Subsynovial Connective Tissue Research Articles

Higher densities of T-lymphocytes in the subsynovial connective tissue of people with carpal tunnel syndrome.

Symptoms in people with carpal tunnel syndrome (CTS) are traditionally attributed to neural tissue, but recent studies suggest that the subsynovial connective tissue (SSCT) may also play a role in CTS. The SSCT undergoes fibrotic thickening which is generally described as "non-inflammatory" based on basic histology. This study uses immunohistochemistry to determine the presence of macrophages and T-cells within SSCT and their relationship with symptoms in people with CTS. SSCT was collected from twenty people with CTS and eight controls undergoing wrist fracture surgery. Immunohistochemical quantification of CD3+ T-cells and CD68+ macrophage densities as well as CD4+/CD8+ T-cell subpopulations were compared between groups using independent t-tests. Spearman correlations were used to identify associations between immune cell densities and CTS symptom scores. The density of CD3+ T-cells was significantly higher in SSCT of people with CTS compared to controls (CTS mean 26.7 (SD 13.7); controls 6.78 (6.3), p = 0.0005) while the density of CD68+ macrophages was lower (CTS mean 9.5 (SD 6.0); controls 17.7 (8.2), p = 0.0058). Neither CD68+ nor CD3+ cell densities correlated with symptom scores. In contrast to previous assumptions, our data show that the SSCT in the carpal tunnel in both people with CTS and controls is not devoid of immune cells. Whereas the higher density of CD68+ macrophages in control participants may be associated with their early recruitment after acute fracture, CD3+ cells within the SSCT may play a role in chronic CTS.

Dynamic Analysis of the Median Nerve in Carpal Tunnel Syndrome from Ultrasound Images Using the YOLOv5 Object Detection Model

Carpal tunnel syndrome (CTS) is caused by subsynovial connective tissue fibrosis, resulting in median nerve (MN) mobility. The standard evaluation method is the measurement of the MN cross-sectional area using static images, and dynamic images are not widely used. In recent years, remarkable progress has been made in the field of deep learning (DL) in medical image processing. The aim of the present study was to evaluate MN dynamics in CTS hands using the YOLOv5 model, which is one of the object detection models of DL. We included 20 normal hands (control group) and 20 CTS hands (CTS group). We obtained ultrasonographic short-axis images of the carpal tunnel and the MN and recorded MN motion during finger flexion–extension, and evaluated MN displacement and velocity. The YOLOv5 model showed a score of 0.953 for precision and 0.956 for recall. The radial–ulnar displacement of the MN was 3.56 mm in the control group and 2.04 mm in the CTS group, and the velocity of the MN was 4.22 mm/s in the control group and 3.14 mm/s in the CTS group. The scores were significantly reduced in the CTS group. This study demonstrates the potential of DL-based dynamic MN analysis as a powerful diagnostic tool for CTS.

Time-varying changes in median nerve deformation and position in response to quantified pinch and grip forces.

The ability of the median nerve (MN) to adapt in response to altered carpal tunnel conditions is important to mitigate compressive stress on the nerve. We assessed changes in MN deformation and position throughout the entire time course of hand force exertions. Fourteen right-handed participants ramped up force from 0% to 50% of maximal voluntary force (MVF) before ramping force back down in three different hand force exertion tasks (pulp pinch, chuck pinch, power grip). Pinch and grip forces were measured with a digital dynamometer, which were time synchronized with transverse carpal tunnel images obtained via ultrasound. Ultrasound images were extracted in 10% increments between 0% and 50% MVF while ramping force up (loading phase) and down (unloading phase). MN deformation and position relative to the flexor digitorum superficialis tendon of the long finger were assessed in concert. During loading, the nerve became more circular while displacing dorsally and ulnarly. These changes primarily occurred at the beginning of the hand force exertions while ramping force up from 0% to 20%, with very little change between 20% and 50% MVF. Interestingly, deformation and position changes during loading were not completely reversed during unloading while ramping force down. These findings indicate an initial reorganization of carpal tunnel structures. Mirrored changes in nerve deformation and position may also reflect strain-related characteristics of adjoining subsynovial connective tissue. Regardless, time-varying changes in nerve deformation and position appear to be an important accommodative mechanism in the healthy carpal tunnel in response to gripping and pinching tasks.

Ultrasound measurement of subsynovial connective tissue thickness in the carpal tunnel: An intrarater/interrater reliability and agreement study

ObjectivesNon-inflammatory thickening of the subsynovial connective tissue (SSCT) in the carpal tunnel is commonly found in subjects with carpal tunnel syndrome (CTS), and quantification may shed light on CTS pathogenesis. To date, information on the reliability of ultrasound quantification of SSCT is scarce. Therefore, we investigated intrarater and interrater reliability/agreement for ultrasound quantification of SSCT thickness in subjects with and without CTS, and predictors for tissue thickness. Material and methodsTwo investigators quantified SSCT thickness and thickness ratio on ultrasound in 16 healthy subjects (age, 24–65 years; 16 left/14 right wrists) and 17 subjects with CTS (age, 37–83 years; 14 left/14 right wrists). Intra- and inter-rater reliability/agreement were assessed on intraclass correlation coefficients, standard error of measurement and minimal detectable change. A mixed-effects model was used to evaluate potential predictors for SSCT thickness. ResultsIntra- and inter-rater reliability analysis showed good to excellent intraclass correlation coefficients in both groups, ranging from 0.772 to 0.965. The maximum percentage standard error of measurement was 8%. The maximum minimal detectable change was 14% within raters, and 20% between raters. Both intra- and inter-rater reliability values for thickness ratio were poor. Presence of CTS (ß = 0.180; p = 0.015) correlated positively with SSCT thickness. ConclusionsUltrasound is a reliable method for quantification of SSCT thickness, but not for thickness ratio. Presence of CTS correlates positively with SSCT thickness.

Carpal tunnel tendon and sub-synovial connective tissue mechanics are affected by reduced venous return

BackgroundThe effects of blood flow occlusion and sex-specific differences in tendon-subsynovial connective tissue relative strain are not well understood. Thus, the purpose of this study was to investigate the influence of blood flow, biological sex, and finger movement speed on carpal tunnel tendon mechanics to further develop our understanding of carpal tunnel syndrome. MethodsColour Doppler ultrasound imaging quantified relative motion between flexor digitorum superficialis tendon and subsynovial connective tissue in 20 healthy male and female participants during repetitive finger flexion-extension under brachial occlusion of blood flow and two movement speeds (0.75 & 1.25 Hz). FindingsFlexor digitorum superficialis and subsynovial connective tissue displacement decreased with occlusion (small effect) and fast speed (large effect). Speed × Condition interactions were found for mean FDS displacement and peak FDS velocity, where slow speed with occlusion reduced both outcomes. Movement speed had a small but significant effect on tendon-subsynovial connective tissue shear outcomes, where MVR decreased with fast finger motion. InterpretationThese results suggest the influence of localized edema through venous occlusion on tendon-subsynovial connective tissue gliding within the carpal tunnel. This insight further develops our understanding of carpal tunnel syndrome pathophysiology and suggests ramifications on carpal tunnel tissue motion when the local fluid environment of the carpal tunnel is disturbed.

Relative motion between the flexor digitorum superficialis tendon and subsynovial connective tissue is time dependent.

The subsynovial connective tissue is an integral component of flexor tendon gliding in the carpal tunnel, which is strained during longitudinal tendon displacement. We tested the effects of repetition frequency and finger load on flexor tendon function throughout active finger movement. Eleven participants performed metacarpophalangeal joint flexion/extension of the long finger cyclically at three repetition frequencies (0.75, 1.00, 1.25 Hz) and two finger loads (3.5, 7 N). Relative displacement between the flexor digitorum superficialis tendon and subsynovial connective tissue was assessed as the shear-strain index with color ultrasound throughout the entire time history of finger flexion and extension. In addition, long finger joint angles were measured with electrogoniometry while flexor digitorum superficialis and extensor digitorum muscle activities were measured with fine-wire electromyography to characterize the finger movements. The shear-strain index increased with greater finger flexion (p = 0.001), representing higher relative displacement between tendon and subsynovial connective tissue; however, no changes were observed throughout finger extension. The shear-strain index also increased with higher repetition frequencies (p = 0.013) and finger loads (p = 0.029), further modulating time-dependent effects during finger flexion versus extension. Using ultrasound, we characterized the time-dependent response of the shear-strain index, in vivo, providing valuable data on flexor tendon function during active finger movement. Our results infer greater subsynovial connective tissue strain and shear during repetitive and forceful finger movements. Future research characterizing time-dependent effects in carpal tunnel syndrome patients may further elucidate the relations between subsynovial connective tissue function, damage, and carpal tunnel syndrome.

β2-Microglobulin Elevates COL5A1 mRNA in the Subsynovial Connective Tissue of Patients Receiving Hemodialysis With Carpal Tunnel Syndrome.

Background Although carpal tunnel syndrome (CTS) is frequently observed in patients undergoing long-term hemodialysis (HD), exactly how CTS arises is unknown. Here, we examined levels of COL5A1 in the subsynovial connective tissue (SSCT) of patients receiving HD and studied its potential regulation by β2-microglobulin (Β2-MG) in SSCT-derived cells (SSCTCs). Methods We extracted SSCT samples from 67 patients with CTS (49 non-HD and 18 HD) during carpal tunnel release. The samples were subjected to quantitative polymerase chain reaction (qPCR) to determine COL5A1 expression. Further, to examine the potential regulation of COL5A1 expression by Β2-MG, SSCTCs were stimulated in the absence (control) or presence of 10 µg/ml Β2-MG. Results The HD group showed significantly elevated COL5A1 levels compared to the non-HD group (P=0.027). Moreover, treating SSCTCs with Β2-MG for 24 h increased the mRNA expression of COL5A1 relative to control conditions (P=0.013). Conclusions Elevated COL5A1 expression may form part of the mechanism underlying the development of CTS, and Β2-MG may play a role in promoting COL5A1 expression in HD patients.

T2-weighted MRI defines critical compression in the distal carpal tunnel that is relieved after decompressive surgery

SummaryIntroductionDespite Carpal Tunnel Syndrome (CTS) being the most common entrapment neuropathy, its pathophysiology remains debated. Sub-synovial connective tissues (SSCT) within the carpal tunnel are thought to play a role but are poorly characterised. MRI analysis offers potentially novel insights into SSCT characteristics.MethodsA pilot study of T2-weighted MRI was performed in healthy controls (n=7), and in CTS patients (n=16) pre- and 6 months post-surgical decompression. Image analysis was performed to quantify SSCT cross-sectional area, SSCT signal intensity ratio, and wrist index (depth/width) at distal, middle and proximal wrist landmarks.ResultsMedian SSCT signal intensity was lower in the distal carpal tunnel of CTS patients pre-operatively (0.96) compared to controls (1.13; P = 0.008) and normalised post-operatively (1.13, P = 0.001). Median wrist index was also lower in CTS patients pre-operatively (0.60) compared to controls (0.67, P = 0.022), and again normalised post-operatively (0.74, P =0.001). This was attributed to changes in carpal depth in the antero-posterior axis with decompression surgery.ConclusionThis pilot study successfully demonstrated MRI assessment of SSCT in patients with CTS. The decreased SSCT signal intensities suggest predominant changes at the distal tunnel, potentially indicating reduced SSCT perfusion pre-surgery which normalised post-surgery. Our preliminary findings merit further investigation in a larger cohort.

Molecular and Clinical Elucidation of the Mechanism of Action of Steroids in Idiopathic Carpal Tunnel Syndrome.

Carpal tunnel steroid injection is a nonoperative intervention for the treatment for idiopathic carpal tunnel syndrome (CTS). The antifibrotic, anti-inflammatory, and antiedematous properties of steroids account for their therapeutic effects in the context of CTS; however, their relative contribution has not been clarified. Fibroblasts from subsynovial connective tissues (SSCT) were intraoperatively collected from patients with idiopathic CTS and were incubated with or without the steroid triamcinolone acetonide (TA) for 1, 3, and 7 days; the expression of fibrosis-related genes and inflammatory cytokines was evaluated using quantitative reverse transcription-polymerase chain reaction. A clinical prospective study was conducted with patients who received carpal tunnel TA injections. We performed clinical and electrophysiological evaluations before and 1, 3, and 5 months after TA injection; and we compared the median nerve, flexor tendon, and SSCT areas and the median nerve flattening ratio before and 1 month after TA injection using 3-T magnetic resonance imaging (MRI). TA induced downregulation of the fibrosis-related genes Col1A1 (collagen type I alpha 1 chain), Col1A2, and Col3A1 but not the inflammation-related genes. The nerve flattening ratio did not change after TA injection according to the MRI-based observation of the median nerve, flexor tendon, and SSCT areas. The therapeutic effects of injected TA are apparently mediated by its antifibrotic rather than its anti-inflammatory and antiedematous properties. TA probably alters the properties but not the morphology of SSCT. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Carpal tunnel syndrome treatment and the subsequent alterations in tendon and connective tissue dynamics

BackgroundCarpal tunnel syndrome patients demonstrate diminished motion of the median nerve and fibrotic changes in the subsynovial connective tissue within the carpal tunnel. Currently, there are few prognostic factors to help predict the outcome of commonly performed treatments including surgical carpal tunnel release and corticosteroid injections. This study aimed to non-invasively assess the changes in the dynamic response of the subsynovial tissue relative to tendon motion after the intervention and to correlate this with disease severity. MethodsA total of 145 patients with carpal tunnel syndrome were recruited into this study. Clinical and demographic data, electrophysiological severity and dynamic ultrasound images were collected before and after treatment, either by injection or surgery. The relative motion of the subsynovial tissue with the underlying middle finger flexor digitorum superficialis tendon was measured using a speckle tracking algorithm and was expressed as a shear index (SI). Baseline and follow-up data, the association between change in SI and severity, and the role of treatment modality were analyzed and statistically compared. FindingsOverall, there was a significant increase (more relative motion) after treatment in the mean shear index from 79.9% (±15.4% SD) to 82.9% (±14.8% SD) (p = 0.03). Secondary analyses showed that this change was mostly present in those with mild disease severity undergoing surgery (p = 0.01). InterpretationThis study shows that the relative subsynovial tissue movement increases in patients after intervention. The present study lays a foundation for future studies to non-invasively assess the role of carpal tunnel dynamics in response to treatment.

Synovial chondromatosis of the temporomandibular joint and its management

Synovial chondromatosis is a condition in which loose fragments of cartilage develop in the synovial membrane of joints due to metaplasia of the subsynovial connective tissue. The resulting symptoms are similar to those of temporomandibular joint (TMJ) dysfunction. Clinical diagnosis can therefore be challenging. Synovial chondromatosis rarely occurs in the TMJ as its predilection is towards larger joints. A systematic review up until June 2010 reported a total 241 cases of TMJ synovial chondromatosis. We present two cases of TMJ synovial chondromatosis seen and treated in our department. CPD/Clinical Relevance: Awareness of TMJ synovial chondromatosis can enable patients to receive appropriate management before progression of the condition.

Karpal Tünel Sendrom Cerrahisinde Tenosinovektominin Hasta Sonuçlarina Etkisi

INTRODUCTION: Carpal tunnel syndrome (CTS) is estimated to be the most frequently seen mononeuropathy, needing surgical intervention. Its prevalence is known to range between 1, and 3 percent. The components contained in this tunnel are the median nerve, four deep digital flexor tendons, as well as four superficial flexors and the tendon of flexor pollicis longus. Between the tendons and bursae an anatomical structure is present called subsynovial connective tissue (SSCT). SSCT absorbs and transmits stress between tendons and the median nerve and it functions as a scaffold for vascular elements. To find out the role of compression or pathologic proliferation of SSCT in the pathogenesis of CTS, we aimed to conduct a study about the surgical technique of this pathology and compared the long- term results of patients operated with or without SSCT excision in our neurosurgery clinic. METHODS: Between 2003 and 2019 we operated 1279 patients at our neurosurgery clinic. Among them 250 patients who had SSCT excision (syn+) were chosen and they were compared with other 250 patients operated without SSCT excision (Syn-). RESULTS: All patients were evaluated preoperatively and 12 months postoperatively based on the results of Boston Carpal Tunnel Syndrome Questionnaire. When pre-, and post-operative results were compared, we didn’t observe a statistically significant intergroup difference. DISCUSSION AND CONCLUSION: Although our primary goal in patients in whom we performed excision of tenosynovium is to relieve the median nerve by increasing decompression, we observed that there was no difference between the two groups in this large-scale study. We think that only liberation of the transverse carpal ligament during surgery will be sufficient.

Ultrasound examination predicts 6-month progression in carpal tunnel syndrome patients.

Carpal tunnel syndrome (CTS) is a peripheral neuropathy resulting from chronic median nerve compression. Chronic compression leads to neurological changes that are quantified through nerve conduction studies (NCS). Although NCS represents the gold standard in CTS assessment, they provide limited prognostic value. Several studies have identified ultrasound as a tool in diagnosing and potentially predicting the progression of CTS in patients. The purpose of this study was to evaluate the predictive value of ultrasound examination in CTS patients. Twenty patients recruited at their first visit with the neurologist completed two NCS and ultrasound examinations approximately 6 months apart. Ultrasound examination consisted of B-mode, pulse-wave Doppler and colour Doppler ultrasound videos and images to quantify median nerve cross-sectional area, intraneural blood flow velocity in three wrist postures (15° flexion, neutral, and 30° extension), and displacement of the flexor digitorum superficialis (FDS) tendon and the adjacent subsynovial connective tissue (SSCT) of the middle finger during repetitive finger flexion-extension cycles. A questionnaire was administered to assess the work-relatedness of CTS. Linear regression analyses revealed that intraneural blood flow velocity (R2 = 0.36, p = .03), assessed in wrist flexion, and relative FDS-SSCT displacement (R2 = 0.27, p = .04) and shear strain index (R2 = 0.28, p = .04) were significant predictors of nerve sensory and motor changes at 6 months. Results suggest the possibility of using a battery of ultrasound measures as viable markers to predict median nerve functional changes within 6 months.

Change to movement and morphology of the median nerve resulting from steroid injection in patients with mild carpal tunnel syndrome

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.

Relative Motion of the Connective Tissue in Carpal Tunnel Syndrome: The Relation with Disease Severity and Clinical Outcome

Excursion of the median nerve and the surrounding subsynovial connective tissue (SSCT) is diminished in patients with carpal tunnel syndrome (CTS). This study sought to determine if SSCT excursion could be utilized to predict surgical outcome. Idiopathic CTS patients were reviewed with ultrasound and electrodiagnostic tests at baseline. A speckle tracking algorithm was used to determine SSCT relative to tendon motion (shear index). Analysis of variance tests were used to compare SSCT motion with disease severity at baseline. Adjusted linear regressions were used to test the association with patient-reported outcome. A total of 90 CTS patients were analyzed and found to have an average shear index of 79% (95% confidence interval: 76.3%–81.6%). SSCT motion was lower in CTS patients with increasing electrophysiological severity (p = 0.0475). There was no significant association of pre-operative SSCT motion with symptomatic improvement (p = 0.268). Overall, SSCT motion is decreased in CTS patients, but exhibits limited correlation with clinical severity.

Subsynovial connective tissue development in the rabbit carpal tunnel.

The carpal tunnel contains the digital flexor tendons and the median nerve, which are embedded in a unique network of fibrovascular interconnected subsynovial connective tissue (SSCT). Fibrous hypertrophy of the SSCT and subsequent adaptations in mechanical response are found in patients with carpal tunnel syndrome (CTS), but not much is known about the development of the SSCT. This observational study describes the morphological development of SSCT using histology and ultramicroscopy in an animal model at four time points between late‐term fetuses through adulthood. A transition is seen between 3 days and 6 weeks post‐partum from a dense solid SSCT matrix to a complex multilayered structure connected with collagenous fibrils. These preliminary data show a developmental pattern that matches an adaptive response of the SSCT to loading and motion. Understanding the anatomical development aids in recognizing the pathophysiology of CTS and supports research on new therapeutic approaches.

Subsynovial connective tissue thickness in carpal tunnel syndrome: A systematic review

BackgroundNon-inflammatory thickening of the subsynovial connective tissue is a common histological finding in carpal tunnel syndrome. This subsynovial connective tissue thickening may precede changes in electrodiagnostic testing. Therefore, measuring subsynovial connective tissue thickness may help in detecting early changes in carpal tunnel syndrome. MethodsTo provide an overview of subsynovial connective tissue thickness characteristics in subjects with and without carpal tunnel syndrome, a systematic review of articles, assessing human subsynovial connective tissue, was performed using MEDLINE, CENTRAL and EMBASE. FindingsSeven studies were included for qualitative analysis. Measurements were done ex vivo (laser (n = 3), photographic (n = 1), micrometric (n = 1)) and in vivo (ultrasound (n = 3)). All four case-control studies showed a significant difference in subsynovial connective tissue thickness between subjects with and without carpal tunnel syndrome. One study showed good correlation between ultrasound and anatomical measurements. No correlation was found between subsynovial connective tissue thickness and symptom duration, electrodiagnostic changes, age and sex. InterpretationSubsynovial connective tissue thickness may be a valuable aid in diagnosing carpal tunnel syndrome. No factors influencing subsynovial connective tissue thickness are identified, although they are not well investigated.

Effect of a monocyte chemoattractant protein-1 synthesis inhibitor on fibroblasts from patients with carpal tunnel syndrome

BackgroundCarpal Tunnel Syndrome (CTS) is an idiopathic fibrotic disorder. Fibrosis in the subsynovial connective tissues (SSCT) of CTS and many other fibrotic diseases is mediated by Transforming growth factor β (TGF-β). Recently monocyte chemoattractant protein-1 (MCP-1) a cytokine involved in cellular recruitment has been suggested to regulate TGF-β activity. It is related to the onset of diseases which are caused by fibrosis, such as idiopathic pulmonary fibrosis, renal fibrosis, and systemic scleroderma. In this study, we evaluated the effect of the MCP-1 synthesis inhibitor, Bindarit, on primary cultures of fibroblasts from the SSCT of five CTS patients. MethodsFibroblasts were treated with Bindarit (10 μM, 50 μM, 100 μM, or 300 μM). Responses to inhibitors were evaluated by regulation of CTS fibrosis-associated genes, fibrosis gene array and Smad luciferase reporter assay. We also assessed the combination effect of Bindarit and SD208, a TGF-β receptor type 1 inhibitor on TGF-β signaling. ResultsCollagen type III A1 (Col3), connective tissue growth factor (CTGF), and SERPINE1 expression were significantly down-regulated by Bindarit (300 μM) compared to vehicle control. In the fibrosis array, expression of inhibin beta E chain precursor (INHBE), beta actin (ACTB), endothelin 1 (EDN1) and hypoxanthine phosphoribosyltransferase 1 (HPRT1) were significantly down-regulated, and integrin beta-3 (ITGB3) was significantly up-regulated by Bindarit (300 μM). Smad signal transduction activation was significantly down-regulated by Bindarit (300 μM) and/or SD208 (1 μM) with TGF-β1 compared to vehicle control with TGF-β1. ConclusionsThese results suggest that Bindarit in combination with SD208 may be beneficial as medical therapy for the SSCT fibrosis associated with CTS.

Blood flow velocity but not tendon mechanics relates to nerve function in carpal tunnel syndrome patients

Carpal tunnel syndrome (CTS) develops from chronic compression of the median nerve. Chronic compression results in a number of vascular, structural and functional changes to the carpal tunnel tissues which ultimately manifest in the characteristic symptoms of CTS. The purpose of this study was to investigate the interplay of median nerve function, median nerve hemodynamics, and finger flexor tendon and subsynovial connective tissue (SSCT) mechanics in CTS patients. Thirty-five patients were recruited following nerve conduction study for this double-blinded imaging study. Ultrasound B-mode, pulse-wave Doppler, and colour Doppler images and videos were collected at the proximal carpal tunnel to quantify: (1) median nerve cross-sectional area, (2) intraneural blood flow velocity in 3 wrist postures (neutral (0°), flexion (15°), extension (30°)), and (3) flexor digitorum superficialis and SSCT displacement. Results demonstrate that intraneural blood flow velocity is dependent on median nerve function and wrist posture such that patients with mild CTS are more susceptible to the effects of non-neutral wrist postures. Tendon-SSCT mechanics do not appear to differ based on severity. This study stresses the importance of limiting exposure to non-neutral wrist postures in patients with early signs of the condition.

Decreased serum periostin level is associated with carpal tunnel syndrome

Aim: Noninflammatory subsynovial connective tissue (SSCT) fibrosis with nerve compression is an obvious feature of carpal tunnel syndrome (CTS). We investigated serum levels of periostin, which is known to have an effect on fibrosis, in patients with CTS. Material and Methods: A total of 39 healthy individuals and 32 patients who were newly diagnosed with CTS were included in this prospective clinical study. Duration of symptoms, severity, unilateral or bilateral side of CTS diagnosis of patients were recorded. Serum samples were received for the measurement of periostin levels from all participants and were analyzed using commercial enzyme-linked immunosorbent assay (ELISA) kits. Results: Serum periostin levels were significantly lower in CTS patients than controls (p=0.030). Additionally, there was no correlation between serum periostin levels and CTS disease regarding the duration of symptoms and electrophysiological severity of symptoms (p > 0.05).Conclusion: In the current study, it was evaluated that there is a significant relation between CTS and serum periostin levels. Periostin may have roles in the pathogenesis of the CTS. This is the first study to determine serum periostin levels in CTS patients.