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Scientific Reports Sep 2020There are conflicting hypotheses regarding the initial pathogenesis of carpal tunnel syndrome (CTS). One hypothesis characterizes it as inflammation of the median nerve...
There are conflicting hypotheses regarding the initial pathogenesis of carpal tunnel syndrome (CTS). One hypothesis characterizes it as inflammation of the median nerve caused by compression, while another hypothesis characterizes CTS as non-inflammatory fibrosis of the subsynovial connective tissue (SSCT). This study aimed to investigate the differences in the ultrasonography parameters before and after a steroid injection, which is effective for CTS, to elucidate the initial pathogenesis of CTS and the mechanisms of action of the injected steroid. Fourteen hands from 14 healthy participants and 24 hands from 24 participants with mild CTS were examined. Dynamic movement and morphology of the median nerve before and after steroid injection were measured. There was no significant difference in the normalized maximal distance of the median nerve, which reflects the degree of fibrosis in the SSCT indirectly, during finger and wrist movements before and after the injection among patients with CTS (p > 0.05). Among the parameters that indirectly reflects the degree of median nerve compression, such as normalized maximal change in the aspect ratio of the minimum-enclosing rectangle (MER), maximal change in the median nerve perimeter, and maximal value of the median nerve cross-sectional area (CSA), statistically significant differences were not observed between values of the normalized maximal change in the aspect ratio of the MER and maximal change in the median nerve perimeter, during finger and wrist movements recorded before and after the injection in patients with CTS (p > 0.05). However, multivariate logistic regression analysis revealed that the change in the normalized maximal value of the median nerve CSA, according to finger and wrist movement was correlated with the administration of the steroid injection (p < 0.05). In conclusion, compared to that noted before steroid injection, the median nerve CSA noted during finger and wrist movements changed significantly after injection in patients with mild CTS. Given the improvement in median nerve swelling after steroid injection, but no improvement in the movement of the median nerve during finger and wrist movements, median nerve swelling due to compression (rather than fibrosis of the SSCT may be the initial pathogenesis of early-stage (mild) CTS, and the fibrous changes around the median nerves (SSCT) may be indicative of secondary pathology after median nerve compression. Further studies are required to validate the findings of our study and confirm the pathogenesis of CTS.
Topics: Aged; Carpal Tunnel Syndrome; Cross-Sectional Studies; Female; Humans; Injections; Male; Median Nerve; Middle Aged; Movement; Steroids; Ultrasonography; Wrist
PubMed: 32973181
DOI: 10.1038/s41598-020-72757-2 -
Eklem Hastaliklari Ve Cerrahisi = Joint... Dec 2018This study aims to evaluate the distance between the median nerve and the hook of the hamate pre- and postoperatively in patients with carpal tunnel syndrome and to...
OBJECTIVES
This study aims to evaluate the distance between the median nerve and the hook of the hamate pre- and postoperatively in patients with carpal tunnel syndrome and to investigate the efficiency of magnetic resonance imaging in diagnosis and postoperative follow-up.
PATIENTS AND METHODS
Median nerve decompression was performed by releasing the carpal tunnel in 15 patients (4 males, 11 females; mean age 51 years; range, 41 to 66 years) with carpal tunnel syndrome. The shortest distance between the median nerve and the hook of the hamate was measured with magnetic resonance imaging preoperatively and at three months after the operation and radial and ulnar translations were assessed. Findings were compared to those of a control group of 15 subjects (5 males, 10 females; mean age 52.2 years; range, 40 to 65 years).
RESULTS
Median nerve shifted ulnarwards in patients with carpal tunnel syndrome. An intragroup evaluation of five patients with thenar atrophy revealed that as disease severity increased, the degree of the nerve's medial translation increased. Compared to preoperation, the median nerve significantly shifted to the radial side after decompression.
CONCLUSION
In carpal tunnel syndrome patients, we observed significant ulnar translation of the median nerve and lateral translation after releasing the carpal tunnel. Magnetic resonance imaging may be used to establish a diagnosis and to assess operation success in advanced carpal tunnel syndrome patients who may recover slowly postoperatively.
Topics: Adult; Aged; Carpal Tunnel Syndrome; Case-Control Studies; Decompression, Surgical; Female; Hamate Bone; Humans; Magnetic Resonance Imaging; Male; Median Nerve; Middle Aged
PubMed: 30376801
DOI: 10.5606/ehc.2018.61262 -
Orthopaedics & Traumatology, Surgery &... Apr 2021Several structures liable to compress the median nerve have been described around the elbow and proximal forearm. Signs of deficit justify surgical exploration and...
INTRODUCTION
Several structures liable to compress the median nerve have been described around the elbow and proximal forearm. Signs of deficit justify surgical exploration and decompression by exoneurolysis. Better knowledge of the locations of these structures would ensure reliable and effective exploration.
HYPOTHESIS
The study hypothesis was that compressive structures show precise topography, with few variations in distance along the median nerve course.
MATERIAL AND METHODS
The study was performed on 36 upper-limb cadaver specimens. The measurement reference level was the humeral bi-epicondylar line. Proximal-to-distal dissection located: (1) Struthers' ligament, (2) the pronator teres bellies (PT) with their anatomic particularities of structure and insertion, (3) the lacertus fibrosus, (4) the fibrous arcade of the flexor digitorum superficialis (FDS), (5) the accessory muscles, (6) the origin of the anterior interosseous nerve (AIN), (7) and the vascular arches.
RESULTS
Struthers' ligament was not located, but 1 case of medial bicipital fibrous arcade was found. The lacertus fibrosus crossed the median nerve at +1.5±0.6cm. PT insertion was high in 19 cases (53%). The humeral PT belly was thin in 21 cases (58%), crossing the median nerve more distally (+1.8±0.8cm) than the thicker muscles (+1±1.1cm) (p=0.016). The ulnar PT belly was fibrous in 14 cases (39%). A fibrous arcade was found between the 2 PT bellies in 23 cases (64%). The FDS arcade was located at 4.5-7cm from the bi-epicondylar line. An accessory flexor pollicis longus belly was found in 11% of cases. The AIN origin was at +4±1.6cm from the reference. A vascular pedicle crossed the median nerve in 3 cases.
DISCUSSION
The present study inventoried and mapped 6 potentially compressive structures neighboring or crossing the median nerve. Except for the FDS arcade, they showed very precise proximal-to-distal location, with variations of 0.5 to 1.5cm.
LEVEL OF EVIDENCE
IV; case series.
Topics: Cadaver; Elbow; Elbow Joint; Forearm; Humans; Median Nerve; Muscle, Skeletal; Tendons
PubMed: 33482406
DOI: 10.1016/j.otsr.2021.102813 -
Modern Rheumatology May 2020This study aimed to compare median nerve stiffness measured by ultrasound real-time tissue elastography in patients with and without rheumatoid arthritis (RA and non-RA... (Clinical Trial)
Clinical Trial
This study aimed to compare median nerve stiffness measured by ultrasound real-time tissue elastography in patients with and without rheumatoid arthritis (RA and non-RA groups, respectively). Altogether, 402 hands of 201 RA group and 222 hands of 111 non-RA group were included in the study. Ultrasonography was performed to evaluate the circumference, cross-sectional area (CSA) and strain ratio as an elasticity of the median nerve at the inlet level of the carpal tunnel and the proximal portion of the carpal tunnel inlet. Using propensity score matching, the difference between RA and non-RA group were analyzed. After propensity score matching, 135 hands in 104 RA group and 70 non-RA group were finally analyzed. There were no significant differences in the circumference and CSA of the median nerve between the two groups. The strain ratio of the median nerve was significantly higher in RA group than in non-RA group only at the inlet of the carpal tunnel level. The nerve stiffness in patients with RA measured by ultrasound real-time tissue elastography was higher than without RA. Inflammatory condition of the flexor tendon and wrist joint in patients with RA may generate fibrotic changes in the median nerve. University Hospital Medical Information Network Clinical Trials Registry: UMIN000015314.
Topics: Adult; Arthritis, Rheumatoid; Carpal Tunnel Syndrome; Elasticity Imaging Techniques; Female; Humans; Male; Median Nerve; Middle Aged
PubMed: 30947583
DOI: 10.1080/14397595.2019.1602914 -
European Journal of Radiology Apr 2018The aim of the current study is to investigate the diagnostic role of shear-wave elastography and diffusion tensor imaging in patients with carpal tunnel syndrome.
PURPOSE
The aim of the current study is to investigate the diagnostic role of shear-wave elastography and diffusion tensor imaging in patients with carpal tunnel syndrome.
MATERIAL AND METHODS
The study included a total of 77 wrists; 18 normal, 35 wrists with mild, 9 wrists with moderate and 15 wrists with severe carpal tunnel syndrome. Elastography of the median nerve was performed by defining the boundaries of a segment of the nerve at sagittal plane at the level of proximal carpal row. Additionally, the cross-sectional area of the median nerve was evaluated. Fractional anisotropy and apparent diffusion coefficient measurements were carried out by placing region-of-interest at three levels: at pisiform bone (carpal tunnel inlet), mid carpal tunnel, and hook of hamate (carpal tunnel outlet).
RESULTS
Patients with carpal tunnel syndrome had higher elasticity values of median nerve (53.0 kPa; IQR 40.8-77.0 kPa) compared to control subjects. (36.8 kPa; IQR 31.0-39.9 kPa) Patients with moderate-severe carpal tunnel syndrome had higher elasticity values (82 kPa; IQR 64.0-95.5 kPa) compared to patients with mild carpal tunnel syndrome. (44 kPa; IQR 32.5-59.5 kPa) Patients with carpal tunnel syndrome had lower fractional anisotropy at mid-carpal level (0.382; IQR 0.330-0.495) compared to the control group. (0.494; IQR 0.434-0.537) Patients with moderate-severe carpal tunnel syndrome had lower fractional anisotropy values (0.366; IQR 0.331-0.407) and higher apparent diffusion coefficient values (1.509 mm/s; IQR 1.374-1.733 mm/s) compared to patients with mild carpal tunnel syndrome. (0,423; IQR 0.324-0.526 and 1.293 mm/s; IQR 0.967-1.514 mm/s) CONCLUSION: Shear-wave elastography and diffusion tensor imaging are helpful imaging modalities in diagnosing carpal tunnel syndrome and assessing its severity.
Topics: Adult; Aged; Anisotropy; Carpal Bones; Carpal Tunnel Syndrome; Case-Control Studies; Diffusion Tensor Imaging; Elasticity Imaging Techniques; Female; Humans; Male; Median Nerve; Middle Aged; Prospective Studies; Wrist; Wrist Joint
PubMed: 29571802
DOI: 10.1016/j.ejrad.2018.02.005 -
BioMed Research International 2017. The purpose of this study was to assess nerve hypervascularization using high resolution ultrasonography to determine the effects of wrist posture and fingertip force... (Clinical Trial)
Clinical Trial
. The purpose of this study was to assess nerve hypervascularization using high resolution ultrasonography to determine the effects of wrist posture and fingertip force on median nerve blood flow at the wrist in healthy participants and those experiencing carpal tunnel syndrome (CTS) symptoms. . The median nerves of nine healthy participants and nine participants experiencing symptoms of CTS were evaluated using optimized ultrasonography in five wrist postures with and without a middle digit fingertip press (0, 6 N). . Both wrist posture and fingertip force had significant main effects on mean peak blood flow velocity. Blood flow velocity with a neutral wrist (2.87 cm/s) was significantly lower than flexed 30° (3.37 cm/s), flexed 15° (3.27 cm/s), and extended 30° (3.29 cm/s). Similarly, median nerve blood flow velocity was lower without force (2.81 cm/s) than with force (3.56 cm/s). A significant difference was not found between groups. . Vascular changes associated with CTS may be acutely induced by nonneutral wrist postures and fingertip force. This study represents an early evaluation of intraneural blood flow as a measure of nerve hypervascularization in response to occupational risk factors and advances our understanding of the vascular phenomena associated with peripheral nerve compression.
Topics: Adult; Blood Flow Velocity; Carpal Tunnel Syndrome; Female; Fingers; Humans; Male; Median Nerve; Middle Aged; Muscle Strength; Posture; Wrist
PubMed: 28286771
DOI: 10.1155/2017/7156489 -
The Journal of Hand Surgery... Apr 2023One controversial question in Carpal Tunnel Syndrome (CTS) diagnosis is whether magnetic resonance imaging (MRI) and Ultrasound (US) imaging tools have any relationship...
One controversial question in Carpal Tunnel Syndrome (CTS) diagnosis is whether magnetic resonance imaging (MRI) and Ultrasound (US) imaging tools have any relationship with electrodiagnostic (EDX) study. The objective of this study is to determine the possible correlation between MRI and US measurements with EDX parameters. Both US and MRI of the median nerve were simultaneously performed in 12 confirmed CTS wrists, at two levels of forearm distal fold (proximal) and the hook of the hamate (distal), to measure various anatomic parameters of the nerve. EDX parameters of median motor distal latency (DL) and median sensory proximal latency (PL) were evaluated in milliseconds. Nerve cross-sectional area (CSA), measured by MRI, correlated with sensory PL at distal level ( = 0.015). At proximal level MRI, nerve width and width to height ratio also correlated with motor DL ( = 0.033 and 0.021, respectively). Median nerve CSA proximal to distal ratio correlated with sensory PL ( = 0.028) at MRI. No correlation was found between US and EDX measurements. Median nerve MRI measurement of nerve CSA at hook of the hamate (distal) level or CSA proximal to distal ratio correlated with EDX parameter of sensory PL. On the other hand, nerve MRI width and width to height ratio at distal level correlated with motor DL in EDX. Level III (Diagnostic).
Topics: Humans; Carpal Tunnel Syndrome; Median Nerve; Wrist; Magnetic Resonance Imaging; Ultrasonography
PubMed: 37120299
DOI: 10.1142/S2424835523500261 -
RoFo : Fortschritte Auf Dem Gebiete Der... Feb 2020
Topics: Fingers; Hamartoma; Humans; Lipomatosis; Magnetic Resonance Imaging; Male; Median Nerve; Metacarpal Bones; Middle Aged; Thumb
PubMed: 31509863
DOI: 10.1055/a-0998-4348 -
Vojnosanitetski Pregled Nov 2015BACGRAUND/AIM: Most often injuries of brachial plexus and its branches disable the injured from using their arms and/or hands. The aim of this study was to investigate...
UNLABELLED
BACGRAUND/AIM: Most often injuries of brachial plexus and its branches disable the injured from using their arms and/or hands. The aim of this study was to investigate the etiology and mechanisms of median and ulnar forearm nerves injuries.
METHODS
This retrospective cohort study included 99 patients surgically treated in the Clinic of Neurosurgery, Clinical Center of Serbia, from January 1st, 2000 to December 31st, 2010. All data are obtained from the patients' histories.
RESULTS
The majority of the injured patients were male, 81 (81.8%), while only 18 (18.2%) were females, both mainly with nerve injuries of the distal forearm--75 (75.6%). Two injury mechanisms were present, transection in 85 patients and traction and contusion in 14 of the patients. The most frequent etiological factor of nerve injuries was cutting, in 61 of the patients. Nerve injuries are often associated with other injuries. In the studied patients there were 22 vascular injuries, 33 muscle and tendon injuries and 20 bone fractures.
CONCLUSION
The majority of those patients with peripheral nerve injuries are represented in the working age population, which is a major socioeconomic problem. In our study 66 out of 99 patients were between 17 and 40 years old, in the most productive age. The fact that the majority of patients had nerve injuries of the distal forearm and that they are operated within the first 6 months after injury, promises them good functional prognosis.
Topics: Adolescent; Adult; Child; Female; Forearm; Humans; Male; Median Nerve; Middle Aged; Neurosurgical Procedures; Retrospective Studies; Risk Factors; Serbia; Ulnar Nerve
PubMed: 26731969
DOI: 10.2298/vsp140818106p -
Ultrasound in Medicine & Biology Nov 2022Median nerve swelling is one of the features of carpal tunnel syndrome (CTS), and ultrasound measurement of maximum median nerve cross-sectional area is commonly used to...
Median nerve swelling is one of the features of carpal tunnel syndrome (CTS), and ultrasound measurement of maximum median nerve cross-sectional area is commonly used to diagnose CTS. We hypothesized that volume might be a more sensitive measure than cross-sectional area for CTS diagnosis. We therefore assessed the accuracy and reliability of 3-D volume measurements of the median nerve in human cadavers, comparing direct measurements with ultrasound images interpreted using deep learning algorithms. Ultrasound images of a 10-cm segment of the median nerve were used to train the U-Net model, which achieved an average volume similarity of 0.89 and area under the curve of 0.90 from the threefold cross-validation. Correlation coefficients were calculated using the areas measured by each method. The intraclass correlation coefficient was 0.86. Pearson's correlation coefficient R between the estimated volume from the manually measured cross-sectional area and the estimated volume of deep learning was 0.85. In this study using deep learning to segment the median nerve longitudinally, estimated volume had high reliability. We plan to assess its clinical usefulness in future clinical studies. The volume of the median nerve may provide useful additional information on disease severity, beyond maximum cross-sectional area.
Topics: Cadaver; Carpal Tunnel Syndrome; Deep Learning; Humans; Median Nerve; Reproducibility of Results; Ultrasonography
PubMed: 35961866
DOI: 10.1016/j.ultrasmedbio.2022.06.011