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Neurology India 2021
Topics: Hamartoma; Humans; Lipoma; Median Nerve; Ulnar Nerve
PubMed: 33642316
DOI: 10.4103/0028-3886.310107 -
Arthritis Research & Therapy Feb 2022Deep learning applied to ultrasound (US) can provide a feedback to the sonographer about the correct identification of scanned tissues and allows for faster and...
BACKGROUND
Deep learning applied to ultrasound (US) can provide a feedback to the sonographer about the correct identification of scanned tissues and allows for faster and standardized measurements. The most frequently adopted parameter for US diagnosis of carpal tunnel syndrome is the increasing of the cross-sectional area (CSA) of the median nerve. Our aim was to develop a deep learning algorithm, relying on convolutional neural networks (CNNs), for the localization and segmentation of the median nerve and the automatic measurement of its CSA on US images acquired at the proximal inlet of the carpal tunnel.
METHODS
Consecutive patients with rheumatic and musculoskeletal disorders were recruited. Transverse US images were acquired at the carpal tunnel inlet, and the CSA was manually measured. Anatomical variants were registered. The dataset consisted of 246 images (157 for training, 40 for validation, and 49 for testing) from 103 patients each associated with manual annotations of the nerve boundary. A Mask R-CNN, state-of-the-art CNN for image semantic segmentation, was trained on this dataset to accurately localize and segment the median nerve section. To evaluate the performances on the testing set, precision (Prec), recall (Rec), mean average precision (mAP), and Dice similarity coefficient (DSC) were computed. A sub-analysis excluding anatomical variants was performed. The CSA was automatically measured by the algorithm.
RESULTS
The algorithm correctly identified the median nerve in 41/49 images (83.7%) and in 41/43 images (95.3%) excluding anatomical variants. The following metrics were obtained (with and without anatomical variants, respectively): Prec 0.86 ± 0.33 and 0.96 ± 0.18, Rec 0.88 ± 0.33 and 0.98 ± 0.15, mAP 0.88 ± 0.33 and 0.98 ± 0.15, and DSC 0.86 ± 0.19 and 0.88 ± 0.19. The agreement between the algorithm and the sonographer CSA measurements was excellent [ICC 0.97 (0.94-0.98)].
CONCLUSIONS
The developed algorithm has shown excellent performances, especially if excluding anatomical variants. Future research should aim at expanding the US image dataset including a wider spectrum of normal anatomy and pathology. This deep learning approach has shown very high potentiality for a fully automatic support for US assessment of carpal tunnel syndrome.
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Neural Networks, Computer; Ultrasonography; Wrist
PubMed: 35135598
DOI: 10.1186/s13075-022-02729-6 -
Rheumatology (Oxford, England) Jan 2015Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy, affecting 9% of women, and it is responsible for significant morbidity and occupational absence.... (Review)
Review
Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy, affecting 9% of women, and it is responsible for significant morbidity and occupational absence. Clinical assessment is used for initial diagnosis and nerve conduction (NC) studies are currently the principal test used to confirm the diagnosis. Sensitivity of NC studies is >85% and specificity is >95%. There is now good evidence that US can be used as an alternative to NC studies to diagnose CTS. US can assess the anatomy of the median nerve and also identify pathology of the surrounding structures that may compress the nerve. Median nerve enlargement (cross-sectional area ≥10 mm(2) at the level of the pisiform bone or tunnel inlet) is the most commonly used parameter to diagnose CTS on US, and sensitivity has been reported to be as high as 97.9% using this parameter. US may also be used to guide therapeutic corticosteroid injection into the carpal tunnel--thus avoiding median nerve injury--and to objectively monitor the response to treatment. There is now sufficient evidence to propose a new paradigm for the diagnosis of CTS that incorporates US. US is proposed as the initial diagnostic test in CTS based on similar sensitivity and specificity to NC studies but higher patient acceptability, lower cost and additional capability to assess carpal tunnel anatomy and guide injection.
Topics: Adrenal Cortex Hormones; Carpal Tunnel Syndrome; Disease Management; Humans; Injections; Mass Screening; Median Nerve; Neural Conduction; Sensitivity and Specificity; Ultrasonography
PubMed: 25118315
DOI: 10.1093/rheumatology/keu275 -
Hand (New York, N.Y.) Nov 2022High-resolution ultrasound (HRU) has demonstrated utility in the diagnosis and treatment of carpal tunnel syndrome (CTS) by measuring the cross-sectional area (CSA) of...
BACKGROUND
High-resolution ultrasound (HRU) has demonstrated utility in the diagnosis and treatment of carpal tunnel syndrome (CTS) by measuring the cross-sectional area (CSA) of the median nerve. We investigated whether HRU could be helpful in evaluating outcomes of carpal tunnel release in patients with severe CTS.
METHODS
Patients greater than 18 years of age with severe CTS on electrodiagnostic (EDX) studies and scheduled to have carpal tunnel release were enrolled. At baseline visit within 6 weeks preoperatively, HRU was used to measure median nerve CSA at the carpal tunnel inlet and forearm, and the wrist/forearm ratio (WFR) was calculated. Patients also completed the Boston Carpal Tunnel Questionnaire (BCTQ). Ultrasound and BCTQ were repeated at 6 weeks and 6 months postoperatively.
RESULTS
Twelve patients completed the study (average age, 69 years; range, 52-80 years). The WFR improved significantly at 6 weeks and reached normal levels at 6 months. The CSA at the wrist also improved at 6 months, although this did not reach statistical significance ( = .059). Boston Carpal Tunnel Questionnaire symptoms and function scores improved significantly at 6 weeks and 6 months.
CONCLUSIONS
High-resolution ultrasound provides an objective assessment of surgical outcomes in cases of severe CTS, demonstrating normalization of WFR in our series of successful cases. Future study of poor outcomes may help determine whether improvement in WFR and CSA can provide reassurance and support for observation rather than reoperation. Ultrasound also provides anatomical evaluation and may be helpful in cases with medicolegal or psychosocial issues while potentially being less costly and better tolerated than EDX or magnetic resonance imaging.
Topics: Humans; Aged; Median Nerve; Carpal Tunnel Syndrome; Wrist; Ultrasonography; Forearm
PubMed: 33487036
DOI: 10.1177/1558944720988075 -
Surgical and Radiologic Anatomy : SRA Sep 2023This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA...
PURPOSE
This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA coexisted with a bilateral bifid median nerve (MN) and two bilateral interconnections (ICs characterized with the symbol -) of the MN with the ulnar nerve (UN) (MN-UN) and a unilateral reverse IC (UN-MN). Emphasis was given to the artery's developmental background.
METHODS
The PMA was identified in an 80-year-old formalin-embalmed donated male cadaver.
RESULTS
The right-sided PMA terminated at the wrist, posterior to the palmar aponeurosis. Two neural ICs were identified: the UN joined the MN deep branch (UN-MN), at the forearm's upper third, and the MN deep stem joined the UN palmar branch (MN-UN), at the lower third (9.7 cm distally to the 1st IC). The left-sided PMA ended in the palm giving off the 3rd and 4th proper palmar digital arteries. An incomplete superficial palmar arch was identified by the contribution of the PMA, radial, and ulnar arteries. After the MN bifurcation into superficial and deep branches, the deep branches formed a loop, that was penetrated by the PMA. The MN deep branch communicated with the UN palmar branch (MN-UN).
CONCLUSIONS
The PMA should be evaluated as a causative factor of carpal tunnel syndrome. The modified Allen's test and the Doppler ultrasound may detect the arterial flow and the angiography may depict the vessel thrombosis in complex cases. PMA could also be a "salvage" vessel for the hand supply, in radial and ulnar artery trauma.
Topics: Humans; Male; Aged, 80 and over; Median Nerve; Ulnar Nerve; Hand; Carpal Tunnel Syndrome; Ulnar Artery; Cadaver
PubMed: 37368116
DOI: 10.1007/s00276-023-03183-y -
Morphologie : Bulletin de L'Association... Mar 2023The cross-section area is a crucial parameter to assess peripheral neuropathy. The ultrasonographic evaluation of cross-section area of median nerve is a low-cost and... (Meta-Analysis)
Meta-Analysis
UNLABELLED
The cross-section area is a crucial parameter to assess peripheral neuropathy. The ultrasonographic evaluation of cross-section area of median nerve is a low-cost and readily available tool for diagnosis and assessment. However, the intra-nerve dimensional variability and its normative reference value in a healthy subject are missing. The current meta-analysis aims to capture the median nerve cross-section area for healthy subjects and generate a comprehensive ultrasonographic reference data set for each population.
METHODS
The full text of manuscripts were collected after short-listing the abstracts collected from search strategy. A quality assurance tool was used to capture the risk of bias of each study after reviewing the included manuscripts. The pooled estimate of cross-section area was stratified according to anatomical landmarks, sex, and ancestry.
RESULTS
A total of 97 observational studies dealt with 6679 wrists of healthy subjects were included. The pooled estimate of the cross-section area of median nerve at carpal tunnel inlet was 8.54mm [95% CI: 8.34-8.74mm]. The same pooled estimate at carpal tunnel outlet was 8.03mm [95% CI: 7.46-8.60mm]. Both these pooled estimates have significant correlation with mean age of population. Age and sex were two primary predictors of the cross-section of median nerve. The flattening ratio, circularity, and wrist-forearm ratio of median nerve were also computed.
CONCLUSION
These normative data could serve as a reference for assessing median nerve pathologies, including carpal tunnel syndrome. The ethnic variation of pooled estimate and heterogeneity will guide clinician set up the reference value for diagnostic criteria.
Topics: Adult; Humans; Median Nerve; Carpal Tunnel Syndrome; Wrist; Cross-Sectional Studies; Ultrasonography
PubMed: 35697557
DOI: 10.1016/j.morpho.2022.05.005 -
BMC Musculoskeletal Disorders Jan 2023Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous...
BACKGROUND
Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes.
METHODS
In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively.
RESULTS
A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p < 0.001 for all comparisons).
CONCLUSIONS
Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.
Topics: Humans; Carpal Tunnel Syndrome; Retrospective Studies; Median Nerve; Pain; Decompression
PubMed: 36717815
DOI: 10.1186/s12891-023-06193-4 -
Risk of nerve injury during elbow arthroscopy: ultrasonographic evaluation of preoperative patients.Journal of Shoulder and Elbow Surgery Mar 2023To clarify the real risk of nerve injury during elbow arthroscopy, the distances of the radial and median nerves to the elbow joint were investigated using...
BACKGROUND
To clarify the real risk of nerve injury during elbow arthroscopy, the distances of the radial and median nerves to the elbow joint were investigated using ultrasonography in patients who underwent surgery.
METHODS
A total of 35 patients who underwent arthroscopic surgery of the elbow were investigated. The distances of the nerves to the capsule and bony landmarks were measured using ultrasonography. The radial nerve distances were measured at the capitellum, joint space, radial head, and radial neck levels. The median nerve distances were measured at the trochlear, joint space, and coronoid process levels. The patients were divided into 2 groups: nine patients in the hydrarthrosis (HA) group and 26 patients in the non-hydrarthrosis (non-HA) group. HA was defined as the intra-articular effusion on magnetic resonance imaging scans.
RESULTS
The radial nerve ran closer to the capsule at the radial neck level in the HA group than in the non-HA group (2.0 mm vs. 5.9 mm, P < .01). In the non-HA group, the radial nerve ran closer to the radial head than in the HA group (6.3 mm vs. 8.5 mm, P = .01). The median nerve ran closer to the capsule at the trochlear level in the HA group than in the non-HA group (5.2 mm vs. 8.8 mm, P < .01). Nerves at a distance of ≤2 mm from the capsule were found in 7 patients at the radial neck of the radial nerve and in 2 patients at the trochlear region of the median nerve in the HA group. In the non-HA group, they were found in 3 patients at the radial head and in 1 patient at the joint space of the radial nerve.
CONCLUSIONS
The dangerous locations for nerve injury during elbow arthroscopy vary according to hydrarthrosis, and this risk should be recognized during arthroscopic surgery.
Topics: Humans; Elbow; Arthroscopy; Elbow Joint; Median Nerve; Radial Nerve
PubMed: 36529383
DOI: 10.1016/j.jse.2022.11.002 -
Musculoskeletal Science & Practice Dec 2017Morphology of the carpal tunnel changes with varying wrist postures and compressive forces applied to the wrist. These changes may affect the morphology and pressure on...
BACKGROUND
Morphology of the carpal tunnel changes with varying wrist postures and compressive forces applied to the wrist. These changes may affect the morphology and pressure on the median nerve and could be used as part of the treatment of the carpal tunnel syndrome patients. Reliability of the ultrasonographic measurements of the median nerve has been widely studied. However, there is a lack of investigation regarding reliability of ultrasonographic measurements of the carpal tunnel.
OBJECTIVE
The purpose of this study was to assess intra-tester and inter-tester reliability of measurement of dimensions of the carpal tunnel and median nerve with ultrasound in asymptomatic volunteers.
DESIGN
A cross-sectional methodological study.
METHODS
Aspects measured were mediolateral and anteroposterior diameters, flattening ratio, circularity, perimeter and cross-section area of the carpal tunnel and median nerve.
RESULTS
Intra-tester reliability was excellent for the carpal tunnel (ICCs from 0.91 to 0.97) and for the median nerve (ICCs from 0.79 to 0.94) measurements. The flattening ratio of the median nerve showed good agreement (ICC = 0.68). Inter-tester reliability was excellent for the carpal tunnel measurements (ICCs from 0.76 to 0.95) and, for the cross sectional area, the perimeter and mediolateral diameter of the median nerve, the ICC values were 0.89, 0.84 and 0.81, respectively.
CONCLUSION
In the context of this study, ultrasound was a reliable instrument for measuring carpal tunnel and median nerve dimensions in asymptomatic subjects.
LEVEL OF EVIDENCE
1b.
Topics: Adult; Carpal Tunnel Syndrome; Cross-Sectional Studies; Female; Humans; Male; Median Nerve; Reproducibility of Results; Ultrasonography; Wrist; Young Adult
PubMed: 28800435
DOI: 10.1016/j.msksp.2017.08.001 -
The Journal of Hand Surgery... Aug 2022Ultrasonography is often used in the diagnosis of carpal tunnel syndrome (CTS). However, we were unable to find normative data regarding the cross-sectional area (CSA)...
Ultrasonography is often used in the diagnosis of carpal tunnel syndrome (CTS). However, we were unable to find normative data regarding the cross-sectional area (CSA) of the median nerve in the Singapore population as measured by ultrasound. The aims of this study were to establish normative values of the CSA of the median nerve at the carpal tunnel inlet in a healthy population, 5 cm proximal to the carpal tunnel inlet, and to determine if the CSA correlated with side, age, gender or race. Sixty-nine wrists of 36 healthy subjects with no history of wrist injury or any signs and symptoms of CTS were examined. The CSA of the median nerve at the carpal tunnel inlet and 5 cm proximal to the carpal tunnel inlet was determined using ultrasound by a trained operator. The mean CSA of the median nerve at the carpal tunnel inlet was 6.41 mm (SD 2.18 mm). These were not significantly different from the values for mean CSA obtained 5 cm proximal to the carpal tunnel inlet. We did not find any correlation between the CSA of the median nerve and age, gender or race. The mean CSA of the median nerve at the carpal tunnel inlet in normal subjects in Singapore was found to be lower than other Asian populations. Wide variations of the median nerve CSA at the carpal tunnel inlet exists in the literature, and this is probably due to the heterogeneity of the study methodology and population. Level III (Diagnostic).
Topics: Bays; Carpal Tunnel Syndrome; Forearm; Humans; Median Nerve; Singapore
PubMed: 35965359
DOI: 10.1142/S242483552250062X