T2 magnetic resonance imaging mapping and morphology of the median nerve before and after surgery in carpal tunnel syndrome.

INTRODUCTION/AIMS: T2 magnetic resonance imaging (MRI) mapping has been applied to carpal tunnel syndrome (CTS) for quantitative assessment of the median nerve. However, quantitative changes in the median nerve before and after surgery using T2 MRI mapping remain unclear. We aimed to investigate whether pathological changes could be identified by pre- and postoperative T2 MRI mapping of the median nerve in CTS patients after open carpal tunnel release. METHODS: This was a prospective study that measured median nerve T2 and cross-sectional area (CSA) values at the distal carpal tunnel, hamate bone, proximal carpal tunnel, and forearm levels pre- and postoperatively. Associations between T2, CSA, and nerve conduction latency were also evaluated. RESULTS: A total of 36 patients with CTS (mean age, 64.5 ± 11.7 years) who underwent surgery were studied. The mean preoperative T2 values significantly decreased from 56.3 to 46.9 ms at the proximal carpal tunnel levels (p = .001), and from 52.4 to 48.7 ms at the hamate levels postoperatively (p = .04). Although there was a moderate association between preoperative T2 values at the distal carpal tunnel levels and distal motor latency values (r = -.46), other T2 values at all four carpal tunnel levels were not significantly associated with CSA or nerve conduction latency pre- or postoperatively. DISCUSSION: T2 MRI mapping of the carpal tunnel suggested a decrease in nerve edema after surgery. T2 MRI mapping provides quantitative information on the median nerve before and after surgery.

Median nerve lesions in pediatric displaced supracondylar humerus fracture: A prospective neurological, electrodiagnostic and ultrasound characterization.

BACKGROUND AND PURPOSE: Supracondylar humerus fractures (SCHFs) are the most common elbow fractures in children. Traumatic median nerve injury and isolated lesions of its pure forearm motor branch, anterior interosseus nerve (AIN), have both been independently reported as complications of displaced SCHFs. Our main objectives were to characterize the neurological syndrome to distinguish median nerve from AIN lesions and to determine the prognosis of median nerve lesions after displaced SCHFs. METHODS: Ten children were prospectively followed for an average of 11.6 months. Patients received a standardized clinical examination and high-resolution ultrasound of the median nerve every 1-3 months starting 1-2 months after trauma. Electrodiagnostic studies were performed within the first 4 months and after complete clinical recovery. RESULTS: All children shared a clinical syndrome with predominant but not exclusive affection of AIN innervated muscles. High-resolution ultrasound uniformly excluded persistent nerve entrapment and neurotmesis requiring revision surgery but visualized post-traumatic median nerve neuroma at the fracture site in all patients. Electrodiagnostic studies showed axonal motor and sensory median nerve neuropathy. All children achieved complete functional recovery under conservative management. Motor recovery required up to 11 months and differed between involved muscles. CONCLUSIONS: It was shown that neurological deficits of the median nerve in displaced SCHFs exceeded an isolated AIN lesion. Notably, detailed neurological follow-up examinations and sonographic exclusion of persistent nerve compression were able to guide conservative therapy in affected children. Under these conditions the prognosis of median nerve lesions was excellent despite severe initial deficits, development of neuroma and axonal injury.

Factors Predicting Prolonged Mechanical Ventilation in Guillain-Barré Syndrome.

BACKGROUND: Up to 30% of patients with Guillain-Barré syndrome require mechanical ventilation and 5% die due to acute complications of mechanical ventilation. There is a considerable group of patients that will need prolonged mechanical ventilation (considered as >14 days) and should be considered for early tracheostomy. The objective of this study is to identify risk factors for prolonged mechanical ventilation. METHODS: We prospectively analyzed patients with Guillain-Barré diagnosis with versus without prolonged mechanical ventilation. We considered clinical and electrophysiological characteristics and analyzed factors associated with prolonged mechanical ventilation. RESULTS: Three hundred and three patients were included; 29% required mechanical ventilation. When comparing the groups, patients with prolonged invasive mechanical ventilation (IMV) have a lower score on the Medical Research Council score (19.5 ± 16.2 vs 27.4 ± 17.5, p = 0.03) and a higher frequency of dysautonomia (42.3% vs 19.4%, p = 0.037), as well as lower amplitudes of the distal compound muscle action potential (CMAP) of the median nerve [0.37 (RIQ 0.07-2.25) vs. 3.9 (RIQ1.2-6.4), p = <0.001] and ulnar nerve [0.37 (RIQ0.0-3.72) vs 1.5 (RIQ0.3-6.6), p = <0.001], and higher frequency of severe axonal damage in these nerves (distal CMAP ≤ 1.0 mV). Through binary logistic regression, severe axonal degeneration of the median nerve is an independent risk factor for prolonged IMV OR 4.9 (95%CI 1.1-21.5) p = 0.03, AUC of 0.774, (95%CI 0.66-0.88), p = < 0.001. CONCLUSIONS: Severe median nerve damage is an independent risk factor for prolonged mechanical ventilation.

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

OBJECTIVE: To compare the effectiveness of I-tape and button hole kinesio taping (KT) techniques added to exercises in the treatment of carpal tunnel syndrome (CTS). DESIGN: Prospective randomized controlled blinded study. SETTING: Physical Medicine and Rehabilitation Outpatient Clinic. PARTICIPANTS: A total of 108 patients (165 wrists) diagnosed with CTS (N=108). INTERVENTIONS: Button hole technique (BG), I-band technique (IG), and exercises (EG). MAIN OUTCOME MEASURES: Visual analog scale (VAS), Douleur Neuropathique 4 Questions (DN4), Boston carpal tunnel syndrome questionnaire, and Jamar dynamometer were used. Median sensory nerve action potential (SNAP), compound muscle action potential (CMAP), median distal sensory latency (DSL), median distal motor latency (DML), sensory conduction velocity, and motor conduction velocity were recorded. Measurements were made at baseline, week 3, and week 12. RESULTS: Thirty-six patients were in each group. Significant statistical improvements in VAS and DN4 scores were found in the BG and IG compared with EG (P<.05). Statistically significant improvements in hand grip strength were observed in the IG compared with the EG (P<.05). Significant improvements in DML levels and motor conduction velocity were observed in the BG and IG compared with the EG (P<.05). A significant increase in sensory conduction velocity was detected in the BG compared with the other groups (P<.05). CONCLUSIONS: Both KT techniques are effective in terms of pain, functionality, symptom severity, grip strength, and electrophysiologically. The button hole technique was more effective in DSL, sensory conduction velocity, CMAP amplitude, and SNAP.

Alternative treatment of carpal tunnel syndrome with ultrasound-guided median nerve hydrodissection in the emergency department.

Hydrodissection is becoming increasingly recognized as a treatment for nerve entrapment syndromes in the orthopedic and rehabilitation world. Carpal Tunnel Syndrome (CTS) is the most prevalent nerve entrapment neuropathy, characterized by compression of the median nerve as it passes through the carpal tunnel. Initial management includes NSAIDs and wrist splints, but surgical intervention is often necessary when these measures fail. Ultrasound-guided hydrodissection of the median nerve is both safe and effective and presents a minimally invasive option when first-line treatments fail to provide adequate symptom relief. This case report demonstrates the potential for an alternative approach to analgesia in the Emergency Department (ED) for patients presenting with pain related to CTS. Here we discuss a case of a 26-year-old female presenting with CTS symptoms and her successful treatment with ultrasound-guided hydrodissection in the ED.

Peripheral nerve injuries associated with dislocated supracondylar fractures of distal humerus in children: incidence and need of surgical treatment.

PURPOSE: The objective of this study was to determine the incidence, necessity for neurosurgical intervention, and overall results of the treatment of pediatric peripheral nerve injuries associated with dislocated supracondylar fractures of the distal humerus. METHOD: A retrospective analysis of pediatric patients with supracondylar fractures treated from April 2019 to April 2022 with a minimum follow-up of 3 months was conducted. RESULTS: Of 453 included patients, there were 51 recorded peripheral nerve injuries. The ulnar nerve was the most frequently injured nerve. Nine patients required neurosurgical intervention, with the most common procedure being the release of entrapped nerves. The combination of a supracondylar fracture and arterial injury was identified as a significant risk factor for peripheral nerve injury (p < 0.001). Only one patient experienced an unsatisfactory outcome. CONCLUSION: Although the prognosis for peripheral nerve injuries in children with supracondylar fractures is generally favorable, these injuries must be properly identified. We recommend an active neurosurgical approach in children with persisting neurological deficits to minimize the risk of permanent neurological impairment.

Influences of Variability in Attenuation Compensation on the Estimation of Backscatter Coefficient of Median Nerves in Vivo.

OBJECTIVE: Peripheral nerves remain a challenging target for medical imaging, given their size, anatomical complexity, and structural heterogeneity. Quantitative ultrasound (QUS) applies a set of techniques to estimate tissue acoustic parameters independent of the imaging platform. Many useful medical and laboratory applications for QUS have been reported, but challenges remain for deployment in vivo, especially for heterogeneous tissues. Several phenomena introduce variability in attenuation estimates, which may influence the estimation of other QUS parameters. For example, estimating the backscatter coefficient (BSC) requires compensation for the attenuation of overlying tissues between the transducer and the underlying tissue of interest. The purpose of this study is to extend prior studies by investigating the efficacy of several analytical methods of estimating attenuation compensation on QUS outcomes in the human median nerve. METHODS: Median nerves were imaged at the volar wrist in vivo and beam-formed radiofrequency (RF) data were acquired. Six analytical approaches for attenuation compensation were compared: 1-2) attenuation estimated by applying spectral difference method (SDM) and spectral log difference method (SLDM) independently to regions of interest (ROIs) overlying the nerve and to the nerve ROI itself; 3-4) attenuation estimation by applying SDM and SLDM to ROIs overlying the nerve, and transferring these properties to the nerve ROI; and 5-6) methods that apply previously published values of tissue attenuation to the measured thickness of each overlying tissue. Mean between-subject estimates of BSC-related outcomes as well as within-subject variability of these outcomes were compared among the 6 methods. RESULTS: Compensating for attenuation using SLDM and values from the literature reduced variability in BSC-based outcomes, compared to SDM. Variability in attenuation coefficients contributes substantially to variability in backscatter measurements. CONCLUSION: This work has implications for the application of QUS to in vivo diagnostic assessments in peripheral nerves and possibly other heterogeneous tissues.

Median Nerve Shear Wave Elastography Is Associated With the Neurophysiological Severity of Carpal Tunnel Syndrome.

OBJECTIVES: This study examines the associations between the median nerve (MN) shear wave elastography (SWE), the MN cross-sectional area (CSA), patient's symptoms, and the neurophysiological severity of carpal tunnel syndrome (CTS). The most appropriate site to perform SWE was also tested. METHODS: This prospective study comprised 86 wrists of 47 consecutive patients who volunteered for MN ultrasound after an electrodiagnostic study. The neurophysiological severity of CTS was assessed according to the results of a nerve conduction study (NCS). The MN CSA was measured at the carpal tunnel inlet (wCSA) and the forearm (fCSA). SWE was performed on the MN in a longitudinal orientation at the wrist crease (wSWE), at the forearm (fSWE), and within the carpal tunnel (tSWE). RESULTS: The wCSA and wSWE correlated positively with the neurophysiological severity of CTS (r = .619, P < .001; r = .582, P < .001, respectively). The optimal cut-off values to discriminate the groups with normal NCS and with findings indicating CTS were 10.5 mm2 for the wCSA and 4.12 m/s for the wSWE. With these cut-off values, wCSA had a sensitivity of 80% and specificity of 87% and wSWE a sensitivity of 88% and specificity of 76%. Neither tSWE nor fSWE correlated with the neurophysiological severity of CTS or differed between NCS negative and positive groups (P = .429, P = .736, respectively). CONCLUSION: Shear wave velocity in the MN at the carpal tunnel inlet increases in CTS and correlates to the neurophysiological CTS severity equivalently to CSA measured at the same site.

Identifying anatomic landmarks and median nerve characteristics for the analysis of persistent carpal tunnel syndrome using magnetic resonance imaging (MRI).

OBJECTIVE: Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy in the USA. In this study, we define anatomical landmarks to assess symptomatic and asymptomatic cohorts with persistent CTS using MRI imaging. MATERIALS AND METHODS: Distal vs proximal incomplete release was determined using the distal most aspect of the hook of hamate and the distal wrist crease. An incomplete release showed the transverse carpal ligament (TCL) intact at either boundary. Twenty-one patients with persistent CTS were analyzed for incomplete release, median nerve enlargement and T2 signal hyperintensity, and flattening ratio using postoperative wrist MRI. These findings were compared to a ten-patient asymptomatic persistent CTS control group. Fisher's exact and a Student's two-tailed t-tests were used to determine statistical significance. RESULTS: In the symptomatic persistent CTS group, 13 (61.9%) incomplete releases were identified, 5 (38.5%) incomplete distally, and 1 (7.7%) incomplete proximally. There was no statistical significance in the rate of incomplete releases when compared to the asymptomatic group (p = 1.00). T2 signal hyperintensity and enlargement at the site of release showed no statistical significance, (p = 0.319 and p = 0.999, respectively). The mean flattening ratio at the site of release in the symptomatic group (2.45 ± 0.7) was statistically significant compared to the asymptomatic group (1.48 ± 0.46), (p = 0.007). CONCLUSION: Utilizing the established landmarks, the full length of the TCL can be assessed via MRI. Additionally, evaluation of the median nerve flattening ratio at the level of the incomplete release may be utilized as an aid to the clinical management of persistent CTS.

Diagnostic efficacy of high-frequency Grey-scale ultrasonography and Sono-elastography in grading the severity of carpal tunnel syndrome in comparison to nerve conduction studies.

OBJECTIVES: To correlate the cross-sectional area (CSA) and elasticity of the median nerve (MN) measured at carpal tunnel inlet between healthy controls and various degrees of carpal tunnel syndrome (CTS) graded as per nerve conduction studies (NCS). MATERIALS AND METHODS: A total of 53 patients (with 81 wrists) presenting with clinical symptoms characteristic of CTS, having their diagnosis confirmed and severity graded by NCS, and 48 healthy controls (with 96 wrists) were included in the study. All the study participants underwent wrist ultrasound which included initial Grey-scale USG followed by strain and shear wave elastography. The CSA and elasticity (in terms of strain ratio and shear modulus) of MN were measured at the carpal tunnel inlet. Statistical analysis was performed using the Mann-Whitney U test to compare between the two groups and for subgroup analysis of cases. The diagnostic performance of each variable was evaluated using the receiver operating characteristic curves. RESULTS: The mean CSA was 9.20 ± 1.64, 11.48 ± 1.05, 14.83 ± 1.19 and 19.87 ± 2.68 mm2, the mean shear modulus was 17.93 ± 2.81, 23.59 ± 2.63, 32.99 ± 4.14 and 54.26 ± 9.24 kPa and the mean strain ratio was 5.26 ± 0.68, 5.56 ± 0.70, 7.03 ± 0.47 and 8.81 ± 0.94 in control, mild, moderate and severe grades of CTS, respectively (p < 0.001). CONCLUSION: The combined utility of Grey-scale USG and Elastography may serve as a painless and cost-effective alternative to NCS in grading the severity of CTS.

Acute Traumatic Coma Awakening Induced by Median Nerve Electrical Stimulation: A Systematic Review and Meta-Analysis.

Traumatic brain injury (TBI) is widely recognized as a major cause of death and disability. Optimizing recovery from coma is a priority for improving patient prognosis. Recently, an increasing number of studies have demonstrated that median nerve electrical stimulation (MNES) may be a potential approach for comatose patients awakening with TBI, although the results of these studies are not consistent. The aim of this study was to evaluate the effects of the MNES on recovery from coma in patients with TBI based on data from randomized controlled trials. The PubMed, Embase, Ovid MEDLINE, Cochrane Library, and China National Knowledge Infrastructure electronic databases were systematically searched from their inception to July 2023 using specific keywords. The χ2 test and I2 test were used to evaluate the heterogeneity across these studies. The mean differences with 95% confidence intervals (CIs) and relative risk (RR) with 95% CIs were adopted to analyze the continuous outcomes and binary outcomes, respectively. A total of 1831 patients from 18 studies were included in this meta-analysis. There were significant differences in the proportions of patients who regained consciousness between the MNES group and the control group after treatment (RR 1.36, 95% CI 1.18-1.56; P < 0.001) and at 6 months after injury (RR 1.31, 95% CI 1.16-1.47; P < 0.001). MNES significantly improved the Glasgow Coma Scale score (mean difference 2.38, 95% CI 1.78-2.98; P < 0.001). Furthermore, no significant differences in complications between the two groups of patients were observed, including pneumonitis (RR 0.86, 95% CI 0.72-1.03; P = 0.107), seizures (RR 1.24, 95% CI 0.49-3.10; P = 0.651), or gastric hemorrhage (RR 1.08, 95% CI 0.60-1.93; P = 0.795).The results of the present study indicate that patients with TBI in the MNES group recovered from coma more rapidly after treatment and at 6 months after injury. These results suggest that MNES is an effective approach for coma awakening after TBI.

Median nerve ultrasonography in Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: The cross-sectional area (CSA) of the median nerve in Parkinson's disease remains unclear. OBJECTIVES: This meta-analysis assesses median nerve CSA changes in Parkinson's using ultrasonography. METHODS: PubMed, Web of Science, Scopus, and EBSCO were selectively searched for literature on Parkinson's disease, Median nerve, and ultrasonography. Following full-text screening, three studies were included in this meta-analysis with 144 Parkinson's disease patients and 127 controls. The primary outcome was the cross-sectional area of the median nerve; other motor parameters were also evaluated. RESULTS: The cross-sectional area of the median nerve was significantly increased in Parkinson's patients compared to controls (p = 0.007); the standardized mean difference was 0.79 [95% CI (0.21 - 1.37)]. The standardized mean difference of the motor parameters of the median nerve, amplitude, and latency was -0.04 [95% CI (-0.85 to 0.77)] and 0.30 [95% CI (-0.04 to 0.64)], respectively, with statistically insignificant (All p > 0.05). CONCLUSION: This meta-analysis concluded that the cross-sectional area of the median nerve is increased in Parkinson's disease patients. The increase in the CSA of the median nerve might explain the higher prevalence of carpal tunnel syndrome in Parkinson's disease. Further studies are needed to quantify carpal tunnel syndrome prevalence accurately in Parkinson's. LIMITATIONS: Heterogeneity exists due to non-standardized CSA calculation methods and varied disease stages. Finger movement during ultrasound may introduce artifacts, compromising CSA measurement accuracy. Establishing a definitive CSA cut-off for carpal tunnel syndrome in Parkinson's requires further investigation.

Excision of large median and ulnar nerve schwannomas: a case series.

OBJECTIVE: Schwannomas are benign, slow-growing tumors originating from Schwann cells in peripheral nerves, commonly affecting the median and ulnar nerves in the forearm and wrist. Surgical excision is the gold standard treatment. This study presents our treatment strategies and outcomes for large-sized ulnar and median nerve schwannomas at the forearm and wrist level. METHODS: From 2012 to 2023, we enrolled 15 patients with schwannomas over 2 cm in size in the median or ulnar nerve at the forearm and wrist. The study included 12 patients with median nerve schwannomas (mean age: 61 years) and 3 with ulnar nerve schwannomas (mean age: 68 years), with a mean follow-up of 26.9 months. RESULTS: After surgery, all patients with median nerve schwannomas experienced mild, transient numbness affecting fewer than two digits, resolving within six months without motor deficits. Ulnar nerve schwannoma excision caused mild numbness in two patients, also resolving within six months, but all three developed ulnar claw hand deformity, which persisted but improved at the last follow-up. Despite this, patients were satisfied with the surgery due to relief from severe tingling pain. CONCLUSIONS: Schwannomas of the median, ulnar, and other peripheral nerves should be removed by carefully dissecting the connecting nerve fascicles to avoid injury to healthy ones. Sensory deficits may occur but are unlikely to significantly impact quality of life. However, in motor-dominant nerves like the ulnar nerve, there is a risk of significant motor deficits that could affect hand function, though not completely. Therefore, thorough preoperative discussion and consideration of interfascicular nerve grafting are essential.

Evaluating the Need for Simultaneous Carpal Tunnel Release With Forearm Fasciotomy.

PURPOSE: The need to include simultaneous carpal tunnel release (sCTR) with forearm fasciotomy for acute compartment syndrome (ACS) or after vascular repair is unclear. We hypothesized that sCTR is more common when: 1) fasciotomies are performed by orthopedic or plastic surgeons, rather than general or vascular surgeons; 2) ACS occurred because of crush, blunt trauma, or fractures rather than vascular/reperfusion injuries; 3) elevated compartment pressures were documented. We also sought to determine the incidence of delayed CTR when not performed simultaneously. METHODS: Retrospective chart review identified patients who underwent forearm fasciotomy for ACS or vascular injury over a period of 10 years. Patient demographics, mechanism of ACS or indication for fasciotomy, surgeon subspecialty, compartment pressure measurements, inclusion of sCTR, complications, reoperations, and timing and method of definitive closure were analyzed. Logistic regression modeling was used to analyze predictors associated with delayed CTR. RESULTS: Fasciotomies were performed in 166 patients by orthopedic (63%), plastic (28%), and general/vascular (9%) surgeons. Orthopedic and plastic surgeons more frequently performed sCTR (67% and 63%, respectively). A total of 107 (65%) patients had sCTR. Fasciotomies for vascular/reperfusion injury were more likely to include sCTR (44%) compared with other mechanisms. If not performed simultaneously, 11 (19%) required delayed CTR at a median of 42 days. ACS secondary to fracture had the highest rate of delayed CTR (35%), and the necessity of late CTR for fractures was not supported by the logistic regression model. Residual hand paresthesias were less frequent in the sCTR group (6.5% vs 20%). Overall complication rates were similar in both groups (63% sCTR vs 70% without sCTR). CONCLUSION: When sCTR is excluded during forearm fasciotomy, 19% of patients required delayed CTR. This rate was higher (35%) when ACS was associated with fractures. Simultaneous CTR with forearm fasciotomy may decrease the incidence of residual hand paresthesias and the need for a delayed CTR. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognosis IV.

Diagnostic meta-analysis of the efficacy of ultrasonography for diagnosing carpal tunnel syndrome: A comparison between Asian and non-Asian populations.

BACKGROUND: Ultrasonography is used to diagnose carpal tunnel syndrome (CTS) according to various criteria. This diagnostic meta-analysis aimed to evaluate the efficacy of ultrasonography for diagnosing CTS, focusing on the cross-sectional area (CSA) of the median nerve (MN) at the inlet of the carpal tunnel and regional variations in diagnostic thresholds between Asian and non-Asian populations. METHODS: A comprehensive literature search was conducted using PubMed, Embase, and the Cochrane Library. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Patient demographic data, diagnostic "gold standards", CSA cutoff values, and diagnostic results were extracted. Meta-analysis was performed to determine the sensitivity, specificity, and optimal CSA cutoff values. RESULTS: For the 25 included studies, a combined sensitivity of 88% and specificity of 84% for CSA measurements at the carpal tunnel inlet were obtained. The Asian group had a sensitivity of 84% and specificity of 86%, while the non-Asian group had a sensitivity of 91% and specificity of 82%. The mean CSA in the Asian group was significantly lower than that in the non-Asian group (12.93 mm2 and 14.77 mm2, respectively; p = 0.042). For the Asian group, the summary receiver operating characteristic curve had an area under the curve (AUC) of 0.92 with an optimal cutoff of 10.5 mm2; for the non-Asian group, an AUC of 0.94 was obtained with a cutoff of 11.5 mm2. CONCLUSION: Ultrasonography is a reliable diagnostic method for CTS, with distinct optimal cutoff values observed between Asian and non-Asian populations. Therefore, population-specific diagnostic criteria for CTS are recommended.

Reliability of Ultrasound Measurements of the Median Nerve in Asymptomatic Subjects Using a Handheld Device.

This study investigated the reliability of measuring the median nerve cross-sectional area (CSA) at the carpal tunnel inlet using a handheld ultrasound device (HUD) compared to a standard ultrasound system, focusing on intra- and inter-operator reproducibility among novice and expert operators. Employing a prospective cross-sectional design, 37 asymptomatic adults were assessed using both devices, with measurements taken by an expert with over five years of experience and a novice with less than six months. The CSA was determined using manual tracing and ellipse methods, with reproducibility evaluated through intraclass correlation coefficients (ICCs) and agreement assessed via Bland-Altman plots. Results showed a high degree of agreement between the devices, with excellent intra-operator reproducibility (ICC > 0.80) for the expert, and moderate reproducibility for the novice (ICCs ranging from 0.539 to 0.841). Inter-operator reliability was generally moderate, indicating acceptable consistency across different experience levels. The study concludes that HUDs are comparable to standard ultrasound systems for assessing median nerve CSA in asymptomatic subjects, with both devices providing reliable measurements. This supports the use of HUDs in diverse clinical environments, particularly where access to traditional ultrasound is limited. Further research with a larger sample and symptomatic patients is recommended to validate these findings.

Frequency-Specific Effects of Noninvasive Median Nerve Stimulation on Gastric Slow Wave Activity in Humans.

OBJECTIVES: The present study explored the effects of different frequencies of noninvasive median nerve stimulation (nMNS) on two autonomic responses: gastric slow waves under water-loading condition and heart rate variability (HRV). To the best of our knowledge, this is the first study to document the effects of different frequencies of nMNS on gastric slow waves (GSW) in humans under 5-minute water-loading condition. MATERIALS AND METHODS: Twenty healthy adult participants were fitted with a noninvasive body-surface gastric mapping, electrocardiogram (ECG), and a transcutaneous electrical nerve stimulation device and administered with four different nMNS frequencies (placebo-0 Hz, 40 Hz, 120 Hz, and 200 Hz) on four separate counterbalanced days. After the baseline and stimulation periods, a 5-minute water-load test was applied, and a post-water-load period also is recorded for ECG and GSW activity. Time-domain HRV parameters are analyzed with repeated-measures one-way analysis of variance (ANOVA) and a post hoc Tukey multiple comparison test. Parameters that failed normality tests underwent a Freidman test with a post hoc Dunn multiple comparison test. GSW data are analyzed with repeated-measures mixed-effects ANOVA. RESULTS: In empty stomach (baseline vs stimulation), only the 40-Hz frequency statistically significantly (p = 0.0129) increased GSW amplitude in comparison with its own baseline. In full (distended) stomach, 40-Hz and 200-Hz stimulations showed a statistically significant difference (post hoc multiple comparison adjusted, p = 0.0016 and p = 0.0183, respectively) in the Gastric Rhythm Index in comparison with the change obtained by placebo stimulation (baseline vs poststimulation periods); 120-Hz nMNS showed a statistically significant difference (p = 0.0300) in the stress index in comparison with the decrease observed in the placebo group. However, 120-Hz nMNS did not induce a statistically significant change in gastric electrical activity compared to placebo stimulation. The nMNS did not follow the linear "dose-response" relationship between nMNS frequency and gastric/HRV parameters. CONCLUSIONS: The 40-Hz and 200-Hz nMNS frequencies showed the most promising results in response to gastric distension, in addition to 40 Hz for an empty stomach. Further research is essential to explore the potential therapeutic effects of these frequencies on gastric diseases such as gastroparesis, gastroesophageal reflux disease, and functional dyspepsia that can be used in wrist wearables.

Clinical-applied anatomy of the carpal tunnel regarding mini-invasive carpal tunnel release.

BACKGROUND: Carpal tunnel release is a widely performed procedure. Despite a high success rate, iatrogenic neurovascular injuries can occur which lead to a painful and unsatisfying outcome. This study conducted a detailed examination of the anatomy of the carpal tunnel and the proximity of neurovascular structures that are particularly susceptible to injury, especially in the context of minimally invasive carpal tunnel release procedures. PATIENTS AND METHODS: The anatomy of the carpal tunnel of 104 wrists of 52 body donors was examined. The precise anatomical location and the presence of variations were recorded for the median nerve, ulnar nerve, ulnar artery and Berrettini branch. The distance between the median nerve, the ulnar artery, the ulnar nerve, and the Berrettini branch was measured in a proximo-distal and radio-ulnar direction in relation to the distal ulnar end of the carpal tunnel. RESULTS: The authors identified four main dangerous anatomical situations. (1) A proximal separation of the Long-Finger/Ring-Finger branch of the median nerve together with a narrow safe-zone; (2) an ulnar take-off of the recurrent muscle branch of the median nerve with a close radio-ulnar distance to the distal ulnar end of carpal tunnel; (3) an ulnar arterial arch lying close to the transverse carpal ligament; and (4) a proximal Berrettini branch also lying close to the latter. All situations are illustrated by photographs. Additionally, the authors present a sonographic carpal tunnel assessment protocol in order to reduce the risk of injury of any neurovascular structure in the proximity of the carpal tunnel. CONCLUSION: Certain patients may inherently face an increased risk of neurovascular injuries during minimally invasive carpal tunnel releases due to their anatomical variations. Four potentially risky scenarios were clearly illustrated. Consequently, one may consider conducting a preoperative ultrasound assessment of neurovascular structures at risk, when endoscopic or ultrasound-guided tunnel release are planned. In high-risk patients, open surgery should be preferred. LEVEL OF EVIDENCE: II.

Immediate effects of Kinesio taping in carpal tunnel syndrome: A randomized controlled double-blind ultrasonographic study.

BACKGROUND: The effects of Kinesio taping (KT) in carpal tunnel syndrome are controversial. PURPOSE: This study aimed to examine whether KT has any effect on the skin, subcutaneous tissue, and median nerve measurements and to compare the effects of two different KT applications. STUDY DESIGN: This is a prospective, double-blinded, randomized trial. This study was prospectively registered on the clinicaltrials.gov (NCT05475197). A total of 34 wrists (21 patients) who were clinically and electrophysiologically diagnosed with mild/moderate carpal tunnel syndrome were randomly divided into two KT intervention groups (group 1: neural technique and area correction technique and group 2: area correction technique). METHODS: At baseline and immediately after the removal of KT (48 hours), pain was assessed with visual analog scale, hand grip strength with a hand-held dynamometer, and pinch strength using a pinch meter. Likewise, using ultrasound, skin and subcutaneous tissue thicknesses, median nerve cross-sectional area and flattening ratio, as well as median nerve depth were measured at the carpal tunnel inlet and outlet levels. RESULTS: While there was significant improvement in the pain scores (compared to the baseline) immediately after the KT in both groups (group 1: p = 0.03, ηp2 = 0.44; group 2: p < 0.001, ηp2 = 0.71), there was no difference in between (p = 0.07, ηp2 = 0.10). Grip strength significantly increased only in group 2 (p = 0.01, ηp2 = 0.35). None of the sonographic measurements displayed significant difference either within or between groups at baseline and after KT (all p > 0.05). CONCLUSIONS: While pain scores improved after KT, they were not coupled with any morphologic changes assessed by ultrasound.

A bilateral four-headed brachialis muscle with a variant innervation: a cadaveric report with possible clinical implications.

PURPOSE: Anterior compartment muscles of the arm present high morphological variability, with possible clinical significance. The current cadaveric report aims to describe a bilateral four-headed brachialis muscle (BM) with aberrant innervation. Emphasis on the embryological background and possible clinical significance are also provided. METHODS: Classical upper limb dissection was performed on an 84-year-old donated male cadaver. The cadaver was donated to the Anatomy Department of the National and Kapodistrian University of Athens. RESULTS: On the left upper limb, the four-headed BM was supplied by the musculocutaneous and the median nerves after their interconnection. On the right upper limb, the four-headed BM received its innervation from the median nerve due to the musculocutaneous nerve absence. A bilateral muscular tunnel for the radial nerve passage was identified, between the BM accessory heads and the brachioradialis muscle. CONCLUSION: BM has clinical significance, due to its proximity to important neurovascular structures and frequent surgeries at the humerus. Hence, knowledge of these variants should keep orthopedic surgeons alert when intervening in this area. Further dissection studies with a standardized protocol are needed to elucidate the prevalence of BM aberrations and concomitant variants.