Evaluating disease status in idiopathic inflammatory myopathies with quantitative muscle ultrasound

INTRODUCTION/AIMS

Muscle strength, functional status, and muscle enzymes are conventionally used to evaluate disease status in idiopathic inflammatory myopathies (IIM). This study aims to investigate the role of quantitative muscle ultrasound in evaluating disease status in IIM patients.

METHODS

Patients with IIM, excluding inclusion body myositis, were recruited along with age- and sex-matched healthy controls (HC). All participants underwent muscle ultrasound and clinical assessments. Six limb muscles were unilaterally scanned using a standardized protocol, measuring muscle thickness (MT) and echo intensity (EI). Results were compared with HC, and correlations were made with outcome measures.

RESULTS

Twenty IIM patients and 24 HC were recruited. The subtypes of IIM were dermatomyositis (6), necrotizing myositis (6), polymyositis (3), antisynthetase syndrome (3), and nonspecific myositis (2). Mean disease duration was 8.7 ± 6.9 years. There were no significant differences in demographics and anthropometrics between patients and controls. MT of rectus femoris in IIM patients was significantly lower than HC. Muscle EI of biceps brachii and vastus medialis in IIM patients were higher than HC. There were moderate correlations between MT of rectus femoris and modified Rankin Scale, Physician Global Activity Assessment, and Health Assessment Questionnaire, as well as between EI of biceps brachii and Manual Muscle Testing-8.

DISCUSSION

Muscle ultrasound can detect proximal muscle atrophy and hyperechogenicity in patients with IIM. The findings correlate with clinical outcome measures, making it a potential tool for evaluating disease activity of patients with IIM in the late phase of the disease.

Decreased abdominal wall muscle mass defined by muscle ultrasound is associated with malnutrition according to Global Leadership Initiative on Malnutrition criteria in renal transplant recipients: A cross-sectional study

BACKGROUND

Changed body composition with increased fat content and decreased muscle mass is seen in renal transplantation recipients (RTRs). Increased fat mass might mask underlying muscle mass loss; measuring low body mass index and weight reduction alone may not be sensitive enough to diagnose malnutrition in RTRs. We aimed to determine the prevalence of malnutrition in stable RTRs using the Global Leadership Initiative on Malnutrition (GLIM) criteria and to assess the use of muscle ultrasonography (US) to compare the performance of various muscle US measurements in the diagnosis of reduced muscle mass.

METHODS

Ninety-one patients who had renal transplantation >6 months ago were enrolled in the study. GLIM criteria were performed for all patients, but not those at risk of malnutrition. Bioelectrical impedance analysis and muscle US were performed to identify reduced muscle mass.

RESULTS

The prevalence of malnutrition according to GLIM criteria was 25.3% (n = 23). All muscle US measurements were lower in the malnourished group than the well-nourished group; however, the malnourished group had substantially lower muscle thicknesses in abdominal muscles, specifically the external oblique (EO) and internal oblique (IO) muscles, than the well-nourished group (P = 0.001 and P = 0.007, respectively). There was a significant association between malnutrition and EO (odds ratio [OR] = 0.338, 95% CI = 0.163-0.699; P = 0.003) and IO (OR = 0.620, 95% CI = 0.427-0.900; P = 0.012) regardless of age and sex.

CONCLUSION

One in four RTRs experience malnutrition. Muscle US could be used effectively for the diagnosis of reduced muscle mass and malnutrition in RTRs according to GLIM criteria.

Muscle Dysfunction and Functional Status in COVID-19 Patients during Illness and after Hospital Discharge

BACKGROUND

COVID-19 pneumonia is associated with SIRS and hypercatabolism. The aim of this study was to determine muscle loss during the acute phase of COVID-19 pneumonia and evaluate long-term sequelae in discharged patients.

METHODS

A total of 16 patients with COVID-19 pneumonia and respiratory insufficiency were included in the study. Selected parameters (weight, BMI, LBM = lean body mass, albumin, CRP, NLR = neutrophil-to-lymphocyte ratio, ultrasound measured thickness of rectus femoris muscle = US RF and rectus femoris + vastus intermedius = US RF + VI, handgrip strength, quality of life = EQ-5D questionnaire, and activities of daily living = Barthel's ADLs) were recorded on admission, discharge, and 1, 3, and 6 months after discharge.

RESULTS

The most significant changes were between hospital admission and discharge: US RF and RF + VI (-1.28 ± 1.97 mm, p = 0.046; -1.76 ± 2.94 mm, p = 0.05), EQ-5D score (14.6 ± 19.2, p = 0.02), and ADLs (17.1 ± 22.6; p = 0.02). There was a significant positive correlation between US RF + VI and handgrip strength (p = 0.014) and a negative correlation between weight and Barthel index (p = 0.012). There was an association between muscle function with an EQ-5D score and ADLs during outpatient check-ups, most noticeably between handgrip strength, US RF+VI, and ADLs (p = 0.08; p = 0.1, respectively). Conclusions: In patients with COVID-19 pneumonia, there is a significant reduction of health-related quality of life, impaired even 6 months after hospital discharge, influenced mainly by muscle loss. During the hospital stay, there was a significant muscle mass reduction. Ultrasound measurement of thigh muscle thickness may be a useful method to monitor muscle loss.

Latency and distance

See article on pages 148–156 in this issue.

Comparison of muscle ultrasound and needle electromyography findings in neuromuscular disorders

INTRODUCTION/AIMS

Needle electromyography (EMG) and muscle ultrasound can be used to evaluate patients with suspected neuromuscular disorders. The relation between muscle ultrasound pathology and the corresponding needle EMG findings is unknown. In this study we compared the results of concurrent ultrasound and needle EMG examinations in patients suspected of a neuromuscular disorder.

METHODS

Retrospective data from 218 patients with pairwise ultrasound and EMG results of 796 muscles were analyzed. We compared overall quantitative and visual muscle ultrasound results to EMGs with neurogenic and myopathic abnormalities and assessed the congruency of both methods in the different clinical diagnosis categories.

RESULTS

In muscles of patients with a neuromuscular disorder, abnormalities were found with EMG in 71.8%, and quantitative and visual muscle ultrasound results were abnormal in 19.3% and 35.4% respectively. In muscles with neurogenic EMG abnormalities, quantitative and visual muscle ultrasound results were abnormal in 18.9% versus 35.6%, increasing up to 43.7% versus 87.5% in muscles with the most pronounced signs of denervation. Congruency of EMG and ultrasound was better for more proximal and cranial muscles than for muscles in the hand and lower limb.

DISCUSSION

Needle EMG and muscle ultrasound typically produce disparate results and identify different aspects of muscle pathology. Muscle ultrasound seems less suited for detecting mild neurogenic abnormalities. As the severity of neurogenic needle EMG abnormalities increased, muscle ultrasound abnormalities were also increasingly found. Visual analysis seems better suited than grayscale quantification for detecting neurogenic abnormalities.

The Role of Muscle Ultrasonography to Diagnose Malnutrition and Sarcopenia in Maintenance Hemodialysis

BACKGROUND

Sarcopenia and malnutrition are commonly seen and fundamental indicators of prognosis and are directly associated with increased mortality in maintenance hemodialysis (MHD) patients. We aimed to reveal the frequency of malnutrition and sarcopenia in patients undergoing MHD and investigate the role of muscle ultrasound (US) parameters to predict sarcopenia and malnutrition.

METHODS

A total of 45 patients who have undertaken MHD for more than 6 months three times a week were evaluated for the present study. The US measurement was performed on gastrocnemius medialis, rectus femoris (RF), and abdominal muscles, including rectus abdominis, external oblique abdominalis, internal oblique abdominalis, and transversus abdominis. Nutritional status of the participants was assessed by mini-nutritional assessment short-form (MNA-SF).

RESULTS

The prevalence of probable and confirmed sarcopenia was 51.1% (n = 23) and 35.6% (n = 16), respectively. The malnutrition and risk of malnutrition were observed in 31.1% of the whole study population (n = 14). All muscle US measurements were lower in the sarcopenic group; however, the difference is meaningful only for RF cross-sectional area (CSA) (P = .046). The malnourished group had substantially lower muscle thickness and CSA, except for the gastrocnemius muscle thickness. The value of RFCSA to predict sarcopenia and malnutrition was observed as 4.61 cm2, respectively (P < .05). RFCSA was independently associated with sarcopenia (odds ratio: 0.37; 95% confidence interval: 0.17-0.79; P = .011) and malnutrition (odds ratio: 0.45; 95% confidence interval: 0.23-0.87; P = .017).

CONCLUSION

RFCSA may be a useful and simple predictor for predicting patients undergoing hemodialysis who are at risk of sarcopenia and malnutrition.

Muscle ultrasound and its application to point-of-care ultrasonography: a narrative review

Technological advances of hand-held ultrasound devices and educational programmes for their use, such as point-of-care ultrasonography (POCUS) training, have contributed to the increasing application of these devices in clinical practice. With the greater impact of frailty and sarcopenia in aging societies, attention is being focused on the use of ultrasound for skeletal muscle assessment. In this narrative review, we discuss how ultrasound can be applied to skeletal muscle assessment, especially that of the quadriceps muscle, in clinical practice. Muscle thickness by ultrasound has been shown to have good reliability and validity for the evaluation of muscle size, and echo intensity has been used to evaluate muscle quality. Muscle ultrasound has not only been useful to diagnose sarcopenia in various settings, but has also been validated to predict health-related outcomes such as death and functional disability. Recommended methods for muscle ultrasound was published recently, and the results of future studies are expected to be comparable. Although several challenging issues with muscle ultrasound remain, if it could be incorporated into educational programmes such as POCUS training, more clinicians may be able to use ultrasound for skeletal muscle assessment in the future.KEY MESSAGESThe evolution of hand-held ultrasound devices enables physicians to perform ultrasound at the bedside as part of regular medical examinations.Muscle ultrasound is considered an effective tool for evaluating muscle size and quality, and has been studied in various settings.More clinicians may be able to evaluate skeletal muscle assessment with the development of educational programmes on muscle ultrasound in the future.

Construct and criterion validity of muscle ultrasonography for assessment of skeletal muscle in patients recovering from COVID-19

Background: The purpose was to investigate the content, construct, and criterion validity of muscle ultrasound in a mixed cohort of participants recovering from mild and critical COVID-19. Methods: A secondary analysis of a prospective cross-sectional study was conducted on data obtained from a battery of muscle and physical function assessments including a muscle biopsy and muscle ultrasonography (US). Rectus femoris (RF) muscle thickness (mT), quadricep complex (QC) mT, RF muscle cross-sectional area (CSA) using 2D freeform trace and estimated from Feret's diameter, and RF echo intensity (EI) were assessed with US. Muscle fiber CSA, fiber type, protein content in muscle fibers, extracellular matrix content (ECM; wheat-germ agglutin), and percent area of collagen in ECM (picrosirius red) were examined from vastus lateralis muscle biopsies. Spearman rho correlations (r) were performed to assess validity of ultrasound parameters. Results: Thirty-three individuals participated including 11 patients surviving critical COVID-19, 15 individuals recovering from mild-COVID, and 7 controls. There were several significant correlations between RF mT, QC mT, RF CSA, and RF EI with age, comorbid burden, body-mass index, and measures of muscle strength, muscle power, and physical function (range r = 0.35-0.83). RF Feret's CSA correlated to CSA of type II muscle fibers (r = 0.41, p = 0.022) and the average size of all muscle fibers (r = 0.39, p = 0.031). RF EI was correlated with collagen in muscle ECM (r = 0.53, p = 0.003) and protein content in muscle tissue (r = -0.52, p = 0.012). Conclusion: Muscle size and quality measured using US has moderate content and construct validity, and to lesser extent, fair to moderate criterion validity in a mixed cohort of individuals recovering from COVID. Muscle ultrasound quality (EI) appears to be sensitive at detecting muscle dysfunction as it is associated with strength, power, physical function, and collagen distribution in a mixed group of individuals recovering from COVID-19.

Three-dimensional quantitative muscle ultrasound in patients with facioscapulohumeral dystrophy and myotonic dystrophy

INTRODUCTION/AIMS

Ultrasound imaging of muscle tissue conventionally results in two-dimensional sampling of tissue. For heterogeneously affected muscles, a sampling error using two-dimensional (2D) ultrasound can therefore be expected. In this study, we aimed to quantify and extend ultrasound imaging findings in neuromuscular disorders by using three-dimensional quantitative muscle ultrasound (3D QMUS).

METHODS

Patients with facioscapulohumeral dystrophy (n = 31) and myotonic dystrophy type 1 (n = 16) were included in this study. After physical examination, including Medical Research Council (MRC) scores, the tibialis anterior muscle was scanned with automated ultrasound. QMUS parameters were calculated over 15 cm of the length of the tibialis anterior muscle and were compared with a healthy reference data set.

RESULTS

With 3D QMUS local deviations from the healthy reference could be detected. Significant Pearson correlations (P < .01) between MRC score and QMUS parameters in male patients (n = 23) included the mean echo intensity (EI) (0.684), the standard deviation of EI (0.737), and the residual attenuation (0.841). In 91% of all patients, mean EI deviated by more than 1 standard deviation from the healthy reference. In general, the proportion of muscle tissue with a Z score >1 was about 50%.

DISCUSSION

In addition to mean EI, multiple QMUS parameters reported in this study are potential biomarkers for pathology. Besides a moderate correlation of mean EI with muscle weakness, two other parameters showed strong correlations: standard deviation of EI and residual attenuation. Local detection of abnormalities makes 3D QMUS a promising method that can be used in research and potentially for clinical evaluation.

Validity and reliability of visual assessment of orofacial muscle ultrasound images using a modified Heckmatt scale

INTRODUCTION/AIMS

Orofacial muscle ultrasound images can be evaluated quantitatively or using a visual grading system. Quantitative muscle ultrasound (QMUS) is currently the most sensitive technique to detect pathology, but can be time-consuming. The aim of this study was to investigate the validity and reliability of two visual grading systems (the original Heckmatt scale or a modified 3-point version) for the optimal grading of orofacial muscle images.

METHODS

A retrospective, comparative, reliability and validity study was performed. Ultrasound images of the digastric, geniohyoid, masseter, temporalis muscles, and intrinsic muscles of the tongue of healthy participants and of patients (suspected of) having a neuromuscular disease were included. QMUS was used as the "gold standard." Two expert raters and one inexperienced rater rated all ultrasound images using both visual grading systems.

RESULTS

A total of 511 ultrasound images were included. Criterion validity showed Spearman rho correlation coefficients of >0.59. Construct validity analysis showed strong to very strong associations between the visual grading systems and mastication and/or swallowing. Inter- and intrarater reliability of the original Heckmatt scale and the modified scale were good and comparable. Rater experience had a beneficial effect on the interrater reliability of both scales.

DISCUSSION

Both the original Heckmatt and the modified Heckmatt scale are valid and reliable tools for the visual grading of orofacial ultrasound images. The modified Heckmatt scale, with only three grades and including an "uncertain" category, is considered easier to use in clinical practice.

Muscle Ultrasound Abnormalities in Individuals with RYR1-Related Malignant Hyperthermia Susceptibility

BACKGROUND

Variants in RYR1, the gene encoding the ryanodine receptor-1, can give rise to a wide spectrum of neuromuscular conditions. Muscle imaging abnormalities have been demonstrated in isolated cases of patients with a history of RYR1-related malignant hyperthermia (MH) susceptibility.

OBJECTIVE

To provide insights into the type and prevalence of muscle ultrasound abnormalities and muscle hypertrophy in patients carrying gain-of-function RYR1 variants associated with MH susceptibility and to contribute to delineating the wider phenotype, optimizing the diagnostic work-up and care for of MH susceptible patients.

METHODS

We performed a prospective cross-sectional observational muscle ultrasound study in patients with a history of RYR1-related MH susceptibility (n = 40). Study procedures included a standardized history of neuromuscular symptoms and a muscle ultrasound assessment. Muscle ultrasound images were analyzed using a quantitative and qualitative approach and compared to reference values and subsequently subjected to a screening protocol for neuromuscular disorders.

RESULTS

A total of 15 (38%) patients had an abnormal muscle ultrasound result, 4 (10%) had a borderline muscle ultrasound screening result, and 21 (53%) had a normal muscle ultrasound screening result. The proportion of symptomatic patients with an abnormal result (11 of 24; 46%) was not significantly higher compared to the proportion of asymptomatic patients with an abnormal ultrasound result (4 of 16; 25%) (P = 0.182). The mean z-scores of the biceps brachii (z = 1.45; P <  0.001), biceps femoris (z = 0.43; P = 0.002), deltoid (z = 0.31; P = 0.009), trapezius (z = 0.38; P = 0.010) and the sum of all muscles (z = 0.40; P <  0.001) were significantly higher compared to 0, indicating hypertrophy.

CONCLUSIONS

Patients with RYR1 variants resulting in MH susceptibility often have muscle ultrasound abnormalities. Frequently observed muscle ultrasound abnormalities include muscle hypertrophy and increased echogenicity.

Imaging biomarkers in the idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of acquired muscle diseases with muscle inflammation, weakness, and other extra-muscular manifestations. IIMs can significantly impact the quality of life, and management of IIMs often requires a multi-disciplinary approach. Imaging biomarkers have become an integral part of the management of IIMs. Magnetic resonance imaging (MRI), muscle ultrasound, electrical impedance myography (EIM), and positron emission tomography (PET) are the most widely used imaging technologies in IIMs. They can help make the diagnosis and assess the burden of muscle damage and treatment response. MRI is the most widely used imaging biomarker of IIMs and can assess a large volume of muscle tissue but is limited by availability and cost. Muscle ultrasound and EIM are easy to administer and can even be performed in the clinical setting, but they need further validation. These technologies may complement muscle strength testing and laboratory studies and provide an objective assessment of muscle health in IIMs. Furthermore, this is a rapidly progressing field, and new advances are going to equip care providers with a better objective assessment of IIMS and eventually improve patient management. This review discusses the current state and future direction of imaging biomarkers in IIMs.

The Sensitivity and Specificity of Split-Hand Index Using Muscle Sonography

BACKGROUND

The split-hand index (SHI) (first dorsal interosseous (FDI) × abductor pollicis brevis (APB)/abductor digiti minimi muscle (ADM)) has been suggested as a useful measure for amyotrophic lateral sclerosis (ALS) diagnosis, using electrophysiological and sonographic indices. In the present study, we aimed to explore the specificity of SHI derived by muscle ultrasound (MUS) for the diagnosis of ALS and spinal muscular atrophy (SMA).

METHODS

Healthy controls (n = 65) were prospectively recruited at the Prosserman Family Neuromuscular clinic at Toronto General Hospital, from October to December 2018. In addition, 181 patients with ALS (n = 91), SMA (n = 33), polyneuropathy (n = 35), and myopathy (n = 22) were prospectively recruited at the neuromuscular clinic at Tel Aviv Sourasky Medical Center, from December 2018 to December 2020. All subjects underwent quantitative sonographic evaluation of muscle thickness, including the right APB, FDI, and ADM muscles. Area under curve (AUC), sensitivity, and specificity were determined for differentiating between groups.

RESULTS

Although SHI showed good to excellent accuracy for differentiating each patient subgroup from controls (AUC 0.83-0.92), poorer diagnostic accuracy was shown for differentiating between different patient subgroups (AUC 0.54-0.74).

CONCLUSIONS

Sonographic SHI is useful for differentiating patients from healthy controls, but might be not specific for motor neuron disease.

Neurologic Outcome Comparison between Fetal Open-, Endoscopic- and Neonatal-Intervention Techniques in Spina Bifida Aperta

INTRODUCTION

In spina bifida aperta (SBA), fetal closure of the myelomeningocele (MMC) can have a neuroprotective effect and improve outcomes. In Europe, surgical MMC closure is offered by fetal-open (OSBAR), fetal-endoscopic (FSBAR), and neonatal (NSBAR) surgical techniques. Pediatric neurologists facing the challenging task of counseling the parents may therefore seek objective outcome comparisons. Until now, such data are hardly available. In SBA, we aimed to compare neurologic outcomes between OSBAR, FSBAR, and NSBAR intervention techniques.

METHODS

We determined intervention-related complications, neuromuscular integrity, and neurologic outcome parameters after OSBAR (n = 17) and FSBAR (n = 13) interventions by age- and lesion-matched comparisons with NSBAR-controls. Neurological outcome parameters concerned: shunt dependency, segmental alterations in muscle ultrasound density (reflecting neuromuscular integrity), segmental motor-, sensory- and reflex conditions, and the likelihood of intervention-related gain in ambulation.

RESULTS

Compared with NSBAR-controls, fetal intervention is associated with improved neuromuscular tissue integrity, segmental neurological outcomes, reduced shunt dependency, and a higher chance of acquiring ambulation in ≈20% of the operated children. Children with MMC-lesions with a cranial border at L3 revealed the most likely intervention-related motor function gain. The outcome comparison between OSBAR versus FSBAR interventions revealed no significant differences.

CONCLUSION

In SBA, OSBAR- and FSBAR-techniques achieved similar neuroprotective results. A randomized controlled trial is helpful in revealing and compare ongoing effects by surgical learning curves.

Relationship Between Skeletal Muscle Quality and Hospital-Acquired Disability in Patients With Sepsis Admitted to the ICU: A Pilot Study

Early risk assessment of functional decline in patients with sepsis is clinically challenging. Recently, there is increasing interest in the nonvolitional evaluation of skeletal muscle quality.

OBJECTIVES

The aim of this study was to assess the relationship between skeletal muscle quality and functional decline after intensive care.

DESIGN SETTING AND PARTICIPANTS

This pilot study was a single-center prospective observational study conducted from March 2021 to February 2022. We included consecutive patients with sepsis who were admitted to our ICU.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospital-acquired disability (HAD), which is defined as a decrease in the Barthel index score of at least 5 points from pre-hospital to hospital discharge. Muscle quality was assessed by: 1) muscle echogenicity with ultrasound and 2) phase angle (PhA) with bioelectrical impedance analysis, both of which were measured on ICU days less than 3, 3-5, 5-7, 7-10, and 10-14. We compared longitudinal changes in muscle echogenicity and PhA between the HAD and non-HAD groups using two-way repeated measures analysis of variance with mixed models.

RESULTS

Among the 22 patients, 7 (31.8%) had HAD. Muscle echogenicity was higher in the HAD group than in the non-HAD group (p < 0.001); however, no interaction effects were found between the two groups (p = 0.189). PhA showed a main effect on each evaluation day in patients (p = 0.040) and a significant interaction effect between the groups, including an early decreased pattern in the HAD group (p = 0.036).

CONCLUSIONS AND RELEVANCE

Higher muscle echogenicity and a decreased PhA pattern are related to HAD. Noninvasive assessment of muscle quality using ultrasound and bioelectrical impedance analysis may be useful in predicting the functional prognosis of patients with sepsis.

Intra- and Inter-Rater Reliability and Agreement of Ultrasound Imaging of Muscle Architecture and Patellar Tendon in Post-COVID-19 Patients Who Had Experienced Moderate or Severe COVID-19 Infection

COVID-19 is associated with musculoskeletal disorders. Ultrasound is a tool to assess muscle architecture and tendon measurements, offering an idea of the proportion of the consequences of the disease, since significant changes directly reflect the reduction in the ability to produce force and, consequently, in the functionality of the patient; however, its application in post-COVID-19 infection needs to be determined. We aimed to assess the intra- and inter-rater reliability of ultrasound measures of the architecture of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), soleus (SO), and tibialis anterior (TA) muscles, as well as the patellar tendon (PT) cross-sectional area (CSA) in post-COVID-19 patients. An observational, prospective study with repeated measures was designed to evaluate 20 post-COVID-19 patients, who were measured for the pennation angle (θp), fascicular length (Lf), thickness, echogenicity of muscles, CSA and echogenicity of the PT. The intra-class correlation coefficient (ICC) and 95% limits of agreement were used. The intra-rater reliability presented high or very high correlations (ICC = 0.71-1.0) for most measures, except the θp of the TA, which was classified as moderate (ICC = 0.69). Observing the inter-rater reliability, all the evaluations of the PT, thickness and echogenicity of the muscles presented high or very high correlations. For the Lf, only the RF showed as low (ICC = 0.43), for the θp, RF (ICC = 0.68), GL (ICC = 0.70) and TA (ICC = 0.71) moderate and the SO (ICC = 0.40) low. The ultrasound reliability was acceptable for the muscle architecture, muscle and tendon echogenicity, and PT CSA, despite the low reliability for the Lf and θp of the RF and SO, respectively.

Muscle ultrasound is a sensitive biomarker in oculopharyngeal muscular dystrophy

INTRODUCTION/AIMS

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset, progressive muscle disease. Quantitative muscle ultrasound (QMUS) assesses structural changes in muscles and is a sensitive biomarker in neuromuscular disorders. Our aim of this study was to determine whether QMUS can detect muscle pathology and can be used as longitudinal imaging biomarker in OPMD.

METHODS

Genetically confirmed OPMD patients, recruited by their treating physicians or from the national neuromuscular database, were examined twice, 20 months apart, using QMUS of orofacial and limb muscles, and measurements of functional capacity and muscle strength. Absolute echo intensity (AEI) and muscle thickness of all muscles were analyzed and correlated with clinical data.

RESULTS

The tongue, deltoid, iliopsoas, rectus femoris, and soleus muscles showed increased AEI at baseline compared with normal values in 43 OPMD patients, with the rectus femoris being most often affected (51%).The AEI and muscle thickness of 9 of 11 muscles correlated significantly with the motor function measure, 10-step stair test, swallowing capacity, dynamometry, Medical Research Council grade, tongue strength, and bite force (r = 0.302 to -0.711). Between baseline and follow-up, deterioration in AEI was found for the temporalis, tongue, and deltoid muscles, and decreased muscle thickness was detected for the temporalis, masseter, digastric, tongue, deltoid, iliopsoas, and soleus muscles (P < .05). No relation was found between the change in AEI and repeat length or disease duration.

DISCUSSION

QMUS detected muscle pathology and disease progression in OPMD over 20 months. We conclude that QMUS should be considered as a biomarker in treatment trials.

Effect of beam attenuation on muscle ultrasound echogenicity measurement in muscular dystrophies

PURPOSE

In advanced muscular dystrophies (AMD), quantification of muscle echo-intensity (EI) may be influenced by ultrasound beam attenuation, due to fibrosis and fatty infiltration of muscle tissue. Objective of the study was to compare EI measurements using grayscale analysis between a superficial and whole-muscle region of interest (ROI) in subjects with advanced and mild-to-moderate muscular dystrophy (MMD).

METHODS

Thirty-two adult subjects diagnosed with a muscular dystrophy and twenty-five matched healthy controls underwent ultrasound assessment of the biceps brachii (BB), rectus femoris (RF) and tibialis anterior (TA) muscles. Based on Heckmatt grading scale of muscles, two disease groups, an AMD (Heckmatt grades 3 or 4) and a MMD (Heckmatt grade 2), were analyzed. Superficial ROI was set as one-fourth of the whole-muscle area, located immediately below the superficial fascia and always inside muscle boundaries.

RESULTS

Muscle EI was significantly higher in the superficial compared to whole-muscle ROI, in all evaluated muscle groups of AMD subjects (BB, p = 0.004/RF, p = 0.027/TA, p = 0.002). EI values in superficial ROIs, for individual muscle analysis using z-scores, were more representative in assessments of muscle abnormality in advanced stages of the disease course (Heckmatt grades 3 and 4). In MMD and healthy muscles, no statistical difference was found in EI measurements between the two ROI types.

CONCLUSIONS

In AMD, selection of superficial ROI is better representative of changes in muscle texture, although caution should be exercised when comparing ROIs of different sizes.

Usefulness of Muscle Ultrasonography in the Nutritional Assessment of Adult Patients with Cystic Fibrosis

Background: Muscle ultrasonography of the quadriceps rectus femoris (QRF) is a technique on the rise in the assessment of muscle mass in application of nutritional assessment. The aim of the present study is to assess the usefulness of muscle ultrasonography in patients with cystic fibrosis, comparing the results with other body composition techniques such as anthropometry, bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), and handgrip strength (HGS). At the same time, we intend to assess the possible association with the nutritional and respiratory status. Methods: This was a prospective observational study in adult patients with cystic fibrosis in a clinically stable situation. Muscle ultrasonography of the QRF was performed, and the results were compared with other measures of body composition: anthropometry, BIA, and DXA. HGS was used to assess muscle function. Respiratory parameters were collected, and nutritional status was assessed using Global Leadership Initiative on Malnutrition (GLIM) criteria. Results: A total of 48 patients were included, with a mean age of 34.1 ± 8.8 years. In total, 24 patients were men, and 24 patients were women. Mean BMI was 22.5 ± 3.8 kg/m2. Mean muscular area rectus anterior (MARA) was 4.09 ± 1.5 cm2, and mean muscular circumference rectus was 8.86 ± 1.61 cm. A positive correlation was observed between the MARA and fat-free mass index (FFMI) determined by anthropometry (r = 0.747; p < 0.001), BIA (r = 0.780; p < 0.001), and DXA (r = 0.678; p < 0.001), as well as muscle function (HGS: r = 0.790; p < 0.001) and respiratory parameters (FEV1; r = 0.445, p = 0.005; FVC: r = 0.376, p = 0.02; FEV1/FVC: r = 0.344, p = 0.037). A total of 25 patients (52.1%) were diagnosed with malnutrition according to GLIM criteria. Differences were observed when comparing the MARA based on the diagnosis of malnutrition (4.75 ± 1.65 cm2 in normo-nourished vs. 3.37 ± 1.04 in malnourished; p = 0.014). Conclusions: In adults with cystic fibrosis, the measurements collected by muscle ultrasound of the QRF correlate adequately with body composition techniques such as anthropometry, BIA, DXA, and handgrip strength. Muscle ultrasound measurements, particularly the MARA, are related to the nutritional status and respiratory function of these patients.

Muscle Sonography in Inclusion Body Myositis: A Systematic Review and Meta-Analysis of 944 Measurements

Inclusion body myositis (IBM) is a slowly progressive muscle weakness of distal and proximal muscles, which is diagnosed by clinical and histopathological criteria. Imaging biomarkers are inconsistently used and do not follow international standardized criteria. We conducted a systematic review and meta-analysis to investigate the diagnostic value of muscle ultrasound (US) in IBM compared to healthy controls. A systematic search of PubMed/MEDLINE, Scopus and Web of Science was performed. Articles reporting the use of muscle ultrasound in IBM, and published in peer-reviewed journals until 11 September 2021, were included in our study. Seven studies were included, with a total of 108 IBM and 171 healthy controls. Echogenicity between IBM and healthy controls, which was assessed by three studies, demonstrated a significant mean difference in the flexor digitorum profundus (FDP) muscle, which had a grey scale value (GSV) of 36.55 (95% CI, 28.65–44.45, p < 0.001), and in the gastrocnemius (GC), which had a GSV of 27.90 (95% CI 16.32–39.48, p < 0.001). Muscle thickness in the FDP showed no significant difference between the groups. The pooled sensitivity and specificity of US in the differentiation between IBM and the controls were 82% and 98%, respectively, and the area under the curve was 0.612. IBM is a rare disease, which is reflected in the low numbers of patients included in each of the studies and thus there was high heterogeneity in the results. Nevertheless, the selected studies conclusively demonstrated significant differences in echogenicity of the FDP and GC in IBM, compared to controls. Further high-quality studies, using standardized operating procedures, are needed to implement muscle ultrasound in the diagnostic criteria.

Preliminary Validation of Muscle Ultrasound in Juvenile Dermatomyositis (JDM)

OBJECTIVE

To compare muscle ultrasound (MUS) parameters in patients with juvenile dermatomyositis (JDM) and healthy controls, and examine their association with JDM disease activity measures and magnetic resonance imaging (MRI).

METHODS

MUS of the right mid-rectus femoris was performed in 21 patients with JDM meeting probable or definite Bohan and Peter criteria and 28 demographically-matched healthy control subjects. MUS parameters were quantitated by digital image processing, and correlated with JDM disease activity measures and semi-quantitative thigh MRI short tau inversion recovery (STIR) and T1 scores.

RESULTS

Rectus femoris MUS echogenicity was increased (median 47.8 vs 38.5, p= 0.002) in patients with JDM compared with controls. Rectus femoris MUS echogenicity correlated with Physician Global Activity (PGA), Manual Muscle Testing (MMT), and Childhood Myositis Assessment Scale (CMAS) (rs 0.4-0.54). Some MUS parameters correlated with functional quantitative measures of muscle strength: resting RF area on MUS strongly correlated with knee extension quantitative muscle testing (QMT) (rs 0.76), and contracted area correlated with proximal MMT, knee extension QMT, and CMAS (rs 0.71-0.80). MUS echogenicity correlated with both STIR and T1 MRI (rs 0.43), and T1 MRI correlated inversely with RF contracted area (rs -0.49) on MUS. There were differences in pre- and post-exercise vascular power and colour Doppler on MUS in patients with JDM vs controls, with the percentage change of post-exercise vascular power Doppler lower in JDM compared with controls (7.1% vs 100.0%).

CONCLUSIONS

These data suggest MUS may be a valuable imaging modality to assess JDM disease activity and damage.

Muscle Thickness and Echo Intensity by Ultrasonography and Cognitive and Physical Dimensions in Older Adults

The purpose of the present study was to investigate the associations between muscle thickness and echo intensity with cognitive and physical dimensions like functional capacity measured in older people. This cross-sectional study involved 20 older adults (15 women and 5 men, mean age ± SD: 85 ± 7 years, body mass index: 25 ± 3 kg/m²) from a geriatric centre in Malaga (Spain). Anthropometric measurements, cognitive assessment with Pfeiffer Short Portable Mental Status Questionnaire and Motor Memory test, Physical Performance with Short Physical Performance Battery, and muscle strength were tested. Additionally, using B-mode ultrasonography, images of wrist flexors, biceps brachii, rectus femoris, vastus lateralis, medial gastrocnemius, and tibialis anterior were captured, and muscle thickness and echo intensity variables were extracted. An association between muscle parameters assessed by ultrasonography and cognitive and physical dimensions were found in older people. Echo intensity was the best predictor in a set of regression models with different muscle parameters and a battery of cognitive and physical tests in older people. Echo intensity adjusted by handgrip strength could be a low cost and ambulatory index and an indirect and reversible indicator of functional capacity.

Three-dimensional quantitative muscle ultrasound in a healthy population

INTRODUCTION/AIMS

Quantitative muscle ultrasound offers biomarkers that aid in the diagnosis, detection, and follow-up of neuromuscular disorders. At present, quantitative muscle ultrasound methods are 2D and are often operator and device dependent. The aim of this study was to combine an existing device independent method with an automated ultrasound machine and perform 3D quantitative muscle ultrasound, providing new normative data of healthy controls.

METHODS

In total, 123 healthy volunteers were included. After physical examination, 3D ultrasound scans of the tibialis anterior muscle were acquired using an automated ultrasound scanner. Image postprocessing was performed to obtain calibrated echo intensity values based on a phantom reference.

RESULTS

Tibialis anterior muscle volumes of 61.2 ± 24.1 mL and 53.7 ± 22.7 mL were scanned in males and females, respectively. Echo intensity correlated with gender**, age**, fat fraction*, histogram kurtosis**, skewness* and standard deviation** (*P < .05, **P < .01). Outcome measures did not differ significantly for different acquisition presets. The 3D quantitative muscle ultrasound revealed the non-uniformity of echo intensity values over the length of the tibialis anterior muscle.

DISCUSSION

Our method extended 2D measurements and confirmed previous findings. Our method and reported normative data of (potential) biomarkers can be used to study neuromuscular disorders.

Ultrasound pattern of anterolateral leg muscles in facioscapulohumeral muscular dystrophy

BACKGROUND/AIMS OF STUDY

To evaluate the degree of tibialis anterior (TA) and peroneus longus (PL) muscle involvement in facioscapulohumeral muscular dystrophy (FSHD) patients using ultrasound.

METHODS

We performed qualitative and quantitative assessments of muscle echogenicity, using Heckmatt's rating scale and gray scale analysis, respectively, in eight patients (five males, mean age 36.9 ± 8.4 years) with genetically confirmed FSHD 1.

RESULTS

Both methods demonstrated a distinct pattern of preferential TA involvement and PL sparing in all FSHD patients, irrespective of the degree of muscle involvement. More specifically, echogenicity was higher in TA compared to PL according to Heckmatt score in the patient group (TA 3.43 ± 0.49/PL 1.43 ± 0.49, p < .001). In the gray-scale histogram, ranging from 0 (black) to 255 (white), the mean measurements of TA were significantly increased in patients compared to healthy (71.60 ± 10.28 vs. 53.70 ± 10.05, p = .012) and significantly higher than PL measurements in the patient group, but not in healthy subjects (p-values .012 and .779, respectively). A strong correlation between TA hyperechogenicity and muscle weakness was demonstrated in patients with mild-to-moderate weakness, but not in patients with severe weakness (r = -.949 and r = .644, respectively).

CONCLUSIONS

This study shows a consistent US pattern of proximal anterolateral leg muscle involvement in FSHD, in agreement with findings of MRI studies and suggests that anterolateral leg muscle US may be a practical, fast and low-cost alternative to MRI.

Global Leadership Initiative on Malnutrition criteria with different muscle assessments including muscle ultrasound with hospitalized internal medicine patients

BACKGROUND

The aim of this study is to identify cutoff values for muscle ultrasound (US) to be used in Global Leadership Initiative on Malnutrition (GLIM) criteria, and to define the effect of reduced muscle mass assessment on malnutrition prevalence at hospital admission.

METHODS

A total of 118 inpatients were enrolled in this cross-sectional study. Six different muscles were evaluated by US. Following defining thresholds for muscle US to predict low muscle mass measured by bioelectrical impedance analysis, malnutrition was diagnosed by GLIM criteria with seven approaches, including calf circumference, mid-upper arm circumference (MAC), handgrip strength (HGS), skeletal muscle index (SMI), rectus femoris (RF) muscle thickness, and cross-sectional area (CSA) in addition to without using the reduced muscle mass criterion.

RESULTS

The median age of patients was 64 (18-93) years, 55.9% were female. RF muscle thickness had moderate positive correlations with both HGS (r = 0.572) and SMI (r = 0.405). RF CSA had moderate correlation with HGS (r = 0.567) and low correlation with SMI (r = 0.389). The cutoff thresholds were 11.3 mm (area under the curve [AUC] = 0.835) and 17 mm (AUC = 0.737) for RF muscle thickness and 4 cm² (AUC = 0.937) and 7.2 cm² (AUC = 0.755) for RF CSA in females and males, respectively. Without using the reduced muscle mass criterion, malnutrition prevalence was 46.6%; otherwise, it ranged from 47.5% (using MAC) to 65.2% (using HGS).

CONCLUSIONS

Muscle US may be used in GLIM criteria. However, muscle US needs a standard measurement technique and specific cutoff values in future studies.

Ultrasonographic and Histological Correlation after Experimental Reconstruction of a Volumetric Muscle Loss Injury with Adipose Tissue

Different types of scaffolds are used to reconstruct muscle volume loss injuries. In this experimental study, we correlated ultrasound observations with histological findings in a muscle volume loss injury reconstructed with autologous adipose tissue. The outcome is compared with decellularized and porous matrix implants. Autologous adipose tissue, decellularized matrix, and a porous collagen matrix were implanted in volumetric muscle loss (VML) injuries generated on the anterior tibial muscles of Wistar rats. Sixty days after implantation, ultrasound findings were compared with histological and histomorphometric analysis. The muscles with an autologous adipose tissue implant exhibited an ultrasound pattern that was quite similar to that of the regenerative control muscles. From a histological point of view, the defects had been occupied by newly formed muscle tissue with certain structural abnormalities that would explain the differences between the ultrasound patterns of the normal control muscles and the regenerated ones. While the decellularized muscle matrix implant resulted in fibrosis and an inflammatory response, the porous collagen matrix implant was replaced by regenerative muscle fibers with neurogenic atrophy and fibrosis. In both cases, the ultrasound images reflected echogenic, echotextural, and vascular changes compatible with the histological findings of failed muscle regeneration. The ultrasound analysis confirmed the histological findings observed in the VML injuries reconstructed by autologous adipose tissue implantation. Ultrasound can be a useful tool for evaluating the structure of muscles reconstructed through tissue engineering.

Spinal Muscular Atrophy Type 3 Showing a Specific Pattern of Selective Vulnerability on Muscle Ultrasound

A 23-year-old woman was admitted for slowly progressive proximal limb muscle weakness from childhood with elevated muscle enzyme levels. Although muscular diseases were suspected, an electromyogram showed remarkable neurogenic changes, and a muscle echogram indicated selective muscle involvement, including dissociation between the soleus and gastrocnemius, which was consistent with previous reports using magnetic resonance imaging (MRI). She was diagnosed with SMA type 3 following genetic testing, and nusinersen was soon initiated. An early diagnosis is mandatory to maximize the benefit of treatment. A muscle echogram may facilitate an early diagnosis in a non-invasive and time-saving manner compared to MRI.

A case of GNE myopathy mimicking hereditary motor neuropathy

A 36-year-old woman who presented with upper limb distal weakness since the age of 15 years, with gradual progression to the lower limbs, is reported. Hereditary motor neuropathy was initially suspected based on distal weakness and hyporeflexia; however, whole exome sequencing accidentally revealed a compound heterozygous variant in the GNE gene, and ultrasound revealed increased homogeneous echogenicity in the involved muscles, which is characteristic of myopathic changes. Muscle magnetic resonance imaging revealed fatty infiltration in all limb muscles, sparing the triceps brachii, vastus lateralis and vastus medialis. Muscle biopsy revealed intracytoplasmic rimmed vacuole, supporting the diagnosis of GNE myopathy.

Ultrasound for Non-invasive Assessment and Monitoring of Quadriceps Muscle Thickness in Critically Ill Patients With Acute Kidney Injury

Background and aims: Critically ill patients with acute kidney injury (AKI) undergo major muscle wasting in the first few days of ICU stay. An important concern in this clinical setting is the lack of adequate tools for routine bedside evaluation of the skeletal muscle mass, both for the determination of nutritional status at admission, and for monitoring. In this regard, the present study aims to ascertain if ultrasound (US) is able to detect changes in quadriceps muscle thickness of critically ill patients with acute kidney injury (AKI) over short periods of time. Methods: This is a prospective observational study with a follow-up at 5 days. All adult patients with AKI hospitalized at the Renal ICU of the Parma University Hospital over 12 months, with a hospital stay before ICU admission no longer than 72 h, and with a planned ICU stay of at least 5 days, were eligible for the study. An experienced investigator assessed quadriceps rectus femoris and vastus intermedius thickness (QRFT and QVIT) at baseline and after 5 days of ICU stay. Results: We enrolled 30 patients with 74 ± 11 years of age and APACHE II score of 22 ± 5. Muscle thickness decreased by 15 ± 13% within the first 5 days of ICU stay (P < 0.001 for all sites as compared to ICU admission). Patients with more severe muscle loss had lower probability of being discharged home (OR: 0.04, 95%CI: 0.00-0.74; P = 0.031). Conclusions: In critically ill patients with AKI, bedside muscle US identifies patients with accelerated muscle wasting.

Muscle ultrasound: Present state and future opportunities

Muscle ultrasound is a valuable addition to the neuromuscular toolkit in both the clinic and research settings, with proven value and reliability. However, it is currently not fulfilling its full potential in the diagnostic care of patients with neuromuscular disease. This review highlights the possibilities and pitfalls of muscle ultrasound as a diagnostic tool and biomarker, and discusses challenges to its widespread implementation. We expect that limitations in visual image interpretation, posed by user inexperience, could be overcome with simpler scoring systems and the help of deep-learning algorithms. In addition, more information should be collected on the relation between specific neuromuscular disorders, disease stages, and expected ultrasound abnormalities, as this will enhance specificity of the technique and enable the use of muscle ultrasound as a biomarker. Quantified muscle ultrasound gives the most sensitive results but is hampered by the need for device-specific reference values. Efforts in creating dedicated muscle ultrasound systems and artificial intelligence to help with image interpretation are expected to improve usability. Finally, the standard inclusion of muscle and nerve ultrasound in neuromuscular teaching curricula and guidelines will facilitate further implementation in practice. Our hope is that this review will help in unleashing muscle ultrasound's full potential.

Comparison between surface electrodes and ultrasound monitoring to measure TMS evoked muscle contraction

INTRODUCTION

Transcranial magnetic stimulation (TMS) is widely used to explore cortical physiology in health and disease. Surface electromyography (sEMG) is appropriate for superficial muscles, but cannot be applied easily to less accessible muscles. Muscle ultrasound (mUS) may provide an elegant solution to this problem, but fundamental questions remain. We explore the relationship between TMS evoked muscle potentials and TMS evoked muscle contractions measured with mUS.

METHODS

In 10 participants, we performed a TMS recruitment curve, simultaneously measuring motor evoked potentials (MEPs) and mUS in biceps (BI), first dorsal interosseous (FDI), tibialis anterior (TA), and the tongue (TO).

RESULTS

Resting motor threshold (RMT) measurements and recruitment curves were found to be consistent across sEMG and mUS.

DISCUSSION

This work supports the use of TMS-US to study less accessible muscles. The implications are broad but could include the study of a new range of muscles in disorders such as amyotrophic lateral sclerosis.

Feeding Your Himalayan Expedition: Nutritional Signatures and Body Composition Adaptations of Trekkers and Porters

High-altitude exposure leads to many physiological challenges, such as weight loss and dehydration. However, little attention has been posed to the role of nutrition and ethnic differences. Aiming to fulfill this gap, five Italian trekkers and seven Nepalese porters, all males, recorded their diet in diaries during a Himalayan expedition (19 days), and the average daily intake of micro and macro-nutrients were calculated. Bioimpedance analysis was performed five times during the trek; muscle ultrasound was performed before and after the expedition, only for the Italians. The Nepalese group consumed a lot of rice and only Italians consumed cheese. Water intake was slightly over 3000 g/d for both groups. Nepalese diet had a higher density of dietary fibre and lower density of riboflavin, vitamins A, K, and B12. Intake of calcium was lower than recommended levels. Body mass index, waist circumference, fat-free mass, and total body water decreased in both groups, whereas resistance (Rz) increased. Italians reactance (Xc) increased at day 9, whereas that of Nepalese occurred at days 5, 9, and 16. The cross-sectional area of the Vastus lateralis was reduced after the expedition. Specific nutritional and food-related risk factors guidance is needed for diverse expedition groups. Loss of muscle mass and balance of fluids both deserve a particular focus as concerns altitude expeditions.

Application of High-Resolution Ultrasound on Diagnosing Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus (DM). The typical manifestation is a length-dependent "glove and sock" sensation. At present, diagnosis is mainly dependent on clinical manifestations. Since the pathogenesis is not clear, there are no effective treatment measures. Management consists mainly of glucose control, peripheral nerve nutrition, and other measures to delay the progress of the disease; early diagnosis is therefore crucial to improving prognosis and quality of life for patients with DPN. Due to the lack of obvious symptoms in 50% of patients and the low sensitivity of neuro-electrophysiology to small fibers, the missed diagnosis rate is high. High-resolution ultrasound (HRU), as a convenient noninvasive tool, has been proven by many studies to have excellent clinical value in diagnosing DPN. With the development of related new technology, HRU shows promise for the screening, diagnosing, and follow-up of DPN, which could serve as a biomarker and provide new diagnostic insights. In this paper, we review the ability of HRU to detect nerve cross-sectional area and blood flow, and echo and other image changes, and in showing the characteristics of peripheral nerve morphological changes in patients with DPN. We also explore the application of two other recent technological developments-shear wave elastography (SWE) and ultrasound scoring systems-in improving the diagnostic efficiency of HRU in peripheral neuropathy.

Managing uncommon and unexpected findings during neuromuscular ultrasound

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.

Neuromuscular Ultrasound in the Pediatric Population

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.

Muscle Hypertrophy and Architectural Changes in Response to Eight-Week Neuromuscular Electrical Stimulation Training in Healthy Older People

Loss of muscle mass of the lower limbs and of the spine extensors markedly impairs locomotor ability and spine stability in old age. In this study, we investigated whether 8 w of neuromuscular electrical stimulation (NMES) improves size and architecture of the lumbar multifidus (LM) and vastus lateralis (VL) along with locomotor ability in healthy older individuals. Eight volunteers (aged 65 ≥ years) performed NMES 3 times/week. Eight sex- and age-matched individuals served as controls. Functional tests (Timed Up and Go test (TUG) and Five Times Sit-to-Stand Test (FTSST)), VL muscle architecture (muscle thickness (MT), pennation angle (PA), and fiber length (FL)), along with VL cross-sectional area (CSA) and both sides of LM were measured before and after by ultrasound. By the end of the training period, MT and CSA of VL increased by 8.6% and 11.4%, respectively. No significant increases were observed in FL and PA. LM CSA increased by 5.6% (left) and 7.1% (right). Interestingly, all VL architectural parameters significantly decreased in the control group. The combined NMES had a large significant effect on TUG (r = 0.50, p = 0.046). These results extend previous findings on the hypertrophic effects of NMES training, suggesting to be a useful mean for combating age-related sarcopenia.

Texture analysis of sonographic muscle images can distinguish myopathic conditions

Given the recent technological advent of muscle ultrasound (US), classification of various myopathic conditions could be possible, especially by mathematical analysis of muscular fine structure called texture analysis. We prospectively enrolled patients with three neuromuscular conditions and their lower leg US images were quantitatively analyzed by texture analysis and machine learning methodology in the following subjects :  Inclusion body myositis (IBM) [N=11] ; myotonic dystrophy type 1 (DM1) [N=19] ; polymyositis/dermatomyositis (PM-DM) [N=21]. Although three-group analysis achieved up to 58.8% accuracy, two-group analysis of IBM plus PM-DM versus DM1 showed 78.4% accuracy. Despite the small number of subjects, texture analysis of muscle US followed by machine learning might be expected to be useful in identifying myopathic conditions. J. Med. Invest. 66 : 237-240, August, 2019.

The effects of calf massage in boys with Duchenne muscular dystrophy: a prospective interventional study

Purpose: We explored the effects of standardized calf massage in ambulant boys with Duchenne muscular dystrophy (DMD) using a prospective study design.Materials and Methods: Twenty boys completed two study visits, 1 week apart. At both visits, each leg received a 10-min calf massage (intervention) and a 10-min control rest period (placebo) in randomized order. Muscle length of calf and hamstrings and gastrocnemius stiffness were measured by a blinded assessor before and after intervention and placebo. Measures of gait function (timed 10-m walk/run and spatio-temporal gait parameters); gastrocnemius muscle ultrasound findings; participant perception of leg pain, stiffness and effort of walking and general psychological well-being were also collected.Results: Consistent significant small increases in muscle length of soleus, gastrocnemius and hamstrings were recorded post-massage, and gastrocnemius stiffness decreased. Small changes in gastrocnemius and soleus length only were also recorded following the control rest period. Gait function and general well-being remained stable throughout. Measurement across both study visits suggested that gains in muscle length may be cumulative with repeated massage.Conclusions: Calf massage is safe and associated with benefits to muscle length and stiffness for ambulant boys with DMD.Implications for RehabilitationIn a small sample of boys with Duchenne muscular dystrophy, calf massage was found to be safe, well-tolerated and associated with increased muscle length and decreased stiffness.The use of massage may assist in managing muscle length in boys with Duchenne muscular dystrophy.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.

Quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in healthy subjects

BACKGROUND

In the current study, we aimed to determine normative values for muscle thickness and fasciculation prevalence in healthy subjects.

METHODS

We performed a prospective study from October to December 2018 in 65 healthy subjects. All subjects underwent quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in the following 8 muscles: Biceps brachii, abductor pollicis brevis, first dorsal interosseous, abductor digiti minimi, quadriceps, tibialis anterior, extensor digitorum brevis, and abductor hallucis brevis.

RESULTS

Subject ages ranged from 21 to 82 years, with 63% women. Normative values for muscle thickness were determined using the fifth percentile. Multivariate regression analysis showed that sex, age, body mass index, and hand dominance affected muscle thickness. Fasciculations were observed frequently only in distal muscles.

CONCLUSIONS

Normal values for muscle thickness were determined, and may enhance neuromuscular ultrasound sensitivity and serve as a basis for future studies. Larger series are needed to confirm these values.

Role of Intraoperative Nerve Monitoring in Postoperative Muscle and Nerve Function of Patients Undergoing Modified Radical Mastectomy

This study aimed to postoperatively evaluate the effects of intraoperative neural monitoring (IONM) on muscles and nerves in patients who underwent modified radical mastectomy (MRM). In the 11 patients included in the study, nerves were determined and protected by nerve monitoring during the axillary dissection (IONM group). In another 11 patients, nerve monitoring was not performed; however, protection of the same nerves was attempted through careful nerve dissection (cautious nerve dissection [CND] group). The control group consisted of 22 healthy subjects. Muscle and nerve functions were blindly evaluated by an experienced physical therapy and rehabilitation specialist using electromyography (EMG) and ultrasonography (US) methods. The EMG values of the pectoralis major muscle were similar in the IONM and control groups (1.97 mV/1.98 mV, p = 0.97) but significantly lower in the CND group (1.57 mV, p < 0.05). Significant differences were found in the US values of the pectoralis major and minor muscles between the IONM and CND groups. No significant difference was found between the IONM and control groups in terms of EMG values of the serratus anterior muscle. This is the first prospective randomized study to objectively evaluate preservation of the nerve through nerve monitoring and its functional results. Monitoring of nerves during MRM is of great importance in terms of demonstrating the positive effects on muscle and nerve functions.

Muscle thickness measured by ultrasound is reduced in neuromuscular disorders and correlates with clinical and electrophysiological findings

INTRODUCTION

Nerve imaging has a limited role in axonal and muscle fiber loss. In this study, we sought to explore the utility of standardized muscle ultrasound (US) assessment in these clinical scenarios.

METHODS

We performed a prospective study from March to August 2018 of patients attending the neuromuscular clinic. All patients underwent clinical evaluation and standardized muscle thickness measurement by US in seven muscles.

RESULTS

The study cohort consisted of 114 participants, including patients with polyneuropathy, motor neuron disease, and myopathy. The smallest distal muscle thickness was found in patients with polyneuropathy, while the smallest proximal muscle thickness was found in patients with myopathy. Muscle thickness was strongly correlated with muscle strength (r ² = 0.62), electrophysiological findings (r ² : 0.44-0.55), and disability score (r ² = 0.53).

DISCUSSION

Standardized muscle thickness measured by US shows diagnostic usefulness in a spectrum of neuromuscular disorders and correlates with clinical and electrophysiological findings.

Ultrasound-Guided Hydroneurolysis of the Median Nerve for Recurrent Carpal Tunnel Syndrome

BACKGROUND

Recurrent carpal tunnel syndrome is often associated with perineural scarring around the median nerve. Surgical options include relatively invasive procedures, such as fat pad grafting, ligament reconstruction, muscle transfer, and nerve wraps. All have limited success because of the possibility of repeated recurrent scarring postoperatively.

METHODS

We discuss a technique involving injection with external hydroneurolysis of the median nerve under ultrasound guidance for recurrent carpal tunnel. Injection enables a gentler dissection of the surrounding tissues compared with open external neurolysis, with less chance of recurrent scarring. This technique is a unique alternative to repeat operative intervention in recurrent carpal tunnel, as well as a prelude to repeat open decompression and salvage procedures.

RESULTS

Ultrasound-guided injection with external hydroneurolysis of the median nerve is a safer, more limited procedure compared with repeat open surgery, usually performed in an office setting. This procedure limits risk, anesthesia, and operating/recovery room expenses, offering relief in 70% to 80% of cases. Furthermore, in the 20% to 30% of patients with inadequate relief, surgery remains a viable option. US provides important information on the anatomy of the median nerve and carpal canal and can rule out covert pathology.

CONCLUSIONS

We offer an alternative treatment for recurrent carpal tunnel syndrome, a difficult problem for which many surgeons recommend nonoperative treatment. US provides objective data concerning residual nerve compression and allows for dynamic assessment. Theoretically, this also offers a viable solution for surgeons and their patients with recurrent carpal tunnel syndrome before being pressed to consider repeat open surgery.

[The possibilities of ultrasound testing in diagnostics of sarcopenia in older patients with chronic heart failure.]

The article presents the results of a study of the possibility of ultrasound testing of sarcopenia in older people suffering from chronic heart failure. All patients (63 persons, mean age 77,2±7,7 years) underwent dual-energy X-ray absorptiometry. Sarcopenia was diagnosed in 31 patients (FNIH sarcopenia project, 2014). The area of the shoulder muscles (m. Biceps brachii), thigh (m. Rectus femoris) and 3 muscles of the forearm (m. brachioradialis, m. extensor carpi radialis longus, m. extensor carpi radialis brevis) was estimated. By performing multiple linear regression analysis, 2 ultrasound models of sarcopenia diagnosis with diagnostic accuracy of 92% and 93,6% are proposed. Models are based on the sum of limb muscle areas adjusted for gender, height and body weight.

Pattern of muscle involvement in inclusion body myositis: a sonographic study

OBJECTIVES

Imaging plays a role in myositis assessment by detecting muscle changes indicative of pathology. This study was conducted to determine the ultrasonographic pattern of muscle involvement in patients with inclusion body myositis (IBM) through an assessment of muscle echointensity.

METHODS

Sixty-two individuals were consecutively studied, 18 with IBM, 16 with polymyositis or dermatomyositis and 28 normal controls. Standardised scans were completed bilaterally for the deltoids, biceps, flexor digitorum profundus (FDP), flexor carpi ulnaris, rectus femoris, tibialis anterior and gastrocnemius assessing for muscle echointensity changes.

RESULTS

Patients with IBM had a markedly increased muscle echointensity when compared with comparator groups for all muscles studied. This was most discriminating at the FDP, gastrocnemius and rectus femoris. Asymmetry between sides and a heterogeneously increased echointensity were also seen.

CONCLUSIONS

Ultrasonography can aid in the assessment of IBM by displaying an increased echointensity in characteristically involved muscles, particularly when combined with assessments for asymmetry and echotexture.

Muscle-ultrasound evaluation in healthy pediatric subjects: Age-related normative data

INTRODUCTION

The muscle ultrasound examination (MUS) is a noninvasive and inexpensive technique for evaluating neuromyopathies. Standardized MUS normative data are incomplete in pediatric subjects.

METHODS

We performed a MUS study with 120 healthy children (59 males; mean age, 10.44 years; age range, 2-16 years). We measured the width and the echogenicity bilaterally in the following muscles: biceps brachii and brachialis, brachioradialis, forearm-flexors, rectus femoris and vastus intermedius, tibialis anterior, extensor hallucis longus, lateral and medial gastrocnemius.

RESULTS

The muscle thickness increased with age for all muscles. Confidence limits were set for each age group muscle width. Echogenicity increased with age only in some muscles.

DISCUSSIONS

Our MUS study provides new data on physiological muscle structural changes in healthy children to address the limited available references in this age group. Muscle Nerve 58: 245-250, 2018.

Muscle ultrasound: A useful tool in newborn screening for infantile onset pompe disease

Our study aimed to evaluate the utility of muscle ultrasound in newborn screening of infantile-onset Pompe disease (IOPD) and to establish a system of severity grading. We retrospectively selected 35 patients with initial low acid alpha-glucosidase (GAA) activity and collected data including muscle ultrasound features, GAA gene mutation, activity/performance, and pathological and laboratory findings. The echogenicity of 6 muscles (the bilateral vastus intermedius, rectus femoris, and sartorius muscles) was compared to that of epimysium on ultrasound and rated either 1 (normal), 2 (mildly increased), or 3 (obviously increased). These grades were used to divide patients into 3 groups. IOPD was present in none of the grade-1 patients, 5 of 9 grade-2 patients, and 5 of 5 grade-3 patients (P < .001). Comparing grade-2 plus grade-3 patients to grade-1 patients, muscle ultrasound detected IOPD with a sensitivity and specificity of 100.0% (95% confidence interval [CI]: 69.2%-100%) and 84.0% (95% CI: 63.9%-95.5%), respectively. The mean number of affected muscles was larger in grade-3 patients than in grade-2 patients (4.2 vs. 2.0, P = .005). Mean alanine transaminase (ALT), aspartate transaminase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH) levels were differed significantly different between grade-3 and grade-1 patients (P < .001). Because it permits direct visualization of injured muscles, muscle ultrasound can be used to screen for IOPD. Our echogenicity grades of muscle injury also correlate well with serum levels of muscle-injury biochemical markers.

Quantitative muscle ultrasound is useful for evaluating secondary axonal degeneration in chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

In chronic inflammatory demyelinating polyneuropathy (CIDP), exclusion of secondary axonal degeneration is challenging with conventional methods such as nerve conduction study (NCS), needle electromyography, and nerve biopsy. Increased echo intensity (EI) and decreased muscle thickness (MT) identified on muscle ultrasound (MUS) examination represent muscle denervation due to axonal degeneration in neurogenic disorders, suggesting MUS as a new tool to detect secondary axonal degeneration in patients with CIDP.

METHODS

EI and MT of abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscles were measured in 16 CIDP patients. Raw values were converted into z-scores using data from 60 normal controls (NCs).

RESULTS

Six of 45 muscles showed abnormally high EI and low MT, suggesting denervation following secondary axonal degeneration. These six muscles belonged to two patients with long disease history, unresponsiveness to treatment, and long interval from onset to initial therapy. There were no significant differences in EI and MT (p = .23 and .67, respectively) between the CIDP and NC groups, although NCS results revealed obvious demyelinating abnormalities in all CIDP patients, suggesting the fact that muscle structures will be preserved, and EI and MT will not change unless secondary axonal degeneration occurs in CIDP.

CONCLUSION

MUS is a promising tool for evaluating secondary axonal degeneration in patients with CIDP.

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.

Muscle ultrasound

Muscle ultrasound is an ideal imaging modality that allows for noninvasive, radiation-free point-of-care neuromuscular imaging. There are many potential applications of muscle ultrasound, including identification of abnormal muscle movements such as fasciculations, evaluation of muscle trauma, identification of physiologic parameters such as pennation angle, accurate performance of chemodenervation, and improved accuracy of challenging electrodiagnostic studies such as phrenic nerve conduction studies or needle electromyogram (EMG) of the diaphragm. Tissue Doppler imaging can be used to help identify inflammatory myopathies. With computer-assisted quantification, muscle ultrasound has high sensitivity and specificity in the diagnosis of pediatric neuromuscular disease and amyotrophic lateral sclerosis, and is a valuable addition to other diagnostic techniques for neuromuscular disease. When used as a first-line screening tool it can obviate the need for more invasive procedures such as EMG or muscle biopsy in certain patients. This chapter provides an overview of the fundamentals, clinical applications, and validation of muscle ultrasound for patients with neuromuscular disorders.