Comparative Effectiveness of Landmark-guided Greater Occipital Nerve (GON) Block at the Superior Nuchal Line Versus Ultrasound-guided GON Block at the Level of C2: A Randomized Clinical Trial (RCT).

OBJECTIVES: The purpose of this single center, prospective randomized controlled trial was to compare clinical outcomes between an ultrasound-guided greater occipital nerve block (GONB) at the C2 vertebral level versus landmark-based GONB at the superior nuchal line. METHODS: Patients with occipital neuralgia or cervicogenic headache were randomized to receive either a landmark-based GONB with sham ultrasound at the superior nuchal line or ultrasound-guided GONB at the C2 vertebral level with blinding of patients and data analysis investigators. Clinical outcomes were assessed at 30 minutes, 2 weeks, and 4 weeks postinjection. RESULTS: Thirty-two patients were recruited with 16 participants in each group. Despite randomization, the ultrasound-guided GONB group reported higher numeric rating scale (NRS) scores at baseline. Those in the ultrasound-guided GONB group had a significant decrease in NRS from baseline compared with the landmark-based GONB group at 30 minutes (change of NRS of 4.0 vs. 2.0) and 4-week time points (change of NRS of 2.5 vs. -0.5). Both groups were found to have significant decreases in Headache Impact Test-6. The ultrasound-guided GONB had significant improvements in NRS, severe headache days, and analgesic use at 4 weeks when compared with baseline. No serious adverse events occurred in either group. CONCLUSIONS: Ultrasound-guided GONBs may provide superior pain reduction at 4 weeks when compared with landmark-based GONBs for patients with occipital neuralgia or cervicogenic headache.

Diagnostic accuracy of gray scale muscle ultrasound screening for pediatric neuromuscular disease.

OBJECTIVE: Gray scale ultrasound (US) has been demonstrated to be a sensitive and specific tool in the diagnosis of pediatric neuromuscular disease (NMD). With recent advances in genetic testing, the diagnostic work up for NMD has evolved. The purpose of this study was to compare the current diagnostic value of gray scale US to previously defined sensitivities and specificities to determine when this test can add value to a patient's diagnostic workup. METHODS: Standardized quantitative gray scale US imaging was performed on 148 pediatric patients presenting for electrodiagnostic testing to evaluate for NMD. Patients were categorized as having an NMD, a non-NMD, or as "uncertain." The US results were defined as normal, borderline or abnormal based on echointensity values. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the test were calculated. RESULTS: Forty-five percent of the patients had an NMD, 54% a non-NMD, and in 1% the diagnosis remained uncertain. US was abnormal in 73% of myopathies, 63% of neuromuscular junction disorders, 60% of generalized neuropathies and 58% of focal neuropathies. After excluding patients in whom muscle US was not expected to be abnormal (eg, sensory neuropathy), sensitivity was 83%, specificity 79%, PPV 75%, NPV 86%, and accuracy 81%. CONCLUSIONS: Quantitative gray scale muscle US still has good diagnostic value as a screening tool in pediatric NMD. As with any diagnostic test, muscle US is best used in conjunction with history and physical examination to increase specificity and diagnostic yield.

Associations of catechol-O-methyltransferase (rs4680) single nucleotide polymorphisms with opioid use and dose among adults with chronic pain.

Catechol-O-methyltransferase (COMT) regulates extracellular catecholamines. A widely studied COMT single nucleotide polymorphism (rs4680) changes the translated amino acid from valine to methionine (Val158Met); the polymorphism has been shown to influence opioid use. The aims of this study were to investigate the influence of COMT Val158Met on the likelihood and dose of opioid use in adults with chronic pain. Adults with chronic pain consecutively admitted to an outpatient pain rehabilitation program were recruited for study participation (N = 298). Individuals were genotyped for COMT Val158Met (rs4680). The polymorphism was analyzed using an additive and codominant genotype model. The distribution of genotypes was 23% (N = 70) for Val/Val, 49% (N = 146) for Val/Met, and 27% (N = 82) for Met/Met (Hardy-Weinberg, P > 0.90). No significant association was observed between opioid use and genotype under the additive model; however, a significant association was observed under the codominant model (P = 0.027). A post hoc comparison demonstrated that the Met/Met genotype was more likely to use opioids compared with the Val/Met genotype (P = 0.0089). No significant association was observed between morphine equivalent dose and genotype under the additive model; however, a significant association was observed under the codominant model (P = 0.0496). A post hoc comparison demonstrated that the Val/Met (P = 0.019) and Met/Met (P = 0.043) genotypes used greater morphine equivalent dose compared with the Val/Val genotype. This study extends key knowledge about the influence of the Met/Met genotype and Met allele on opioid use in adults with chronic pain.

The effects of slow-paced versus mechanically assisted breathing on autonomic function in fibromyalgia patients.

Paced breathing has shown efficacy in fibromyalgia (FM), but the mechanisms associated with symptom change are largely unknown. We investigated whether changes in respiratory rate (RR) alone resulted in autonomic changes during normal, paced, and mechanically assisted breathing in untrained FM patients and controls. Participants included 20 FM patients and 14 controls matched for age and body mass index. During a single visit, participants completed three 15-minute breathing sessions: 1) normal breathing, 2) slow-paced breathing, and 3) mechanically assisted breathing (continuous positive airway pressure) while supine. Continuous blood pressure and electrocardiogram were recorded, and measures of heart rate variability (HRV) and spontaneous baroreceptor sensitivity (sBRS) were calculated. During normal breathing, FM patients had higher heart rate (HR), but lower HRV and sBRS variables compared to controls with no difference in RR. Compared to the paced breathing condition, FM patients had significantly lower HR with higher HRV and sBRS variables during mechanically assisted breathing, despite no significant change in RR. Mechanically assisted breathing provided greater benefits in autonomic function than paced breathing in untrained FM patients. Future research will be needed to elucidate the central pathways involved in these autonomic changes and whether training in paced breathing can eventually replicate the results seen in mechanically assisted patients.

Reliability of a novel ultrasound system for gray-scale analysis of muscle.

INTRODUCTION: Ultrasound is increasingly used as an adjunct in the diagnosis of neuromuscular disease by measuring muscle thickness and echointensity (EI). Reproducibility is limited because of variations in scanning technique and proprietary algorithms that alter EI values. METHODS: We developed a standardized scanning protocol and a portable machine without any postimaging processing. Ten subjects underwent scanning of 6 muscles by 3 sonographers on 2 separate days. One of the sonographers repeated the protocol with 4 different machine/transducer combinations. Gray-scale values were measured from each image with the use of a region of interest (ROI) box. RESULTS: Combined intraclass correlation coefficients were 0.92 (intra-rater), 0.88 (inter-rater), and 0.96 (inter-system). The biceps had the highest variability (coefficient of variance [COV] 12.7%), and the medial gastrocnemius had the lowest variability (COV 7.4%). CONCLUSIONS: We demonstrate excellent reliability of a reproducible ultrasound system for gray-scale analysis of muscle that has potential applicability as a screening tool for neuromuscular disease. Muscle Nerve 56: 408-412, 2017.

Utility Of diaphragm ultrasound in myopathy.

INTRODUCTION: Ultrasound (US) evaluation of diaphragm thickness and contractility is an effective tool in neurogenic diaphragm dysfunction. There are limited data about the value of this technique in patients with myopathy. METHODS: We performed a retrospective chart review of cases with electromyography (EMG) -confirmed myopathy and real-time US evaluation of the diaphragm. Diaphragm thickness and thickening ratio (maximal inspiration/expiration) were measured. Demographic, imaging, pathology, and genetic data were reviewed, and the clinical diagnosis was recorded. RESULTS: There were 19 eligible cases, of which 14 (73.7%) had abnormal US findings. Mean diaphragm thickness was 0.12 cm (SD 0.10), and the mean thickening ratio was 1.29 (SD 0.35). In all cases with abnormal US evaluation, the thickening ratio was abnormal. There were no cases with abnormal thickness alone. CONCLUSIONS: US examination can detect diaphragm dysfunction in myopathy. It is important to measure both the baseline thickness and thickening ratio to maximize sensitivity. Muscle Nerve 55: 427-429, 2017.

Neuromuscular choristoma presenting with unilateral limb hypoplasia in a 3-year-old boy.

INTRODUCTION: Neuromuscular choristomas (NMCs) are rare benign peripheral nerve lesions in which skeletal muscle tissue is admixed with nerve fascicles. METHODS: We describe a case of sciatic nerve NMC presenting with unilateral limb hypoplasia, monoparesis, and equinovarus contracture in a pediatric patient. We outline the unique clinical presentation and diagnostic work-up for our patient, including electromyographic and imaging studies. RESULTS: MRI revealed fusiform enlargement of the sciatic nerve, <50% intralesional fat, and signal characteristics similar to those of muscle tissue. Ultrasound was utilized to characterize atrophy and fatty infiltration of affected muscles. The patient was treated conservatively with a customized physical therapy program and lower limb orthosis. CONCLUSIONS: Emerging diagnostic criteria are highlighted with the goal of distinguishing NMCs from more common peripheral nerve lesions. This can have important clinical consequences, as unnecessary biopsies are associated with aggressive fibromatosis, a potentially devastating complication. Muscle Nerve 54: 797-801, 2016.

Midshaft clavicular fractures: comparison of intramedullary pin and plate fixation.

BACKGROUND: Intramedullary pin and plate fixation for midshaft clavicular fractures both have their proponents, but little comparative data are available. We performed a retrospective comparison of these 2 techniques. MATERIALS AND METHODS: A retrospective review was performed on 40 consecutive patients with closed, simple, or wedge-type midshaft clavicular fractures that were identified from a prospectively collected orthopedic trauma database. Eight patients were excluded due to incomplete follow-up. Intramedullary pins were used in 18 patients and plates in 14; of these, 7 plates were placed superiorly, 6 anteriorly, and 1 inferiorly. Treatment method was determined by preference of the treating surgeon. RESULTS: Among the patients treated with intramedullary pin fixation, all 18 fractures healed, and each underwent a planned procedure for pin removal. Complications included 1 intraoperative pin breakage, 1 superficial wound infection, 2 prominent symptomatic pins, and 1 transient brachial plexopathy. Among the patients treated with plating, delayed union occurred in 1, and refractures occurred in 2 (1 required a second procedure). Three patients underwent plate removal for symptomatic hardware. No patients in either group had significant loss of shoulder motion. CONCLUSION: Intramedullary pin fixation for acute, simple, or wedge-type midshaft clavicular fractures provides a safe and predictable alternative to plate and screw fixation.

Nuclear localisation is crucial for the proapoptotic activity of the HtrA-like serine protease Nma111p.

Programmed cell death is induced by the activation of a subset of intracellular proteins in response to specific extra- and intracellular signals. In the yeast Saccharomyces cerevisiae, Nma111p functions as a nuclear serine protease that is necessary for apoptosis under cellular stress conditions, such as elevated temperature or treatment of cells with hydrogen peroxide to induce cell death. We have examined the role of nuclear protein import in the function of Nma111p in apoptosis. Nma111p contains two small clusters of basic residues towards its N-terminus, both of which are necessary for efficient translocation into the nucleus. Nma111p does not shuttle between the nucleus and cytoplasm during either normal growth conditions or under environmental stresses that induce apoptosis. The N-terminal half of Nma111p is sufficient to provide the apoptosis-inducing activity of the protein, and the nuclear-localisation signal (NLS) sequences and catalytic serine 235 are both necessary for this function. We provide compelling evidence that intranuclear Nma111p activity is necessary for apoptosis in yeast.