Brachial Plexus Root Avulsion Injury Research Articles

Brachial Plexus Root Avulsion Injury-Induced Endothelin-Converting Enzyme-Like 1 Overexpression Is Associated with Injured Motor Neurons Survival.

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.

Prespinal Versus Conventional Hemicontralateral C7 Nerve Transfer in the Treatment of Total Brachial Plexus Roots Avulsion Injuries: A Retrospective Study With a Minimum Follow-Up Period of 4 Years

Contralateral C7 (CC7)-to-median nerve transfer has been commonly used to restore hand function in brachial plexus injury. To shorten the nerve graft, the prespinal route was described and achieved direct coaptation when combined with humeral shortening osteotomy. The limb was positioned at 0° shoulder abduction and neutral head position. Given our concern about donor-site morbidity when harvesting the whole CC7 nerve and tension across the neurorrhaphy site after mobilization, we aimed to describe our modified prespinal route and compare its outcomes and complications with the conventional hemi-CC7 transfer. From 2004 to 2014, 39 patients with preganglionic total brachial plexus root avulsion injuries, with a minimum of 4 years of follow-up, were included. Overall, 20 and 19 patients underwent the conventional hemi-CC7-to-median nerve and hemi-CC7-to-lower trunk (LT) transfer through the modified prespinal route, respectively. The modified prespinal route was combined with bilateral clavicle shortening osteotomy to achieve direct coaptation to the LT at 45° shoulder abduction. The modified prespinal route showed the median period to achieve ≥M3 hand grip assessed in clinical follow-up was shorter (26.5 months vs 45.5 months), and a higher proportion of patients achieved ≥M3 hand grip recovery (63% vs 30%). One patient experienced symptomatic phrenic nerve injury; however, the hemidiaphragm fully recovered after 6 months. The long-term donor-site complication rate was 2.6%, including one sensory abnormality, and no permanent donor-site weakness after hemi-CC7 harvesting was observed. The modified prespinal route combined with clavicle osteotomy allowed direct coaptation to the LT and did not require head immobilization. It may allow a higher proportion of patients to achieve ≥M3 hand grip more quickly than conventional hemi-CC7 transfer. Therapeutic IV.

Motor neuron survival is associated with reduced neuroinflammation and increased autophagy after brachial plexus avulsion injury in aldose reductase-deficient mice

Brachial plexus root avulsion (BPRA) is frequently caused by high-energy trauma including traffic accident and birth trauma, which will induces massive motoneurons (MNs) death as well as loss of motor and sensory function in the upper limb. The death of MNs is attributed to energy deficiency, neuroinflammation and oxidative stress at the injured ventral horn of spinal cord triggered by BPRA injury. It has been reported which aldose reductase (AR), an endogenous enzyme that catalyzes fructose synthesis, positively correlates with the poor prognosis following cerebral ischemic injury, diabetic retinopathy and diabetic peripheral neuropathy. However, the role of AR in BPRA remains unknown. Herein, we used a mouse model and found that in the spinal cord of BPRA mice, the upregulation of AR correlated significantly with (1) an inactivated SIRT1–AMPK–mTOR pathway and disrupted autophagy; (2) increased byproducts accumulation of lipid peroxidation metabolism and neuroinflammation; and (3) increased MNs death. Furthermore, our results demonstrated the role of AR in BPRA injury whereby the absence of AR (AR knockout mice, AR−/−) prevented the hyper-neuroinflammation and disrupted autophagy as well as motor neuron death caused by BPRA injury. Finally, we further demonstrate that AR inhibitor epalrestat is neuroprotective against BPRA injury by increasing autophagy level, alleviating neuroinflammation and rescuing MNs death in mice. Collectively, our data demonstrate that the AR upregulation in the spinal cord is an important factor contributing to autophagy disruption, neuroinflammation and MNs death following brachial plexus roots avulsion in mice. Our study also provides a promising therapy drug to assist re-implantation surgery for the treatment of BPRA.

Cytokine profile and glial activation following brachial plexus roots avulsion injury in mice

Inflammation and tissue infiltration by various immune cells play a significant role in the pathogenesis of neurons suffering the central nervous systems diseases. Although brachial plexus root avulsion (BPRA) leads to dramatic motoneurons (MNs) death and permanent loss of function, however, the knowledge gap on cytokines and glial reaction in the spinal cord injury is still existing. The current study is sought to investigate the alteration of specific cytokine expression patterns of the BPRA injured spinal cord during an acute and subacute period. The cytokine assay, transmission electron microscopy, and histological staining were utilized to assess cytokine network alteration, ultrastructure morphology, and glial activation and MNs loss within two weeks post-injury on a mouse unilateral BPRA model. The BPRA injury caused a progressively spinal MNs loss, reduced the alpha-(α) MNs synaptic inputs, whereas enhanced glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule-1 (IBA-1), F4/80 expression in ipsilateral but not the contralateral spinal segments. Additionally, cytokine assays revealed BPRA significantly altered the level of CXCL1, ICAM1, IP10, MCP-5, MIP1-α, and CD93. Notably, the elevated MIP1-α was mainly expressed in the injured spinal MNs. While the re-distribution of CD93 expression, from the cytoplasm to the nucleus, occasionally occurred at neurons of the ipsilateral spinal segment after injury. Overall, these findings suggest that the inflammatory cytokines associated with glial cell activation might contribute to the pathophysiology of the MNs death caused by nerve roots injury.

Bone marrow mesenchymal stem cells repair brachial plexus injury in rabbits through ERK pathway.

To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) on repairing brachial plexus injury in rabbits and their influence on expression of the extracellular signal-regulated kinase (ERK) pathway. With big-ear rabbits as the objects, the BMSCs were first isolated, and the cluster of differentiation (CD)45- and CD90+ BMSCs were sorted out via flow cytometry. BMSCs were transfected with red fluorescent protein (RFP), and the transfection effect was detected. Then, the big-ear rabbits were subjected to brachial plexus root avulsion injury (BPAI) to establish injury Model group and sham-operation group (Sham group). Later, the BMSCs were transfected with RFP to construct RFP-BMSCs. The RFP-BMSCs (5×106, Treat group) and normal saline (Model group) were intraperitoneally injected, and the recovery rate of wet weight of the upper limb muscle was measured by weighing. The injured nerve tissues were embedded for hematoxylin and eosin (HE) staining and observation of pathological changes. The electrophysiological measurement of the compound muscle action potential (CMAP) on the injured side was conducted for the rabbits to be sacrificed immediately using an electromyogram instrument, and the CMAP amplitude and latency were applied to evaluate the recovery of upper limb muscle. Finally, the location of RFP-BMSCs in the nerve tissues was traced by a fluorescence microscope, and the protein expression levels of phosphorylated ERK (p-ERK) and phosphorylated mitogen-activated protein kinase (p-MAPK) in the injured nerve tissues were determined by means of Western blotting. Persistently expressed red fluorescence was observed in CD45- and CD90+ BMSCs sorted via flow cytometry under the fluorescence microscope, indicating that the RFP-BMSCs were constructed successfully. Compared with Sham group, Model group had a remarkably decreased recovery rate of wet muscle weight (p<0.05), while Treat group exhibited a notably increased recovery rate of wet muscle weight in comparison with Model group. The CMAP amplitude was reduced markedly (p<0.05), while the CMAP latency was prolonged significantly (p<0.05) in Model group compared with those in Sham group. Moreover, Treat group had distinctly higher CMAP amplitude and evidently shorter CMAP latency than Model group (p<0.05). It was discovered under the fluorescence microscope that RFP-BMSCs were visibly arranged on both sides of nerve fibers in Treat group. The expressions of p-MAPK and p-ERK were raised prominently in Model group in comparison with those in Sham group (p<0.05), and they were lowered apparently in Treat group compared with those in Model group (p<0.05). BMSCs can repair the impaired brachial plexus neurons and restore their physiological functions, and the protective effect of the BMSCs on the neurons is associated with the mediated MAPK/ERK pathway.

Study on the neuroprotection and its molecular mechanisms of erythropoietin against brachial plexus root avulsion injury in rats

Objective The neuroprotective and adverse effects, associated with low dosage erythropoietin (EPO) for the spinal cord neuron following nerve avulsion will be researched. Methods 180 Wistar rats were randomly divided into two groups: control group (avulsion + 1 ml normal saline s. c. on alternate days), EPO treated group (avulsion + 1 000 U/kg EPO s. c. on alternate days). The rats were sacrificed at day 0 (before avulsion), 1, 2, 4, 7 and 14 d after avulsion for harvesting C5-T1 spinal samples. We used Nissl, terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL), and Cleaved-poly adenosine diphosphate-ribose polymerase (c-PARP) stainings to analyze the survival and apoptotic neurons. Results (1) The percentage of survivial neurons was significantly decreased, EPO group has more survival neurons compared with C group at 7 d [(78.42±2.64)% and (67.46±3.78)%] and 14 d [(57.32±4.07)% and (46.42±3.14)%]. (2) TUNEL positive (apoptotic) neurons appeared at 2 d, followed by a gradual change until 14 d. The TUNEL in EPO group was significantly decreased at 4 d [(303.1±59.9) and (861.6±85.4)] and 7 d [(419.8±74.2) and (983.2±83.9)] compared to C group. (3) The c-PARP, which is a critical apoptotic factor, was showed a pronounced decrease in EPO group than control ones at 2 d and 4 d. (4)There are no significant differences on blood routine examination in two groups at all time points. Conclusion With administration of 1 000 U/kg EPO, the survival rate of neurons was enhanced and apoptosis was alleviated without significant erythropothesis effect. Key words: Brachial plexus root avulsion injury; Neuron; Apoptosis; Cleaved-poly adenosine diphosphate-ribose polymerase

Simultaneous Phrenic and Intercostal Nerves Transfer for Elbow Flexion and Extension in Total Brachial Plexus Root Avulsion Injury.

To report the results of restoring the elbow flexion and extension in patients with total brachial root avulsion injuries by simultaneous transfer of the phrenic nerve to the nerve to the biceps and three intercostal nerves to the nerve of the long head of the triceps. Ten patients with total brachial root avulsion injuries underwent the spinal accessory nerve transfer to the suprascapular nerve for shoulder reconstruction. Simultaneous transfer of the phrenic nerve to the nerve to the biceps via the sural nerve graft and three intercostal nerves to the nerve of the long head of the triceps was done for restoration of the elbow flexion and extension. Trunk flexion exercise program was used for all patients postoperatively. The mean follow up period was 36 months. For elbow flexion, there were two M4, seven M3, and one M1. For elbow extension, there were three M4, four M3, two M2, and one M1. No patient demonstrated a respiratory problem clinically postoperatively. The average FVC% decreased to 61% of the predicted value at 24 months after surgery. The simultaneous nerve transfer using the phrenic nerve to the nerve to the biceps and 3 intercostal nerves to the nerve of the long head of the triceps with postoperative trunk flexion exercise provide a comparable result for restoration of elbow function in total brachial plexus root avulsion injury. The patients who appear to have a respiratory problem and are unable to comply with the post-operative respiratory muscles training should be contraindicated for this simultaneous transfer.

Dynamic alterations of the levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β in rat primary motor cortex during transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following brachial plexus avulsion injuries.

The transfer of a contralateral healthy seventh cervical spinal nerve root (cC7) to the recipient nerve in the injured side is considered a reliable and effective procedure for restoration of the physiological functions of an injured hand after brachial plexus root avulsion injury (BPAI). Growing evidence shows that the transhemispheric cortical reorganization is induced after cC7 nerve transfer surgery. However, little is known about the underlying molecular mechanism. Proinflammatory cytokines reportedly play an important role in the neural plasticity. We hypothesize that proinflammatory cytokines are involved in the transhemispheric functional reorganization after cC7 transfer. In the present study, we investigated the level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the rat primary motor cortex after cC7 transfer following BPAI by enzyme-linked immunosorbent assay. The results showed that, in the sham group, no statistical significance was observed between the level of TNF-α, IL-6, and IL-1β at each time point after the operation compared with that at day 0, respectively. However, in the unrepaired and repaired groups, the level of TNF-α, IL-6, and IL-1β changed dynamically. The study is the first to provide evidence for the involvement of proinflammatory cytokines in transhemispheric functional reorganization after cC7 transfer following BPAI, which are useful for understanding the underlying mechanism.

Microanatomy of the brachial plexus roots and its clinical significance.

To provide the anatomical basis of brachial plexus roots for the diagnosis and treatment of brachial plexus root avulsion injury. The morphological features of brachial plexus roots were observed and measured on 15 cervicothoracic spine of adult cadavers. The relationship of brachial plexus nerve roots and the surrounding tissues also were observed, as well as the blood supply of anterior and posterior roots of the brachial plexus. Origination of the nerve roots in the dorsal-ventral direction from the midline was fine-tuned at each level along the spinal cord. The minimum distance of the origin of the nerve root to midline was 2.2mm at C 5, while the maximum was 3.1mm at T 1. Inversely, the distance between the origin of the posterior root and the midline of the spinal cord gradually decreased, the maximum being 4.2mm at C 5 and minimum 2.7mm at T 1. Meanwhile, there was complicated fibrous connection among posterior roots of the brachial plexus. The C 5-6 nerve roots interlaced with tendons of the scalenus anterior and scalenus medius and fused with the transverse-radicular ligaments in the intervertebral foramina. However, these ligaments were not seen in C 7-8, and T 1. The blood supply of the anterior and posterior roots of the brachial plexus was from the segmental branches of the vertebral artery, deep cervical artery and ascending cervical artery, with a mean outer diameter of 0.61mm. The systematic and comprehensive anatomic data of the brachial plexus roots provides the anatomical basis to diagnose and treat the brachial plexus root avulsion injury.

Outcome of Contralateral C7 Nerve Transfer in the Treatment of Total Brachial Plexus Root Avulsion Injury Patient

Objective: The objective of this study was to evaluate the outcome of patients treated with contralateral C7 (cC7) transfer and to determine the factors that affect the outcome of this procedure. Materials and Methods: A retrospective review of 73 patients with total brachial plexus root avulsion injury (BPAI) who underwent cC7 transfer was conducted. All of the surgeries were performed by 2 stages, and the pedicled ulnar nerve was the bridged nerve. The 73 patients were divided into 2 groups according to different number of the recipient nerves. In group 1 (51 patients), the cC7 nerve was used to transfer to median nerve only. The entire cC7 was used in 11 patients; the posterior division together with the lateral part of the anterior division was used to transfer to median nerve in 15 patients; and the anterior or the posterior division alone was used to transfer to median nerve in 25 patients. In group 2, the cC7 nerve was used to transfer to 2 nerves simultaneously. The entire cC7 was used to transfer to median nerve and biceps branch in 12 patients and to median nerve and triceps branch in 10 patients. The mean follow-up period was 7.3 years. Results: The efficient of these 73 patients was 54.8% in wrist and finger flexor, 57.5% in median nerve area sensation, 66.7% in the elbow flexor, and 20% in the elbow extensor. The patients with entire cC7 root transfer achieved significantly better recovery than the patients with partial cC7 root transfer. The best function recovery could be induced if the interval between 2 stages was 4 to 8 months. Functional recovery of biceps branch was significantly better than that of triceps branch. Conclusion: Contralateral C7 transfer is an effective procedure in treating total BPAI patients. If transferred to single nerve, the entire C7 root transfer can obtain significantly better recovery, and we emphasize using the entire root as the donor. The optimal interval between 2 surgery stages is 4 to 8 months. If transferred to 2 nerves, the 2 recipient nerves should be collaborative in motor function.

Passage through the carotid sheath: An alternative path to the pre-spinal route for direct repair of contralateral C7 to the lower trunk in total brachial plexus root avulsion injury.

Context:In surgical management of global brachial plexus injuries, direct repair of contralateral C7 (cC7) to the anterior division of the lower trunk, can produce good extrinsic finger flexion. The pitfalls associated with the pre-spinal passage have, perhaps, proved to be a deterrent for using this technique routinely.Aims:The aim of this study is to demonstrate an alternative to pre-spinal route for cC7 transfer in brachial plexus avulsion injuries.Methods:We noted that the mobilised lower trunk, which reaches the level of the scalenus anterior by passage deep to the clavicle, can be brought to the suprasternal notch when brought out from below the clavicle. This area was dissected in two cadavres, and safe passage was found through the carotid sheath with the common carotid artery medially and the internal jugular vein with the vagus nerve laterally. The cC7 root dissected medial to the scalenus anterior muscle can be directly transferred along this path to the subcutaneous plane at the suprasternal notch. This study allowed us to execute a direct repair in ten clinical cases of global brachial plexus injuries. In each case, the passage was prepared rapidly and uneventfully. The repair was technically simple and could be performed comfortably using suitable fine suture materials. In none of these cases, did we need to shorten the humerus.Results:The clinical outcome of this technique is awaited.Conclusions:We advocate carotid sheath route to approximate the cC7 to the injured lower trunk in global palsies, as the risks associated with the pre-spinal route can be readily avoided.

Expressions of miR-132, miR-134, and miR-485 in rat primary motor cortex during transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following brachial plexus avulsion injuries.

The transfer of a contralateral healthy seventh cervical spinal nerve root (cC7) to the recipient nerve in the injured side is considered a promising procedure for restoration of the physiological functions of an injured hand after brachial plexus root avulsion injury (BPAI). Growing evidence shows that transhemispheric cortical reorganization plays an important role in the functional recovery of the injured arm after cC7 nerve transfer surgery. However, the molecular mechanism underlying the transhemispheric cortical reorganization after cC7 transfer remains elusive. In the present study, we investigated the expression of miR-132, miR-134, and miR-485 in the rat primary motor cortex after cC7 transfer following BPAI by quantitative PCR. The results demonstrated the dynamic alteration in the expression of miR-132, miR-134, and miR-485 in the primary motor cortex of rats after cC7 transfer following BPAI. It indicates that microRNAs are involved in the dynamic transhemispheric functional reorganization after cC7 root transfer following BPAI. Together, this study is the first to provide evidence for the involvement of microRNAs during dynamic transhemispheric functional reorganization after cC7 transfer following BPAI. The results are useful for understanding the mechanism underlying transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following BPAI.

Remote Paraparesis due to a Traumatic Extradural Arachnoid Cyst Developing 2 Years after Brachial Plexus Root Avulsion Injury: Case Report and Review of the Literature

Traumatic extradural arachnoid cyst is a rare entity. However, late appearance of paraparesis due to formation of an extradural arachnoid cyst as a sequel of brachial plexus injury is extremely rare and the literature regarding this issue is scarce revealing only 11 cases. Herein, we report a patient with delayed progressive spastic paraparesis appearing after a multilevel brachial plexus root avulsion injury where imaging revealed formation of a large traumatic extradural arachnoid cyst at the cervicothoracic region. Furthermore, to propose that a high-energy trauma might simultaneously result in delayed formation of an extradural arachnoid cyst. However, preganglionic root avulsion injury with pseudomeningocele formation in association with extradural arachnoid cyst is not reported previously. A case of a 36-year-old man with spastic paraparesis developing 2 years after a multilevel brachial plexus root avulsion injury is presented. Root avulsion had immediately resulted in complete paralysis of the left upper limb that had not ameliorated. Imaging studies of the cervicothoracic region disclosed left-sided multilevel pseudomeningoceles and a large extradural arachnoid cyst extending from C5 to T2. After appropriate en bloc laminotomy, the cyst was excised and the causative dural tear was closed. Subsequently, three large defects of pseudomeningoceles were obliterated with artificial dural patch for the prevention of cord herniation. This was followed with laminoplasty of the corresponding levels after dural closure. The postoperative course was uneventful and paraparesis recovered steadily within 2 months. Paraparesis even years after brachial plexus injury should be regarded as a serious event that deserves extensive imaging survey for the possibility of the formation of an extradural arachnoid cyst. Careful review of the literature disclosed that the current case is the 12th case that an extradural arachnoid cyst has developed after brachial plexus injury and the first example that the pathogenic factor that might be implicated in occurrence of this rare association could be clarified with review of the MRI features. Actually, the presence of posttraumatic pseudomeningoceles in association with an arachnoid cyst in the current case is in favor of the belief that only preganglionic root injuries that are in close proximity to the spinal canal had been the cause dural tear with remote formation of extradural arachnoid cyst.

Complications of contralateral C-7 transfer through the modified prespinal route for repairing brachial plexus root avulsion injury: a retrospective study of 425 patients.

In this report, the authors review complications related to the modified prespinal route in contralateral C-7 transfer for repairing brachial plexus nerve root avulsion injury and suggest a prevention strategy. A retrospective, nonselected amalgamation of every case of modified contralateral C-7 transfer through the prespinal route was undertaken. The study population comprised 425 patients treated between February 2002 and August 2009. The patients were managed according to a standardized protocol by one senior professor. The surgical complications were grouped into one of the following categories: those associated with tunnel making through the prespinal route, those related to the dissection and transection of the contralateral C-7 nerve root, and those that occurred in the postoperative period. The study population included 379 male and 46 female patients whose average age was 21 years (range 3 months to 56 years). A total of 401 patients were diagnosed with traumatic brachial plexus injury, the leading cause of which was motor vehicle accident, and 24 patients were diagnosed with obstetrical brachial plexus palsy. The contralateral C-7 nerve root was cut at the proximal side of the division portion of the middle trunk in 15 cases and sectioned at the distal end of the anterior and posterior divisions in 410 cases. The overall incidence of complications was 5.4% (23 of 425). Complications associated with making a prespinal tunnel occurred in 12 cases, including severe bleeding due to vertebral artery injury during the procedure in 2 cases (0.47%), temporary recurrent laryngeal nerve palsy in 5 cases (1.18%), pain and numbness in the donor upper extremity during swallowing in 4 cases (0.94%), and dyspnea caused by thrombosis of the brainstem 42 hours postoperatively in 1 case (0.24%); this last patient died 38 days after the operation. Complications related to exploration and transection of the contralateral C-7 nerve root occurred in 11 cases, including deficiency in extensor strength of the fingers and thumb in 4 cases (0.94%) due to injury to the posterior division of the lower trunk, unbearable pain on the donor upper extremity in 3 cases (0.71%), Horner's syndrome in 2 children (0.47%) who suffered birth palsy, a section of C-6 nerve root mistaken as C-7 in l case (0.24%), and atrophy of the sternocostal part of the pectoralis major in 1 case (0.24%). The most serious complications of using the modified prespinal route in contralateral C-7 transfer were vertebral artery laceration and injury to the posterior division of the lower trunk. The prevention of such complications is necessary to popularize this surgical procedure and attain good long-term clinical results.

Clinical results of intercostal nerve transfer to the musculocutaneous nerve in brachial plexus root avulsion injuries

Objective To observe the treatment outcomes of restoring elbow flexion by transferring intercostal nerves to the musculocutaneous nerve.Methods From August 2006 to May 2012,6 cases of brachial plexus root avulsion injuries were treated with intercostal nerve transfer to the musculocutaneous nerve at our hospital.Among these patients 5 were male and 1 was female.Their ages ranged from 19 to 55 years,the average being 35 years.The average time between injury and the operation was 5 months,ranging from 1 to 8 months.All the patients were treated with intercostal nerve transfer to the musculocutaneous nerve by direct coaptation.Postoperative follow-up ranged from 18 to 62 months,with an average of 38 months.Muscle power of the biceps and elbow flexion function were evaluated.Result The biceps muscle power recovered to some extent in all six patients.Three of them regained biceps muscle power of M4,while one exhibited M3,one M2 and one M1.Good or excellent motor recovery of the biceps was achieved in 66.7％ of the patients.Conclusion Intercostal nerve transfer to the musculocutaneous nerve for elbow flexion restoration is an effective procedure for brachial plexus root avulsion injuries. Key words: Intercostal nerve; Musculocutaneous nerve; Nerve transfer; Brachial plexus; Injury

Contralateral c7 transfer for treatment of brachial plexus root avulsion.

Since the first report of the clinical application of contralateral C7 transfer, this procedure has become widely accepted and is used in the treatment of brachial plexus root avulsion injuries. The technique of this procedure has been markedly improved during the past years. The prespinal route may lead to a shorter nerve graft or even to direct coaptation. The results differ a lot from the different studies. There are many factors affecting the results of contralateral C7 transfer, such as age, time for regeneration and techniques of contralateral C7 transfer. Although dividing C7 will not cause a permanent loss in sensory and motor function of the healthy limb, it is worth pointing out that the C7 transection level should not be too distal, otherwise the fibers from the upper and lower trunk could be injured and permanent motor and sensory deficits may occur. Also, the surgeons should balance the risks and benefits for the patient before making the decision to operate in this manner.

Double free gracilis muscle transfer after complete brachial plexus injury: First Canadian experience

Traumatic brachial plexus root avulsions are devastating injuries, and are complex and challenging to reconstruct. Double free muscle transfer using the gracilis muscles is a potentially effective method of restoring upper extremity function. The authors report on the first two patients treated using this technique in Canada. Both sustained traumatic brachial plexus root avulsion injuries resulting in a flail arm. In the first step of this two-stage procedure, a gracilis muscle was transferred to restore elbow flexion, and wrist and digit extension. Months later, the transfer of the second gracilis muscle was performed to enhance elbow flexion and to enable wrist and digit flexion. Postoperatively, both patients achieved Medical Research Council grade 4 elbow flexion, functional handgrip and were able to return to gainful employment. Patient satisfaction was high and active range of motion improved substantially. The authors' experience supports the use of this technique following severe brachial plexus injury.

Penile erectile dysfunction after brachial plexus root avulsion injury in rats.

Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine (via a subcutaneous injection in the neck) to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion + spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combination of brachial plexus root avulsion and spinal cord injury.

Double free gracilis muscle transfer after complete brachial plexus injury: First Canadian experience

Traumatic brachial plexus root avulsions are devastating injuries, and are complex and challenging to reconstruct. Double free muscle transfer using the gracilis muscles is a potentially effective method of restoring upper extremity function. The authors report on the first two patients treated using this technique in Canada. Both sustained traumatic brachial plexus root avulsion injuries resulting in a flail arm. In the first step of this two-stage procedure, a gracilis muscle was transferred to restore elbow flexion, and wrist and digit extension. Months later, the transfer of the second gracilis muscle was performed to enhance elbow flexion and to enable wrist and digit flexion. Postoperatively, both patients achieved Medical Research Council grade 4 elbow flexion, functional handgrip and were able to return to gainful employment. Patient satisfaction was high and active range of motion improved substantially. The authors' experience supports the use of this technique following severe brachial plexus injury.

Valproic acid protection against the brachial plexus root avulsion‐induced death of motoneurons in rats

In this study, the role of valproic acid (VPA) in protecting motoneuron after brachial plexus root avulsion was investigated in adult rats. Sixty rats were used in this study, and underwent the brachial plexus root avulsion injury, which was created by using a micro-hemostat forceps to pull out brachial plexus root from the intervertebral foramen. The animals were divided into two groups, VPA group administered with VPA dissolved in drinking water (300 mg/kg) daily, and control group had drinking water every day. The spinal cords (C5-T1) were harvested at day 1, 2, 3, 7, 14, and 28 for immunohistochemistry analysis, TUNEL staining, Nissl staining, and electron microscopy, respectively. The results showed that with VPA administration, the survival of motoneurons was promoted and the cell apoptosis was inhibited. The number of c-Jun and Bcl-2 positive motoneurons was increased immediately after avulsion both in control and VPA group, however, the percent of c-Jun positive motoneurons was decreased and the percent of Bcl-2 positive motoneurons was increased by VPA treatment significantly. Our results indicated that motoneurons were protected by VPA against cell death induced by brachial plexus root avulsion through c-Jun inhibition and Bcl-2 induction.