Review of Ultrasonography in the Diagnosis of Carpal Tunnel Syndrome and a Proposed Scanning Protocol

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome

BACKGROUND

This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome.

METHODS

We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed.

RESULTS

Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %.

CONCLUSIONS

Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases.

LEVEL OF EVIDENCE

Diagnostic III.

Association between electrodiagnosis and neuromuscular ultrasound in the diagnosis and assessment of severity of carpal tunnel syndrome

BACKGROUND

Neuromuscular ultrasound plays an increasing role in diagnosing carpal tunnel syndrome (CTS). There are limited data supporting the correlation between the electrodiagnostic studies and ultrasound measurements in CTS.

OBJECTIVE

To assess the association between different electrodiagnostic severities and ultrasound measurements of the median nerve in CTS.

DESIGN

A retrospective cohort study.

SETTING

An academic tertiary care center.

PATIENTS

Patients 18 years or older evaluated with upper limb electrodiagnostic studies and neuromuscular ultrasound.

MAIN OUTCOME MEASUREMENT

Ultrasound measurements of the median nerve cross-sectional area (CSA) at the wrist and the calculated wrist-to-forearm ratio (WFR) were compared with the electrodiagnostic severity (normal, mild, moderate, and severe). Mean analysis and analysis of variance test (α = 0.05) were performed to assess the association.

RESULTS

A total of 1359 limbs were identified. There was a statistically significant association between electrodiagnostic severity of CTS and median nerve CSA at the wrist (p < .001), as well as the WFR (p < .001). The mean median nerve CSA at the wrist and WFR were 7.01 ± 2.06 mm2 (95% CI: 6.80-7.20) and 1.24 ± 0.36 (95% CI: 1.16-1.24) in electrodiagnostically normal median nerves, 10.47 ± 2.82 mm2 (95% CI: 10.25-10.75) and 2.06 ± 0.67 (95% CI: 2.04-2.16) in electrodiagnostically mild CTS, 12.95 ± 4.74 mm2 (95% CI: 12.41-13.59) and 2.49 ± 1.04 (95% CI: 2.37, 2.63) in electrodiagnostically moderate CTS, and 14.69 ± 5.38 mm2 (95% CI: 13.95-15.44) and 2.71 ± 1.02 (95% CI: 2.56-2.84) in electrodiagnostically severe CTS, respectively.

CONCLUSION

This study suggests a direct association between electrodiagnostic severity and ultrasound measurements of the median nerve in patients with suspected CTS.

The relationship between ultrasound and electrodiagnostic findings in relation of the severity of carpal tunnel syndrome

INTRODUCTION

Carpal tunnel syndrome is the most common compression neuropathy. Grading the severity of carpal tunnel syndrome is an important factor in deciding on the type of treatment. This study aims to determine the relationships between the findings of the electrodiagnosis and ultrasonography methods based on the severity of carpal tunnel syndrome.

METHODS

In this prospective clinical study, 50 patients (96 wrists) who were referred to the Physical Medicine and Rehabilitation Department of the Shohada Tajrish Hospital, Tehran, Iran (from March 2021 to November 2022) were studied. All patients with a history and clinical examination related to CTS underwent electrodiagnosis studies. Based on the results of electrodiagnosis, patients were divided into three groups: mild, moderate, and severe. All eligible patients underwent ultrasound at the cross-section of the wrist (at the level of the pisiform bone, the entrance of the canal) and the middle of the forearm.

RESULTS

In this study, the cross-sectional area of the median nerve was measured in 96 wrists of 50 patients with a mean age of 51.78 ± 9.80 years. The mean CSA of the median nerve in the mild, moderate, and severe groups was reported as 0.12 ± 0.03, 0.14 ± 0.02, and 0.21 ± 0.06, respectively. The mean WFR in different groups of CTS was reported as 1.85 ± 0.56, 1.93 ± 0.56, and 2.45 ± 0.49, respectively. A significant relationship between ultrasound findings, including CSA-inlet and WFR, and electrodiagnosis findings was presented (P value < 0.05).

CONCLUSION

Based on our findings, there is a statistically significant relationship between the sonographic findings, including the mean CSA-inlet and WFR, and the severity of CTS based on the electrodiagnosis study. Our findings revealed that as disease severity increases, sonographic parameters also increase significantly.

Diagnostic Accuracy of Neuromuscular Ultrasound vs. Electrodiagnostic Studies for Carpal Tunnel Syndrome: Systematic Review and Meta-analysis of Paired Accuracy Studies

This systematic review with meta-analysis compared the diagnostic accuracy of neuromuscular ultrasound (NMUS) and electrodiagnostic studies (EDX) as confirmatory tests for carpal tunnel syndrome (CTS) diagnosis. We used bivariate random-effects models to estimate pooled sensitivity and specificity and generate hierarchical summary receiver-operating characteristic curves to assess diagnostic test accuracy. Nine paired accuracy studies were included, representing 1751 hands (743 clinically diagnosed CTS; 1008 without CTS) that underwent NMUS and EDX. Compared to the clinical diagnosis reference standard, the pooled sensitivity was 86.4% for NMUS and 91.6% for EDX. Pooled specificity was 79.3% for NMUS and 81.9% for EDX. The positive likelihood ratios were 4.2 and 5.1 for NMUS and EDX, respectively, and the negative likelihood ratios were 0.17 and 0.10, respectively. The diagnostic odds ratio was 24 for NMUS and 49 for EDX. No statistically significant differences were identified between NMUS and EDX for sensitivity, specificity, or overall diagnostic accuracy. Overall, the diagnostic accuracy of NMUS is similar to that of EDX for CTS diagnosis, with high sensitivity and moderate specificity for each. The choice between these confirmatory diagnostic tests should incorporate shared decision-making between patients and providers that weighs diagnostic accuracy as well as factors such as patient preferences, test availability, cost, and tolerability.

Comparison of the Effectiveness of 2 Different Kinesio Taping Techniques Added to Exercises in the Treatment of Carpal Tunnel Syndrome: Randomized Controlled Trial, Double-Blind, Parallel Groups

OBJECTIVE

To compare the effectiveness of I-tape and button hole kinesio taping (KT) techniques added to exercises in the treatment of carpal tunnel syndrome (CTS).

DESIGN

Prospective randomized controlled blinded study.

SETTING

Physical Medicine and Rehabilitation Outpatient Clinic.

PARTICIPANTS

A total of 108 patients (165 wrists) diagnosed with CTS (N=108).

INTERVENTIONS

Button hole technique (BG), I-band technique (IG), and exercises (EG).

MAIN OUTCOME MEASURES

Visual analog scale (VAS), Douleur Neuropathique 4 Questions (DN4), Boston carpal tunnel syndrome questionnaire, and Jamar dynamometer were used. Median sensory nerve action potential (SNAP), compound muscle action potential (CMAP), median distal sensory latency (DSL), median distal motor latency (DML), sensory conduction velocity, and motor conduction velocity were recorded. Measurements were made at baseline, week 3, and week 12.

RESULTS

Thirty-six patients were in each group. Significant statistical improvements in VAS and DN4 scores were found in the BG and IG compared with EG (P<.05). Statistically significant improvements in hand grip strength were observed in the IG compared with the EG (P<.05). Significant improvements in DML levels and motor conduction velocity were observed in the BG and IG compared with the EG (P<.05). A significant increase in sensory conduction velocity was detected in the BG compared with the other groups (P<.05).

CONCLUSIONS

Both KT techniques are effective in terms of pain, functionality, symptom severity, grip strength, and electrophysiologically. The button hole technique was more effective in DSL, sensory conduction velocity, CMAP amplitude, and SNAP.

Ultrasound Diagnosis of Upper Extremity Peripheral Entrapment Neuropathies: A Narrative Review

» Diagnostic ultrasound evaluation has become an important adjunct to electrodiagnostic studies in the diagnosis of upper extremity entrapment neuropathy. » For the common median and ulnar entrapment neuropathies, published normative values for nerve cross-sectional area at the wrist and elbow have demonstrated a high degree of diagnostic validity of diagnostic ultrasound. » Expert consensus on best practice for the clinical use of these reference is lacking and should be a logical next step in the deployment of ultrasound for upper extremity neuropathy evaluation.

Current and future utility of ultrasound imaging in upper extremity musculoskeletal rehabilitation: A scoping review

STUDY DESIGN

This study was a scoping review.

BACKGROUND

Continued advances in musculoskeletal sonography technology and access have increased the feasibility of point-of-care use to support day-to-day clinical care and decision-making. Sonography can help improve therapeutic outcomes in upper extremity (UE) rehabilitation by enabling clinicians to visualize underlying structures during treatment.

PURPOSE OF THE STUDY

This study aimed to (1) evaluate the growth, range, extent, and composition of sonography literature supporting UE rehabilitation; (2) identify trends, gaps, and opportunities with regard to anatomic areas and diagnoses examined and ultrasound techniques used; and (3) evaluate potential research and practice utility.

METHODS

Searches were completed in PubMed, CINAHL, SPORTDiscus, PsycINFO, and BIOSIS. We included data-driven articles using ultrasound imaging for upper extremity structures in rehabilitation-related conditions. Articles directly applicable to UE rehabilitation were labeled direct articles, while those requiring translation were labeled indirect articles. Articles were further categorized by ultrasound imaging purpose. Article content between the two groups was descriptively compared, and direct articles underwent an evaluation of evidence levels and narrative synthesis to explore potential clinical utility.

RESULTS

Average publication rates for the final included articles (n = 337) steadily increased. Indirect articles (n = 288) used sonography to explore condition etiology, assess measurement properties, inform medical procedure choice, and grade condition severity. Direct articles (n = 49) used sonography to assess outcomes, inform clinical reasoning, and aid intervention delivery. Acute UE conditions and emerging sonography technology were rarely examined, while tendon, muscle, and soft tissue conditions and grayscale imaging were common. Rheumatic and peripheral nerve conditions and Doppler imaging were more prevalent in indirect than direct articles. Among reported sonography service providers, there was a high proportion of nonradiologist clinicians.

CONCLUSION

Sonography literature for UE rehabilitation demonstrates potential utility in evaluating outcomes, informing clinical reasoning, and assisting intervention delivery. A large peripheral knowledge base provides opportunities for clinical applications; however, further research is needed to determine clinical efficacy and impact for specific applications.

Application of radiomics model based on ultrasound image features in the prediction of carpal tunnel syndrome severity

OBJECTIVE

The aim of our study is to develop and validate a radiomics model based on ultrasound image features for predicting carpal tunnel syndrome (CTS) severity.

METHODS

This retrospective study included 237 CTS hands (106 for mild symptom, 68 for moderate symptom and 63 for severe symptom). There were no statistically significant differences among the three groups in terms of age, gender, race, etc. The data set was randomly divided into a training set and a test set in a ratio of 7:3. Firstly, a senior musculoskeletal ultrasound expert measures the cross-sectional area of median nerve (MN) at the scaphoid-pisiform level. Subsequently, a recursive feature elimination (RFE) method was used to identify the most discriminative radiomic features of each MN at the entrance of the carpal tunnel. Eventually, a random forest model was employed to classify the selected features for prediction. To evaluate the performance of the model, the confusion matrix, receiver operating characteristic (ROC) curves, and F1 values were calculated and plotted correspondingly.

RESULTS

The prediction capability of the radiomics model was significantly better than that of ultrasound measurements when 10 robust features were selected. The training set performed perfect classification with 100% accuracy for all participants, while the testing set performed accurate classification of severity for 76.39% of participants with F1 values of 80.00, 63.40, and 84.80 for predicting mild, moderate, and severe CTS, respectively. Comparably, the F1 values for mild, moderate, and severe CTS predicted based on the MN cross-sectional area were 76.46, 57.78, and 64.00, respectively..

CONCLUSION

This radiomics model based on ultrasound images has certain value in distinguishing the severity of CTS, and was slightly superior to using only MN cross-sectional area for judgment. Although its diagnostic efficacy was still inferior to that of neuroelectrophysiology. However, this method was non-invasive and did not require additional costs, and could provide additional information for clinical physicians to develop diagnosis and treatment plans.

Carpal tunnel syndrome prediction with machine learning algorithms using anthropometric and strength-based measurement

OBJECTIVES

Carpal tunnel syndrome (CTS) stands as the most prevalent upper extremity entrapment neuropathy, with a multifaceted etiology encompassing various risk factors. This study aimed to investigate whether anthropometric measurements of the hand, grip strength, and pinch strength could serve as predictive indicators for CTS through machine learning techniques.

METHODS

Enrollment encompassed patients exhibiting CTS symptoms (n = 56) and asymptomatic healthy controls (n = 56), with confirmation via electrophysiological assessments. Anthropometric measurements of the hand were obtained using a digital caliper, grip strength was gauged via a digital handgrip dynamometer, and pinch strengths were assessed using a pinchmeter. A comprehensive analysis was conducted employing four most common and effective machine learning algorithms, integrating thorough parameter tuning and cross-validation procedures. Additionally, the outcomes of variable importance were presented.

RESULTS

Among the diverse algorithms, Random Forests (accuracy of 89.474%, F1-score of 0.905, and kappa value of 0.789) and XGBoost (accuracy of 86.842%, F1-score of 0.878, and kappa value of 0.736) emerged as the top-performing choices based on distinct classification metrics. In addition, using variable importance calculations specific to these models, the most important variables were found to be wrist circumference, hand width, hand grip strength, tip pinch, key pinch, and middle finger length.

CONCLUSION

The findings of this study demonstrated that wrist circumference, hand width, hand grip strength, tip pinch, key pinch, and middle finger length can be utilized as reliable indicators of CTS. Also, the model developed herein, along with the identified crucial variables, could serve as an informative guide for healthcare professionals, enhancing precision and efficacy in CTS prediction.

[Analysis of the echographic parameters described in the study of carpal tunnel syndrome: A systematic review]

Carpal tunnel syndrome (CTS) is the most common entrapment mononeuropathy; the diagnosis is established by electrodiagnostic tests with until 34% of false positives/negatives. We present the following systematic review which objective is to analyze the most recent literature related to the ultrasound parameters described to study CTS. We selected studies that evaluated ultrasound parameters in patients with clinical suspicion following the Cochrane manual's recommendations. We include systematic reviews, meta-analyses, case-control studies and diagnostic tests, evaluating retrospective studies and bibliographic reviews with proper methodological quality. Articles published between 2005 and 2019. We included eight articles (two systematic reviews/meta-analyses, two case-control studies, one diagnostic test study, two literature reviews, and one retrospective). The parameters analyzed were cross-sectional area, wrist-forearm index, entry-exit index, thinning range, palmar bowing of the flexor retinaculum, and vascularity/mobility. Current evidence allows us to affirm that ultrasound is useful in screening for CTS.

Acroparesthesias: An Overview

Acroparesthesia is a symptom characterized by a subjective sensation, such as numbness, tingling, prickling, and reduced sensation, affecting the extremities (fingers and toes). Despite its frequency, data regarding its diagnostic approach and management are scarce. The etiological diagnosis of acroparesthesia is sometimes challenging since it can be due to abnormality anywhere along the sensory pathway from the peripheral nervous system to the cerebral cortex. Acroparesthesia can reveal several diseases. It can be associated with rheumatic complaints such as arthritis or myalgia. Further cautions are required when paresthesia is acute (within days) in onset, rapidly progressive, severe, asymmetric, proximal, multifocal, or associated with predominant motor signs (limb weakness) or severe dysautonomia. Acroparesthesia may reveal Guillain-Barré syndrome or vasculitis, requiring rapid management. Acroparesthesia is a predominant symptom of polyneuropathy, typically distal and symmetric, often due to diabetes. However, it can occur in other diseases such as vitamin B12 deficiency, monoclonal gammopathy of undetermined significance, or Fabry's disease. Mononeuropathy, mainly carpal tunnel syndrome, remains the most common cause of acroparesthesia. Ultrasonography contributes to the diagnosis of nerve entrapment neuropathy by showing nerve enlargement, hypoechogenic nerve, and intraneural vascularity. Besides, it can reveal its cause, such as space-occupying lesions, anatomical nerve variations, or anomalous muscle. Ultrasonography is also helpful for entrapment neuropathy treatment, such as ultrasound-guided steroid injection or carpal tunnel release. The management of acroparesthesia depends on its causes. This article aimed to review and summarize current knowledge on acroparesthesia and its causes. We also propose an algorithm for the management of acroparesthesia.

Evaluation of ultrasound as diagnostic tool in patients with clinical features suggestive of carpal tunnel syndrome in comparison to nerve conduction studies: Study protocol for a diagnostic testing study

BACKGROUND

Carpal Tunnel Syndrome (CTS) is the most common compressive neuropathy, accounting for 90% of all neuropathies. Its prevalence ranges from 3.8%-7.8% in the population. The gold standard for its diagnosis is the neurophysiological study (85% sensitivity and 95% specificity), with the disadvantage of being invasive, complex and expensive, which means an increase in cost and time for the diagnosis of the disease. The main objective of this diagnostic test evaluation study is to investigate the value of ultrasound in the diagnosis of CTS, and among the secondary objectives, to establish the ultrasound parameters that are predictors of CTS in comparison with neurophysiological studies, attempting to standardize a protocol and reference values that determine the presence or absence of CTS.

METHODS

Prospective, cross-sectional study. The reference test with which we compared the ultrasound is the neurophysiological test (NPT). Patients will come consecutively from the Neurophysiology Department of the Virgen Macarena Hospital, with clinical suspicion of CTS and fulfilling the inclusion/exclusion criteria. To calculate the sample size (EPIDAT program) we proposed a sensitivity of 78% and specificity of 87% with a confidence level of 95%, requiring 438 patients (264 NPT positive, 174 NPT negative). We followed an ultrasound study protocol that included the ultrasound variables: cross-sectional area at the entrance and exit of the tunnel, range of nerve thinning, wrist-forearm index, flexor retinaculum bulging, power Doppler uptake and the existence of adjacent wrists or masses. We propose a timeline for the study to be performed between 2020 and 2023. Finally, we propose a cost-effectiveness analysis.

DISCUSSION

Ultrasound not only allows to objectify the alterations of the median nerve but also the underlying pathological mechanisms in CTS. A multitude of ultrasound parameters have been described that should be regarded in syndrome's study, among which we included the cross-sectional area, the range of nerve thinning, the wrist-forearm index, flexor retinaculum bulging, power Doppler uptake and assessment of anatomical alterations. The use of ultrasound as a diagnostic tool in CTS has many advantages for both doctors and the patients, as it is a non-invasive, convenient, and fast tool increasingly accessible to professionals.

TRIAL REGISTRATION

Trials registry number: NCT05556278.

Deep Radiomics Features of Median Nerves for Automated Diagnosis of Carpal Tunnel Syndrome With Ultrasound Images: A Multi-Center Study

OBJECTIVES

Ultrasound is widely used in diagnosing carpal tunnel syndrome (CTS). However, the limitations of ultrasound in CTS detection are the lack of objective measures in the detection of nerve abnormality and the operator-dependent nature of ultrasound imaging. Therefore, in this study, we developed and proposed externally validated artificial intelligence (AI) models based on deep-radiomics features.

METHODS

We have used 416 median nerves from 2 countries (Iran and Colombia) for the development (112 entrapped and 112 normal nerves from Iran) and validation (26 entrapped and 26 normal nerves from Iran, and 70 entrapped and 70 normal nerves from Columbia) of our models. Ultrasound images were fed to the SqueezNet architecture to extract deep-radiomics features. Then a ReliefF method was used to select the clinically significant features. The selected deep-radiomics features were fed to 9 common machine-learning algorithms to choose the best-performing classifier. The 2 best-performing AI models were then externally validated.

RESULTS

Our developed model achieved an area under the receiver operating characteristic (ROC) curve (AUC) of 0.910 (88.46% sensitivity, 88.46% specificity) and 0.908 (84.62% sensitivity, 88.46% specificity) with support vector machine and stochastic gradient descent (SGD), respectively using the internal validation dataset. Furthermore, both models consistently performed well in the external validation dataset, and achieved an AUC of 0.890 (85.71% sensitivity, 82.86% specificity) and 0.890 (84.29% sensitivity and 82.86% specificity), with SVM and SGD models, respectively.

CONCLUSION

Our proposed AI models fed with deep-radiomics features performed consistently with internal and external datasets. This justifies that our proposed system can be employed for clinical use in hospitals and polyclinics.

The role of ultrasound in determining the presence and severity of carpal tunnel syndrome in diabetic patients

Carpal tunnel syndrome (CTS) is seen in 5% of the population and 14%-30% in diabetics. Although electrophysiological tests are used as the gold standard method in the diagnosis, alternative methods are being studying. We aimed to investigate whether the measurement of median nerve cross-sectional area (CSA) by ultrasound is associated with the presence and severity of CTS. This prospective, cross-sectional observational study includes 128 randomly selected T2DM patients. Electrodiagnostic study was performed for all patients to diagnose CTS. Median nerve CSA were measured with ultrasound examination. The severity of the CTS was determined by Padua method. Among 128 diabetes mellitus (DM) patients, 54 (28%) had CTS and 53 (41%) had diabetic peripheral polyneuropathy. The mean duration of DM was 11.55 years. Median nerve CSAs of the patients were significantly higher in patients with CTS (CTS (-): 10.47 ± 2.67 vs CTS: (+) 12.37 ± 3.17; p < 0.001). Median nerve CSA cutoff value of >10 mm2 predicts the diagnosis of CTS. However, minimal, mild, and moderate CTS groups had similar CSA according to Padua classification (p > 0.05 for all). CSA measurement with ultrasonography can be used as an effective method in diagnosing severe CTS disease. However, median nerve CSA values should not be used to reveal the severity of CTS, in order not to miss the demonstration of minimal, mild, and moderate groups, as well as being an indicator of only the severe CTS group.

Median nerve ultrasound cross sectional area and wrist-to-forearm ratio in relation to carpal tunnel syndrome related axonal damage and patient age

Objective

Primary objective was to retrospectively examine the effects of patient age and carpal tunnel syndrome (CTS) related axon loss on median nerve (MN) high resolution ultrasound (HRUS) in younger and older patients. HRUS parameters evaluated in this study were MN cross sectional area at the wrist (CSA) and wrist-to-forearm ratio (WFR).

Methods

The material comprised 467 wrists of 329 patients. The patients were categorized into younger (<65 years) and older (≥65 years) groups. Patients with moderate to extreme CTS were included in the study. Axon loss of the MN was assessed by needle EMG and graded by the interference pattern (IP) density. The association between axon loss and CSA and WFR was studied.

Results

The older patients had smaller mean CSA and WFR values compared to the younger patients. CSA correlated positively to the CTS severity only in the younger group. However, WFR correlated positively to CTS severity in both groups. In both age groups, CSA and WFR correlated positively with IP reduction.

Conclusions

Our study complemented recent findings on the effects of patient age on the CSA of the MN. However, although the MN CSA did not correlate with the CTS severity in older patients, the CSA increased in respect to the amount of axon loss. Also, as a new result, we presented the positive association of WFR with CTS severity among older patients.

Significance

Our study supports the recently speculated need for different MN CSA and WFR cut-off values for younger and older patients in assessing the severity of CTS. With older patients, WFR may be a more reliable parameter to assess the CTS severity than the CSA. CTS related axonal damage of the MN is associated to additional nerve enlargement at the carpal tunnel intel site.

Comparison efficacy of ultrasound-guided needle release plus corticosteroid injection and mini-open surgery in patients with carpal tunnel syndrome

This retrospective study was to compare clinical outcomes of ultrasound-guided needle release with corticosteroid injection vs. mini-open surgery in patients with carpal tunnel syndrome (CTS). From January 2021 to December 2021, 40 patients (40 wrists) with CTS were analyzed in this study. The diagnosis was based on clinical symptoms, electrophysiological imaging, and ultrasound imaging. A total of 20 wrists were treated with ultrasound-guided needle release plus corticosteroid injection (Group A), and the other 20 wrists were treated with mini-open surgery (Group B). We evaluated the Boston carpal tunnel questionnaire, electrophysiological parameters (distal motor latency, sensory conduction velocity, and sensory nerve action potential of the median nerve), and ultrasound parameters (cross-sectional area, flattening ratio, and the thicknesses of transverse carpal ligament) both before and 3 months after treatment. Total treatment cost, duration of treatment, healing time, and complications were also recorded for the two groups. The Boston carpal tunnel questionnaire and electrophysiological and ultrasound outcomes at preoperatively and 3 months postoperatively had a significant difference for each group (each with P &lt; 0.05). There were no complications such as infection, hemorrhage, vascular, nerve, or tendon injuries in both groups. Ultrasound-guided needle release and mini-open surgery are both effective measures in treating CTS patients. Ultrasound-guided needle release plus corticosteroid injection provides smaller incision, less cost, less time of treatment, and faster recovery compared with mini-open surgery. Ultrasound-guided needle release plus corticosteroid injection is better for clinical application.

Longitudinal Median Nerve Ultrasound Changes in Individuals With Spinal Cord Injury and an Age- and Sex-Matched Nondisabled Cohort

Objectives

To assess the natural history for development of carpal tunnel syndrome (CTS) in persons with acute spinal cord injury (SCI) at 1 year postdischarge from initial rehabilitation and to assess baseline median nerve (MN) cross-sectional area (CSA) above/below 10 mm2 correlates with any longitudinal changes in quantitative ultrasound (US) of the MN.

Design

A prospective cohort study of persons with acute SCI evaluated for CTS using quantitative US and compared to a group without SCI (non-SCI).

Setting

Academic medical center.

Participants

N=69 total (N=34 SCI, N=35 non-SCI). The average age in both groups was 28 and the SCI group included 30 males and 2 females and the non-SCI group included 30 males and 3 females.

Interventions

Not applicable.

Main Outcome Measures

The primary outcome was the change in quantitative US parameters of the MN, including CSA and grayscale, from baseline to 1-year follow-up in those with SCI and those without SCI. CTS symptomatology and physical exam sum score and US measures for dominant and nondominant arms were considered secondary outcomes.

Results

The SCI had darker nerves at baseline (P=.036, nondominant), greater CTS symptoms at follow-up (P≤.036, bilateral), and no differences in all change scores (all P≥.056). Individuals with smaller nerves at baseline had larger increases in nerve size (P=.029, nondominant) vs those with larger nerves. Change in CTS symptoms CSA (nondominant) and nerve echogenicity (dominant) were inversely associated with their respective baseline values (all P≤.045).

Conclusions

We observed few differences between the SCI group and the non-SCI control group and between those with smaller vs larger MN. In general, MN pathology changes (CTS symptoms and US variables) over 1 year were more common in the nondominant arm and appear to be a function of MN pathology at enrollment. Individuals with SCI may experience increased CTS symptoms as soon as 1 year after injury.

Ultrasonographical Evaluation of the Median Nerve Mobility in Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis

Diagnostic ultrasound is widely used for evaluating carpal tunnel syndrome (CTS), an entrapment neuropathy of the median nerve (MN). Decreased mobility of the MN inside the carpal tunnel has been reported in CTS, and various methods have been used to evaluate MN mobility; however, there is still no conclusive understanding of its connection with CTS. The purpose of this study is to conduct a systematic review and meta-analysis of the current published literature on ultrasonographic evaluations of transverse and longitudinal MN displacement and to identify the relationship between MN mobility and CTS. This study was conducted in accordance with the 2020 PRISMA statement and the Cochrane Collaboration Handbook. Comparative studies that investigated differences in MN displacement between CTS patients and healthy controls were retrieved by searching the Cochrane Library, Embase and PubMed. A total of 15 case–control studies were included. Nine of 12 studies evaluating transverse MN displacement and 4 of 5 studies evaluating longitudinal MN gliding showed that the MN was less mobile in CTS patients than in healthy subjects. Despite the large heterogeneity among the 15 included studies, this systematic review and meta-analysis provide evidence that the mobility of the MN is significantly reduced in both transverse and longitudinal planes in CTS patients compared to healthy controls. Five of the 15 included studies reported that a decrease in transverse or longitudinal MN displacement in CTS was correlated with clinical symptoms or with severity as measured by a nerve conduction study (NCS).

Tourniquet Does Not Affect Long-term Outcomes in Minor Hand Surgery: A Randomized Controlled Trial

Surgeons often prefer to use a tourniquet during minor procedures, such as carpal tunnel release (CTR) or trigger finger release (TFR). Besides the possible discomfort for the patient, the effect of tourniquet use on long-term results and complications is unknown. Our primary aim was to compare the patient-reported outcomes 1 year after CTR or TFR under local anesthesia with or without tourniquet. Secondary outcomes included satisfaction, sonographically estimated scar tissue thickness after CTR‚ and postoperative complications.

Ultrasonography for carpal tunnel syndrome in pregnancy: a prospective cross-sectional study

Confirmation of carpal tunnel syndrome (CTS) diagnosis with sonographic measurement of the median nerve cross sectional area (MN-CSA) is increasing in popularity. We aimed to analyse the ultrasonography (USG) values of MN-CSA in pregnant women with and without CTS symptoms. MN-CSAs of third trimester pregnant women were measured with USG and they were asked about the presence of CTS symptoms. Symptomatic participants were assigned to the CTS group and remaining participants were assigned to the Control group. The groups were compared according to MN-CSA. Twenty-five participants were grouped in CTS group and the remaining 64 participants were grouped in Control group. The MN-CSA was higher in the CTS group (9.44 ± 2.68) than in the Control group (7.20 ± 1.99), p = .00004. Obstetricians can use USG measurement of MN-CSA to confirm CTS diagnosis and consequently can offer conservative management, which is the widely accepted treatment modality in this cohort.Impact statementWhat is already known on this subject? CTS is the most common mononeuropathy of pregnancy, with up to 62% prevalence rates. The American Association of Neuromuscular & Electrodiagnostic Medicine practice guideline for the diagnosis of CTS recommends sonographic measurement of median nerve swelling at the carpal tunnel inlet as an accurate diagnostic test (Level A).What do the results of this study add? We found that a simple sonographic measurement of median nerve cross sectional area (MN-CSA) at the wrist appears to be a convenient method to confirm clinical CTS diagnosis in pregnant women. This study offers to use USG to confirm clinical CTS diagnosis in third trimester pregnant women before delivery.What are the implications of these findings for clinical practice and/or further research? This study will help to raise awareness of obstetricians about CTS during pregnancy. USG can be an effective first-line confirmatory test for CTS diagnosis in the pregnant population, but further research is necessary to determine a clear cut-off value for MN-CSA. We advise obstetricians to use sonographic measurement of MN-CSA in pregnant women with typical CTS symptoms, which will increase uniformity for consensus development. Obstetricians can offer advice for conservative management of CTS during pregnancy, which is the widely accepted treatment in this cohort.

Difference and ratio of the cross-sectional area of median nerve at the carpal tunnel and the pronator quadratus muscle in diagnosing carpal tunnel syndrome: a cross-sectional study

Background

At present, the most commonly used diagnostic method of carpal tunnel syndrome (CTS) is based on clinical manifestations and electrophysiology, but the electrophysiology is not cheap, invasive, and lacks the presentation of peripheral nerve conditions, which is exactly the advantage of ultrasound (US). The purpose of this study was to evaluate the accuracy and effectiveness of US in the diagnosis of CTS by calculating the cross-sectional area (CSA) at the carpal tunnel and proximally at the level of the pronator quadratus muscle., and to find an appropriate index that can be used to achieve the diagnosis in a more cost-effective manner.

Methods

Forty-three wrists from 35 symptomatic CTS patients and 23 wrists from 18 asymptomatic volunteers were evaluated. Diagnosis in the CTS group was based on the American Academy of Neurology clinical diagnostic criteria. The ultrasonic probe was placed at the carpal tunnel and the distal 1/3 of the pronator muscle respectively, and the carpal tunnel cross-sectional area (CSAC) and the proximal cross-sectional area (CSAP) was calculated, with a further calculation of their difference (ΔCSA) and ratio (R-CSA).

Results

There was a significant difference between the 2 groups regarding mean ± standard deviation (SD) of CSAC, CSAP, ΔCSA, and R-CSA (P<0.01). The cutoff value of 12.14 mm² for CSAC had a sensitivity and specificity of 90.7% and 100%, respectively; the cutoff value of 1.235 mm² for R-CSA had a sensitivity and specificity of 97.67% and 95.65%, respectively; and the cutoff value of 2.035 mm² for ΔCSA had a sensitivity and specificity of 100% and 100%, respectively. Therefore, US was found to be an effective method for the diagnosis of CTS. Receiver operating characteristic curve (ROC) analysis of all patients showed area under the curve (AUC) was 0.9778 for CSAC, 0.9949 for R-CSA and 1.000 for ΔCSA.

Conclusions

US can provide reference values for the diagnosis of CTS. CSAC, ΔCSA, and R-CSA can be used for CTS diagnosis and evaluation. The ROC curve analysis showed that among the 3 values, ΔCSA was the most useful in the diagnosis of patients with CTS. ΔCSA is considered a valid diagnostic value for CTS, as its threshold of 2.04 mm² showed the highest sensitivity and specificity.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies

The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice.

A Review of Upper Extremity Peripheral Nerve Injuries in Throwing Athletes

Peripheral nerve injuries in the upper extremities may be common in throwing athletes as the throwing motion places extreme stress on the dominant arm. The combination of extreme stress along with repetitive microtrauma from throwing uniquely places the throwing athlete at elevated risk of upper extremity peripheral nerve injury. However, because symptoms can be non-specific and frequent co-exist with pathology in the upper extremity, the diagnosis of peripheral nerve injury is often delayed. Diagnosis of peripheral nerve injuries may require a combination of history and physical exam, diagnostic imaging, electrodiagnostic testing, and diagnostic ultrasound guided injections. The primary management should include physical therapy focusing on throwing mechanics and kinetic chain evaluation. However, some athletes require surgical intervention if symptoms do not improve with conservative management. The purpose of this focused narrative review is to highlight upper extremity peripheral neuropathies reported in throwing athletes and to provide an overview of the appropriate clinical diagnosis and management of the throwing athlete with a peripheral nerve injury. This article is protected by copyright. All rights reserved.

Diagnostic modalities and physical therapy in patients with Carpal tunnel syndrome

Carpal tunnel syndrome (CTS) represents one of the most common compressive peripheral neuropathies on the upper extremities, and is characterized by compression of the medial nerve on its way through the carpal tunnel area. The first changes experienced by patients with CTS are sensory and occur mainly at night, and if they are not recognized and treated in time, they progress and become continuously present. Prolonged compression of the medial nerve in the region of the carpal tunnel can lead to permanent damage to this nerve, which can result in the patient losing the ability to distinguish between hot and cold, as well as atrophy of the thenar muscles and difficulty in palmar abduction of the thumb. The diagnosis of CTS is generally made based on the patient's symptoms, clinical history and anamnesis, as well as electrodiagnostic tests. In addition to these methods, provocative tests, nuclear magnetic resonance (NMR) and ultrasound examinations are used in the evaluation of CTS. In patients with CTS, a large number of treatment methods, both surgical and non-surgical, are used in clinical practice. Myofascial massage, ultrasound, interference currents, continuous short-wave diathermy, extracorporeal shock wave therapy (ESWT) have been shown to be beneficial in reducing pain and symptoms or improving function in patients with CTS in the short and medium term. It was also pointed out that there are no firm conclusions about optimal doses and therapeutic parameters. A better understanding of the etiology and pathophysiological mechanisms of CTS, as well as the effects of certain therapeutic modalities in the treatment of this condition, will contribute to further understanding of the origin and progression of CTS, as well as the possibilities of prevention and treatment of these patients in order to improve the quality of their life and the functionality of the affected limb.

Diagnosis of carpal tunnel syndrome in non-diabetic patients with hemodialysis using ultrasound: Is it a useful adjunctive tool?

OBJECTIVE

(1) To examine the ultrasound (US) characteristics in patients with hemodialysis-related carpal tunnel syndrome (H-CTS) and (2) to evaluate the accuracy of a proposed US parameter-dynamic ratio of median nerve-to-hamate hook distance (RMHD) in diagnosis of H-CTS.

DESIGN

A case-control study.

SETTING

In a tertiary medical center and a secondary hospital from Nov. 2017 to Mar. 2021.

PARTICIPANTS

Consecutive non-diabetes patients under hemodialysis were recruited and divided into a hemodialysis without CTS (H-Control) group and an H-CTS group. Age-matched volunteers without diabetes or upper extremity disorders were enrolled as the Control group.

INTERVENTION

Ultrasound examinations by two operators blinded to the patient's clinical information.

MAIN OUTCOME MEASURES

US parameters including cross-sectional area of the median nerve at the carpal tunnel inlet (CSA-I) and outlet (CSA-O), the flattening ratio of the median nerve at the inlet (FR-I) and outlet (FR-O), and RMHD.

RESULTS

Handedness and arteriovenous fistula showed no associations with CSA-I/O and FR-I/O. Compared with Control group (n=69), the CSA-I was significantly larger in the H-Control group (n=63) and H-CTS group (n=76) (p<0.05). There were no significant differences in the FR-I/-O among the three groups. For the second aim, in the H-CTS group(n=38), there was a significantly lower RMHD compared with both the Control (n=20) and H-Control groups (n=30) (0.1%±2.2% versus 3.5±2.3% and 3.8±1.7%, p<0.05). An RMHD cutoff value of <2.7% yielded a specificity of 80.0%, a sensitivity of 94.7%, and an overall accuracy of 88.2% in the diagnosis of H-CTS.

CONCLUSIONS

Neither CSA-I/-O or FR-I/-O have a role in the diagnosis of H-CTS. RMHD might be a useful US parameter in the diagnosis of CTS in non-diabetic patients undergoing hemodialysis.

Diagnostic value of median nerve shear wave ultrasound elastography in diagnosis and differentiation of carpal tunnel syndrome severity

Background

Carpal tunnel syndrome (CTS) is the commonest type of peripheral nerve entrapment syndromes. The study aimed at evaluation of diagnostic value of median nerve stiffness measured by shear wave ultrasound elastography for diagnosis and differentiation of CTS severity, correlated to electrophysiological studies. This case–control study involved 40 patients (56 wrists) with CTS of different severity and 40 controls (40 wrists). All participants underwent electrophysiological study to assess the CTS severity, high-resolution conventional B-mode ultrasound to assess cross-sectional area “CSA” of median nerve at carpal tunnel, ratio of median nerve CSA at carpal tunnel and forearm, and shear wave ultrasound elastography with measurement of median nerve mean stiffness and correlation to electrophysiological results as the reference standard.

Results

Mean median nerve stiffness by shear wave US elastography was increased in patients with CTS compared to controls and across the different CTS severity groups (P value < 0.001 & 0.001, respectively). The cutoff value by ROC curve analysis for median nerve stiffness to differentiate between patients with CTS and control group was 65.4 kPa (P value < 0.001, 94.6% sensitivity, 97.3% specificity). Higher diagnostic accuracy was noted with the combination of shear wave elastography and conventional B-mode US with improved AUC (B-mode + shear wave; 0.962, P value < 0.001).

Conclusions

Shear wave ultrasound elastography of median nerve was able to discriminate different severity subgroups of CTS with high sensitivity, while conventional US couldn’t. The diagnostic accuracy of CTS was improved when combined high-resolution conventional B-mode US and complementary shear wave ultrasound elastography.

Influence of temperature on sonographic images of the median nerve for the diagnosis of carpal tunnel syndrome: a case control study

Background

In addition to nerve conduction studies (NCSs), ultrasonography has been widely used as an alternative tool for diagnosing carpal tunnel syndrome (CTS). Although the results of NCSs are influenced by local skin temperature, few studies have explored the effects of skin temperature on ultrasonography of the median nerve. Since swelling and intraneural blood flow of the median nerve might be influenced by local temperature changes, the aim of this study was to evaluate the cross-sectional area (CSA) and intraneural blood flow of the median nerve under three skin temperatures (30 °C, 32 °C, 34 °C).

Methods

Fifty patients with CTS and 50 healthy volunteers were consecutively recruited from a community hospital. Each participant received physical examinations and NCSs and underwent ultrasonography, including power Doppler, to evaluate intraneural vascularity.

Results

The CSA of the median nerve in the CTS patients was significantly larger than that in the healthy controls at all three temperatures. However, significant differences in the power Doppler signals of the median nerve between the two studied groups were observed only at 30 and 32 °C, not at 34 °C.

Conclusion

The significant difference in the intraneural vascularity of the median nerve between the patients with CTS and the healthy subjects was lost at higher temperatures (34 °C). Therefore, the results of power Doppler ultrasonography in diagnosing CTS should be cautiously interpreted in patients with a high skin temperature or those who reside in warm environments.

Automated Segmentation of Median Nerve in Dynamic Sonography Using Deep Learning: Evaluation of Model Performance

There is an emerging trend to employ dynamic sonography in the diagnosis of entrapment neuropathy, which exhibits aberrant spatiotemporal characteristics of the entrapped nerve when adjacent tissues move. However, the manual tracking of the entrapped nerve in consecutive images demands tons of human labors and impedes its popularity clinically. Here we evaluated the performance of automated median nerve segmentation in dynamic sonography using a variety of deep learning models pretrained with ImageNet, including DeepLabV3+, U-Net, FPN, and Mask-R-CNN. Dynamic ultrasound images of the median nerve at across wrist level were acquired from 52 subjects diagnosed as carpal tunnel syndrome when they moved their fingers. The videos of 16 subjects exhibiting diverse appearance and that of the remaining 36 subjects were used for model test and training, respectively. The centroid, circularity, perimeter, and cross section area of the median nerve in individual frame were automatically determined from the inferred nerve. The model performance was evaluated by the score of intersection over union (IoU) between the annotated and model-predicted data. We found that both DeepLabV3+ and Mask R-CNN predicted median nerve the best with averaged IOU scores close to 0.83, which indicates the feasibility of automated median nerve segmentation in dynamic sonography using deep learning.

"Physiological localization by sensory and motor inching studies and structural abnormalities detected by ultrasonographic changes in carpal tunnel syndrome"

OBJECTIVE

To study mild to moderate carpal tunnel syndrome (CTS), compare median nerve entrapment sites detected by electrophysiologic inching studies with ultrasonographic abnormalities of cross-sectional area (CSA), and correlate focal points of conduction delays detected by sensory and motor inching recorded from the third digit and second lumbrical muscle DESIGN: Analytic cross-sectional study SETTING: Department of Rehabilitation Medicine, King Chulalongkorn Memorial Hospital.

PARTICIPANTS

A total of 15 normal hands from 10 healthy participants and 40 hands with mild to moderate CTS from 29 participants were selected by convenience sampling.

INTERVENTIONS

Not applicable MAIN OUTCOME MEASURE: Correlation of electrophysiologic entrapment site localization by inching study with anatomical entrapment site detected by ultrasound (US).

RESULTS

In all 40 hands tested, a sharply localized latency was found to increase across a 1 cm segment, most commonly 2-3 cm distal to the distal wrist crease for both sensory and motor studies, showing a good match between the two with Pearson correlation coefficient value, r = 0.72. The US revealed a narrowing CSA of the median nerve at 1-2 cm distal to the distal wrist crease.

CONCLUSIONS

This study showed a high correlation for focal point conduction delay detected by sensory and motor nerve conduction study. Recording from the second lumbricalis facilitated motor inching along the straight course of the nerve instead of the arcuate recurrent branch innervating the abductor pollicis brevis, the muscle traditionally used. US examination also revealed a localized narrowing of the median nerve CSA at 1-2 cm distal to the distal wrist crease, a possible site for anatomical entrapment. The most enlarged CSA was seen at the distal wrist crease, a level corresponding to the inlet of the carpal tunnel.

THAI CLINICAL TRIALS REGISTRY NUMBER

TCTR20190605001.

The Neurophysiological Severity of Carpal Tunnel Syndrome Cannot Be Predicted by Median Nerve Cross-Sectional Area and Wrist-to-Forearm Ratio

PURPOSE

The median nerve cross-sectional area at the wrist (CSA) and the wrist-to-forearm ratio of the cross-sectional areas (WFR) are ultrasound parameters used in the diagnosis and grading of carpal tunnel syndrome. This study aimed to determine the diagnostic accuracy of the CSA and WFR as well as to compare their diagnostic value.

METHODS

A retrospective evaluation was conducted of a cohort of 218 patients who had undergone nerve conduction studies (NCSs) and an ultrasound of the median nerve. The examined wrists were classified into an NCS negative and three NCS positive (mild, moderate, and severe) categories. The CSA and WFR were compared across the categories.

RESULTS

The CSA and WFR were significantly smaller in the NCS negative category than in the NCS positive categories. The WFR was significantly smaller in the mild category than in the moderate category. The CSA could not be used to differentiate across the NCS positive categories.

CONCLUSIONS

The CSA and WFR are satisfactorily reliable in detecting carpal tunnel syndrome, but they cannot be considered as surrogate indicators of electrophysiological severity.

Variant Median Nerve Anatomy: Ultrasound Evidence of a Pseudoconduction Block

INTRODUCTION

A conduction block at a noncompressible site warrants further investigation.

METHODS AND MATERIALS

A 36-year-old woman with a history of Hodgkin lymphoma and chemotherapy-induced polyneuropathy developed bilateral hand numbness and paresthesias. Workup revealed bilateral carpal tunnel syndrome and an apparent superimposed conduction block of the median nerve in the forearm. Given the history of cancer, there was concern for an infiltrative or an immune-mediated process.

RESULTS

Neuromuscular ultrasound demonstrated that the median nerve descended the upper extremity along an atypical path, deep along the posteromedial aspect of the upper arm, and relatively medially in the forearm. Ultrasound-directed nerve stimulation revealed there was no conduction block. This anatomical variant has been rarely described and has not been reported previously to mimic conduction block or been documented via ultrasound.

CONCLUSIONS

This case demonstrates that neuromuscular ultrasound may supplement the electrodiagnostic study and limit confounding technical factors because of rare anatomic variation.

Comparison of the Diagnostic Performance of Strain Elastography and Shear Wave Elastography for the Diagnosis of Carpal Tunnel Syndrome

OBJECTIVES

To compare the diagnostic performance between strain elastography and shear wave elastography (SWE) for the diagnosis of carpal tunnel syndrome (CTS).

METHODS

Between July 2018 and June 2019, 66 consecutive patients with 95 imaged wrists underwent wrist ultrasound, including grayscale ultrasound, strain elastography, and SWE, because of the suspicion of CTS. During wrist ultrasound, the cross-sectional area (CSA), strain ratio, elasticity, and shear wave velocity of each median nerve were measured at the proximal carpal bone level (scaphoid to pisiform). The variables were compared between the normal and CTS groups by using the independent t test, and subgroup analyses were performed using one-way analysis of variance. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of each variable.

RESULTS

CSA, elasticity, and shear wave velocity showed significant intergroup differences (P < 0.001, P < 0.001, and P = 0.002, respectively). However, the strain ratio showed no statistically significant intergroup difference (P = 0.639). In the subgroup analyses, elasticity showed significantly higher values in the severe group than in the mild and moderate groups (P < 0.001 and P = 0.001, respectively). Other parameters showed no significant differences among the different subgroups. The areas under the ROC curve were 0.823 for CSA, 0.772 for elasticity, and 0.779 for shear wave velocity. The differences in the areas under the ROC curve among CSA, elasticity, and shear wave velocity were not statistically significant (all P > 0.05).

CONCLUSIONS

SWE has a good diagnostic value in CTS. In particular, elasticity can discriminate the severe group from the other groups.

Accurate automated diagnosis of carpal tunnel syndrome using radiomics features with ultrasound images: A comparison with radiologists' assessment

PURPOSE

Ultrasonography is the most common imaging modality used to diagnose carpal tunnel syndrome (CTS). Recently artificial intelligence algorithms have been used to diagnose musculoskeletal diseases accurately without human errors using medical images. In this work, a computer-aided diagnosis (CAD) system is developed using radiomics features extracted from median nerves (MN) to diagnose CTS accurately.

METHOD

This study is performed on 228 wrists from 65 patients and 57 controls, with an equal number of control and CTS wrists. Nerve conduction study (NCS) is considered as the gold standard in this study. Two radiologists used two guides to evaluate and categorize the pattern and echogenicity of MNs. Radiomics features are extracted from B-mode ultrasound images (Ultrasomics), and the robust features are fed into support vector machine classifier for automated classification. The diagnostic performances of two radiologists and the CAD system are evaluated using ROC analysis.

RESULTS

The agreement of two radiologists was excellent for both guide 1 and 2. The honey-comb pattern clearly appeared in control wrists (based on guide 1). In addition, CTS wrists indicated significantly lower number of fascicles in MNs (based on guide 2). The area under ROC curve (AUC) of the radiologist 1 and 2 are 0.658 and 0.667 based on guide 1 and 0.736 and 0.721 based on guide 2, respectively. The CAD system indicated higher performance than two radiologists with AUC of 0.926.

CONCLUSION

The proposed CAD system shows the benefit of using ultrasomics features and can assist radiologists to diagnose CTS accurately.

Assessing Diagnostic and Severity Grading Accuracy of Ultrasound Measurements for Carpal Tunnel Syndrome Compared to Electrodiagnostics

BACKGROUND

The combined sensory index (CSI) is the most sensitive electrodiagnostic criteria for carpal tunnel syndrome (CTS), and the CSI and Bland criteria have been shown to predict surgical treatment outcomes. The proposed ultrasound measurements have not been assessed against the CSI for diagnostic accuracy and grading of CTS severity.

OBJECTIVE

To investigate the use of ultrasound evaluations for both diagnosis and assessment of severity grading of CTS in comparison to electrodiagnostic assessment.

DESIGN

All patients underwent an electrodiagnostic evaluation using the CSI and Bland severity grading. Each patient underwent an ultrasound evaluation including cross-sectional area (CSA), the change in CSA from the forearm to the tunnel (∆CSA), and the wrist-forearm ratio (WFR). These measurements were assessed for diagnostic and severity grading accuracy using the CSI as the gold standard.

SETTING

Tertiary academic center.

PARTICIPANTS

All patients referred for electrodiagnostic evaluation for CTS were eligible for the study. Only those with idiopathic CTS were included and those with prior CTS treatment were also excluded. Ninety-five patients were included in the study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The primary study outcome measure was concordance between CSI diagnosis and severity categories and the ultrasound measurements. Both outcomes were also assessed using Bland criteria.

RESULTS

Optimal cut-points for diagnosis of CTS were found to be CSA ≥12 mm² , ∆CSA ≥4 mm² , WFR ≥1.4. Using these cut-points, C-statistics comparing diagnosis of CTS using ultrasound measurements versus using the CSI ranged from 0.893-0.966. When looking at CSI severity grading compared to ∆CSA, however, the C-statistics were 0.640-0.661 with substantial overlap between severity groups.

CONCLUSIONS

Although ultrasound measurements had high diagnostic accuracy for CTS based on the CSI criteria, ultrasound measurements were unable to adequately distinguish between CSI severity groups among patients with CTS.

Tingling hand: magnetic resonance imaging of median nerve pathologies within the carpal tunnel

Compressive neuropathy of the median nerve at the level of the carpal tunnel, known as carpal tunnel syndrome, is the most common entrapment neuropathy, affecting about 0.1-1% of the general population. Magnetic resonance reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. Magnetic resonance imaging (MRI) serves as an extremely useful tool for evaluation of primary nerve pathologies and for the assessment of space-occupying lesions leading to its compression. We present a pictorial review of the MRI findings in the multitude of pathologies implicated in the causation of carpal tunnel syndrome. All the images were obtained from the Department of Radiodiagnosis in our own institution.

Shearwave Elastography in the Differentiation of Carpal Tunnel Syndrome Severity

BACKGROUND

There is emerging evidence that ultrasound elastography may provide additional diagnostic information in peripheral neuropathies.

OBJECTIVE

To investigate the use of ultrasound elastography to evaluate median nerve stiffness in patients with carpal tunnel syndrome (CTS), as well as the relationship between the elastographic stiffness and electrophysiological severity.

DESIGN

Case control study.

SETTING

Tertiary hospital outpatient neurophysiology clinic.

PARTICIPANTS

Twenty eight patients (47 wrists) with CTS and 25 control patients (25 wrists).

INTERVENTIONS

None.

MAIN OUTCOME MEAURES

Ultrasound parameters (median nerve cross-sectional area [CSA] at carpal tunnel, ratio of median nerve CSA at carpal tunnel and forearm), shearwave elastography parameter (median nerve stiffness), and electrophysiological severity of carpal tunnel syndrome.

RESULTS

In patients with CTS, median nerve stiffness by ultrasound elastography was increased between the different severity groups (control 83.5 ± 24.8, EDx negative CTS 84.2 ± 46.4, mild 117.7 ± 79.3, moderate 144.0 ± 71.1, severe 196.6 ± 48.4). The control versus moderate and severe subgroup was statistically significant.

CONCLUSIONS

In total, this study has demonstrated that ultrasound elastography was able to discriminate the severity of CTS whereas conventional ultrasound parameters did not.

Minimally Invasive Carpal Tunnel Release (CTR) Using the Wongsiri Technique with MiniSURE

INTRODUCTION

The standard open technique for carpal tunnel surgery has wound problems and complications significantly more than minimally invasive surgery using the Wongsiri technique with MiniSURE Kit® (Surgical Innovation Healthcare Co., Ltd, Bangkok, Thailand) and in particular, the open technique surgery requires a longer time for return to work. CTR surgery with endoscopic devices improves the results with fewer wound problems when compared with the commonly used open technique; however, nerve complications and injury are more prevalent with endoscopic surgery than with the open technique. The Wongsiri technique produces good results with new medical devices such as the MiniSURE View, for improved vision and line-of-sight, and the MiniSURE Cut for improved and complete cutting via the supraretinacular technique that may reduce the nerve problems associated with endoscopic tooling in the carpal tunnel.

PURPOSE

To evaluate the results of the operation and postoperative outcomes of the Wongsiri technique with a MiniSURE Kit®.

METHODS

20 patients underwent carpal tunnel release using the Wongsiri technique and a MiniSURE Kit® with a five-step surgery: MIS starts when the surgeon makes a 1.5-1.8 cm incision, creates a working space, inserts the visual tube of MiniSURE View, inserts the freer, and then cuts the transverse carpal ligament by using the MiniSURE Cut.

RESULTS

All 20 successes of the Wongsiri technique and MiniSURE Kit® surgery occurred within 6.8 minutes operative time and a 12 mm wound size. A single outlier, in one case (6.7%), the patient experienced pillar pain which abated within one month. Patients can return to work in 7.3 days.

CONCLUSIONS

The Wongsiri technique with the MiniSURE Kit® demonstrated good outcomes similar to the endoscope. By contrast with the endoscopic surgery, the Wongsiri technique with the MiniSURE Kit® reduced preop, operating, and postop time, many resources, and significant costs and resulted in no nerve problems or complications.

Ultrasonography Findings in Severe Carpal Tunnel Syndrome

Background: Increasing severity of carpal tunnel syndrome (CTS), as graded by nerve conduction studies (NCS), has been demonstrated to predict the speed and completeness of recovery after carpal tunnel release (CTR). The purpose of this study is to compare the cross-sectional area (CSA) of the median nerve in patients with severe and nonsevere CTS as defined by NCS. Methods: Ultrasound CSA measurements were taken at the carpal tunnel inlet at the level of the pisiform bone by a hand fellowship-trained orthopedic surgeon. Severe CTS on NCS was defined as no response for the distal motor latency (DML) and/or distal sensory latency (DSL). Results: A total of 274 wrists were enrolled in the study. The median age was 51 years (range: 18-90 years), and 72.6% of wrists were from female patients. CSA of median nerve and age were comparatively the best predictors of severity using a linear regression model and receiver operator curves. Using cutoff of 12 mm² for severe CTS, the sensitivity and specificity are 37.5% and 81.9%, respectively. Conclusions: Ultrasound can be used to grade severity in younger patients (<65 years) with a CTS-6 score of >12.

Imaging of the Peripheral Nerve: Concepts and Future Direction of Magnetic Resonance Neurography and Ultrasound

Advanced imaging is increasingly used by upper extremity surgeons in the diagnosis and evaluation of peripheral nerve pathology. Ultrasound and magnetic resonance neurography (MRN) have emerged as the most far-reaching modalities for peripheral nerve imaging and often provide complimentary information. Technology improvements allow better depiction of the peripheral nervous system, allowing for more accurate diagnoses and preoperative planning. The purpose of this review is to provide an overview of current modalities and expected advances in peripheral nerve imaging with a focus on practical applications in the clinical setting. Ultrasound is safe, inexpensive, and readily available, and allows dynamic imaging with high spatial resolution as well as immediate evaluation of the contralateral nerve for comparison. It is primarily limited by its dependency on skilled operators and soft tissue contrast. The spatial evaluation of the perineural environment, fascicular echostructure, and nerve diameter are features of particular use in the diagnosis and treatment of nerve tumors, compressive lesions, and nerve trauma. Sonoelastrography has shown promise as a useful adjunct to standard sonographic imaging. MRN refers to the optimization of magnetic resonance image sequences and technology for visualization and contrasting nerves from surrounding structures. MRN provides excellent soft tissue contrast, depicts the entire nerve in 3 dimensions, allows for early evaluation of downstream muscle injury, and functions without operator dependency limits. Images provide details of nerve anatomic relationships, congruency, size, fascicular pattern, local and intrinsic fluid status, and contrast enhancement patterns, making MRN particularly useful in the setting of trauma, tumor, compressive lesions, and evaluation of brachial plexus injuries. Advances in MR volume and cinematic rendering software, magnet and coil technology, nerve-specific contrast media, and diffusion-weighted and tensor imaging will likely continue to expand the clinical application and indications for MRN.

Ratio and difference of the cross-sectional area of median nerve to ulnar nerve in diagnosing carpal tunnel syndrome: a case control study

BACKGROUND

To evaluate the diagnostic accuracy of the median-to-ulnar nerve ratio (MUR) and the median-to-ulnar nerve difference (MUD) in patients with carpal tunnel syndrome (CTS).

METHODS

In this study, 32 patients with CTS and 32 healthy volunteers were evaluated. All participants received a series of tests and ultrasound examination for the evaluation of the following criteria: cross-sectional area of the median nerve at the pisiform level (CSA-P), swelling ratio (SR), MUR, MUD, and flattening ratio (FR).

RESULTS

CSA-P, SR, MUR, and MUD were all significantly larger in the patients with CTS than in the healthy volunteers. The areas under the receiver operator characteristic curves of MUD, MUR, CSA-P, and SR were 0.78, 0.75, 0.70, and 0.61 respectively. MUD had higher sensitivity (84%) than MUR, CSA-P, and SR (sensitivity: 63, 63, and 53%, respectively).

CONCLUSIONS

By using the ulnar nerve area at the pisiform level as an internal control parameter, the MUD and MUR methods showed higher diagnostic accuracy than SR in patients with CTS. Further application of these methods in research and clinical settings is recommended.

TRIAL REGISTRATION

Clinicaltrial.gov NCT03033173. Registered 18 January 2017. Retrospectively registered.

Ultrasound-guided insulin injection for carpal tunnel syndrome in type 2 diabetes mellitus patients

OBJECTIVE

To compare effectiveness of ultrasound-guided local insulin injection, local steroid injection, and local steroid followed by insulin injections in treating mild to moderate carpal tunnel syndrome (CTS) in type 2 diabetes mellitus (DM).

METHOD

Study included 60 patients with electrophysiologic evidence of mild to moderate CTS. They were randomly divided into three groups: group I received insulin injection locally into the affected carpal tunnel at first visit and a similar dose after 2 weeks; group II received single injection of 40 mg methylprednisolone acetate injection; and group III received steroid injection then followed by insulin injection twice after 2 and 4 weeks. All injections were performed with ultrasonographic guidance. All patients were assessed by modified Boston Carpal Tunnel Questionnaire (FD score), CTS severity score (SS score), and neurophysiological and ultrasonographic assessments at baseline and 10 weeks after treatment.

RESULTS

A significant improvement in mean FD score, SS score, DML (distal motor latency), SNCV (sensory nerve conduction velocity), PSL (peak sensory latency), Samp (sensory amplitude), and CSA (cross-sectional area of median nerve) observed in all groups (with exception of mean DML and Samp in the second group and mean Samp in the third group). Group III showed significant improvement in CSA especially when compared to group II by post hoc analysis (P = 0.005).

CONCLUSIONS

Local insulin injection is as effective as steroid in treating mild to moderate CTS in type 2 DM and is a safer alternative. Adding insulin injections after steroid shows more sonographic improvement than steroid alone. Key Points • Local insulin injection is as effective as steroid in treating mild to moderate CTS in type 2 diabetic patients. • Measuring CSA of median nerve at CT inlet by US is a better tool for monitoring median nerve changes after treatment. • Adding insulin injections after steroid has more sonographic improvement than steroid alone.

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.

Ultrasonographic reference values for the median nerve at the level of pronator teres muscle

PURPOSE

The purpose of this study was to investigate the ultrasonographic reference values for diameters and cross-sectional area (CSA) of the median nerve between the two heads of the pronator teres muscle in healthy population as well as to correlate the findings with height, weight, sex and age.

METHODS

Fifty-five healthy Caucasian volunteers (110 median nerves) were included in this study. The reference range (mean ± 2 standard deviations; 2.5th-97.5th quintiles) and the upper limit of side-to-side difference of the median nerve between the two heads of the pronator teres muscle were investigated using high-frequency ultrasound. The effects of age, sex, height, handedness, and body mass index (BMI) were examined.

RESULTS

The mean age was 39.4 ± 10.6 years (range 18-75 years). The mean ± 2SD of the median CSA was 4.9-12.9 mm². The upper limit of normal side-to-side difference was 3.0 mm². The differences between genders and between the dominant and non-dominant hands were not significant. The mean antero-posterior and transverse diameters were 7.2 ± 1.5 and 10.7 ± 2.4 mm, respectively. Significant correlations were observed between the dominant-side CSA and BMI (r = 0.33; p = 0.01) and age (r = 0.31; p = 0.02). The correlation between the CSA and height (r = 0.19; p = 0.16) was not significant.

CONCLUSIONS

The measurements obtained in this study are of importance for examining median nerve entrapments in the forearm using high-frequency ultrasound. Age and BMI showed to be correlated with median nerve CSA; while gender and height were not.

Ultrasound-guided needle release of the transverse carpal ligament with and without corticosteroid injection for the treatment of carpal tunnel syndrome

BACKGROUND

To compare the clinical effectiveness of ultrasound-guided needle release of the transverse carpal ligament (TCL) with and without corticosteroid injection in carpal tunnel syndrome (CTS).

METHODS

From June 2016 to June 2017, 49 CTS patients (50 wrists) were included in this study. Twenty-five wrists were treated with ultrasound-guided needle release of the TCL plus corticosteroid injection (group A), and 25 wrists were treated with single ultrasound-guided needle release of the TCL (group B). The following parameters were assessed and compared including postprocedure results according to relief of symptoms, ultrasound parameters (cross-sectional area of the median nerve at the levels of pisiform, flattening ratio of median nerve at the levels of the hamate bone, and the thicknesses of TCL on the cross-section at the level of the hamate bone), and electrophysiological parameters (distal motor latency and sensory conduction velocity).

RESULTS

Group A had higher overall excellent and good rate 3 months after the procedure than group B (84 vs 52%, P < 0.05). There were significant differences regarding the above ultrasonic and electrophysiological parameters between the baseline and postprocedure values in both groups (all P < 0.05). There were significant differences regarding the postprocedure values of above ultrasonic and electrophysiological parameters between the two groups (all P < 0.05). No complications such as infection or tendon rupture were noted. No procedures were converted to the open release.

CONCLUSIONS

Both techniques are effective in treating CTS. Ultrasound-guided needle release of the TCL with corticosteroid injection had better treatment benefits than single ultrasound-guided needle release of the TCL in treating CTS.