Nerve Stiffness Research Articles

Piezo1 promotes peripheral nerve fibrotic scar formation through Schwann cell senescence

After peripheral nerve injury (PNI), the long-term healing process at the injury site involves a progressive accumulation of collagen fibers and the development of localized scar tissue. Excessive formation of scar tissue within nerves hinders the process of nerve repair. In this study, we demonstrate that scar formation following nerve injury induces alterations in the local physical microenvironment, specifically an increase in nerve stiffness. Recent research has indicated heightened expression of Piezo1 in Schwann cells (SCs). Our findings also indicate Piezo1 expression in SCs and its association with suppressed proliferation and migration. Transcriptomic data suggests that activation of Piezo1 results in elevated expression of senescence-associated genes. GO enrichment analysis reveals upregulation of the TGF-β pathway. Overall, our study highlights the potential for Piezo1-induced signaling to regulate SC senescence and its potential significance in the pathophysiology of fibrotic scar formation surrounding peripheral nerves.

Elastography of nerves in the wrists of cyclists.

This study aimed to investigate changes in the elasticity of the median and ulnar nerves in cyclists. The study included 30 cyclists and 2 non-biking reference groups that included 32 healthy volunteers and 32 individuals with ulnar nerve entrapment neuropathies. All participants underwent physical, ultrasonographic, and elastographic examinations including assessment of nerve cross-sectional area (CSA) and stiffness (SWE). The cyclists' group was tested before and after a 2-hour workout. The values of ulnar nerve CSA and stiffness in Guyon's canal in resting cyclists were 5.30 ± 1.51 mm2 and 49.05 ± 11.18 kPa, respectively. These values were significantly higher than in the healthy volunteers, but not higher than in the nerve entrapment group. Median nerve CSA and stiffness at rest were 9.10 ± 2.61 mm2 and 38.54 ± 14.87 kPa, respectively. Both values were higher than respective values in the healthy group. Cycling induced an increase in all these parameters, although the increase in nerve stiffness was more noticeable than in CSA. The elasticity of the median and ulnar nerve in cyclists remains within normal limits, questioning the belief that cyclists are at risk of nerve palsy in Guyon's canal. However, cycling workout does exert compression, resulting in transient oedema of both nerves. The dynamics of changes was more noticeable in SWE examination than in conventional ultrasound, which may depend on SWE sensitivity.

In Vivo Effects of Joint Movement on Nerve Mechanical Properties Assessed with Shear-Wave Elastography: A Systematic Review and Meta-Analysis

Peripheral nerves are subjected to mechanical tension during limb movements and body postures. Nerve response to tensile stress can be assessed in vivo with shear-wave elastography (SWE). Greater tensile loads can lead to greater stiffness, which can be quantified using SWE. Therefore, this study aimed to conduct a systematic review and meta-analysis to perform an overview of the effect of joint movements on nerve mechanical properties in healthy nerves. The initial search (July 2023) yielded 501 records from six databases (PubMed, Embase, Scopus, Web of Science, Cochrane, and Science Direct). A total of 16 studies were included and assessed with a modified version of the Downs and Black checklist. Our results suggest an overall tendency for stiffness increase according to a pattern of neural tensioning. The main findings from the meta-analysis showed a significant increase in nerve stiffness for the median nerve with wrist extension (SMD [95%CI]: 3.16 [1.20, 5.12]), the ulnar nerve with elbow flexion (SMD [95%CI]: 2.91 [1.88, 3.95]), the sciatic nerve with ankle dorsiflexion (SMD [95%CI]: 1.13 [0.79, 1.47]), and the tibial nerve with both hip flexion (SMD [95%CI]: 2.14 [1.76, 2.51]) and ankle dorsiflexion (SMD [95%CI]: 1.52 [1.02, 2.02]). The effect of joint movement on nerve stiffness also depends on the nerve segment, the amount of movement of the joint mobilized, and the position of other joints comprised in the entirety of the nerve length. However, due to the limited number of studies, many aspects of nerve behavior together with the effect of using different ultrasound equipment or transducers for nerve stiffness evaluation still need to be fully investigated.

Multimodal ultrasound evaluation of asymptomatic ulnar nerve dislocation at the cubital tunnel.

Ultrasonography has received broad acceptance as an effective peripheral nervous imaging examination. Shear wave elastography (SWE) can quantitatively assess the stiffness of nerves; however, little research has been conducted on elastography for ulnar nerve dislocation. The purpose of this study was thus to investigate the characteristics of multimodal ultrasound, including high-resolution ultrasonography and SWE, for asymptomatic ulnar nerve dislocation at cubital tunnel. In this prospective cross-sectional study, 41 participants were recruited in Shandong Provincial Hospital Affiliated to Shandong First Medical University in July 2022. The inclusion criteria for participants were being in good health and being 18-60 years of age. Meanwhile, the exclusion criterion was a history of upper limb pain or fractures, peripheral neuropathy, or systemic or immunological diseases. Finally, 38 participants were enrolled. Two ultrasound doctors measured the maximum diameter, the maximum cross-sectional area (CSA), and the shear modulus of the ulnar nerve at the cubital tunnel independently. Another two ultrasound doctors determined whether dislocation was present during dynamic elbow flexion and extension and divided the elbows into a dislocation group and a control group. The descriptive statistics and independent sample t-test were used for data analysis, and intragroup correlation coefficient (ICC) was used to determine the consistency of evaluation between observers. Ulnar nerve dislocation was observed in 15.8% (12/76) of the ulnar nerves. There was no significant difference in the maximum diameter between the dislocation group (0.194±0.022 cm) and the control group (0.181±0.023 cm) (t=1.888; P=0.063). The CSA and SWE of the ulnar nerve were 0.064±0.009 cm2 and 43.629±6.737 kPa in the dislocation group, respectively, and were 0.050±0.008 cm2 and 31.293±7.858 kPa in the control group, respectively. There were significant differences between the two groups in terms of CSA (P<0.001) and SWE (P<0.001). The ICCs of the maximum diameter, CSA, and SWE values between observers were 0.970, 0.900, and 0.915, respectively. Multimodal ultrasound consisting of high-resolution ultrasonography combined with elastography can comprehensively and quantitatively evaluate the morphological changes and mechanical properties of the dislocated ulnar nerve and monitor disease progress.

Acute effect of static stretching on non-muscular tissue stiffness and joint flexibility: a comparative study between older and young men.

Non-muscular tissue stiffness is assumed to have a negative impact on joint flexibility, and a reduction in non-muscular tissue stiffness may be important, especially in older adults. The present study aimed to compare the acute effects of static stretching on non-muscular tissue stiffness between older and young adults and to investigate whether a decrease in tissue stiffness improves joint flexibility. Twenty older (62-83years) and 20 young (21-24years) males participated. Ankle dorsiflexion static stretching (five sets of 90s each) was performed, and before and after stretching, the ankle dorsiflexion range of motion (RoM), passive ankle joint stiffness, and shear wave speed (SWS) (an index of stiffness) of the sciatic nerve, tibial nerve, and posterior thigh fascia were measured. Stretching led to an increase in RoM and a decrease in passive joint stiffness in both groups (P < 0.001) with no significant between-group differences (P ≥ 0.055). The between-group difference in the effect of stretching on SWS was evident only for the sciatic nerve, and a decline in sciatic nerve SWS was only observed in the older adult group (pre-stretching: 2.5 ± 0.3m/s; post-stretching: 2.3 ± 0.4m/s; P = 0.027). A significant positive repeated-measures correlation was observed between the sciatic nerve SWS and passive joint stiffness (P = 0.014, rrm = 0.540). The reduction in sciatic nerve stiffness by stretching was noticeable in older men and led to improved joint flexibility. These findings may provide insight into tissue adaptation by stretching and may be used to explore effective exercises for improving joint flexibility in older adults.

Utility of shear wave elastography for diagnosing carpal tunnel syndrome with psoriatic arthritis.

Carpal tunnel syndrome (CTS) is a type of peripheral entrapment neuropathy and common for the patients with psoriatic arthritis (PsA). Shear wave elastography (SWE) is a new ultrasonography technique that can be used for diagnosing CTS, but not studied in PsA patients. The aim of this study to measure the stiffness of median nerve and hand muscles by quantitative SWE to identify whether SWE can be used for diagnosing CTS in patients with PsA or not. To diagnose CTS, all patients had electrodiagnostic study. The stiffness values of the median nerve, abductor pollicis brevis, and abductor digiti minimi were determined using SWE. Muscle stiffness ratio was also calculated. Consideration is given to 48 patients with PsA (93 wrists) and 29 healthy volunteers (57 wrists). Median nerve stiffness was found to be significantly higher, and abductor pollicis brevis' stiffness and muscle stiffness ratio were significantly lower in PsA patients' wrists compared to control group (p = 0.002, p < 0.001, p = 0.001, respectively) and in CTS wrists compared to others (p < 0.001, p < 0.001, p = 0.001, respectively). Receiver operating characteristic analysis identified 28.2 kPA as the median nerve stiffness cut-off point for differentiating CTS in PsA patients (p = 0.001). We found that SWE has a good diagnostic value for CTS with PsA patients; hence, we can conclude that SWE could diagnose CTS in PsA patients.

Shear wave elastography combined with two-dimensional ultrasonography for detecting optic nerve sheath: An effective tool for assessing preeclampsia.

This study aimed to investigate two-dimensional ultrasound and shear-wave elastography (SWE) in evaluating optic neuropathy in preeclampsia. Ninety-one singleton pregnant women (51 with preeclampsia [observation group]; 40 without complications [control group]) admitted between January 2022 and April 2022 participated in this study. Optic nerve sheath diameter (ONSD) and optic nerve stiffness measurement (ONSM) were measured using two-dimensional ultrasound and SWE, respectively, and compared between the two groups. Receiver operating characteristic curves were employed to evaluate the performance of ONSD, ONSM, and combination (ONSD + ONSM) for diagnosing preeclampsia. The observation (preeclampsia) group ONSD and ONSM were significantly higher than those in the control group (p < 0.05). Optimal diagnostic values for ONSD and ONSM were 4.10 mm and 11.20 kPa, respectively. Areas under the curve for diagnosing preeclampsia were 0.958 (95% confidence interval [CI], 0.926-0.990) for ONSD, 0.939 (95% CI, 0.894-0.985) for ONSM, and 0.982 (95% CI, 0.962-1.000) for ONSD + ONSM. There was no significant difference between ONSD and ONSM in diagnosing preeclampsia (p = 0.436). However, ONSD + ONSM was significantly advantageous over ONSD or ONSM alone in diagnosing preeclampsia (p = 0.033; p = 0.014). Ultrasonic evaluation of the optic nerve can quantitatively assess optic nerve changes in pregnant women with preeclampsia.

The elastography of distal ulnar nerve branches in cyclists

IntroductionForced elbow flexion and pressure during bicycling result in ulnar nerve traction and pressure exerted in Guyon’s canal or the nerve’s distal branches. The compression of the nerves causes a change in their stiffness related to edema and eventually gradual fibrosis. PurposeThis study aimed to evaluate the elastography of terminal branches of the ulnar nerve in cyclists. Study DesignCross-sectional study. MethodsThirty cyclists, 32 healthy individuals, and 32 volunteers with ulnar nerve entrapment neuropathies participated in the study. Each participant underwent a nerve examination of the cubital tunnel, Guyon’s canal and the deep and superficial branches of the ulnar nerve using shear wave elastography. The cyclist group was tested before and after a 2-hour-long workout. ResultsBefore cycling workouts, the ulnar nerve stiffness in the cubital tunnel and Guyon’s canal remained below pathological estimates. Cycling workouts altered nerve stiffness in the cubital tunnel only. Notably, the stiffness of the ulnar terminal branches in cyclists was increased even before training. The mean deep branch stiffness was 50.85 ± 7.60 kPa versus 20.43 ± 5.95 kPa (p < 0.001) in the cyclist and healthy groups, respectively, and the mean superficial branch stiffness was 44 ± 12.45 kPa versus 24.55 ± 8.05 kPa (p < 0.001), respectively. Cycling contributed to a further shift in all observed values. DiscussionThese observations indicate the existence of persistent anatomical changes in the distal ulnar branches in resting cyclists that result in increased stiffness of these nerves. The severity of these changes remains, however, to be determined. ConclusionsThese data show elastography values of the ulnar terminal branches in healthy individuals and cyclists where despite lack of clinical symptoms that they seem to be elevated twice above the healthy range.

The evaluation of tibial nerve using shear-wave elastography and ultrasound in patients with systemic sclerosis: A cross-sectional study.

The study aimed to evaluate stiffness and the cross-sectional area (CSA) of the tibial nerve (TN) using shear wave elastography (SWE) and ultrasound (US) and investigate the relationship of these with disease activity, quality of life, and severity of neuropathic pain in patients with systemic sclerosis (SSc). This cross-sectional study included 28 SSc patients (1 male, 27 females; mean age: 50±11 years; range, 28 to 67 years) and 22 age- and sex-matched healthy controls (4 males, 18 females; mean age: 48±6 years; range, 37 to 66 years) between March and April 2022. US and SWE were performed on the TN, and CSA and nerve stiffness were measured. The TN was examined by a radiologist, 4 cm proximal to the medial malleolus. A few days later, an evaluation was performed in the second session by a second observer to investigate inter-and intraobserver agreement. Interobserver agreement was evaluated using the intraclass correlation coefficient (ICC). The Scleroderma Health Assessment Questionnaire, European League Against Rheumatism European Scleroderma Trial and Research (EUSTAR) group activity index, and Douleur-Neuropathique 4 scores of the patients were evaluated. Correlations between the questionnaires and measurements of nerve stiffness and CSA were assessed. Patients with SSc had significantly higher stiffness and CSA values of the right TN compared to healthy controls (p<0.001 and p=0.015, respectively). The nerve stiffness values of the right TN were positively correlated with the EUSTAR activity index (p=0.004, r=0.552). The CSA of the left TN was larger in patients with SSc (21.3±4.9 mm2 ) than in controls (12.8±3.4 mm2 ), and the nerve elasticity was positively correlated with the EUSTAR activity index (p=0.001, r=0.618). The interobserver agreement was moderate to good for measuring stiffness and CSA of the TN (ICC were 0.660 and 0.818, respectively). There was a good to excellent intraobserver agreement for measuring stiffness and CSA of TN (ICC were 0.843 and 0.940, respectively). The increased disease activity in patients with SSc is associated with TN involvement, which can be demonstrated by US and SWE.

Evaluation of the median nerve by shear wave elastography in patients with Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease type 1A (CMT1A) is characterized by enlargement and stiffness of peripheral nerves due to edema with large numbers of "onion bulbs" in the endoneurium. Ultrasound elastography seems to be an ideal method to detect this condition. The aim of this study was to analyze the shear wave elastography (SWE) features of peripheral nerves in patients with CMT1A. We included 24 CMT1A patients with a mean age of 28 years, along with 24 age- and gender-matched controls. All patients presented with mutations of the PMP22 gene and showed length-dependent polyneuropathy. The motor nerve conduction velocity (MNCV) of the median nerve ranged from 5.2 to 37.4 m/s. SWE and cross-sectional area (CSA) were used to evaluate the bilateral median nerves at predefined sites in both patients and con-trols. The average elastography value (EV) of the median nerve was 73.5±11.7 kPa in patients with CMT1A and 37.5±6.1 kPa in control subjects. The difference between the two groups was statistically significant (P<0.05). In CMT1A pa-tients, the average EV at the proximal and distal parts of the median nerve were 81.4±9.4 kPa and 65.2±8.1 kPa, respectively. The average CSAs at the proximal and distal parts of the median nerve were 0.29±0.06 cm2 and 0.20±0.05 cm2, respectively. The EV on SWE was positively correlated with CSA (p< 0.01) and negatively correlated with MNCV in the median nerve (p< 0.01). Peripheral nerve stiffness dramatically increases in CMT1A and is correlated with the severity of nerve involvement.

Study on the Crush Injury Model of the Sciatic Nerve in Rabbits by Conventional Ultrasound and Elastography.

The crush injury model of the sciatic nerve in rabbits is a common nerve injury model, but there is little literature on the evaluation of nerve stiffness by ultrasound elastography. To explore the value of ultrasound elastography in diagnosing crush injury of the sciatic nerve in rabbits. Forty cases of crush injury model of the sciatic nerve in rabbits were examined by conventional ultrasound and elastography. The sonographic manifestations and stiffness of the model were analyzed, and the regularity of nerve injury with time was summarized. Ultrasound could clearly show the location, range, and thickness of the injured nerve in this model. The thickness of the injured area reached a peak in the 2nd week and returned to normal thickness in the 8th week. The nerve stiffness of the injured area increased gradually with time. Conventional ultrasound combined with elastography can comprehensively and quantitatively evaluate the morphological changes and mechanical properties of the injured sciatic nerve in rabbits, which may be of great significance to the repair and rehabilitation of peripheral nerve crush injuries.

Evaluation of Sciatic Nerve Stiffness Using Shear Wave Elastography in Patients with Unilateral Diabetic Foot Ulcers.

To evaluate the stiffness of the sciatic nerve by shear wave elastography (SWE) and to determine whether SWE can be used to predict diabetic foot ulcer (DFU) in a patient with diabetic peripheral neuropathy (DPN). Sixteen patients (thirty-two lower limbs) with unilateral DFU were studied retrospectively. The ultrasonographic parameters including cross-sectional area (CSA) of sciatic nerve, intraneural blood flow, peak systolic velocity (Vmax) and resistive index (RI) in the intraneural artery of the sciatic nerve, and the SWE stiffness value of the sciatic nerve were measured. The examinations of arteries of the lower limbs were also performed by ultrasound. According to the presence or absence of DFU, the 32 lower limbs were divided into two groups: the DFU group and the non-DFU group. The ultrasonographic parameters were compared between these two groups. There was no significant difference (p > 0.05) between the two groups for CSA, intraneural blood flow, Vmax and RI in the intraneural artery of the sciatic nerve, and numbers of severe artery stenosis or full occlusion of the artery in the lower limbs. However, SWE stiffness values in the sciatic nerve in the DFU group are higher than the non-DFU group (p < 0.05). When the SWE stiffness values were used for prediction of DFU in patients with DPN, the area under the ROC curve (AUC) was 0.727 (95% CI: 0.541-0.868). When the best SWE stiffness value of 24.48 kPa was taken as a cutoff for prediction of DFU, the sensitivity was 62.50% (95% CI: 35.4-84.8%), and the specificity was 75% (95% CI: 47.6-92.7%). Sciatic nerve stiffness is significantly higher in lower limbs with DFU. SWE is a noninvasive imaging method that may be used to evaluate sciatic nerve stiffness, then potentially predict DFU in patients with DPN.

The sono-elastography evaluation of the immediate effects of neurodynamic mobilization technique on median nerve stiffness in patients with carpal tunnel syndrome

ObjectivesThe stiffness of median nerve increases in carpal tunnel syndrome (CTS) even at mild stage of syndrome which could be regarded as a diagnostic criterion. The aim of this study was to evaluate the immediate effects of neurodynamic technique on median nerve stiffness and cross-sectional area (CSA) at wrist and elbow in individuals with CTS. Material and methodsIt was a quasi-experimental study. Twenty patients were recruited for this study. They were included if aged 18–65 years and diagnosed with CTS based on electrodiagnostic and clinical findings. The exclusion criteria were previous surgeries at wrist or elbow. Patients were assessed by shear wave sono-elastography before and immediately after one session of neurodynamic mobilization technique (NDM). The primary outcome measure was the stiffness of the median nerve at wrist and the secondary outcomes were nerve stiffness at elbow and CSA of nerve at wrist and elbow. ResultsMedian nerve stiffness and CSA decreased significantly at wrist immediately after a session of NDM. These parameters also decreased at elbow but were not statistically significant. ConclusionOne session of NDM reduced the stiffness and CSA of median nerve at wrist in patients with CTS as detected by sono-elastography verifying that sono-elastography is able to quickly detect the immediate biomechanical changes of the median nerve.

Supersonic shear wave imaging of the tibial nerve for diagnosis of diabetic peripheral neuropathy: A meta-analysis.

BackgroundDiabetic peripheral neuropathy (DPN) is the most common diabetes-associated complication and imposes a significant burden to healthcare systems. Thus, early diagnosis of DPN is extremely critical for management and outcome of diabetic patients. Supersonic Shear Wave Imaging (SSI) enables the noninvasive measurement of nerve stiffness. However, previous studies on SSI in the diagnosis of DPN were limited in sample sizes and reported various results. In this meta-analysis, we aimed to obtain comprehensive evidence on the value of tibial nerve stiffness measurement by SSI in the diagnosis of DPN.MethodsA comprehensive literature search in English and Chinese electronic database was conducted for studies (published until January 25, 2022) that investigated the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. Summary receiver operating characteristics (SROC) modelling was constructed to conduct the meta-analysis of diagnostic accuracy of SSI for detecting DPN.ResultsFinally, a total of 12 eligible studies with 1325 subjects were included for evaluation, and a meta-analysis was conducted to evaluate the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. For tibial nerve stiffness measurement by SSI, the summary sensitivity and specificity for the diagnosis of DPN were 80% (95% confidence interval [CI]: 73%–86%) and 86% (95% CI: 82%–89%), respectively. The summary area under the ROC curve (AUROC) value of the SROC was 0.90 (95% CI: 0.87–0.92), for diagnosing DPN. A subgroup analysis of 11 SSI studies from China revealed similar diagnostic performance, with a summary sensitivity of 79% (95% CI: 72%–85%), specificity of 86% (95% CI: 82%–89%) and summary AUROC value of the SROC of 0.90 (95% CI: 0.87–0.92) for diagnosing DPN.ConclusionsOur meta-analysis suggests that a tibial nerve stiffness measurement by SSI shows good performance in diagnosing DPN and has considerable potential as a noninvasive tool for detecting DPN.

Shear wave elastography as a quantitative biomarker of diabetic peripheral neuropathy: A systematic review and meta-analysis.

BackgroundDiabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes and the strongest initiating risk factor for diabetic foot ulceration. Early diagnosis of DPN through screening measures is, therefore, of great importance for diabetic patients. Recently, shear wave elastography (SWE) has been used as a method that is complementary to neuroelectrophysiological examination in the diagnosis of DPN. We aimed to conduct a meta-analysis based on currently available data to evaluate the performance of tibial nerve stiffness on SWE for diagnosing DPN.MethodsBoth PubMed, EMBASE, the Cochrane Library, and Web of Science were searched for studies that investigated the diagnostic performance of SWE for DPN up to March 1th, 2022. Three measures of diagnostic test performance, including the summary area under receiver operating characteristics curve (AUROC), the summary sensitivity and specificity, and the summary diagnostic odds ratios were used to assess the diagnostic accuracy of SWE. All included studies were published between 2017 and 2021.ResultsSix eligible studies (with 170 DPN patients, 28 clinically defined DPN patients, 168 non-DPN patients, and 154 control participants) that evaluated tibial nerve stiffness were included for meta-analysis. The summary sensitivity and specificity of SWE for tibial nerve stiffness were 75% (95% confidence interval [CI]: 68–80%) and 86% (95% CI: 80–90%), respectively, and the summary AUROC was 0.84 (95% CI: 0.81–0.87), for diagnosing DPN. A subgroup analysis of five two-dimensional SWE studies revealed similar diagnostic performance, showing the summary sensitivity and specificity of 77% (95% CI: 69–83%) and 86% (95% CI: 79–91%), respectively, and a summary AUROC value of 0.86 (95% CI: 0.83–0.89).ConclusionsSWE is found to have good diagnostic accuracy for detecting DPN and has considerable potential as an important and noninvasive adjunctive tool in the management of patients with DPN.

Changes in tibial nerve stiffness during ankle dorsiflexion according to in-vivo analysis with shear wave elastography.

A more detailed assessment of pathological changes in the tibial nerve (TN) is needed to better assess how physical therapy influences TN pathologies. The cross-sectional nerve area can be used for TN assessment but may be influenced by individual differences in parameters, such as body height, body weight, and foot length. Therefore, there are no known reliable noninvasive quantitative methods for assessing TN neuropathy. Although recent ultrasonographic studies reported that TN stiffness changes could be used to assess TN neuropathies of the foot, these studies did not consider the joint position, and peripheral nerve tension can change with joint movement. Therefore, we considered that TN stiffness assessment could be improved by analyzing the relationship between ankle joint position and TN stiffness. This study aimed to investigate the relationship between TN stiffness and ankle angle changes using shear wave elastography. We hypothesized that the TN shear wave velocity significantly increases with ankle dorsiflexion and that the total ankle range or maximum dorsiflexion range correlates with the shear wave velocity.This cross-sectional study included 20 TNs of 20 healthy adults. Ultrasonography and shear wave elastography were used to evaluate the TN. TN stiffness was measured at 5 ankle positions as follows: maximum dorsiflexion (100% df), plantar flexion in the resting position (0% df), and 3 intermediate points (25% df, 50% df, and 75% df).TN shear wave velocity increased with an increase in ankle df angle. While total ankle range was significantly and negatively correlated with TN stiffness in all ankle positions, the maximum ankle df angle was significantly and negatively correlated only at 75% and 100% df.TN stiffness below 50% df may be affected by gliding or decreased nerve loosening, and TN stiffness above 75% df may be influenced by nerve tensioning. When measuring TN stiffness for diagnostic purposes, TN should be assessed at an ankle joint angle below 50% df.

Quantitative shear wave elastography assessment of tibial nerve in diagnosis of diabetic peripheral neuropathy

BackgroundDiabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus. Diagnosis of DPN is very important in the prognosis of disease and treatment as early treatment of DPN decreases both short-term and long-term morbidities. SWE elastography is a noninvasive and reproducible method for the precise evaluation of nerve stiffness.ResultsTibial nerve stiffness is notably high at SWE in diabetic patients with DPN (mean shear wave elastography value of RT tibial SWE 75.3 ± 15.1 kPa) compared to patients without DPN (mean shear wave elastography value of RT tibial SWE 37.8 ± 11.6 kPa) and nerve stiffness in healthy control subjects (mean shear wave elastography value of RT tibial SWE 24.9 ± 6.3 kPa). There is a significant increase in the cross-sectional area (CSA) among diabetic patients with DPN (mean cross-sectional area of the right tibial nerve of 17 ± 1.9 mm2) and without DPN (mean cross-sectional area of the right tibial nerve of 14.5 ± 3.8 mm2) in comparison with control subjects (mean cross-sectional area of the right tibial nerve of 13.2 ± 3.1 mm2) in the right side. Borderline significance of the CSA parameters of the tibial nerve study on the left side in different groups. The cutoff point to determine DPN among diabetic patients in the right lower limb is more than 63.8 kPa. With 89% sensitivity and 100% specificity in the detection of DPN on the right side, the SWE has 100% PPV and 95.5% NPV in the detection of DPN on the right side.ConclusionSWE is an effective assistant method in the diagnosis of DPN and is useful when a suspected neuropathy is not detectable by electrophysiology.

Ultrasonography for the diagnosis of carpal tunnel syndrome: an umbrella review.

Numerous sonographic modalities and parameters have been used to diagnose carpal tunnel syndrome (CTS), with varying accuracy. Our umbrella review aimed to summarize the evidence from systematic reviews and meta-analyses regarding the use of ultrasound imaging to diagnose CTS. Systematic reviews and meta-analyses meeting the inclusion criteria were searched in PubMed, Embase, Medline, Web of Science, and Cochrane databases from inception to March 2022. Critical appraisal, data extraction, and synthesis were performed in accordance with the criteria for conducting an umbrella review. Sixteen reviews were included. Three reviews were classified as high quality, one as moderate, four as low, and eight as critically low. The cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet demonstrated the best reliability and diagnostic accuracy among multiple parameters. A cutoff CSA value of 9-10.5mm2 gave the highest diagnostic performance in the general population. The degree of CSA enlargement was correlated with CTS severity. Sonoelastography and Doppler ultrasound might provide additional insights into CTS evaluation as median nerve stiffness and vascularity at the wrist were increased in these patients. Sonography is a reliable tool to diagnose CTS, with inlet CSA being the most robust parameter. Sonoelastography and Doppler ultrasound can serve as auxiliary tools to confirm CTS diagnoses. Further studies are needed to expand the use of sonography for diagnosing CTS, especially in the presence of concomitant neuromuscular disease(s).

Diagnostic value of shear wave ultrasound elastography of tibial nerve in patients with diabetic peripheral neuropathy

BackgroundDiabetic peripheral neuropathy (DPN) is a major complication of Diabetes mellitus. So this study aimed at investigation of the value of tibial nerve stiffness measured by shear wave ultrasound elastography (SWE) for detection of DPN. This case–control study involved 50 patients with DPN, 50 patients with diabetes mellitus but without DPN, and 50 healthy controls. Clinical examination, nerve conduction study of both tibial nerves, high resolution ultrasound and SWE to assess cross sectional area "CSA" of tibial nerves, and tibial nerves mean stiffness, respectively. ROC curve analysis was also performed.ResultsMean tibial nerve stiffness by SWE was higher in patients with DPN compared to other groups (P value < 0.001). The CSA of the tibial nerve in the DPN group was significantly larger than that in the other groups (P value = 0.01). The cutoff value by ROC curve analysis for tibial nerve stiffness to differentiate patients with DPN and control group was 70.6 kPa (P value < 0.001, 95.4% sensitivity, 94.7% specificity, AUC = 0.963), while 86.5 kPa was the optimal cutoff point to differentiate patients with DPN and other groups with a 94.6% sensitivity, 93.8% specificity, AUC of 0.975 and P value < 0.001. Higher diagnostic accuracy was found when combination of SWE and high resolution US (high resolution US + shear wave; 0.987, P value < 0.001).ConclusionsTibial nerve stiffness was increased in patients with DPN. SWE can be used as an effective complementary method in diagnosis of DPN with high sensitivity and accuracy.

Spatial variation in mechanical properties along the sciatic and tibial nerves: An ultrasound shear wave elastography study

Ultrasound shear wave elastography has become a promising method in peripheral neuropathy evaluation. Shear wave velocity, a surrogate measure of stiffness, tends to increase in peripheral neuropathies regardless of etiology. However, little is known about the spatial variation in shear wave velocity of healthy peripheral nerves and how tensile loading is distributed along their course. Sixty healthy young adults were scanned using ultrasound shear wave elastography. Five regions of the sciatic (SciaticPROXIMAL, SciaticDISTAL) and tibial nerve (TibialPROXIMAL, TibialINTERMEDIATE, and TibialDISTAL) were assessed in two hip positions that alter nerve tension: 1) neutral in supine position; and 2) flexed at 90°. Knee and ankle remained in full-extension and neutral position. We observed spatial variations in shear wave velocity along the sciatic and tibial nerve (P < 0.0001). Shear wave velocities were significantly different between all nerve locations with the exception of SciaticDISTAL vs. TibialINTERMEDIATE (P = 0.999) and TibialPROXIMAL vs. TibialINTERMEDIATE (P = 0.708), and tended to increase in the proximal-distal direction at both upper and lower leg segments. Shear wave velocity increased with hip flexion (+54.3%; P < 0.0001), but the increase was not different among nerve locations (P = 0.233). This suggests that the increase in tensile loading with hip flexion is uniformally distributed along the nerve tract. These results highlight the importance of considering both limb position and transducer location for biomechanical and clinical assessments of peripheral nerve stiffness. These findings provide evidence about how tension is distributed along the course of sciatic and tibial nerves.