Brachial plexus avulsion injury (BPAI) causes violent detachment of cervical ventral roots and rapid degeneration of spinal motor neurons (SMNs), driven by abrupt energy failure, axonal disconnection, and a rapidly escalating neuroinflammatory microenvironment. Current evidence demonstrates that SMN loss arises from the coordinated activation of multiple programmed cell death (PCD) pathways-including apoptosis, necroptosis, pyroptosis, ferroptosis, and impaired autophagy-regulated by oxidative stress, mitochondrial dysfunction, calcium overload, iron dyshomeostasis, and inflammasome activation. Crosstalk among these pathways, amplified by microglial priming, macrophage infiltration, and astrocytic reactivity, forms a self-propagating neurodegenerative network extending beyond the avulsion site. This review integrates recent mechanistic advances, highlighting key regulators such as the METTL14-EEF1A2 m6A axis, RIPK1/RIPK3/MLKL necrosome, NLRP3-GSDMD pyroptotic signaling, GPX4-dependent ferroptosis, and AR-SIRT1-AMPK-mTOR-mediated autophagy disruption. We further summarize emerging interventions-including PCD-targeted inhibitors, immunomodulatory therapies, biomaterial-based delivery systems, gene therapy, and neural organoid transplantation-toward precision neuroprotection and improved functional recovery after BPAI.

Objective Manual goniometry is the standard for hand range of motion assessment but is time-consuming and requires in-person visits. This pilot study aimed to develop an AI-based measurement method and to compare its agreement with manual goniometry in both healthy volunteers and patients. Methods In this prospective cross-sectional pilot study (July 2022 to February 2023), an AI-based method was developed using six hand gestures and MediaPipe Hands. Geometric optimization was used for metacarpophalangeal and proximal interphalangeal flexion measurements. For comparison, manual goniometry was performed to evaluate measurement errors. Agreement was evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results The study consisted of 25 healthy individuals (50 hands) and 34 patients (68 hands). The mean difference between the AI-based method and manual measurements was 0.4°±8.8°. Geometric optimization reduced the mean absolute error by 13.5° for metacarpophalangeal and proximal interphalangeal flexion measurements and by 3.5 percentage points for Swanson score. Across all parameters, the overall mean absolute error was 5.14°, root mean square error was 7.05°, and normalized RMSE was 8.7%. For the Swanson score, the method demonstrated excellent consistency (ICC: 0.95) with the manual measurements, and Bland-Altman analysis showed a narrower 95% limits of agreement after optimization (-3.5%, 7.7%) compared to the pre-optimized results (-2.4%, 13.2%). Conclusions This AI-based method showed acceptable agreement with manual goniometry for most measurements. The Swanson score measurement was clinically acceptable, but thumb movements and proximal interphalangeal flexion require further refinement. The method may serve as a supportive tool for hand function assessment, pending validation in more severe hand impairments and varied environmental conditions.

Corticospinal tracts (CST) from the contralateral side spontaneously sprouting into the denervated motor neurons in the impaired spinal hemicord allow the contralateral motor cortex to control the paralyzed limb, improving the impaired limb function after unilateral brain injury. However, the intrinsic potential for axon outgrowth in adults is limited, restricting the functional recovery through CST sprouting. While ribosomal RNA modification has been reported in regulating CST sprouting, the role of transfer RNA (tRNA) modifications remains unclear. Here, we investigated METTL1, the methyltransferase for tRNA m7G modification, as a potential regulator of CST sprouting. In a mouse model of unilateral traumatic brain injury, we found overexpression of METTL1 in contralesional corticospinal neurons improved motor function recovery and promoted CST sprouting. Mechanistically, METTL1 upregulates tRNA m7G modification level, which augments the translation efficiency of mRNAs associated with axon outgrowth, particularly those within the mTOR signaling pathway. Critically, pharmacological inhibition of mTOR signaling with rapamycin diminishes the beneficial effects of METTL1 overexpression on axon outgrowth and CST sprouting. Our findings reveal a novel role for METTL1-mediated tRNA m7G modification in promoting neural repair and identify a potential therapeutic strategy for enhancing recovery after unilateral brain injury.

Background Shoulder pain is a highly prevalent musculoskeletal disorder that severely compromises patients’ quality of life. The Constant-Murley Scale (CMS) is a well-established method for shoulder function evaluation. However, the necessity of clinician involvement constrains its utility in continuous monitoring. Recent improvements in human pose estimation and inertial sensors provide possibilities for automated functional assessment. Objective This study introduces an automated CMS assessment system that can provide objective measuring results using movement images and inertial sensor data (Mobile Constant) and aims to evaluate its reliability by comparison with standard results from human raters. Methods The Mobile Constant system integrated subjective symptom questionnaires, range-of-motion analysis, and strength assessment. Patients presenting with shoulder concerns were enrolled consecutively, with movement images and inertial sensor data collected from each participant. The dataset was structured as follows: patients recruited from February to November 2022 at our hospital formed the training set, those enrolled between December 2022 and February 2023 served as the internal validation set, and patients recruited from April to July 2025 at an independent hospital constituted the external validation set. Gold standard assessments were determined independently by 2 raters using standardized protocols. Six machine learning models (logistic regression, k-nearest neighbors, decision tree, support vector machine, random forest, and adaptive boosting) were developed. The reliability of the system was determined by comparison with human raters using differences, Cohen κ coefficients, and intraclass correlation coefficients (ICCs). Agreement across human raters was also evaluated by comparison between 4 independent clinicians. Results Data from 141 patients with shoulder pain and stiffness were collected (training set: n=83, 58.9%; internal validation set: n=28; 19.9%; external validation set: n=30, 21.3%). For range-of-motion analysis, the Mobile Constant system showed fair to substantial reliability, achieving κ coefficients ranging from 0.498 to 0.819 and ICCs ranging from 0.898 to 0.956 in the internal validation set. In the external validation set, κ coefficients ranged from 0.198 to 0.699, and ICCs ranged from 0.584 to 0.922. For abduction strength assessment, the k-nearest neighbors model demonstrated substantial reliability, yielding a κ coefficient of 0.707 and an ICC of 0.759 in internal validation and higher agreement in external validation (κ=0.809; ICC=0.906). Conclusions The self-reported method for shoulder function evaluation demonstrated substantial agreement with experienced human raters. The proposed system enabled reliable patient-conducted assessment using mobile phone–integrated cameras and inertial sensors and exhibited strong potential for remote monitoring.

Patients with brachial plexus injuries often require long-term follow-up, and the frequent hospital visits can be a burden. Remote monitoring of these patients could be facilitated using Human Pose Estimation algorithms. We evaluated the performance of seven recently released algorithms and developed a WeChat mini-program using the best performing model. The validity of this program was then assessed in brachial plexus injured patients by comparing its results with those of manual goniometry. Our results demonstrated acceptable accuracy of this model, with mean differences of 4° and 7° when compared with manual goniometry in shoulder abduction and elbow flexion, respectively. Remote monitoring using a WeChat mini-program is a reliable and convenient tool for the follow-up of brachial plexus injury patients.Level of evidence: II.

OBJECTIVE:Depth camera-based measurement has demonstrated efficacy in automated assessment of upper limb Fugl-Meyer Assessment for paralysis rehabilitation. However, there is a lack of adequately sized studies to provide clinical support. Thus, we developed an automated system utilizing depth camera and machine learning, and assessed its feasibility and validity in a clinical setting.DESIGN:Validation and feasibility study of a measurement instrument based on single cross-sectional data.SETTING:Rehabilitation unit in a general hospital.PARTICIPANTS:Ninety-five patients with hemiparesis admitted for inpatient rehabilitation unit (2021-2023).MAIN MEASURES:Scores for each item, excluding those related to reflexes, were computed utilizing machine learning models trained on participant videos and readouts from force test devices, while the remaining reflex scores were derived through regression algorithms. Concurrent criterion validity was evaluated using sensitivity, specificity, percent agreement and Cohen's Kappa coefficient for ordinal scores of individual items, as well as correlations and intraclass correlation coefficients for total scores. Video-based manual assessment was also conducted and compared to the automated tools.RESULT:The majority of patients completed the assessment without therapist intervention. The automated scoring models demonstrated superior validity compared to video-based manual assessment across most items. The total scores derived from the automated assessment exhibited a high coefficient of 0.960. However, the validity of force test items utilizing force sensing resistors was relatively low.CONCLUSION:The integration of depth camera technology and machine learning models for automated Fugl-Meyer Assessment demonstrated acceptable validity and feasibility, suggesting its potential as a valuable tool in rehabilitation assessment.

BACKGROUND:Brachial plexus injury is recognized as one of the most severe clinical challenges due to the complex anatomical configuration of the brachial plexus and its propensity for variation, which complicates safe clinical interventions. This study aimed to ascertain the prevalence and characterize the types of brachial plexus variations, and to elucidate their clinical implications.MATERIALS AND METHODS:We conducted meticulous dissections of 60 formalin-fixed cadavers' upper arm, axilla and lower neck to reveal and assess the roots, trunks, divisions, cords, and branches of the brachial plexus. The pattern of branching was noted by groups of dissecting medical students and confirmed by the senior anatomists. The variations discovered were record and photographed using a digital camera for further analysis.RESULTS:Variations in the brachial plexus were identified in 40 of the 60 cadavers, yielding a prevalence rate of 66.7%. These variations were classified into root anomalies (2.1%), trunk anomalies (8.5%), division anomalies (2.1%), and cord anomalies (4.3%). Notably, anomalies in communicating branches were observed in 39 cadavers (83.0%): 14 with bilateral anomalies, 14 with anomalies on the left side, and 11 on the right side. These communicating branches formed connections between the roots and other segments, including trunks, cords, and terminal nerves, and involved the median, musculocutaneous, and ulnar nerves.CONCLUSION:The frequency and diversity of brachial plexus variations, particularly in communicating branches, are significant in cadavers. It is imperative that these variations are carefully considered during the diagnostic process, treatment planning, and prior to procedures such as supraclavicular brachial plexus blocks and nerve transfers, to mitigate the risk of iatrogenic complications.

The purpose of this cross-sectional study was to determine the precision and accuracy of the measurement of finger motion with a depth camera. Fifty-five healthy adult hands were included. Measurements were done with a depth camera and compared with traditional manual goniometer measurements. Repeated measuring showed that the overall repeatability and reproducibility of extension measured with the depth camera were within 3° and 4° and that of flexion were within 13° and 14°. Compared with traditional manual goniometry, biases of extension of all finger joints and flexion of metacarpophalangeal joints were less than 5°, and the average bias of flexion of proximal and distal interphalangeal joints was 29°. We conclude that the measurement of finger extension and flexion of the metacarpophalangeal joints with a depth camera was reliable, but improvement is required in the precision and accuracy of interphalangeal joint flexion.

Background Telemedicine support virtual consultations and evaluations in hand surgery for patients in remote areas during the COVID-19 era. However, traditional physical examination is challenging in telemedicine and it is inconvenient to manually measure the hand range of motion (ROM) from images or videos. Here, we propose an automatic method using the hand pose estimation technique, aiming to measure the hand ROM from smartphone images. Methods Twenty-eight healthy volunteers participated in the study. An eight-hand gestures measurement protocol and the Google MediaPipe Hands were used to analyze images and calculate the ROM automatically. Manual goniometry was also performed according to the guideline of the American Medical Association. The correlation between the automatic and manual methods was analyzed by the intraclass correlation coefficient and Pearson correlation coefficient. The clinical acceptance was testified using Bland-Altman plots. Results A total of 32 parameters of each hand were measured by both methods, and 1792 measurement results were compared. The mean difference between automatic and manual methods is −2.21 ± 9.29° in the angle measurement and 0.48 ± 0.48 cm in the distance measurement. The intraclass correlation coefficient of 75% of parameters was higher than 0.75, the Pearson correlation coefficient of 84% of parameters was over 0.6, and 40.6% of parameters reached well-accepted clinical agreements. Conclusions The proposed method provides a helpful protocol for automatic hand ROM measurement based on smartphone images and the MediaPipe Hands pose estimation technique. The automatic measurement is acceptable and comparable with existing methods, showing a possible application in the telemedicine examination of hand surgery.

Purpose:Quantitative measurement of hand motion is essential in evaluating hand function. This study aimed to investigate the validity and reliability of a novel depth camera-based contactless automatic measurement system to assess hand range of motion and its potential benefits in clinical applications.Methods:Five hand gestures were designed to evaluate the hand range of motion using a depth camera-based measurement system. Seventy-one volunteers were enrolled in performing the designed hand gestures. Then, the hand range of motion was measured with the depth camera and manual procedures. System validity was evaluated based on 3 dimensions: repeatability, within-laboratory precision, and reproducibility. For system reliability, linear evaluation, the intraclass correlation coefficient, paired t -test and bias were employed to test the consistency and difference between the depth camera and manual procedures.Results:When measuring phalangeal length, repeatability, within-laboratory precision, and reproducibility were 2.63%, 12.87%, and 27.15%, respectively. When measuring angles of hand motion, the mean repeatability and within-laboratory precision were 1.2° and 3.3° for extension of 5 digits, 2.7° and 10.2° for flexion of 4 fingers, and 3.1° and 5.3° for abduction of 4 metacarpophalangeal joints, respectively. For system reliability, the results showed excellent consistency (intraclass correlation coefficient = 0.823; P < .05) and good linearity with the manual procedures (r = 0.909-0.982, approximately; P < .001). Besides, 78.3% of the measurements were clinically acceptable.Conclusions:Our depth camera-based evaluation system provides acceptable validity and reliability in measuring hand range of motion and offers potential benefits for clinical care and research in hand surgery. However, further studies are required before clinical application.Clinical relevance:This study suggests a depth camera-based contactless automatic measurement system holds promise for assessing hand range of motion in hand function evaluation, diagnosis, and rehabilitation for medical staff. However, it is currently not adequate for all clinical applications.

Objective To validate the use of key point matrix technology based contactless automatic measurement for evaluation of joint motion of hand. Methods Thirty-three volunteers were enrolled to evaluate the extension and flexion of hand joints between May 2021 and November 2021. There were 20 males and 13 females, the age ranged from 16 to 70 years with an average of 30.2 years. The extension angles of 14 joints of 5 fingers (including hyperextension) and the flexion angles of 12 joints of 4 fingers (excluding thumb) of volunteers were measured by key point matrix technology and manual goniometer, respectively. Then 5 participants and repeated measurement experiment were employed to test the system repeatability and accuracy; 28 participants and paired measurement experiment were employed to test the system accuracy. Results The average repeatability of finger joint motion measured by the key point matrix technology was 1.801° (extension) and 7.823° (flexion), respectively. Compared with manual measurement, the average differences of each finger joint measured by the key point matrix technology were 3.225° in extension and 14.145° in flexion, respectively. The key point matrix technology based contactless automatic evaluation system offered excellent consistency with the manual goniometers ( ICC=0.875). While most of the consistency with manual goniometer of individual joints were at moderate levels (median of ICC, 0.440). The correlation coefficients between the measurement results of the two methods were mainly positive in the extension of the joint ( P<0.05) and negative in the flexion of the joints ( P<0.05). Conclusion The key point matrix technology based contactless automatic evaluation provides sufficient measurement repeatability and accuracy in evaluation for the joint motion of hand.

Background Radial, ulnar, or median nerve injuries are common peripheral nerve injuries. They usually present specific abnormal signs on the hands as evidence for hand surgeons to diagnose. However, without specialized knowledge, it is difficult for primary healthcare providers to recognize the clinical meaning and the potential nerve injuries through the abnormalities, often leading to misdiagnosis. Developing technologies for automatically detecting abnormal hand gestures would assist general medical service practitioners with an early diagnosis and treatment. Methods Based on expert experience, we selected three hand gestures with predetermined features and rules as three independent binary classification tasks for abnormal gesture detection. Images from patients with unilateral radial, ulnar, or median nerve injuries and healthy volunteers were obtained using a smartphone. The landmark coordinates were extracted using Google MediaPipe Hands to calculate the features. The receiver operating characteristic curve was employed for feature selection. We compared the performance of rule-based models with logistic regression, support vector machine and of random forest machine learning models by evaluating the accuracy, sensitivity, and specificity. Results The study included 1,344 images, twenty-two patients, and thirty-four volunteers. In rule-based models, eight features were finally selected. The accuracy, sensitivity, and specificity were (1) 98.2, 91.7, and 99.0% for radial nerve injury detection; (2) 97.3, 83.3, and 99.0% for ulnar nerve injury detection; and (3) 96.4, 87.5, and 97.1% for median nerve injury detection, respectively. All machine learning models had accuracy above 95% and sensitivity ranging from 37.5 to 100%. Conclusion Our study provides a helpful tool for detecting abnormal gestures in radial, ulnar, or median nerve injuries with satisfying accuracy, sensitivity, and specificity. It confirms that hand pose estimation could automatically analyze and detect the abnormalities from images of these patients. It has the potential to be a simple and convenient screening method for primary healthcare and telemedicine application.

Background Range of motion (ROM) measurements are essential for diagnosing and evaluating upper extremity conditions. Clinical goniometry is the most commonly used methods but it is time-consuming and skill-demanding. Recent advances in human tracking algorithm suggest potential for automatic angle measuring from RGB images. It provides an attractive alternative for at-distance measuring. However, the reliability of this method has not been fully established. The purpose of this study is to evaluate if the results of algorithm are as reliable as human raters in upper limb movements. Methods Thirty healthy young adults (20 males, 10 females) participated in this study. Participants were asked to performed a 6-motion task including movement of shoulder, elbow and wrist. Images of movements were captured by commercial digital cameras. Each movement was measured by a pose tracking algorithm (OpenPose) and compared with the surgeon-measurement results. The mean differences between the two measurements were compared. Pearson correlation coefficients were used to determine the relationship. Reliability was investigated by the intra-class correlation coefficients. Results Comparing this algorithm-based method with manual measurement, the mean differences were less than 3 degrees in 5 motions (shoulder abduction: 0.51; shoulder elevation: 2.87; elbow flexion:0.38; elbow extension:0.65; wrist extension: 0.78) except wrist flexion. All the intra-class correlation coefficients were larger than 0.60. The Pearson coefficients also showed high correlations between the two measurements ( p < 0.001). Conclusions Our results indicated that pose estimation is a reliable method to measure the shoulder and elbow angles, supporting RGB images for measuring joint ROM. Our results presented the possibility that patients can assess their ROM by photos taken by a digital camera. Trial registration This study was registered in the Clinical Trials Center of The First Affiliated Hospital, Sun Yat-sen University (2021–387).

Purpose Treatment of total brachial plexus avulsion (TBPA) is a challenge in the clinic, especially the restoration of hand function. The current main surgical order is from proximal to distal joints. The purpose of this study was to demonstrate the outcomes of “distal to proximal” surgical method. Methods Thirty-nine patients underwent contralateral C7 (CC7) nerve transfer to directly repair the lower trunk (CC7-LT) and phrenic nerve transfer to the suprascapular nerve (PN-SSN) during the first stage, followed by free functional gracilis transplantation (FFGT) for elbow flexion and finger extension. Muscle strength of upper limb, degree of shoulder abduction and elbow flexion, and Semmes–Weinstein monofilament test and static two-point discrimination of the hand were examined according to the modified British Medical Research Council (mBMRC) scoring system. Results The results showed that motor recovery reached a level of M3 + or greater in 66.7% of patients for shoulder abduction, 87.2% of patients for elbow flexion, 48.7% of patients for finger extension, and 25.6% of patients for finger flexion. The mean shoulder abduction angle was 45.5° (range 0–90°), and the average elbow flexion angle was 107.2° (range 0–142°), with 2.5 kg average flexion strength (range 0.5–5 kg). In addition, protective sensibility (≥ S2) was found to be achieved in 71.8% of patients. Conclusion In reconstruction of TBPA, CC7 transfer combined with free functional gracilis transplantation is an available treatment method. It could help patients regain shoulder joint stability and the function of elbow flexion and finger extension and, more importantly, provide finger sensation and partial finger flexion function. However, the pick-up function was unsatisfied, which needed additional surgery.

Background This study aimed to investigate outcomes after extremity arterial injury repair and examined the association between outcomes and the degree of soft tissue injury and vascular repair methods. Methods A retrospective study was conducted on 106 patients (108 cases) who underwent emergent microsurgical repair of extremity arterial injury due to trauma and non-perfusion of the affected extremity. The cases were divided into three groups by degree of associated soft tissue injuries: (A) adequate soft tissue coverage over the injured major vessels after radical debridement, (B) inadequate soft tissue coverage over the injured major vessels after radical debridement, and (C) radical debridement was not feasible due to unclear extent of injured soft tissue. Differences in vascular repair methods and outcomes among the three groups were analyzed. Results In Group A (n = 61), microvascular suture and vessel graft achieved 95.1% and 85.0% successful limb reperfusion, respectively. In Group B (n = 31), vessel reconstruction with flap coverage achieved 100% successful reperfusion. Vessel graft achieved 28.6% successful limb reperfusion, while there were no cases of successful reperfusion using microvascular sutures. In Group C (n = 16), no vascular repair method achieved successful reperfusion. There were significant differences among the three groups in successful reperfusion (p < 0.001) and limb salvage (p < 0.001). Conclusion The extent of associated soft tissue injury was associated with different vascular repair methods and outcomes. We propose a new system for classifying these injuries according to the degree of associated soft tissue injury.

Objective:To investigate the preoperative risk factors affecting early extremity blood supply after repair of major arterial injury so as to provide clues for prevention of limb ischemia.Methods:The clinical data were retrospectively analyzed of the 139 patients (140 extremities) with major extremity arterial injury who had been admitted to Department of Microsurgery, Orthopaedic Trauma and Hand Surgery, The First Hospital Affiliated to Sun Yat-sen University from January 2003 to December 2019. There were 112 males and 27 females, with a mean age of 30 (20, 44) years. The primary outcome was the early status of blood supply to the injured extremity (48 hours after surgery). Univariate analysis was conducted of such factors as gender, age, ischemia time, injury mechanism, injury site, fracture, soft tissue lesion, and duration of surgery. The significant factors ( P<0.1) were then analyzed by logistic regression, and P<0.05 was considered statistically significant. Results:Ischemia happened in 44 (31.4%, 44/140) extremities within 48 hours after surgery. There were significant differences in injury mechanism, ischemia time, fracture, and soft tissue lesion between patients with and without postoperative extremity ischemia ( P<0.05). Logistic regression analysis indicated that blunt injury ( OR=5.639, 95% CI: 1.068 to 29.761, P=0.042) and soft tissue lesion ( OR=12.568, 95% CI: 3.402 to 46.431, P<0.001) were significant preoperative risk factors affecting the early blood supply after repair of major extremity arterial injury. Conclusion:As blunt injury and soft tissue defect are preoperative risk factors for early extremity ischemia after repair of major extremity arterial injury, surgeons should pay more attention to them when assessing patients and making repair protocols.

Objective. This study aimed to evaluate whether the site of C7 neurotomy affects spinal cord glial cell activation and pain-related behavior on the paralyzed side in a rat stroke model. Methods. After middle cerebral artery occlusion (MCAO) was induced in male Sprague-Dawley rats, they underwent C7 neurotomy 0, 2, and 4 mm distal to the intervertebral foramen on the paralyzed side. Pain-related behavior and immunofluorescence examination of spinal cord glial cell activation in the ipsilateral C7 dorsal horn were evaluated. Results. Mechanical paw withdrawal threshold (MPWT) was lower, and the number of microglia and astrocytes (/mm(2)) was higher as the distance between the site of C7 neurotomy and the intervertebral foramen decreased from 4 mm to 0. Conclusion. The site of C7 neurotomy affects MPWT and spinal cord glial proliferation in rats with MCAO. Nerve division closer to intervertebral foramen resulted in lower MPWT and higher degree of glial proliferation in the spinal cord.

Horner syndrome is a clinical constellation that presents with miosis, ptosis, and facial anhidrosis. It is important as a warning sign of the damaged oculosympathetic chain, potentially with serious causes. However, the diagnosis of Horner syndrome is operator dependent and subjective. This study aims to present an objective method that can recognize Horner sign from facial photos and verify its accuracy. A total of 173 images were collected, annotated, and divided into training and testing groups. Two types of classifiers were trained (two-stage classifier and one-stage classifier). The two-stage method utilized the MediaPipe face mesh to estimate the coordinates of landmarks and generate facial geometric features accordingly. Then, ten machine learning classifiers were trained based on this. The one-stage classifier was trained based on one of the latest algorithms, YOLO v5. The performance of the classifier was evaluated by the diagnosis accuracy, sensitivity, and specificity. For the two-stage model, the MediaPipe successfully detected 92.2% of images in the testing group, and the Decision Tree Classifier presented the highest accuracy (0.790). The sensitivity and specificity of this classifier were 0.432 and 0.970, respectively. As for the one-stage classifier, the accuracy, sensitivity, and specificity were 0.65, 0.51, and 0.84, respectively. The results of this study proved the possibility of automatic detection of Horner syndrome from images. This tool could work as a second advisor for neurologists by reducing subjectivity and increasing accuracy in diagnosing Horner syndrome.

Background: The purpose of this study was to illustrate the characteristics of skeletal muscle ECM hydrogels and assess the function and underlying mechanisms of hydrogels combined with TGFβ1 for the myogenesis of skeletal muscle stem cells (SkMSCs). Methods: Six methods were used to obtain extracellular matrix (ECM) from rat skeletal muscle. Hydrogel components and cytocompatibility were assessed by Masson’s trichrome staining, scanning electron microscopy, the sulfated glycosaminoglycan (s-GAG) and bFGF contents and a cell viability assay. Satellite cells were sorted, identified and seeded into skeletal muscle ECM hydrogels with TGFβ1. To determine the function of decellularized aligned skeletal muscle ECM hydrogels with TGFβ1 for the proliferation and differentiation of SkMSCs, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2′-deoxyuridine (EdU) analysis and immunofluorescence staining were conducted. RNA stability assay and Gene set enrichment analysis (GSEA) were used to further investigated the mechanism underlying the function. Results: Our study established a highly efficient method for the decellularization of skeletal muscle and fabricated an ECM hydrogel without cell components that preserves the rich ECM composition. This hydrogel formed a three-dimensional microstructure and showed good biocompatibility. We found that the decellularized aligned ECM scaffold with TGFβ1 promoted SkMSC proliferation and suppressed SkMSC differentiation through extracellular signal-regulated kinase (ERK) signaling. Our study suggested that TGFβ1 increases the m6A methylation of the integrin mRNA 3’UTR, thereby inducing the phosphorylation of ERK and promoting SkMSCs proliferation and differentiation.Conclusions: Our study explored a highly efficient method for the decellularization of skeletal muscle and fabricated an ECM hydrogel with a three-dimensional microstructure and good biocompatibility. Furthermore, we demonstrated that decellularized aligned ECM scaffolds with TGFβ1 promoted SkMSC proliferation and differentiation through enhancing the m6A methylation of the integrin mRNA 3’UTR, which may serve as a potential therapeutic strategy for the acute and chronic muscle injuries

Background Ultrasonic measurement has not been utilized to assess the functional recovery of transplanted muscle. This study aimed to investigate the feasibility of using B-ultrasound measurement to assess muscle recovery following free functioning gracilis transfer. Methods From January 2009 to January 2014, 35 patients receiving free functioning gracilis transfer to treat total brachial plexus injury were enrolled. B-ultrasound was adopted to determine the cross-sectional area (CSA) of transplanted gracilis muscle at rest and contraction state. The ratio of pre- to post-transplant CSA value at rest state was defined as muscle bulk ratio (MBR). The ratio of CSA value at contraction state to rest state was defined as contraction ratio (CR). Results Patients with muscle strength M ≥ 4 had significantly higher CR1 (post-transplant), CR2 (pre-transplant), and range of motion (ROM, joint mobility) than those with muscle strength M < 4. The CR1 > CR2 group had significantly higher CR1, muscle strength, and ROM than the CR1 ≤ CR2 group. The MBR > 1 group had significantly higher muscle strength than the MBR ≤ 1 group. CR1 value was highly correlated with muscle strength and with ROM. CR2 value was moderately correlated with muscle strength and ROM. Multivariate linear regression analysis showed that a higher CR1/CR2 value was associated with a higher muscle strength and joint mobility. The CR1 > CR2 group had better muscle strength and ROM than the CR1 ≤ CR2 groups. Conclusion B-ultrasound measurement can quantitatively reflect muscle strength following gracilis transfer, and CR value could be a potential indicator for functional recovery of the transplanted gracilis muscle. Level of Evidence: Prognostic studies, Level II.