The undulating characteristics of nerve fibers and the endoneurium are important factors in resisting traction force. The diagnostic accuracies of magnetic resonance neurography and ultrasonography for nerve injuries are 85.4% and 70.6%, respectively. Epineurial repair is the most commonly used nerve repair technique. Nerve grafts are generally required when the defect exceeds 2 cm. Nerve transfers are primarily indicated for brachial plexus root avulsions or intraforaminal lesions. Painful neuromas can be treated with target muscle reinnervation. Surgery yields reliable results for carpal-tunnel syndrome, cubital-tunnel syndrome, the common peroneal nerve entrapment, and the lateral femoral cutaneous nerve entrapment syndrome. Effective rehabilitation interventions related to the central nervous system include sensory reeducation, cross-modal sensory substitution, motor imagery, and action observation with simultaneous peripheral nerve stimulation.

Brachial plexus root avulsion (BPRA), a well-known form of peripheral nerve injury, results in motor function loss in the affected forelimb due to motoneuron (MN) death, which may be influenced by neuroinflammation following a lesion in the spinal cord. Although synthase-stimulator of interferon genes (STING) signaling can contribute to chronic inflammation and tissue damage in a number of pathological conditions, the essential role of STING signaling in BPRA remains to be reported. Based on our previous findings that the STING mRNA level is upregulated in the anterior horn of the segment of the affected spinal cords of mice with BPRA, STING may be associated with motor recovery in BPRA. In the present study, STING knockout transgenic mice were used to establish a BPRA re-implantation model, which was followed by behavioral tests, histochemical staining and quantitative reverse transcription polymerase chain reaction. The results demonstrated that STING deficiency can increase the body weight, promote motor recovery, decrease MN death, inhibit pyroptosis and neuroinflammation, increase remyelination, and reduce the atrophy of the biceps brachii in mice with BPRA. These combined results suggest that inhibition of STING may be a promising strategy for treating BPRA.

FNDC5-overexpressed BMSCs Attenuated Brachial Plexus Root Avulsion by Enhancing BMSCs Survival and Inhibiting Motoneurons Apoptosis

Background/Objectives: Hereditary transthyretin amyloidosis (ATTRv) is an autosomal dominant disorder characterized by systemic deposition of amyloid fibrils, leading to peripheral neuropathy and multisystemic involvement. Peripheral nerve ultrasound is a promising tool for detecting structural nerve changes, yet its use in Latin American populations is limited. This study aimed to characterize nerve ultrasound findings in Brazilian patients with ATTRv. Methods: We conducted a cross-sectional study of 72 genetically confirmed ATTRv individuals from two Brazilian centers. Participants were classified into symptomatic patients with polyneuropathy (n = 31) and asymptomatic TTR variant carriers (n = 41). All participants underwent a standardized neurological examination, and nerve ultrasound was used to assess the median nerve, brachial plexus, and C6 root. Cross-sectional areas (CSAs) from the right side were used for analysis and compared to reference values. Results: Symptomatic patients showed increased CSAs in the median nerve (wrist: 10.17 mm2, arm: 9.8 mm2), C6 root (8.55 mm2), and brachial plexus (70.82 mm2; all p < 0.05), but not in the forearm. Notably, asymptomatic carriers exhibited nerve enlargement in the median nerve at the wrist, the C6 root, and the brachial plexus, despite lacking clinical signs of neuropathy. Peripheral nerve enlargement in ATTRv affects both symptomatic patients and asymptomatic carriers, with a predilection for proximal and entrapment sites. Conclusions: These findings support the utility of nerve ultrasound as a non-invasive biomarker for early nerve involvement in ATTRv. Further studies are warranted to validate its role in disease monitoring and guide therapeutic interventions, especially in genetically at-risk populations.

BackgroundThe accurate evaluation of Narakas type IV obstetrical brachial plexus palsy (OBPP) has been limited due to certain shortcomings in imaging technology. High-frequency ultrasonography may offer clearer observation of the brachial plexus, providing a more reliable imaging method in diagnosis and treatment for children with Narakas type IV OBPP. This study aimed to investigate the role of high-frequency ultrasound technology in assessing the location and injury characteristics of nerve root lesions in children with Narakas type IV OBPP.MethodsA total of 24 patients underwent brachial plexus reconstruction at the Children’s Hospital of Fudan University between December 2020 and November 2021 after ultrasound examination. Ultrasound exploration of the bilateral brachial plexus roots of all patients was performed with an ACUSON Sequoia ultrasound system by a single sonologist before ultrasound results were compared with findings from intraoperative exploration.ResultsA total of 24 out of 27 patients who sought medical attention underwent an operation before an ultrasound examination. Among the 24 patients, nerve trunk injuries identified by ultrasonography were classified into two categories based on the distance from the intervertebral foramen: (I) abnormality beside the intervertebral foramen, suggesting the presence of nerve root avulsion injury, and (II) postganglionic abnormality, suggesting the presence of postganglionic nerve root rupture. All injuries of the C5–7 nerves could be observed by ultrasound, whose accuracy in diagnosing the injury to the C5, C6, and C7 nerves was 83.3%, 75.0%, and 75.0%, respectively. The detection rate for ultrasound of C8 nerve injury was 37.0%, but the accuracy of ultrasound in 10 patients was 100%.ConclusionsHigh-frequency ultrasonography clearly showed the course, lesion locations, and injury characteristics of the C5–C7 nerve roots with a relatively high accuracy, but was limited in examining the C8 and T1 nerve roots.

Cervical ribs, also known as "accessory ribs" or "supernumerary ribs in the cervical region," are the congenital excessive development of the transverse processes, especially of the seventh cervical vertebra. They occur in approximately 0.5% of the population, are usually bilateral, although often asymmetrical, and are more common in women. The most common cervical rib is type III, followed by type I according to Gruber's classification. They are usually asymptomatic but can cause discomfort in the functioning of the brachial plexus roots or the subclavian artery/vein. This occurs when the most anterior portion of the transverse process exceeds the anterior border of the middle scalene muscle, which can cause superior thoracic outlet syndrome. Therefore, their presence must be documented in the written report. They are diagnosed incidentally on a chest or cervical spine x-ray.

BackgroundBrachial plexus root avulsion (BPRA) often occurs in high-speed traffic accidents or shoulder dystocia, resulting in motor dysfunction. S-ketamine, a clinical anesthetic and antidepressant drug, is an NMDA receptor antagonist that may be effective against glutamate excitotoxicity after nerve injury. Therefore, we aimed to elucidate the potential effectiveness of S-ketamine on motor function recovery after BPRA in mice.MethodsA mouse model of BPRA and reimplantation was established, and mice were randomly assigned to either the S-ketamine group or the control group, receiving a low, subanesthetic dose of S-ketamine or normal saline, respectively. The restoration of the motor neural circuit—from spinal cord and myocutaneous nerve to biceps muscle—was evaluated. Fluoro-Gold retrograde tracing was utilized to assess the connectivity between the central and peripheral nerve systems. Behavioral tests such as CatWalk, grooming test, and grip strength were applied to assess motor function recovery. The underlying mechanism was analyzed by Western blot, and the rescue experiment was assessed via motor function behavioral tests.ResultsS-ketamine increased motor neuron survival, enhanced central and peripheral nervous connectivity, promoted axon regeneration and remyelination, improved the neuromuscular junction integrity, and prevented muscle atrophy. As a result, motor function recovery was significantly improved, which was attributed to increased BDNF production via ERK-CREB phosphorylation. The BDNF receptor antagonist, ANA12, counteracted the functional recovery induced by S-ketamine.ConclusionS-ketamine increases the BDNF concentration by ERK/CREB phosphorylation, thereby promoting motor neural circuit repair and facilitating motor function recovery.

Brachial plexus root avulsion [BPRA] and concomitant spinal cord injury [SCI] represent devastating injuries that come with limited hope for recovery owing to the adult spinal cord's loss of intrinsic ability to spontaneously regenerate. BPRA/SCI is an enormous public health issue the world over, and its catastrophic impact goes beyond the patient, the family, businesses, and national health budgets, draining billions of dollars annually. The rising population and economic growth have seen the incidence of SCI surging. Genomic, transcriptomic, and proteomic studies have yielded loads of information on the various molecular events that precede, regulate, and support both regenerative and degenerative pathways post-SCI. Metabolomics, on the other hand, comes in as the search for a cure and the objective monitoring of SCI severity and prognosis remains on the horizon. Despite the large number of review articles on metabolomics and its application fields such as in cancer and diabetes research, there is no comprehensive review on metabolite profiling to study disease mechanisms, biomarkers, or neuroprotection in SCI. First, we present a short review on BPRA/SCI. Second, we discuss potential benefits of metabolomics as applied in BPRA/SCI cases. Next, a look at the analytical techniques that are used in metabolomics. Next, we present an overview of the studies that have used metabolomics to reveal SCI metabolic fingerprints and point out areas of further investigation. Finally, we discuss future research directions.

Brachial plexus injuries (BPI) can be devastating for patients, often resulting in notable physical, psychological, and socioeconomic distress1. Violent accidents that torque the head away from the shoulder frequently damage the upper brachial plexus roots, with varying severity of damage to the lower roots1. Patients having pan-plexus injuries typically present with a flail extremity, loss of sensory function, and generalized atrophy. To improve activities of daily living, the treatment of pan-plexus injuries focuses on restoring antigravity motion of the upper extremity, with elbow flexion being a high priority muscle group2. Although nerve transfers are an excellent option, this treatment path is not always viable. In such cases, free functioning muscle transfers, especially gracilis transfers, have emerged as a primary reconstructive approach, with excellent outcomes in complete BPI lesions2,3. In this video article, we present the exploration of a complex BPI in which the creation of a gracilis free flap is executed for elbow flexion reconstruction. We provide a comprehensive guide from markings, flap elevation, microsurgical technique, and inset, with educational operative pearls at every step. The procedure involves harvesting the gracilis muscle as a free functioning muscle transfer. The gracilis, which will become a type-II muscle flap, is carefully dissected with its pedicle and nerve preserved. The muscle is then transferred to the upper extremity, where its proximal origin is anchored to the clavicle and its distal tendon is inserted into the biceps tendon with use of a Pulvertaft weave. Vascular anastomoses are performed utilizing branches of the thoracoacromial trunk and venous couplers under a microscope. The muscle is innervated with the spinal accessory nerve and tensioned to ensure optimal elbow flexion. Surgical alternatives include nerve transfers (e.g., Oberlin transfer), tendon transfers, or other free muscle transfers (e.g., latissimus dorsi transfer). Nonsurgical alternatives include orthotic devices to compensate for elbow flexion loss, and physical therapy to maximize existing function. Gracilis free flap transfer is a reliable option for restoring functional elbow flexion in patients with severe BPI when intra-plexal nerve donors are unavailable. Compared with nerve transfers or tendon transfers, gracilis free flap transfer offers consistent outcomes with greater than M3 muscle strength (with M3 indicating movement against gravity but not against resistance, and M4 indicating movement against both gravity and resistance)2. Unlike orthotic devices, this technique provides active elbow flexion, critical for functional independence. The long tendon and reliable vascular pedicle make the gracilis ideal for this purpose. Free flap gracilis muscle transfer for elbow flexion reconstruction has shown promising outcomes in patients with traumatic brachial plexus injuries. Armangil et al. reported that 68.8% of patients achieved M3 or M4 elbow flexion strength, with a median active range of motion of 75° (range, 30° to 100°), and significant improvements in postoperative DASH and SF-36 scores4. De Rezende et al. (2021) demonstrated that 61.9% of patients achieved M4 strength, with 95.2% achieving M2 or higher, and a mean active range of motion of 77° (range, 10° to 110°) across the total cohort5. These findings suggest that free gracilis muscle transfer provides reliable functional improvements, enabling meaningful elbow flexion restoration and enhancing quality of life. Utilize Doppler ultrasound to confirm the location of a skin perforator over the gracilis to aid in postoperative monitoring.Preoperative markings are key. Mark the orientation of the gracilis muscle belly and pedicle preoperatively for efficient harvesting.The gracilis inserts distal to the knee, so extending the knee can help distinguish it from the adductor longus.Preserve all fascia over the gracilis muscle to optimize muscle gliding.Ensure proper resting tension during gracilis insertion to prevent over- or under-tightening, optimize function, and avoid complications like hyperextension or limited flexion.Position the elbow at 90° of flexion and the forearm in supination when tensioning.Make accommodation for any vessel size mismatch between the gracilis pedicle and recipient vessels to minimize complications.Confirm intraoperative vessel patency with use of Doppler flow checks after completing the anastomoses.Confirm nerve viability intraoperatively with use of nerve stimulation, ensuring a strong muscle contraction response.Secure the nerve repair without tension and with the appropriate coaptation in order to maximize reinnervation success.Utilize drains to avoid fluid collections that can create pressure on the pedicle.Place the gracilis tendon insertion precisely with use of the Pulvertaft weave technique, ensuring secure fixation and proper alignment with the biceps tendon. BPI = brachial plexus injuryDASH = Disabilities of the Arm, Shoulder and HandDVT = deep vein thrombosisEMG = electromyographyFFMT = free functioning muscle transferFGMT = free gracilis muscle transferICN = intercostal nerve transferM3/M4 = muscle strength grade 3 or 4MCA = medial circumflex arteryMCN = musculocutaneous nerveNCS = nerve conduction studyPPX = prophylaxisSAN = spinal accessory nerveSF-36 = Short Form-36.

ABSTRACT Objectives Brachial plexus neuralgia (BPN) can result from injury, trauma, or cancer, and it significantly impacts the patient’s quality of life. This study investigated electroacupuncture (EA) vs. pregabalin on the structural changes in the peripheral nervous system (PNS) and central nervous system (CNS) in rats with BPN. Methods Male Sprague-Dawley rats were randomized to the sham-operated (Con), BPN (using cobra venom), BPN+EA (EA), and BPN+pregabalin (PGB) groups (n = 8/group). EA or pregabalin was given from postoperative day (POD)14 to POD35. Structural alterations were determined by transmission electron microscopy in the primary sensory cortex, forelimb region (S1FL), anterior cingulate cortex (ACC), hippocampus, thalamus, cervical, thoracic, and lumbar spinal cords on POD40, and in the bilateral brachial plexus and dorsal root ganglions (DRG) at the cervical, thoracic and lumbar levels. Results Compared with the CON group, BPN rats exhibited significant changes in mechanical withdrawal threshold (MWT) (p < 0.05). The MWT showed a significant increase compared with the BNP group after EA or pregabalin (p < 0.05), but the long-term analgesic effects of EA appeared superior to pregabalin (p < 0.05). Furthermore, EA alleviated myelin sheath damage at the spinal cord levels. Damage, including demyelination, was limited to the ipsilateral DRG at the corresponding segment and bilateral CNS. Conclusion Neuropathic pain-induced damage is limited to the ipsilateral DRG at corresponding segment and bilateral CNS pain centers. EA and pregabalin each partially attenuate neuropathic pain and alleviate neuronal damage in BPN, but EA has a longer-term analgesic effect.

Background and objective Leprosy, an infectious disease caused byMycobacterium leprae, induces irreversible damage, necessitating early detection. The disease's neurotropism, which extends to the peripheral nerves, is well recognized. In recent years, there has been an acknowledgment of its expanding horizon beyond this traditional boundary. This study aims to explore the involvement of atypical sites such as the central nervous system, brachial plexus, and spinal nerve root ganglion through dedicated neuroimaging via magnetic resonance imaging (MRI) across diverse spectra of leprosy. Methods In a retrospective case series conducted from July 2020 to July 2022 at a tertiary care hospital, leprosy patients with specific neurological signs were analyzed. Neurologists had recommended MRI for suspected central nervous system (CNS)/proximal nerve root involvement in these patients. Two expert radiologists assessed theMRI imaging results. Results Eleven such patients were identified, of which six with positive MRI findings were scrutinized. Six multi-drug therapy (MDT) naive male leprosy patients in the age range of 24-44 years were analyzed. MRI revealed signal intensity alterations (SIA) in the brain, cervical cord, and bilateral/unilateral brachial plexus/ganglion. After a year of MDT, follow-up imaging revealed diverse responses: complete resolution of brain SIA (n=1), persistent declining hyperintensity in the cervical cord with declining (n=1), unchanged ganglionitis/plexitis (n=2), and no observable changes in cord and brachial plexus SIA (n=1). Conclusion This study reveals diverse neuroimaging patterns in leprosy patients.Neuroimaging may reveal abnormalities, particularly in patients with leprosy presenting with lower motor neuron-type facial palsy. A deeper understanding of these radiological findings could offer valuable insights into the pathophysiology of leprosy.

Brachial plexus root avulsion (BPRA) is often caused by road collisions, leading to total loss of motor function in the upper limb. At present, effective treatment options remain limited. Edaravone (EDA), a substance that eliminates free radicals, exhibits numerous biological properties, including neuroprotective, antioxidant and anti-inflammatory effects. However, the specific role and molecular mechanisms of EDA in the treatment of BPRA remain to be fully elucidated. The present study used a rat model of BPRA, following avulsion of the fifth, sixth and seventh cervical (C5, C6 and C7) anterior roots. Notably, C6 was replanted following a subcutaneous injection of either saline or 30 mg/kg/day EDA for seven continuous days. Subsequently, behavioral, histochemical, Western blot and reverse transcription-quantitative PCR (RT-PCR) analyses were conducted. Results of the present study revealed that treatment with EDA improves motor dysfunction, indicated by the increased Grooming test score, usage of the affected limb, and Irvine, Beatties and Bresnahan (IBB) score, following BPRA. In addition, EDA reduced the death of motoneurons (MNs), indicated by the increased number of Nissl-positive neuron, at the site of the affected limb, inhibited neuroinflammation and cellular pyroptosis, indicated by the decreased expression levels of IL-1β, IL-6, TNF-α, IL-18, p-p65, NLRP3, GSDMD and Caspase-1, improved the morphology of the abnormal myocutaneous nerve fibers, promoted axon remyelination, indicated by increased mRNA expression levels of remyelination-associated genes, including egr2, GAP-43, hmgcr, L1CAM, mpz, pmp22 and prx and demyelination-associated genes, including ngfr, notch1, pou3f1 and sox2, and alleviated muscle atrophy, indicated by the increased weight and volume of biceps brachii muscle, and the decreased number of fibroblasts and increased diameters in the fibers. Collectively, results of the present study suggested that EDA may support axonal remyelination and inhibit pyroptosis-associated neuroinflammation, enhancing MN survival and facilitating functional motor recovery. Thus, the present study may provide a novel theoretical basis for the use of EDA in the treatment of BPRA.

The high physiologic demands of sports create dynamic stress on joints, soft tissues, and nerves which may lead to injuries in the athlete. Electrodiagnostic (EDx) assessment is essential to identify the correct diagnosis, localization, and prognosis, to guide management of sports-related neuropathies. A comprehensive review was performed to provide the EDx medical consultant with a practical approach to the common peripheral nerve disorders seen in athletes. Sports-related neuropathies reviewed include transient traumatic irritation of the brachial plexus and/or cervical nerve roots ("Burners and stingers,") suprascapular and axillary neuropathies, ulnar neuropathy at the elbow (UNE) in throwers, ulnar neuropathy at the hand/wrist in cyclists, multi-ligamentous knee injury, and foot/ankle neuropathies including tarsal tunnel syndrome. A thorough understanding of peripheral anatomy, possible entrapment sites, mechanisms of injury, and key physical examination findings is essential for correct diagnosis. EDx assessments beyond routine studies are generally required for sports-related neuropathy, which may not necessarily follow typical entrapment patterns. Adjunct diagnostic imaging, such as point-of-care ultrasound and magnetic resonance imaging, are helpful tools to identify associated musculoskeletal pathology such as compressive cysts or nerve entrapment, which may be amenable to interventional or surgical treatment. When no clear reversible structural pathology exists, management of sports-related neuropathy is athlete-specific and generally multi-modal, involving a combination of physical rehabilitation techniques to address muscle imbalances, load management, protective equipment, and interventional pain procedures.

The indications and symptoms in the upper extremity brought on by compression of the brachial plexus, subclavian vein, and/or subclavian artery at the thoracic outlet were originally referred to as thoracic outlet syndrome (TOS). The symptoms of neurogenic thoracic outlet syndrome (NTOS) are caused by compression of the brachial plexus roots as they travel through the thoracic outlet. The most typical symptom of thoracic outlet syndrome is neurogenic thoracic outlet syndrome (NTOS). The brachial plexus is compressed and irritated, which causes its symptoms.A cross-sectional study was conducted from March 2023 to June 2023 among patients visiting Physical therapy outpatient department of public sector tertiary care hospitals Peshawar. The DASH questionnaire was distributed to all patients according to inclusion criteria from different hospitals to collect data on the prevalence of thoracic outlet syndrome.The study found that the prevalence of thoracic outlet syndrome was higher in female. The prevalence was higher among female housewives (77.77%) compared to male (63%). Risk factors associated with this pain included improper posture in same position while working, long work durations, repetitive tasks, and restricted neck movements.

Insights into the Medial Pectoral Nerve Transfer for Shoulder Abduction in Brachial Plexus Injuries: A Retrospective Case Series Analysis

Biomechanical characterization of cadaveric brachial plexus regions using uniaxial tensile tests

3D SHINKEI neurography is a new sequence for imaging the peripheral nerves. The study aims at assessing traumatic brachial plexus injury using this sequence. Fifty-eight patients with suspected trauma induced brachial plexus injury underwent MR neurography (MRN) imaging in 3D SHINKEI sequence at 3 T. Surgery and intraoperative somatosensory evoked potentials or clinical follow-up results were used as the reference standard. MRN, surgery and electromyography (EMG) findings were recorded at four levels of the brachial plexus-roots, trunks, cords and branches. Fifty-eight patients had pre- or postganglionic injury. The C5–C6 nerve postganglionic segment was the most common (average 42%) among the postganglionic injuries detected by 3D SHINKEI MRN. The diagnostic accuracy (83.75%) and the specificity (90.30%) of MRN higher than that of EMG (p < 0.001). There was no significant difference in the diagnostic sensitivity of MRN compared with EMG (p > 0.05). Eighteen patients with brachial plexus injury underwent surgical exploration after MRN examination and the correlation between MRN and surgery was 66.7%. Due to the high diagnostic accuracy and specificity, 3D SHINKEI MRN can comprehensively display the traumatic brachial plexus injury. This sequence has great potential in the accurate diagnosis of traumatic brachial plexus injury.

Transient traumatic neuropraxia of either the brachial plexus or cervical nerve root(s) is commonly described as a "stinger" or "burner" by the athlete. Stingers in American Football commonly occur acutely as isolated injuries; however, concomitant injuries, including cervical spine pathologies, have also been reported. Among National Football League (NFL) athletes, the incidence rate of stingers is higher during the regular season than during the preseason and among positions with high velocity impacts such as running backs, linebackers, defensive backs, and receivers. Retrospective epidemiology study. Level 4. Aggregation of all in-game injuries with a clinical impression of "neck brachial plexus stretch" or "neck brachial plexus compression" entered into the NFL injury surveillance database through the centralized league-wide electronic medical record system over 5 years (2015-2019 seasons). Incidence rates per player-play were calculated and reported. A total of 691 in-game stingers occurred during the study period, with a mean of 138.2 per year. Average single-season injury risk for incident stinger was 3.74% (95% CI, 3.46%-4.05%). The incidence rate was higher during regular season games than during preseason games (12.26 per 100,000 player-plays [11.30-13.31] vs 8.87 [7.31-10.76], P < 0.01, respectively). The highest reported stinger incidence rates were among running backs and linebackers (both >15 per 100,000 player-plays). Among stingers, 76.41% did not miss time. Of those that resulted in time lost from football activities, mean time missed due to injury was 4.79 days (range, 3.17-6.41 days). Concomitant injuries were relatively low (7.09%). In-game stinger incidence was stable across the study period and occurred most frequently in running backs and linebackers. Stingers were more common during the regular season, and most players did not miss time. Concomitant injuries were relatively rare. An improved understanding of the expected time loss due to stinger and concomitant injuries may provide insight for medical personnel in managing these injuries.

Brachial plexus root avulsion (BPRA) injury arises from challenging delivery during childbirth, sports-related incidents, or car accidents, leading to extensive loss of motor neurons (MNs) and subsequent paralysis, including both motor and sensory impairment. Surgical nerve re-implantation cannot effectively restore motor function, and the survival of injured MNs is vital for axon regeneration and re-innervating the target muscles. Therefore, identifying novel molecular targets to improve injured MNs survival is of great significance in the treatment of BPRA injuries. Endothelin-converting enzyme-like 1 (ECEL1), a membrane-bound metallopeptidase, was initially identified as a molecule associated with nerve injuries. Damaged neurons exhibit a significant increase in the expression of ECEL1 following various types of nerve injuries, such as optic nerve injury and sciatic nerve injury. This study aimed to investigate the relationship between ECEL1 overexpression and the survival of injured MNs following BPRA injury. Our results observed a significant elevation in ECEL1 expression in injured MNs and positively correlated with MNs survival following BPRA injury. The transcription of ECEL1 is regulated by the transcription factors c-Jun and ATF3 in the context of BPRA injury, which is consistent with previous other nerve injuries study. In addition, the expression of TrkA gradually decreases in ECEL1-positive MNs and ECEL1 possibly preserves the activity of downstream AKT-GSK3β pathway of TrkA in injured MNs. In conclusion, our results introduce a promising therapeutic molecular target to assist re-implantation surgery for the treatment of BPRA injury.

Recent evidence highlights the potential of axonal degeneration as a biomarker for amyotrophic lateral sclerosis (ALS) detection. However, the diagnostic potential of peripheral nerve axon changes in ALS remains unclear. To evaluate the diagnostic performance of quantitative MRI of the brachial plexus and limb-girdle muscles (LGMs) in patients with upper extremity onset of ALS. Retrospective. 47 patients with upper extremity onset of ALS and 20 healthy volunteers. 3-T, three-dimensional sampling perfection with application-optimized contrasts using different flip angle evolutions with short-tau inversion recovery sequences, T2-weighted turbo spin-echo Dixon sequence. The cross-sectional area (CSA) and nerve-muscle T2 signal intensity ratio (nT2) of the bilateral brachial plexus as well as the CSA and fat fraction (FF) of the bilateral LGMs were assessed by two radiologists. Disease severity and clinical stage of ALS patients were assessed by two neurologists. Student's t-test, Wilcoxon rank-sum test, binary logistic regression, interclass correlation coefficient, receiver operating characteristic analysis, and correlation analysis were performed for MRI quantitative metrics and clinical variables. Significance level: P < 0.05. In the affected limbs of patients with ALS, the CSA of the brachial plexus roots, trunks, and cords and the nT2 values of the brachial plexus trunks were significantly smaller than in the healthy controls. In the LGMs, the affected limbs of ALS showed significantly smaller CSA and higher FF than controls. The model containing parameters such as brachial plexus trunk CSA, subscapularis CSA, infraspinatus CSA, and subscapularis FF had excellent diagnostic efficacy for ALS. Additionally, increased subscapularis FF and supraspinatus FF were correlated with disease severity, and subscapularis CSA was negatively correlated with the clinical stage. Brachial plexus thinning, LGM atrophy, and fatty infiltration might serve as MRI-derived biomarkers for ALS with upper extremity onset. 4 TECHNICAL EFFICACY: Stage 2.