednisone (0.75 mg/kg) (n = 65), daily deflazacort (0.90 mg/kg) (n = 65), or intermittent prednisone (0.75 mg/kg for 10 days on and then 10 days off) (n = 66). Main Outcomes and Measures: The global primary outcome comprised 3 end points: rise from the floor velocity (in rise/seconds), forced vital capacity (in liters), and participant or parent global satisfaction with treatment measured by the Treatment Satisfaction Questionnaire for Medication (TSQM; score range, 0 to 100), each averaged across all study visits after baseline. Pairwise group comparisons used a Bonferroni-adjusted significance level of .017. Results: Among the 196 boys randomized (mean age, 5.8 years [SD, 1.0 years]), 164 (84%) completed the trial. Both daily prednisone and daily deflazacort were more effective than intermittent prednisone for the primary outcome (P < .001 for daily prednisone vs intermittent prednisone using a global test; P = .017 for daily deflazacort vs intermittent prednisone using a global test) and the daily regimens did not differ significantly (P = .38 for daily prednisone vs daily deflazacort using a global test). The between-group differences were principally attributable to rise from the floor velocity (0.06 rise/s [98.3% CI, 0.03 to 0.08 rise/s] for daily prednisone vs intermittent prednisone [P = .003]; 0.06 rise/s [98.3% CI, 0.03 to 0.09 rise/s] for daily deflazacort vs intermittent prednisone [P = .017]; and -0.004 rise/s [98.3% CI, -0.03 to 0.02 rise/s] for daily prednisone vs daily deflazacort [P = .75]). The pairwise comparisons for forced vital capacity and TSQM global satisfaction subscale score were not statistically significant. The most common adverse events were abnormal behavior (22 [34%] in the daily prednisone group, 25 [38%] in the daily deflazacort group, and 24 [36%] in the intermittent prednisone group), upper respiratory tract infection (24 [37%], 19 [29%], and 24 [36%], respectively), and vomiting (19 [29%], 17 [26%], and 15 [23%]). Conclusions and Relevance: Among patients with Duchenne muscular dystrophy, treatment with daily prednisone or daily deflazacort, compared with intermittent prednisone alternating 10 days on and 10 days off, resulted in significant improvement over 3 years in a composite outcome comprising measures of motor function, pulmonary function, and satisfaction with treatment; there was no significant difference between the 2 daily corticosteroid regimens. The findings support the use of a daily corticosteroid regimen over the intermittent prednisone regimen tested in this study as initial treatment for boys with Duchenne muscular dystrophy. Trial Registration: ClinicalTrials.gov Identifier: NCT01603407.

Ultrasound guidance for sural nerve conduction studies.

INTRODUCTION: Ultrasound can potentially identify nerves and guide recording and stimulating electrode placement for nerve conduction studies (NCS). This prospective study was performed to determine whether ultrasound guidance of sural NCS results in higher action potential amplitude, fewer stimuli required, lower stimulus strength required, and less pain experienced. METHODS: Fourteen healthy individuals underwent bilateral sural NCS, both with and without ultrasound guidance. Studies were separated by at least 48 h, and the order of testing was randomly assigned. RESULTS: Ultrasound guidance resulted in significantly fewer stimuli and lower stimuli strength required to obtain supramaximal responses (P < 0.01-0.03). Ultrasound guidance required significantly more time to perform than standard sural NCS (P < 0.01). There was no difference in sural nerve amplitude or pain rating between the 2 groups. DISCUSSION: Neuromuscular ultrasound can be used effectively to guide electrode placement during sural NCS. Muscle Nerve 59:705-707, 2019.

Neuromuscular ultrasound for evaluation of scapular winging.

INTRODUCTION: Clinicians who treat nerve and muscle disorders may be asked to evaluate patients who have unilateral or bilateral scapular winging. Traditionally, this evaluation has relied upon a thorough history, physical examination, and electrodiagnostic testing to localize the cause of winging and detect the underlying neuromuscular pathology. Neuromuscular ultrasound has emerged as a non-invasive technique that can be used for structural evaluation of nerve and muscle abnormalities. METHODS: Previous studies of imaging in scapular winging and experiences from our diagnostic laboratory are reviewed. RESULTS: Four standard and 4 ancillary ultrasound views are described for evaluation of scapular winging. CONCLUSION: Ultrasound is a non-invasive, painless, and radiation-free technology that can be used to evaluate scapular winging. Muscle Nerve 56: 7-14, 2017.