Muscle changes in amyotrophic lateral sclerosis: a longitudinal ultrasonography study

Automatic Quantitative Assessment of Muscle Strength Based on Deep Learning and Ultrasound

Skeletal muscle is a vital organ that promotes human movement and maintains posture. Accurate assessment of muscle strength is helpful to provide valuable insights for athletes' rehabilitation and strength training. However, traditional techniques rely heavily on the operator's expertise, which may affect the accuracy of the results. In this study, we propose an automated method to evaluate muscle strength using ultrasound and deep learning techniques. B-mode ultrasound data of biceps brachii of multiple athletes at different strength levels were collected and then used to train our deep learning model. To evaluate the effectiveness of this method, this study tested the contraction of the biceps brachii under different force levels. The classification accuracy of this method for grade 4 and grade 6 muscle strength reached 98% and 96%, respectively, and the overall average accuracy was 93% and 87%, respectively. The experimental results confirm that the innovative methods in this paper can accurately and effectively evaluate and classify muscle strength.

Dynamic analysis of muscles and the internal structure of the peripheral nerve as biomarkers of amyotrophic lateral sclerosis: A pilot study with ultrasound imaging

INTRODUCTION

The aim of this study was to determine the behaviour of ultrasound biomarkers of fascicle density and muscle strength in patients with amyotrophic lateral sclerosis (ALS).

METHODS

We conducted an observational, cross-sectional pilot study of 14 patients with ALS (28.6% women) and 14 controls. Bilateral cross-sectional ultrasound scans were performed in the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles, with recording of muscle thickness (MT) at rest and in contraction, and the difference in thickness. In the median, sciatic, and common peroneal nerves, we analysed the cross-sectional area (CSA), number of fascicles (NF) and fascicle density (FD). Analyses were nested by laterality.

RESULTS

Intra- and interrater agreement regarding NF was very good, with a minimum detectable error of < 0.7%. In patients with ALS, MT was lower in the APB both at rest (P = .003; g-Hedges = 1.03) and in contraction (P = .017; g-Hedges = 0.78) and in TA at rest (P = .002; g-Hedges = 0.15) and in contraction (P = .001; g-Hedges = 0.46), with lower thickening capacity. In the nerves, patients displayed lower CSA, with lower NF and higher FD. Significant correlations were found between MT of the ABP and Medical Research Council (MRC) scores for muscle strength (r = 0.34; r2 = 12%; P = .011) and with revised ALS Functional Rating Scale scores (r = 0.44; r2 = 19%; P < .001). The difference in TA thickening correlated with MRC scores (r = 0.30; r2 = 15%; P = .003) and with revised ALS Functional Rating Scale scores (r = 0.26; r2 = 7%; P = .049). NF in the sciatic nerve showed a significant correlation with MRC scores (r = 0.35; r2 = 12%; P = .008).

CONCLUSION

MT measurements derived from dynamic testing together with NF and FD may be useful biomarkers for monitoring patients with ALS and establishing a prognosis.

Evaluating surface EMG control of motorized wheelchairs for amyotrophic lateral sclerosis patients

Background

This study evaluated a novel control method for patients unable to independently control powered wheelchairs. Patients with amyotrophic lateral sclerosis often require a wheelchair but struggle with sufficient hand dexterity required for joystick control making them a population that needs this type of control method.

Methods

The study employed a novel control mechanism, using electromyography surface sensors applied to temporalis muscles able to measure the myoelectric voltage. Pattern and magnitude control of muscle contraction allowed for steering intention recognition and were used to manipulate their power wheelchair joystick. Four patients ages 51 to 69, two female and two male with amyotrophic lateral sclerosis, conducted Wheelchair Skills Test developed by Dalhousie University and were surveyed on the experience’s Clinical Global Impression of Change.

Results

Findings showed independent steering was capable for patients without hand function and provided recommendations for improved human-machine interface. All patients demonstrated the ability to engage the system, with varying precision, for driving their wheelchair in a controlled environment.

Conclusions

Three patients in the pilot trial reported the highest score of clinical global impression of change, all of whom had lost independent control of their wheelchair joystick. Patient four retained impaired hand dexterity for joystick control and reported negative impression of change, comparatively. Feedback from the study will be leveraged to improve training outcomes.

Trial registration Subjects provided signed informed consent according to the Declaration of Helsinki to enter the study that was approved by the Mayo Clinic Institutional Review Board in Rochester, Minnesota. The study is registered on ClinicalTrials.gov under identifier NCT04800926 as of March 14, 2021 retrospectively registered.

Sensitivity of Awaji Criteria and Revised El Escorial Criteria in the Diagnosis of Amyotrophic Lateral Sclerosis (ALS) at First Visit in a Tunisian Cohort

Background

Amyotrophic lateral sclerosis (ALS) is a fatal disease whose diagnosis and early management can improve survival. The most used diagnostic criteria are the revised El Escorial criteria (rEEC) and Awaji criteria (AC). The comparison of their sensitivities showed contradictory results. Our study aimed to compare the sensitivities of these two criteria in the diagnosis of definite ALS, at first visit, in a Tunisian hospital cohort.

Materials and Methods

This was a retrospective study including 173 patients diagnosed with ALS at the Department of Neurology of the Razi Hospital between January 2003 and April 2018.After studying the clinical features of the disease in our study population,each patient was categorized according to the rEEC and AC based on data collected in his medical record during his first visit to our department. Then, we compared the sensitivities of these two criteria in the diagnosis of definite ALS.

Results

Our Tunisian cohort was characterized by a slower disease progression. The sensitivity of the AC (69.4%) was significantly higher than that of the rEEC (40.5%) (p < 0.001). When the clinical signs evolved for less than 6 months, the sensitivities were 61% for AC and 12% for rEEC (p < 0.001). After 24 months of disease progression, the sensitivities were 78.2% for AC and 69.1% for rEEC (p = 0.063). It was impossible to categorize seventeen patients by the two criteria.

Conclusion

Our study demonstrated that patients in AC are more sensitive than rEEC in the early diagnosis of ALS in our Tunisian cohort. However, this superiority is gradually reduced during the evolution of the disease.

Diagnostic Value of Muscle Ultrasound for Myopathies and Myositis

Purpose of Review

The purpose of this review is to critically discuss the use of ultrasound in the evaluation of muscle disorders with a particular focus on the emerging use in inflammatory myopathies.

Recent Findings

In myopathies, pathologic muscle shows an increase in echogenicity. Muscle echogenicity can be assessed visually, semi-quantitatively, or quantitatively using grayscale analysis. The involvement of specific muscle groups and the pattern of increase in echogenicity can further point to specific diseases. In pediatric neuromuscular disorders, the value of muscle ultrasound for screening and diagnosis is well-established. It has also been found to be a responsive measure of disease change in muscular dystrophies. In chronic forms of myositis like inclusion body myositis, ultrasound is very suitable for detecting markedly increased echogenicity and atrophy in affected muscles. Acute cases of muscle edema show only a mild increase in echogenicity, which can also reverse with successful treatment.

Summary

Muscle ultrasound is an important imaging modality that is highly adaptable to study various muscle conditions. Although its diagnostic value for neuromuscular disorders is high, the evidence in myositis has only begun to accrue in earnest. Further systematic studies are needed, especially in its role for detecting muscle edema.

Application of muscle ultrasound for the evaluation of patients with amyotrophic lateral sclerosis: An observational cross-sectional study

INTRODUCTION

We evaluated the association between muscle ultrasound, number of motor units, and clinical parameters, and assessed their utility for distinguishing amyotrophic lateral scleorisis (ALS) patients from healthy individuals.

METHODS

Three muscle pairs (abductor pollicis brevis, abductor digiti minimi, and tibialis anterior) of 18 ALS patients and 18 controls underwent muscle ultrasound (echointensity and thickness) and assessment of motor unit number index (MUNIX). The clinical and functional status of participants were also assessed.

RESULTS

Mean age of the patients was 53.8 ± 12.1 years, and score on the ALS Functional Rating Scale-Revised was 38.9 ± 4.1. Echointensity of all tested muscles of ALS participants was significantly higher than that of controls, but there was no significant difference in muscle thickness. Muscle echointensity correlated significantly with clinical and electrophysiological parameters.

CONCLUSION

Echointensity of muscles was highly associated with clinical scales and MUNIX, confirming its relevance as an ancillary diagnostic test in ALS patients.

Current advances and research in ultrasound imaging to the assessment and management of musculoskeletal disorders

Currently evidence-based practice has given scientific weight to the physical therapist profession; it is essential that all medical professional and physical therapists know the usefulness of new tools that optimize the effectiveness of their interventions and allow the growing of the scientific knowledge base. The use of ultrasound imaging (USI) by physiotherapists has evolved in recent years, consolidating as an increasingly standardized technique, low cost compared to other imaging techniques, quickly of execution, feasible and reliable tool. USI offers a wide range of opportunities in clinical practice as well as in different research areas. Therefore, ultrasound has been currently used as a diagnostic tool by physicians and in recent years there has been an expansion of the use of ultrasound equipment by non-physicians professionals such as physical therapist or physical trainers, who incorporates USI as a means of assessing musculoskeletal system architecture and composition, musculoskeletal changes in dysfunction, pain or injury conditions, as an interventional technique assisting echo-guided procedures or using the visual real-time information as a biofeedback in control motor approaches, as guiding tool in clinical decisions as well as to improve the understanding of tissue adaptations to exercise or movement. The purpose of this article is to review and provide an overview about the currently research of the USI applications and their benefits for the diagnosis and management in individuals with musculoskeletal conditions.

Current and future applications of ultrasound imaging in peripheral nerve disorders

Neuromuscular ultrasound (NMUS) is a rapidly evolving technique used in neuromuscular medicine to provide complimentary information to standard electrodiagnostic studies. NMUS provides a dynamic, real time assessment of anatomy which can alter both diagnostic and management pathways in peripheral nerve disorders. This review describes the current and future techniques used in NMUS and details the applications and developments in the diagnosis and monitoring of compressive, hereditary, immune-mediated and axonal peripheral nerve disorders, and motor neuron diseases. Technological advances have allowed the increased utilisation of ultrasound for management of peripheral nerve disorders; however, several practical considerations need to be taken into account to facilitate the widespread uptake of this technique.

Count of Fasciculation in Ultrasound Can Predict the Prognosis of Amyotrophic Lateral Sclerosis

Background:

Although muscle ultrasound (MUS) is known to facilitate the diagnosis and evaluation of the severity of amyotrophic lateral sclerosis (ALS), the number of fasciculation has been scarcely examined as a predictive marker of the prognosis in ALS.

Objective:

The objective of this study was to examine the predictive value of fasciculation number for the prognosis of ALS.

Materials and Methods:

We examined fasciculation count (FasC), defined as the number of fasciculation per unit of time and area in MUS, of 11 patients with clinically probable or definite ALS. Thereafter, they were observed for maximally 2 years, unless they reached the endpoint of decease or receiving tracheostomy.

Results:

Six patients, who thereafter reached the endpoint within 2 years, had significantly higher FasC (223 [49.3] vs. 34 [13], P = 0.0043) and shorter disease duration (7 [2.3] vs. 33 [17], P = 0.0022) at MUS than the remaining five patients without reaching the endpoint.

Discussion and Conclusion:

Our study suggested that high FasC in MUS can predict rapid progression in ALS. Due to the limitations such as small sample size, suboptimal length of the observational period, and confounding factor of disease duration, further investigations are required.

Neuromuscular Ultrasound: Clinical Applications and Diagnostic Values

Advances in high-resolution ultrasound have provided clinicians with unique opportunities to study diseases of the peripheral nervous system. Ultrasound complements the clinical and electrophysiology exam by showing the degree of abnormalities in myopathies, as well as spontaneous muscle activities in motor neuron diseases and other disorders. In experienced hands, ultrasound is more sensitive than MRI in detecting peripheral nerve pathologies. It can also guide needle placement for electromyography exam, therapeutic injections, and muscle biopsy. Ultrasound enhances the ability to detect carpal tunnel syndrome and other focal nerve entrapment, as well as pathological nerve enlargements in genetic and acquired neuropathies. Furthermore, ultrasound can potentially be used as a biomarker for muscular dystrophy and spinal muscular atrophy. The combination of electromyography and ultrasound can increase the diagnostic certainty of amyotrophic lateral sclerosis, aid in the localization of brachial plexus or peripheral nerve trauma and allow for surveillance of nerve tumor progression in neurofibromatosis. Potential limitations of ultrasound include an inability to image deeper structures, with lower sensitivities in detecting neuromuscular diseases in young children and those with mitochondrial myopathies, due to subtle changes or early phase of the disease. As well, its utility in detecting critical illness neuromyopathy remains unclear. This review will focus on the clinical applications of neuromuscular ultrasound. The diagnostic values of ultrasound for screening of myopathies, neuropathies, and motor neuron diseases will be presented.

Clinical and research applications of neuromuscular ultrasound in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by dysfunction at multiple levels of the neuraxis. It remains a clinical diagnosis without a definitive diagnostic investigation. Electrodiagnostic testing provides supportive information and, along with imaging and biochemical markers, can help exclude mimicking conditions. Neuromuscular ultrasound has a valuable role in the diagnosis and monitoring of ALS and provides complementary information to clinical assessment and electrodiagnostic testing as well as insights into the underlying pathophysiology of this disease. This review highlights the evidence for ultrasound in the evaluation of bulbar, limb and respiratory musculature and peripheral nerves in ALS. Further research in this evolving area is required.

Neuromuscular ultrasound in clinical practice: A review

Neuromuscular ultrasound (NMUS) is becoming a standard element in the evaluation of peripheral nerve and muscle disease. When obtained simultaneously to electrodiagnostic studies, it provides dynamic, structural information that can refine a diagnosis or identify a structural etiology. NMUS can improve patient care for those with mononeuropathies, polyneuropathy, motor neuron disease and muscle disorders. In this article, we present a practical guide to the basics of NMUS and its clinical application. Basic ultrasound physics, scanning techniques and clinical applications are reviewed, along with current challenges.

Long-term use of implanted peroneal functional electrical stimulation for stroke-affected gait: the effects on muscle and motor nerve

BACKGROUND

Peripheral changes to muscle and motor nerves occur following stroke, which may further impair functional capacity. We investigated whether a year-long use of an implanted peroneal FES system reverses stroke-related changes in muscles and motor nerves in people with foot drop in the chronic phase after supratentorial stroke.

METHODS

Thirteen persons with a chronic stroke (mean age 56.1 years, median Fugl-Meyer Assessment leg score 71%) were included and received an implanted peroneal FES system (ActiGait®). Quantitative muscle ultrasound (QMUS) images were obtained bilaterally from three leg muscles (i.e. tibialis anterior, rectus femoris, gastrocnemius). Echogenicity (muscle ultrasound gray value) and muscle thickness were assessed over a one-year follow-up and compared to age-, sex-, height- and weight-corrected reference values. Compound motor action potentials (CMAPs) and motor evoked potentials (MEPs) were obtained from the tibialis anterior muscle. Generalized estimated equation modeling was used to assess changes in QMUS, CMAPs and MEPs outcomes over the follow-up period.

RESULTS

Echogenicity of the tibialis anterior decreased significantly during the follow-up on the paretic side. Z-scores changed from 0.88 at baseline to - 0.15 after 52 weeks. This was accompanied by a significant increase in muscle thickness on the paretic side, where z-scores changed from - 0.32 at baseline to 0.48 after 52 weeks. Echogenicity of the rectus femoris normalized on both the paretic and non-paretic side (z-scores changed from - 1.09 and - 1.51 to 0.14 and - 0.49, respectively). Amplitudes of CMAP and MEP (normalized to CMAP) were reduced during follow-up, particularly on the paretic side (ΔCMAP = 20% and ΔMEP = 14%).

CONCLUSIONS

We show that the structural changes to muscles following stroke are reversible with FES and that these changes might not be limited to electrically stimulated muscles. No evidence for improvement of the motor nerves was found.

ULTRASOUND IN THE DIAGNOSIS AND MONITORING OF AMYOTROPHIC LATERAL SCLEROSIS: A REVIEW

Neuromuscular ultrasound is complementary to electrodiagnostic (EDx) testing and is useful in enhancing the diagnosis of mononeuropathies, peripheral nerve trauma, and demyelinating polyneuropathies. There is increasing interest in using ultrasound both to aid in the diagnosis of amyotrophic lateral sclerosis (ALS) and to monitor its progression. In this article we review the relevant literature on ultrasound in ALS. Ultrasound is more sensitive than EDx in identifying fasciculations in patients with ALS. It can detect decreased muscle thickness, increased muscle echointensity and echovariance, and reduced peripheral nerve size in these patients. Ultrasound is also a helpful tool in assessment of diaphragm function. Although additional studies are required to define the exact role of ultrasound in the evaluation and monitoring of ALS, it can improve the diagnostic yield in patients when ALS is suspected, but insufficiently supported, by clinical and EDx examinations. Muscle Nerve 60: 114-123, 2019.

A pilot study of neuromuscular ultrasound as a biomarker for amyotrophic lateral sclerosis

INTRODUCTION

This study explores the reliability and responsiveness of neuromuscular ultrasound in amyotrophic lateral sclerosis (ALS).

METHODS

Investigations were conducted with 10 healthy controls, 10 patients with ALS (single point in time), and 10 different patients with ALS (followed over 6 months; 4 completed follow-up). Ultrasound was used to measure the thickness of the geniohyoid, bilateral biceps/brachialis, bilateral tibialis anterior, and bilateral hemidiaphragms (at inspiration and expiration). Interrater and intrarater reliability and change in muscle thickness over 6 months were measured.

RESULTS

Interrater correlation coefficients ranged between 0.80 and 0.99 in healthy controls and between 0.78 and 0.97 in patients with ALS. Intrarater correlation coefficients ranged between 0.83 and 0.98 in healthy controls. The mean percentage decline in muscle thickness over 6 months was 20.25%.

DISCUSSION

Muscle ultrasound appears to be a reliable technique for measuring important muscles in patients with ALS. Larger studies with age-matched controls should be conducted to assess further the responsiveness of this biomarker in ALS. Muscle Nerve 59:181-186, 2019.

Sonoelastography for the Assessment of Muscle Changes in Amyotrophic Lateral Sclerosis: Results of a Pilot Study

The purpose of this study was to assess the sonoelastographic features of four different muscles in patients with amyotrophic lateral sclerosis compared with healthy controls and to evaluate the relationship of these features to muscle strength and other ultrasonographic variables. Fourteen patients with amyotrophic lateral sclerosis and 20 controls were examined using strain sonoelastography scanning. The RGB channel fraction ratio was analyzed with ImageJ software (Version 1.48). Two main sonoelastographic patterns could be distinguished in the controls: a clear predominance of the blue channel (hard areas) and a more heterogeneous pattern with predominance of the green channel (intermediate stiffness). These patterns were also observed in patients, although a higher green channel score was observed in mildly impaired muscles, whereas a higher blue channel score was observed in the most severely impaired muscle. Sonoelastography may be a good complementary biomarker in the detection and monitoring of muscle changes in amyotrophic lateral sclerosis.

Comparison of cross-sectional areas and distal-proximal nerve ratios in amyotrophic lateral sclerosis

INTRODUCTION

This study explored potential diagnostic markers of nerve ultrasound in differentiating amyotrophic lateral sclerosis (ALS) from mimic disorders.

METHODS

Ultrasound of the median, ulnar, and tibial nerves was conducted in 53 patients with ALS, 32 patients with ALS-mimic disorders, and 30 controls. Nerve cross-sectional area (CSA) and distal-proximal ratios were calculated.

RESULTS

The median nerve CSA in the upper arm was decreased (7.9 ± 1.3 mm² vs. 9.0 ± 1.4 mm² , P < 0.05), and the median nerve wrist-upper arm ratio was increased in ALS patients compared with controls (1.3 ± 0.4 vs. 1.1 ± 0.2; P < 0.01). In differentiating ALS from mimic presentations, assessment of median nerve CSA in the upper arm and comparison of a median and ulnar nerve CSA distal-proximal ratio provide diagnostic potential.

DISCUSSION

Assessment of nerve CSA combined with calculation of nerve CSA distal-proximal ratio provides a useful marker to aid in the diagnosis of ALS. Muscle Nerve 58:777-783, 2018.

New insights into the pathophysiology of fasciculations in amyotrophic lateral sclerosis: An ultrasound study

OBJECTIVE

To describe the fasciculation pattern in ALS and to analyse its clinical and pathophysiological significance.

METHODS

Ultrasound of 19 muscles was performed in 44 patients with a recent diagnosis (<90 days) of ALS. The number of fasciculations was recorded in each muscle and the muscle thickness and strength were additionally measured in limb muscles. A subgroup of patients were electromyographically assessed.

RESULTS

US was performed in 835 muscles and EMG was available in 263 muscles. US detected fasciculations more frequently than EMG. Fasciculations were widespread, especially in upper limbs onset patients and in the cervical region. Fasciculations' number inversely associated with ALSFR-R and body mass index (BMI) and directly with BMI loss and upper motor neuron (UMN) impairment. Our statistical model suggest that fasciculations increase with the initial lower motor neuron (LMN) degeneration, reach their peak when the muscle became mildly to moderately weak, decreasing afterwards with increasing muscle weakness and atrophy.

CONCLUSIONS

Our study suggests that both UMN and LMN degeneration trigger fasciculations causing BMI loss. The degree of LMN impairment could account for differences in fasciculations' rates within and between muscles.

SIGNIFICANCE

In ALS, fasciculations could explain the link between hyperexcitability and BMI loss.

Split hand muscle echo intensity index as a reliable imaging marker for differential diagnosis of amyotrophic lateral sclerosis

OBJECTIVE

The objective of this study was to investigate the usefulness of muscle ultrasound in evaluating dissociated small hand muscle atrophy, termed 'split hand', and its feasibility in the diagnosis of amyotrophic lateral sclerosis (ALS).

METHODS

Forty-four patients with ALS, 18 normal subjects and 9 patients with other neuromuscular disorders were included in this study. The hand muscles were divided into three regions, the median-innervated lateral hand muscle group (ML), the ulnar-innervated lateral hand muscle (UL) and the ulnar-innervated medial hand muscle (UM), and the muscle echo intensity (EI) and compound muscle action potential (CMAP) were measured. We calculated the split hand index (SHI) using muscle EI (SHI_mEI) and CMAP (SHI_CMAP) for comparison among groups. The SHI was derived by dividing muscle EI (or CMAP) measured at the ML and UL by that measured at the UM.

RESULTS

The SHI_mEI was significantly higher in patients with ALS (51.7±28.3) than in normal controls (29.7±9.9) and disease controls with other neuromuscular disorders (36.5±7.3; P<0.001), particularly in upper limb-onset ALS (66.5±34.0; P<0.001). Receiver operating characteristic curve analysis indicated that the SHI_mEI had significantly better diagnostic accuracy than the SHI_CMAP.

CONCLUSIONS

The SHI_mEI was more sensitive in evaluating dissociated small hand muscle atrophy compared with the SHI_CMAP and may be a reliable diagnostic marker for differentiating ALS from other neuromuscular disorders and healthy controls.

Monitoring Progression of Amyotrophic Lateral Sclerosis Using Ultrasound Morpho-Textural Muscle Biomarkers: A Pilot Study

The need is increasing for progression biomarkers that allow the loss of motor neurons in amyotrophic lateral sclerosis (ALS) to be monitored in clinical trials. In this prospective longitudinal study, muscle thickness, echointensity, echovariation and gray level co-occurrence matrix textural features are examined as possible progression ultrasound biomarkers in ALS patients during a 5-mo follow-up period. We subjected 13 patients to 3 measurements for 20 wk. They showed a significant loss of muscle, an evident tendency to loss of thickness and increased echointensity and echovariation. In regard to textural parameters, muscle heterogeneity tended to increase as a result of the neoformation of non-contractile tissue through denervation. Considering some limitations of the study, the quantitative muscle ultrasound biomarkers evaluated showed a promising ability to monitor patients affected by ALS.

Quantitative Muscle Ultrasonography Using Textural Analysis in Amyotrophic Lateral Sclerosis

The purpose of this study was to analyze differences in gray-level co-occurrence matrix (GLCM) parameters, as assessed by muscle ultrasound (MUS), between amyotrophic lateral sclerosis (ALS) patients and healthy controls, and to compare the diagnostic accuracy of these GLCM parameters with first-order MUS parameters (echointensity [EI], echovariation [EV], and muscle thickness [MTh]) in different muscle groups. Twenty-six patients with ALS and 26 healthy subjects underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor, quadriceps femoris, and tibialis anterior muscle groups. MTh was measured with electronic calipers, and EI, EV, and GLCM were obtained using Image J (v.1.48) software. Sensitivity, specificity, likelihood ratios, and area under the curve (AUC) were performed by logistic regression models and receiver operating characteristic curves. GLCM parameters showed reduced granularity in the muscles of ALS patients compared with the controls. Regarding the discrimination capacity, the best single diagnostic parameter in forearm flexors and quadriceps was GLCM and in biceps brachialis and tibialis anterior was EV. The respective combination of these two parameters with MTh resulted in the best AUC (over 90% in all muscle groups and close to the maximum combination model). The use of new textural parameters (EV and GLCM) combined with usual quantitative MUS variables is a promising biomarker in ALS.

Ultrasonography in Peripheral Nervous System Diagnosis

PURPOSE OF REVIEW

High-resolution ultrasound has made it possible to view most nerves and muscles in real time and to identify pathologic change in size, echo texture, and vascularity. This article focuses on the principles underlying ultrasound imaging and the application of ultrasound imaging to clinical disorders commonly seen in an electrodiagnostic laboratory.

RECENT FINDINGS

Ultrasound is a sensitive and specific tool for evaluating myopathic and neurogenic muscle disease. It provides useful information about muscles difficult to study with other technologies, such as the tongue and diaphragm, and is also helpful in evaluating smaller muscles in the hands or feet where correlation with electrodiagnostic studies is possible. For nerves, the resolution of ultrasound is such that it can sensitively identify focal nerve enlargement, which is accurate in the diagnosis of entrapment neuropathies. Furthermore, it can recognize diffuse or multifocal nerve enlargement seen in hereditary and inflammatory neuropathies.

SUMMARY

Neuromuscular ultrasound is an informative noninvasive tool for evaluating nerve and muscle disease. As the technology continues to advance and becomes widely available, it may become a routine part of residency training, neuromuscular research, and clinical practice.

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.

Panoramic ultrasound: a novel and valid tool for monitoring change in muscle mass

BACKGROUND

The strong link between reduced muscle mass and morbidity and mortality highlights the urgent need for simple techniques that can monitor change in skeletal muscle cross-sectional area (CSA). Our objective was to examine the validity of panoramic ultrasound to detect change in quadriceps and gastrocnemius size in comparison with magnetic resonance imaging (MRI) in subjects randomized to 70 days of bed rest (BR) with or without exercise.

METHODS

Panoramic ultrasound and MRI images of the quadriceps and gastrocnemius muscles were acquired on the right leg of 27 subjects (26 male, 1 female; age: 34.6 ± 7.8 years; body mass: 77.5 ± 10.0 kg; body mass index: 24.2 ± 2.8 kg/m² ; height: 179.1 ± 6.9 cm) before (BR-6), during (BR3, 7, 11, 15, 22, 29, 36, 53, 69), and after (BR+3, +6, +10) BR. Validity of panoramic ultrasound to detect change in muscle CSA was assessed by Bland-Altman plots, Lin's concordance correlation coefficient (CCC), sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

Six hundred ninety-eight panoramic ultrasound CSA and 698 MRI CSA measurements were assessed. Concordance between ultrasound and MRI was excellent in the quadriceps (CCC: 0.78; P < 0.0001), whereas there was poor concordance in the gastrocnemius (CCC: 0.37; P < 0.0006). Compared with MRI, panoramic ultrasound demonstrated high accuracy in detecting quadriceps atrophy and hypertrophy (sensitivity: 73.7%; specificity: 74.2%) and gastrocnemius atrophy (sensitivity: 83.1%) and low accuracy in detecting gastrocnemius hypertrophy (specificity: 33.0%).

CONCLUSIONS

Panoramic ultrasound imaging is a valid tool for monitoring quadriceps muscle atrophy and hypertrophy and for detecting gastrocnemius atrophy.

Muscular Echovariation: A New Biomarker in Amyotrophic Lateral Sclerosis

The purpose of the work described here was to assess the characteristics of echovariation in amyotrophic lateral sclerosis (ALS) compared with other muscle ultrasonography parameters. Twenty-six ALS patients (8 women, mean age 58.9 y, standard deviation 12.02 y) and 26 healthy controls (17 women, mean age 59.6 y, standard deviation 6.41 y) were included in this observational study. They underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor group, quadriceps femoris and tibialis anterior. Muscular thickness, echo-intensity and echovariation were analyzed. Muscles affected by ALS had increased echo-intensity, decreased thickness and decreased echovariation. Echovariation in all muscles except the quadriceps femoris strongly correlated with muscle strength (explained variance between 21.8% in the biceps/brachialis and 37.5% in the tibialis anterior) and the ALS Functional Rating Scale Revised score (explained variance between 26% in the biceps/brachialis and 36.7% in the forearm flexor group). Echovariation is an easy-to-obtain quantitative muscle ultrasonography parameter that could distinguish ALS patients from healthy controls more accurately than previous described biomarkers.

Assessment of Motor Units in Neuromuscular Disease

The motor unit comprises the anterior horn cell, its axon, and the muscle fibers that it innervates. Although the true number of motor units is unknown, the number of motor units appears to vary greatly between different muscles and between different individuals. Assessment of the number and function of motor units is needed in diseases of the anterior horn cell and other motor nerve disorders. Amyotrophic lateral sclerosis is the most important disease of anterior horn cells. The need for an effective biomarker for assessing disease progression and for use in clinical trials in amyotrophic lateral sclerosis has stimulated the study of methods to measure the number of motor units. Since 1970 a number of different methods, including the incremental, F-wave, multipoint, and statistical methods, have been developed but none has achieved widespread applicability. Two methods (MUNIX and the multipoint incremental method) are in current use across multiple centres and are discussed in detail in this review, together with other recently published methods. Imaging with magnetic resonance and ultrasound is increasingly being applied to this area. Motor unit number estimates have also been applied to other neuromuscular diseases such as spinal muscular atrophy, compression neuropathies, and prior poliomyelitis. The need for an objective measure for the assessment of motor units remains tantalizingly close but unfulfilled in 2016.

Quantitative muscle ultrasound as a biomarker in Charcot-Marie-Tooth neuropathy

OBJECTIVE

The utility of quantitative muscle ultrasound as a marker of disease severity in Charcot-Marie-Tooth (CMT) disease subtypes was investigated.

METHODS

Muscle ultrasound was prospectively performed on 252 individual muscles from 21 CMT patients (9 CMT1A, 8 CMTX1, 4 CMT2A) and compared to 120 muscles from 10 age and gender-matched controls. Muscle ultrasound recorded echogenicity and thickness in representative muscles including first dorsal interosseus (FDI) and tibialis anterior (TA).

RESULTS

Muscle volume of FDI and thickness of TA correlated with MRC strength. Muscle echogenicity was significantly increased in FDI (65.05 vs 47.09; p<0.0001) and TA (89.45 vs 66.30; p<0.0001) of CMT patients. In TA, there was significantly higher muscle thickness (23 vs 18 vs 16mm; p<0.0001) and lower muscle echogenicity (80 vs 95 vs 108; p<0.0001) in CMT1A compared to CMTX1 and CMT2A. This corresponded to disease severity based on muscle strength (MRC grading CMT1A vs CMTX1 vs CMT2A: 59 vs 48 vs 44; p=0.002).

CONCLUSION

In CMT, quantitative muscle ultrasound of FDI and TA is a useful marker of disease severity.

SIGNIFICANCE

The current findings suggest that quantitative muscle ultrasound has potential as a surrogate marker of disease progression in future interventional trials in CMT.

Bilateral changes in muscle architecture of physically active people with chronic stroke: A quantitative muscle ultrasound study

OBJECTIVE

Changes in muscle architecture after stroke are usually assessed by investigating inter-limb differences. As a result bilateral changes of muscle architecture might be missed. Our aim was to investigate whether bilateral architectural changes in skeletal muscle can be detected in chronic, physically active stroke patients using quantitative muscle ultrasound (QMUS).

METHODS

Twenty-eight patients (mean time since stroke 5.2years, median Brunnström stage 4) were recruited. QMUS images were obtained bilaterally from 2 arm and 4 leg muscles. Corrected echogenicity (muscle ultrasound grayvalue) and muscle thickness were compared to reference values obtained from healthy subjects. Correlations of muscle changes with demographic, clinical and neurophysiological characteristics were explored.

RESULTS

Out of 6 muscles, a significant increase in mean echogenicity was found in 4 paretic and 3 non-paretic side muscles. Significant decreases in mean muscle thickness were found in 2 paretic side muscles and 1 non-paretic side muscle. Echogenicity of the medial gastrocnemius correlated moderately with walking speed (inversely) and time since stroke.

CONCLUSIONS

This study showed that QMUS is a feasible technique to investigate architectural changes in skeletal muscles in the chronic phase of stroke and that abnormalities can be found in muscles on both the hemiparetic and non-paretic side.

SIGNIFICANCE

Intriguing data on bilateral changes in muscles of people with stroke is presented. Directions for future research are provided.

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.

Clinical Measures of Disease Progression in Amyotrophic Lateral Sclerosis

Progressive weakness remains the clinical hallmark of amyotrophic lateral sclerosis (ALS). Accordingly, a variety of tools has been developed to capture this disease feature, including questionnaires, such as the ALS-functional rating scale, strength testing, pulmonary function tests, electrophysiologic measures, including motor unit number estimation, and imaging techniques. Despite this plethora of approaches, there is little agreement as to what measures to use in a given clinical trial or in the clinic during routine patient care. Part of the reason for this uncertainty is that ALS is a remarkably protean disease. Some individuals progress rapidly, others slowly; some patients have considerable upper motor neuron dysfunction, whereas others have little; and there is considerable variation in the sequence of body regions affected, in some the disease beginning in the bulbar musculature and in others in one arm or one leg. Here, I present a variety of basic and more complex clinical measures for potential use in therapeutic trials with the aim of offering a balanced and practical set of recommendations, as well as considerations for future studies.

Quantifying disease progression in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) exhibits characteristic variability of onset and rate of disease progression, with inherent clinical heterogeneity making disease quantitation difficult. Recent advances in understanding pathogenic mechanisms linked to the development of ALS impose an increasing need to develop strategies to predict and more objectively measure disease progression. This review explores phenotypic and genetic determinants of disease progression in ALS, and examines established and evolving biomarkers that may contribute to robust measurement in longitudinal clinical studies. With targeted neuroprotective strategies on the horizon, developing efficiencies in clinical trial design may facilitate timely entry of novel treatments into the clinic.

Lean tissue imaging: a new era for nutritional assessment and intervention

Body composition refers to the amount of fat and lean tissues in our body; it is a science that looks beyond a unit of body weight, accounting for the proportion of different tissues and its relationship to health. Although body weight and body mass index are well-known indexes of health status, most researchers agree that they are rather inaccurate measures, especially for elderly individuals and those patients with specific clinical conditions. The emerging use of imaging techniques such as dual energy x-ray absorptiometry, computerized tomography, magnetic resonance imaging, and ultrasound imaging in the clinical setting have highlighted the importance of lean soft tissue (LST) as an independent predictor of morbidity and mortality. It is clear from emerging studies that body composition health will be vital in treatment decisions, prognostic outcomes, and quality of life in several nonclinical and clinical states. This review explores the methodologies and the emerging value of imaging techniques in the assessment of body composition, focusing on the value of LST to predict nutrition status.

Muscle ultrasonography as an additional diagnostic tool for the diagnosis of amyotrophic lateral sclerosis

OBJECTIVE

We aimed to determine the utility of muscle ultrasonography (MUS) in addition to electromyography (EMG) in the diagnosis of amyotrophic lateral sclerosis (ALS).

METHODS

In all, 60 patients with ALS and 20 with other neuromuscular disorders underwent MUS and EMG. In addition, 30 healthy controls underwent only MUS. Occurrence of fasciculations and fibrillations was evaluated. Ultrasonic echogenicity was graded semiquantitatively.

RESULTS

The incidence of fasciculations was significantly higher in patients undergoing MUS than in those undergoing EMG (p<0.05), even in muscles of full strength (p<0.001). However, EMG was more sensitive in detecting fibrillations (p<0.05). MUS had an overall higher sensitivity in detecting spontaneous activity in the tongue (p<0.05). Patients with ALS showed significantly increased muscle echo intensity (EI) compared to patients who were initially suspected as having ALS and normal controls (p<0.05), irrespective of the clinical or electrophysiological status.

CONCLUSION

Our results showed that the sensitivity and specificity of MUS in diagnosing ALS was almost equivalent to those of EMG, using the Awaji criteria. Combination of MUS and EMG enhances the diagnostic accuracy compared to EMG alone (p<0.05).

SIGNIFICANCE

The combination of EMG and MUS can be used to evaluate the lower motor neuron affection by reducing the use of the often painful and uncomfortable EMG examinations but without decreasing the diagnostic sensitivity and specificity.

3D-Ultrasonography for evaluation of facial muscles in patients with chronic facial palsy or defective healing: a pilot study

Background

While standardized methods are established to examine the pathway from motorcortex to the peripheral nerve in patients with facial palsy, a reliable method to evaluate the facial muscles in patients with long-term palsy for therapy planning is lacking.

Methods

A 3D ultrasonographic (US) acquisition system driven by a motorized linear mover combined with conventional US probe was used to acquire 3D data sets of several facial muscles on both sides of the face in a healthy subject and seven patients with different types of unilateral degenerative facial nerve lesions.

Results

The US results were correlated to the duration of palsy and the electromyography results. Consistent 3D US based volumetry through bilateral comparison was feasible for parts of the frontalis muscle, orbicularis oculi muscle, depressor anguli oris muscle, depressor labii inferioris muscle, and mentalis muscle. With the exception of the frontal muscle, the facial muscles volumes were much smaller on the palsy side (minimum: 3% for the depressor labii inferior muscle) than on the healthy side in patients with severe facial nerve lesion. In contrast, the frontal muscles did not show a side difference. In the two patients with defective healing after spontaneous regeneration a decrease in muscle volume was not seen. Synkinesis and hyperkinesis was even more correlated to muscle hypertrophy on the palsy compared with the healthy side.

Conclusion

3D ultrasonography seems to be a promising tool for regional and quantitative evaluation of facial muscles in patients with facial palsy receiving a facial reconstructive surgery or conservative treatment.