Whole-body fasciculation detection in amyotrophic lateral sclerosis using motor unit MRI.

OBJECTIVE: Compare fasciculation rates between amyotrophic lateral sclerosis (ALS) patients and healthy controls in body regions relevant for diagnosing ALS using motor unit MRI (MUMRI) at baseline and 6 months follow-up, and relate this to single-channel surface EMG (SEMG). METHODS: Tongue, biceps brachii, paraspinals and lower legs were assessed with MUMRI and biceps brachii and soleus with SEMG in 10 healthy controls and 10 patients (9 typical ALS, 1 primary lateral sclerosis [PLS]). RESULTS: MUMRI-detected fasciculation rates in typical ALS patients were higher compared to healthy controls for biceps brachii (2.40 ± 1.90 cm-3min-1vs. 0.04 ± 0.10 cm-3min-1, p = 0.004), paraspinals (1.14 ± 1.61 cm-3min-1vs. 0.02 ± 0.02 cm-3min-1, p = 0.016) and lower legs (1.42 ± 1.27 cm-3min-1vs. 0.13 ± 0.10 cm-3min-1, p = 0.004), but not tongue (1.41 ± 1.94 cm-3min-1vs. 0.18 ± 0.18 cm-3min-1, p = 0.556). The PLS patient showed no fasciculation. At baseline, 6/9 ALS patients had increased fasciculation rates compared to healthy controls in at least 2 body regions. At follow-up every patient had increased fasciculation rates in at least 2 body regions. The MUMRI-detected fasciculation rate correlated with SEMG-detected fasciculation rates (τ = 0.475, p = 0.006). CONCLUSION: MUMRI can non-invasively image fasciculation in multiple body regions and appears sensitive to disease progression in individual patients. SIGNIFICANCE: MUMRI has potential as diagnostic tool for ALS.

Split Phenomenon of Fasciculation between Antagonistic Muscles in Amyotrophic Lateral Sclerosis: An Ultrasound Study.

OBJECTIVE: Paresis of muscle groups in patients with amyotrophic lateral sclerosis (ALS) tends to present split phenomena. We explored the split phenomenon of fasciculation in multiple antagonistic muscle groups in ALS patients. METHODS: One hundred and forty ALS patients and 66 non-ALS patients were included from a single ALS center. Muscle ultrasonography (MUS) was performed to detect fasciculation in elbow flexor-extensor, wrist flexor-extensor, knee flexor-extensor, and ankle flexor-extensor. Split phenomena of fasciculation between different antagonistic muscle groups were summarized, and the possible influence factors were analyzed through stratified analysis. RESULTS: The frequency of split phenomenon of fasciculation intensity was significantly higher than those of muscle strength (26.1% vs. 7.1% for elbow flexor-extensor, 38.3% vs. 5.7% for wrist flexor-extensor, 37.9% vs. 3.0% for knee extensor-flexor, and 33.6% vs. 14.4% for ankle flexor-extensor) (P < 0.01). For muscles with 0-1 level of muscle strength (the Medical Research Council, MRC, score), significance difference in mean fasciculation intensity was observed only in ankle flexor-extensor. For muscles with 2-5 level of muscle strength, significant dissociation of fasciculation grade was common, especially among patients with slow rapid progression rate and both upper and lower motor neuron (UMN and LMN) involvement. As for non-ALS patients, no significant difference was observed in fasciculation intensity between antagonistic muscles. CONCLUSION: Split phenomenon of fasciculation between antagonistic muscles was common and relatively specific in ALS patients. Muscle strength, progression rate, and UMN involvement were influence factors of the split phenomenon of fasciculation intensity.

Differentiation Between Amyotrophic Lateral Sclerosis and Mimics Using Quantitative Analysis of Fsciculation with Muscle Ultrasound.

Objective To determine the diagnostic accuracy of the intensity of fasciculation evaluated by muscle ultrasound in the differential diagnosis of amyotrophic lateral sclerosis (ALS). Methods We prospectively recruited patients who had ALS and neuropathy-radiculopathy attending Peking Union Medical College Hospital from 2017 to 2020. Healthy adults from a community were recruited as healthy controls. Muscle strength was assessed using the Medical Research Council (MRC) scale. At the first visit to the hospital, patients were assessed for maximal grade of fasciculations, total fasciculation score, and fasciculation grade in 16 muscle groups of bilateral upper and lower limbs using ultrasonography. The sensitivity and specificity of maximal grade of fasciculations, total fasciculation score, and fasciculation grade for the diagnosis of ALS were assessed by receiver operating characteristic analyses. Results The percentage of limb muscles with a maximal fasciculation grade higher than grade 2 in ALS patients and neuropathy-radiculopathy patients was 84.9% and 9.8%, respectively (χ2 = 172.436, P < 0.01). Of the 16 limb muscles detected, the total fasciculation score [median (interquartile range)] was 29 (15, 41) in ALS patients and 3 (0, 8) in neuropathy-radiculopathy patients (Z = 9.642, P < 0.001). Remarkable fasciculations were seen in ALS patients whose muscles with a MRC score ranging from 2 to 4, followed by patients with MRC score 5, and then in those with MRC score 0 and 1. The sensitivity and specificity of total fasciculation score for diagnosis of ALS were 80.6% and 93.4%, respectively (cut-off value 14). In patients with ALS, for muscles with MRC score 4 and 5, the percentage of muscles with fasciculation grades ≥ 3 was 42.3% and 24.1% respectively, while in neuropathy-radiculopathy patients, the percentage for muscles with MRC score 4 and 5 was only 1.7% and 0, respectively. Conclusion A combined analysis of fasciculation intensity and MRC score of the limb muscles may be helpful for differential diagnosis of ALS.

Quantitative sonographic assessment of muscle thickness and fasciculations distribution is a sensitive tool for neuromuscular disorders.

INTRODUCTION: Loss of muscle thickness can be demonstrated in a wide spectrum of neuromuscular disorders, while fasciculations are more frequent in amyotrophic lateral sclerosis (ALS). In the current study, we aimed to determine the sensitivity and specificity of quantitative sonographic assessment of muscle thickness and the presence of fasciculations for diagnosing various neuromuscular disorders. METHODS: The thickness and the presence of fasciculations in eight muscles were determined by sonography in patients with myopathy (22), polyneuropathy (36), ALS (91), and spinal muscular atrophy (SMA) (31) and compared to normative values determined in 65 heathy control subjects. RESULTS: Reduced muscle thickness in at least one relaxed muscle showed 92-100% sensitivity for diagnosing a neuromuscular disease, with a specificity of 85% for differentiating patients from heathy controls (AUC = 0.90). Subtracting distal from proximal muscle thickness may differentiate between myopathy and polyneuropathy. Fasciculations in ≥1 proximal muscle showed good diagnostic accuracy (AUC = 0.87) for diagnosing ALS. DISCUSSION: Sonographic assessment of muscle thickness is a sensitive tool for diagnosing a wide spectrum of neuromuscular diseases, and may facilitate diagnosis even in patients with normal strength on neurological examination, while the presence of fasciculations in proximal muscles may facilitate ALS diagnosis.

Differentiation Between Amyotrophic Lateral Sclerosis and Mimics Using Quantitative Analysis of Fsciculation with Muscle Ultrasound / 中国医学科学杂志(英文版)

Objective To determine the diagnostic accuracy of the intensity of fasciculation evaluated by muscle ultrasound in the differential diagnosis of amyotrophic lateral sclerosis (ALS). Methods We prospectively recruited patients who had ALS and neuropathy-radiculopathy attending Peking Union Medical College Hospital from 2017 to 2020. Healthy adults from a community were recruited as healthy controls. Muscle strength was assessed using the Medical Research Council (MRC) scale. At the first visit to the hospital, patients were assessed for maximal grade of fasciculations, total fasciculation score, and fasciculation grade in 16 muscle groups of bilateral upper and lower limbs using ultrasonography. The sensitivity and specificity of maximal grade of fasciculations, total fasciculation score, and fasciculation grade for the diagnosis of ALS were assessed by receiver operating characteristic analyses. Results The percentage of limb muscles with a maximal fasciculation grade higher than grade 2 in ALS patients and neuropathy-radiculopathy patients was 84.9% and 9.8%, respectively (χ2 = 172.436, P < 0.01). Of the 16 limb muscles detected, the total fasciculation score [median (interquartile range)] was 29 (15, 41) in ALS patients and 3 (0, 8) in neuropathy-radiculopathy patients (Z = 9.642, P < 0.001). Remarkable fasciculations were seen in ALS patients whose muscles with a MRC score ranging from 2 to 4, followed by patients with MRC score 5, and then in those with MRC score 0 and 1. The sensitivity and specificity of total fasciculation score for diagnosis of ALS were 80.6% and 93.4%, respectively (cut-off value 14). In patients with ALS, for muscles with MRC score 4 and 5, the percentage of muscles with fasciculation grades ≥ 3 was 42.3% and 24.1% respectively, while in neuropathy-radiculopathy patients, the percentage for muscles with MRC score 4 and 5 was only 1.7% and 0, respectively. Conclusion A combined analysis of fasciculation intensity and MRC score of the limb muscles may be helpful for differential diagnosis of ALS.

Early diagnosis of amyotrophic lateral sclerosis based on fasciculations in muscle ultrasonography: A machine learning approach.

OBJECTIVE: Although fasciculation on muscle ultrasonography (MUS) is useful in diagnosing amyotrophic lateral sclerosis (ALS), its applicability to early diagnosis remains unclear. We aimed to develop and validate diagnostic models especially beneficial to early-stage ALS via machine learning. METHODS: We investigated 100 patients with ALS, including 50 with early-stage ALS within 9 months from onset, and 100 without ALS. Fifteen muscles were bilaterally observed for 10 s each and the presence of fasciculations was recorded. Hierarchical clustering and nominal logistic regression, neural network, or ensemble learning were applied to the training cohort comprising the early-stage ALS to develop MUS-based diagnostic models, and they were tested in the validation cohort comprising the later-stage ALS. RESULTS: Fasciculations on MUS in the brainstem or thoracic region had high specificity but limited sensitivities and predictive profiles for diagnosis of ALS. A machine learning-based model comprising eight muscles in the four body regions had a high sensitivity (recall), specificity, and positive predictive value (precision) for both early- and later-stage ALS patients. CONCLUSIONS: We developed and validated MUS-fasciculation-based diagnostic models for early- and later-stage ALS. SIGNIFICANCE: Fasciculation detected in relevant muscles on MUS can contribute to the diagnosis of ALS from the early stage.

Ultrasound-Guided Botulinum Toxin Injection for the Treatment of Teres Major Fasciculations.

ABSTRACT: This case study presents a 31-yr-old male weightlifter without known neuromuscular disease who presented with 5 wks of atraumatic, constant fasciculations of his right teres major muscle without recent injury. Electromyography identified fasciculation potentials within the teres major and pronator teres, suggesting an acute C6 radiculopathy, although a cervical magnetic resonance imaging demonstrated no significant neuroforaminal stenosis. Trigger point injections and multiple medications failed to stop the fasciculations. Under electromyography and ultrasound guidance, he was focally injected with botulinum toxin to the teres major 10 wks from initial onset with subsequent complete resolution of the symptoms and no side effects.

Muscle ultrasonography in detecting fasciculations: A noninvasive diagnostic tool for amyotrophic lateral sclerosis.

BACKGROUND AND OBJECTIVES: Muscle ultrasound (MUS) is an emerging noninvasive tool to identify fasciculations in amyotrophic lateral sclerosis (ALS). We assessed the utility of MUS in detecting fasciculations in suspected ALS patients. METHODS: Thirty-three patients (25 men) with possible (n = 7), probable (n = 12), or definite ALS according to Awaji criteria were studied. Electromyography was done in biceps brachii, quadriceps, and thoracic paraspinal muscles and MUS in biceps, triceps, deltoid, abductor-digiti-minimi, quadriceps, hamstrings, tibialis anterior, thoracic paraspinal, and tongue muscles. RESULTS: The age at onset and illness duration was 49.73 ± 12.7 years and 13.57 ± 9.7 months, respectively. Limb-onset = 24 patients (72.7%) and bulbar-onset = 9 (27.3%). Totally 561 muscles were examined by MUS. Fasciculations were detected in 84.3% of muscles, 98.4% with and 73% without clinical fasciculations (p < 0.001). Fasciculation detection rate (FDR) by MUS was significantly higher in muscles with wasting (95.6%) than without wasting (77.6%, p < 0.001). Compared with EMG, FDR was significantly higher with MUS in quadriceps (81.8% vs. 51.5%, p = 0.002) and thoracic paraspinal muscles (75.8% vs. 42.4%, p = 0.013). The proportion of patients with definite ALS increased from 42% by clinical examination to 70% after combining EMG and MUS findings. CONCLUSIONS: MUS is more sensitive in detecting fasciculations than electromyography (EMG) and provides a safer, faster, painless, and noninvasive alternative to EMG in detecting fasciculations in ALS.

Fasciculation differences between ALS and non-ALS patients: an ultrasound study.

BACKGROUND: Fasciculation is an important sign for the diagnosis of amyotrophic lateral sclerosis (ALS). Our study aimed to analyze the difference in fasciculation detected with muscle ultrasonography (MUS) between ALS patients and non-ALS patients with symptoms resembling ALS. METHODS: Eighty-eight ALS patients and fifty-four non-ALS (eight multifocal motor neuropathy, 32 chronic inflammatory demyelinating polyneuropathy/Charcot-Marie-Tooth, and 14 cervical spondylopathy or lumbar spondylopathy) patients were recruited. MUS was performed on 19 muscle groups in cervical, lumbosacral, bulbar, and thoracic regions for each patient. The intensity of fasciculation was divided into five grades based on firing frequency and number in the involved muscle groups. RESULTS: The overall detection rates were 72.8% in ALS and 18% in non-ALS patients. The fasciculation grades (median [IQR]) were 2 (0-3) in ALS and 0 (0-0) in non-ALS patients (P < 0.001). Fasciculations were observed in four regions for ALS patients and primarily distributed in proximal limbs. Fasciculations in non-ALS patients were primarily low-grade and mostly distributed in distal limbs. DISCUSSION: The fasciculation grade was higher in ALS than non-ALS patients. The distribution pattern of fasciculation was different between ALS and non-ALS patients. CONCLUSIONS: The fasciculation grade and distribution pattern detected with MUS could help distinguish ALS from non-ALS patients.

A model incorporating ultrasound to predict the probability of fast disease progression in amyotrophic lateral sclerosis.

OBJECTIVE: We aimed to develop a model to predict amyotrophic lateral sclerosis (ALS) disease progression based on clinical and neuromuscular ultrasound (NMUS) parameters. METHODS: ALS patients were prospectively recruited. Muscle fasciculation (≥2 over 30-seconds, examined in biceps brachii-brachialis (BB), brachioradialis, tibialis anterior and vastus medialis) and nerve cross-sectional area (CSA) (median, ulnar, tibial, fibular nerve) were evaluated through NMUS. Ultrasound parameters were correlated with clinical data, including revised ALS Functional Rating Scale (ALSFRS-R) progression at one year. A predictive model was constructed to differentiate fast progressors (ALSFRS-R decline ≥ 1/month) from non-fast progressors. RESULTS: 40 ALS patients were recruited. Three parameters emerged as strong predictors of fast progressors: (i) ALSFRS-R slope at time of NMUS (p = 0.041), (ii) BB fasciculation count (p = 0.027) and (iii) proximal to distal median nerve CSA ratio < 1.22 (p = 0.026). A predictive model (scores 0-5) was built with excellent discrimination (area under curve: 0.915). Using a score of ≥ 3, the model demonstrated good sensitivity (81.3%) and specificity (91.0%) in differentiating fast from non-fast progressors. CONCLUSION: The current model is simple and can predict the probability of fast disease progression. SIGNIFICANCE: This model has potential as a surrogate biomarker of ALS disease progression.

Machine learning to extract muscle fascicle length changes from dynamic ultrasound images in real-time.

BACKGROUND AND OBJECTIVE: Dynamic muscle fascicle length measurements through B-mode ultrasound have become popular for the non-invasive physiological insights they provide regarding musculoskeletal structure-function. However, current practices typically require time consuming post-processing to track muscle length changes from B-mode images. A real-time measurement tool would not only save processing time but would also help pave the way toward closed-loop applications based on feedback signals driven by in vivo muscle length change patterns. In this paper, we benchmark an approach that combines traditional machine learning (ML) models with B-mode ultrasound recordings to obtain muscle fascicle length changes in real-time. To gauge the utility of this framework for 'in-the-loop' applications, we evaluate accuracy of the extracted muscle length change signals against time-series' derived from a standard, post-hoc automated tracking algorithm. METHODS: We collected B-mode ultrasound data from the soleus muscle of six participants performing five defined ankle motion tasks: (a) seated, constrained ankle plantarflexion, (b) seated, free ankle dorsi/plantarflexion, (c) weight-bearing, calf raises (d) walking, and then a (e) mix. We trained machine learning (ML) models by pairing muscle fascicle lengths obtained from standardized automated tracking software (UltraTrack) with the respective B-mode ultrasound image input to the tracker, frame-by-frame. Then we conducted hyperparameter optimizations for five different ML models using a grid search to find the best performing parameters for a combination of high correlation and low RMSE between ML and UltraTrack processed muscle fascicle length trajectories. Finally, using the global best model/hyperparameter settings, we comprehensively evaluated training-testing outcomes within subject (i.e., train and test on same subject), cross subject (i.e., train on one subject, test on another) and within/direct cross task (i.e., train and test on same subject, but different task). RESULTS: Support vector machine (SVM) was the best performing model with an average r = 0.70 ±0.34 and average RMSE = 2.86 ±2.55 mm across all direct training conditions and average r = 0.65 ±0.35 and average RMSE = 3.28 ±2.64 mm when optimized for all cross-participant conditions. Comparisons between ML vs. UltraTrack (i.e., ground truth) tracked muscle fascicle length versus time data indicated that ML tracked images reliably capture the salient qualitative features in ground truth length change data, even when correlation values are on the lower end. Furthermore, in the direct training, calf raises condition, which is most comparable to previous studies validating automated tracking performance during isolated contractions on a dynamometer, our ML approach yielded 0.90 average correlation, in line with other accepted tracking methods in the field. CONCLUSIONS: By combining B-mode ultrasound and classical ML models, we demonstrate it is possible to achieve real-time tracking of human soleus muscle fascicles across a number of functionally relevant contractile conditions. This novel sensing modality paves the way for muscle physiology in-the-loop applications that could be used to modify gait via biofeedback or unlock novel wearable device control techniques that could enable restored or augmented locomotion performance.

Utility of transoral motion-mode ultrasonography to detect tongue fasciculation in patients with amyotrophic lateral sclerosis.

INTRODUCTION: Increasing evidence suggests the utility of the submandibular approach for ultrasonography to detect tongue fasciculation in amyotrophic lateral sclerosis (ALS). We hypothesized that transoral motion-mode ultrasonography (TOMU) would be useful to detect tongue fasciculation in patients with ALS. METHODS: Patients with sporadic ALS showing clinically definite tongue fasciculation were enrolled, and the ultrasonography findings of patients' tongues on TOMU and ultrasonography by the conventional submandibular approach were analyzed. RESULTS: Six patients with clinically definite ALS were enrolled in this study. Although small, irregular muscle movements of 5 to 10 mm in amplitude and 0.1 to 0.2 second in duration were detected in all patients by TOMU, similar muscle movements were detected in only two of the six patients by the submandibular approach. DISCUSSION: TOMU appeared to be useful for detecting tongue fasciculation in ALS patients. Further study is needed to better determine its role as a diagnostic tool for ALS.

Fasciculation score: a sensitive biomarker in amyotrophic lateral sclerosis.

OBJECTIVE: The aim of our study was to elucidate the characteristic of fasciculation distributions in amyotrophic lateral sclerosis (ALS) using a fasciculation score (FS) of muscle ultrasound (MUS) and to compare the diagnostic values of three MUS fasciculation parameters in patients. METHODS: Thirty ALS patients, 16 ALS mimics, and 10 healthy subjects were involved. MUS of unilateral 10 muscles in each patient and needle electromyography (EMG) of total 204 muscles were performed to detect fasciculations and spontaneous activity respectively in ALS. Control groups underwent only MUS. Fasciculation was graded semiquantitatively with FS. RESULTS: Three hundred fifty muscles in ALS and 260 in controls were examined. The fasciculation detection rates, total FS, the number of muscles with fasciculation, and the total number of fasciculations in ALS were all significantly higher than those of controls (P < 0.001). ALS patients exhibited a multifocal continuous pattern of fasciculation in limbs, whereas there were few fasciculations in controls. Compared with other parameters, total FS had the largest area under the curve (AUC) (AUC = 0.899, P < 0.001) in ALS diagnosis. The detection rates of lower motor neuron (LMN) acute lesions by MUS (70.6%) and EMG (72.1%) were nearly the same, and a positive correlation between the FS and spontaneous activity grades (P < 0.001, r = 0.359) was proved. CONCLUSIONS: ALS patients exhibited the multifocal continuous pattern of fasciculation in limbs. FS showed high sensitivity and specificity in differentiating ALS from non-ALS patients, and the optimal cut-off value was determined as 4. The combination of MUS and EMG can provide additional information about specific muscles.

Fasciculation frequency at the biceps brachii and brachialis muscles is associated with amyotrophic lateral sclerosis disease burden and activity.

INTRODUCTION: Fasciculations are most commonly seen in the biceps brachii muscle in amyotrophic lateral sclerosis (ALS). In this study we have explored the association between fasciculation frequency in a single location-biceps brachii and brachialis muscles (BB), and disease burden and activity. METHODS: Sonographic muscle studies were performed in 90 ALS patients, 47 of whom were seen in subsequent follow-up. The association between fasciculations frequency at the BB and ALS Functional Rating Scale-Revised (ALSFRS-R) and manual muscle testing (MMT) scores was determined. RESULTS: High fasciculation frequency at the BB, where detection rate was the highest, was associated with shorter disease duration, greater muscle thickness, higher MMT scores, and faster rate of decline in ALSFRS-R initially, and MMT subsequently. DISCUSSION: High fasciculation frequency at the BB as determined by sonography, is associated with less impairment at time of examination, and a more active disease with a more rapid progression.

Difference in distribution of fasciculations between multifocal motor neuropathy and amyotrophic lateral sclerosis.

OBJECTIVE: To examine differences in fasciculation distribution between patients with multifocal motor neuropathy (MMN) and amyotrophic lateral sclerosis (ALS) based on muscle ultrasound. METHODS: Forty-one muscles (tongue muscle and 40 muscles of the trunk and limbs on both sides) in 5 MMN patients and 21 muscles (tongue muscle and 20 muscles on the onset side) in 21 ALS patients were subjected to muscle ultrasound individually for 60 seconds to detect the presence of fasciculations. RESULTS: Fasciculation detection rates on the onset side were significantly higher in ALS (42.4 ± 18.3%, mean ± SD) than in MMN (21.9 ± 8.8%) patients (p < 0.05). In MMN patients, no fasciculation was detected in the tongue or truncal muscles. There was no difference in the fasciculation detection rate between the onset and non-onset sides or between upper and lower limbs in MMN patients. CONCLUSIONS: In MMN patients, fasciculations were detected extensively in the limbs. However, the detection rate in patients with MMN was lower than in those with ALS. SIGNIFICANCE: Demonstration of the absence of fasciculations in the tongue and truncal muscles in MMN patients by extensive muscle ultrasound examination may help distinguish MMN from ALS.

Muscle ultrasonography in the diagnosis of amyotrophic lateral sclerosis.

Objectives: The aims of this study were to investigate the differences of fasciculations detected by muscle ultrasonography (MUS) among patients with amyotrophic lateral sclerosis (ALS), patients with ALS mimics and healthy controls, and to propose a simplified MUS fasciculation score for the diagnosis of ALS.Methods: We included 16 patients with ALS (ALS group), 10 patients with ALS mimics (disease-control group), and 10 healthy adults (healthy control group). Subjects underwent MUS in 11 muscles, including the tongue, and bilateral upper trapezius, biceps brachii, abductor pollicis brevis, rectus femoris, and tibialis anterior.Results: The number of muscles with fasciculations per person was more in the ALS group (6.44 ± 2.56) than in the disease-control group (1.20 ± 1.87, P = 0.001) and healthy control group (0.50 ± 1.08, P < 0.001). Fasciculations in 3 of 11 muscles could predict the ALS diagnosis with high sensitivity (88.2%) and specificity (94.7%).Conclusions: Fasciculations detected by MUS can be a simple and useful diagnostic tool for ALS.

Relationship between EMG-detected and ultrasound-detected fasciculations in amyotrophic lateral sclerosis: A prospective cohort study.

OBJECTIVES: Fasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas). METHODS: Thirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort. RESULTS: The mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ±â€¯0.25 mV and 3.21 ±â€¯0.88, respectively) than in those with both FP and MUS-fas (1.22 ±â€¯0.92 mV and 3.74 ±â€¯1.39, respectively; p < 0.0001 and p = 0.017, Welch's t-test). CONCLUSION: Small FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS. SIGNIFICANCE: Clinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.

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.

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.