Root Avulsion Research Articles

Central Neuropathic Pain and Complex Regional Pain Syndrome Following Brachial Plexus Injury Treated Successfully With Dorsal Root Entry Zone Lesioning

Abstract INTRODUCTION Central neuropathic pain (CNP) and complex regional pain syndrome (CRPS) present as chronic, unrelenting, and disabling pain resulting from central and peripheral nervous system injuries. For patients who have failed conservative management, dorsal root entry zone (DREZ) lesioning may serve as an alternative for the management of intractable pain. METHODS A 36-yr-old male presented with complete right brachial plexus injury and avulsion of nerve roots following a motorcycle accident. He developed disabling type I CRPS of the right upper extremity. After failing medical therapy, he underwent a trial of conventional SCS using 2 percutaneous leads in the upper cervical spine but did not get topographical coverage. He underwent a second SCS trial with the placement of a paddle lead using burst therapy, but his initial partial pain relief subsided after 3 d. Subsequently, he underwent SCS removal, C2 to T1 right DREZ lesioning, and C4 to T1 laminoplasty. The patient gained a significant pain relief and became more functional. Five months postoperatively, he experienced an improvement in his pain and narcotic consumption. RESULTS Using an insulated neurotomy electrode, 2-mm-deep lesions were made at 75°C for 15 s. A total of 83 lesions were made from T2 to C3. Each lesion was spaced 1 mm apart. The impedance was less than 1000 ohms, which was consistent within an area of injury. Somatosensory and motor-evoked potentials were at baseline during the case without significant changes. CONCLUSION When SCS fails, lesioning of the dorsal root entry zone is a useful tool in the armamentarium for the management of refractory brachial plexus neuropathic pain.

Enhanced regeneration and reinnervation following timed GDNF gene therapy in a cervical ventral root avulsion

Avulsion of spinal nerve roots is a severe proximal peripheral nerve lesion. Despite neurosurgical repair, recovery of function in human patients is disappointing, because spinal motor neurons degenerate progressively, axons grow slowly and the distal Schwann cells which are instrumental to supporting axon extension lose their pro-regenerative properties. We have recently shown that timed GDNF gene therapy (dox-i-GDNF) in a lumbar plexus injury model promotes axon regeneration and improves electrophysiological recovery but fails to stimulate voluntary hind paw function. Here we report that dox-i-GDNF treatment following avulsion and re-implantation of cervical ventral roots leads to sustained motoneuron survival and recovery of voluntary function. These improvements were associated with a twofold increase in motor axon regeneration and enhanced reinnervation of the hand musculature. In this cervical model the distal hand muscles are located 6,5 cm from the reimplantation site, whereas following a lumber lesion this distance is twice as long. Since the first signs of muscle reinnervation are observed 6 weeks after the lesion, this suggests that regenerating axons reached the hand musculature before a critical state of chronic denervation has developed. These results demonstrate that the beneficial effects of timed GDNF-gene therapy are more robust following spinal nerve avulsion lesions that allow reinnervation of target muscles within a relatively short time window after the lesion. This study is an important step in demonstrating the potential of timed GDNF-gene therapy to enhance axon regeneration after neurosurgical repair of a severe proximal nerve lesion.

Diagnostic accuracy of MRI for traumatic adult brachial plexus injury: A comparison study with surgical findings

We studied the diagnostic accuracy of MRI in 35 adult patients with traumatic brachial plexus injury in comparison with intra operative findings. The overall sensitivity to detect root avulsions was 39% and specificity was 75%. MRI was more useful in the diagnosis of lower root avulsions. At trunk and division level injuries, the sensitivity was 87% but specificity was only 26%. It was not able to differentiate the type and extent of post-ganglionic injuries. The accuracy of pseudomeningocele as avulsion on surgical finding was 96% (27/28). Pseudomeningocele correlates well with root avulsions. Its presence warrants early referral and surgical exploration.

Up-regulation of heat shock protein 27 inhibits apoptosis in lumbosacral nerve root avulsion-induced neurons

Lumbosacral nerve root avulsion leads to widespread death of neurons in the anterior horn area of the injured spinal cord, which results in dysfunction in the lower extremities. Heat shock protein 27 (Hsp27) has been found to play cytoprotective roles under adverse conditions. However, the role of Hsp27 in neurons after lumbosacral nerve root avulsion is unknown. The aim of the present study was to investigate the effects and mechanism of action of Hsp27 on neurons after lumbosacral nerve root avulsion. It was found that Hsp27 expression was elevated in the anterior horn area of the injured spinal cord and the up-regulation of Hsp27 protected neurons against apoptosis after lumbosacral nerve root avulsion. In addition, Hsp27 plays an anti-apoptotic role by suppressing oxidative stress reactions. These findings indicated that Hsp27 may play a key role in resistance to lumbosacral nerve root avulsion-induced neuron apoptosis and may prove to be a potential strategy for improving prognosis after lumbosacral nerve root avulsion.

Erythropoietin alleviates spinal neuron apoptosis via c-Jun N-terminal kinase-c-Jun pathway

Objective To study the neural protective mechanism of erythropoietin (EPO) following root avulsion (RA). Methods Sixty-three adult 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 0 (after awake), 1, 2, 4, 7 and 14 days after avulsion for harvesting C5-T1 spinal samples. Immunohistochemistry was used to detect cleaved-poly adenosine diphosphate-ribose polymerase (Cleaved-PARP), c-Jun and phosphorylated c-Jun N-terminal kinase (p-JNK) in spinal neurons. Results (1) The expression of Cleaved-PARP was significantly decreased in EPO-treated group at 2, 4, and 7 days post-avulsion (3 173.3±153.1, 8 943.2±351.5 and 7 017.9±424.7) as compared with control group (10 575.1±594.3, 12 737.1±385.3 and 10 256.9±629.4) (F=4 363.938, 1 587.489, 545.925, P<0.01). (2) The expression of c-Jun in EPO-treated group was significantly lower at 1, 2, 4 and 7 day(s) (1 351.2±253.7, 2 386.8±305.8, 1 898.2±138.0 and 1 547.1±163.9) than in control group (2 165.8±205.7, 3 378.1±272.5, 2 835.2±166.8, 2 579.8±264.8) (F=186.613, 175.719, 562.005, 329.896, P<0.01). (3) The expression of p-JNK in EPO-treated group was significantly lower at 1, 2, 4 days after avulsion (1 407.1±121.7, 1 925.6±126.6 and 4 892.3±330.2) than in control group (3 041.5±139.6, 9 243.8±573.9 and 5 486.6±358.4) (F=2 336.447, 4 651.806, 44.617, P<0.01). The peak of p-JNK was postponed to 4th day in EPO-treated group as compared with 2nd day in control group. Conclusion Down-regulation of p-JNK and c-Jun is the anti-apoptosis mechanism of EPO for spinal neurons. Key words: Root avulsion injury; Erythropoietin; Spinal cord neuron; C-poly adenosine diphosphate-ribose polymerase; C-Jun N-terminal kinase; C-Jun

Biomechanical Effects of Peripheral Stabilization for the Extruded Medial Meniscus and its Effect on Tibiofemoral Contact Biomechanics

Objectives: To quantitatively evaluate the biomechanical effects of a novel peripheral stabilization technique for the treatment of posterior medial meniscus root (PMMR) avulsions and to identify an optimal diagnostic position to assess for the presence of meniscal extrusion. Methods: Meniscal extrusion and tibiofemoral contact mechanics were measured using 3D digitization and pressure sensors, respectively, in ten nonpaired, human cadaver knees. The PMMR of each knee was tested under 6 states: (1) intact; (2) complete root detachment; (3) anatomic transtibial pull-out root repair; (4) anatomic transtibial pull-out repair with peripheral stabilization; (5) nonanatomic transtibial pull-out repair; and (6) nonanatomic transtibial pull-out repair with peripheral stabilization, with randomization of the order of conditions 3 &amp; 4, and 5 &amp; 6. The testing protocol loaded knees with a 1000 N axial compressive force at four flexion angles (0°, 30°, 60°, 90°) in each state. Meniscal extrusion was recorded at 0° and 90° in both loaded and unloaded states at three locations along the peripheral rim of the medial tibial plateau. Degree of meniscal extrusion was defined as the radial displacement of the medial meniscus from three corresponding points on the posteromedial edge of the tibial plateau: (1) posterior border of MCL; (2) posteromedial capsule midway between the MCL and posterior root; and (3) the direct posterior capsule. Peak contact pressure, contact area, and total contact pressure were also recorded for all states at all flexion angles. Results: Statistical analysis investigated the independent effects of flexion, state, and loading using three, distinct two-factor models. In unloaded knees in full extension, the highest degree of meniscal extrusion was observed at the posterior border of the MCL across all repair testing states (p &lt; 0.001). At full extension, loaded knees exhibited significantly higher extrusion in comparison to unloaded across all knee states at the MCL position (mean 1.1 mm, 95% CI [0.8, 1.4], p &lt;0.001). Significantly more extrusion was observed at 90° of flexion (mean 0.7 mm, 95% CI [0.36, 1.1], p &lt; 0.001). In loaded knees at 90° of flexion, all repair states had significantly lower extrusion than the root tear state (all p &lt;0.05). Only anatomic repair with peripheral stabilization had significantly lower extrusion than both nonanatomic repairs with or without peripheral stabilization (both p &lt; 0.01). Differences in the contact mechanics between repair techniques were most notable at higher flexion angles, demonstrating significantly higher average and peak contact pressures for non-anatomic repair variations when compared to anatomic repairs with and without peripheral stabilization (all p &lt;0.05). Root tear states were significantly higher than intact states for all comparisons except for peak pressure at 0° of flexion (all p &lt; 0.01). Conclusion: Anatomic and anatomic with peripheral suture repair techniques best restore contact mechanics of the knee. In current clinical scenarios where knees are unloaded and imaged in full extension, extrusion is best measured in the coronal plane at the posterior border of the MCL. However, this is likely a “best-case” scenario, as this study has shown that the degree of extrusion increases as the knee is loaded and flexed to 90°. When only a non-anatomic repair can be performed the addition of this peripheral stabilization technique may be beneficial for patients in reducing pathologic extrusion of the meniscus. [Table: see text]

Non anatomic reinsertion after amputation of the anterior horn of the lateral meniscus

Anatomical reinsertion is the optimal treatment for meniscal root injuries. However, in chronic settings, tissue fraying of the meniscal root may impede it. This study describes a salvage technical procedure performed in 3 cases of chronic anterior root avulsion of the lateral meniscus with profuse tissue degeneration in which remnant debridement resulted in amputation of the root. Reinsertion of the meniscus at the remaining healthy tissue was performed using an all-inside anchoring technique.

LINGO-1 shRNA Loaded by Pluronic F-127 Promotes Functional Recovery After Ventral Root Avulsion.

Spinal root avulsion typically leads to massive motoneuron death and severe functional deficits of the target muscles. Multiple pathological factors such as severe neuron loss, induction of inhibitory molecules, and insufficient regeneration are responsible for the poor functional recovery. Leucine-rich repeat and immunoglobulin-like domain-containing Nogo receptor-interacting protein 1 (LINGO-1), a central nervous system (CNS)-specific transmembrane protein that is selectively expressed on neurons and oligodendrocytes, serves as a potent negative mediator of axonal regeneration and myelination in CNS injuries and diseases. Although accumulating evidence has demonstrated improvement in axonal regeneration and neurological functions by LINGO-1 antagonism in CNS damage, the possible effects of LINGO-1 in spinal root avulsion remain undiscovered. In this study, a LINGO-1 knockdown strategy using lentiviral vectors encoding LINGO-1 short hairpin interfering RNA (shRNA) delivered by the Pluronic F-127 (PF-127) hydrogel was described after brachial plexus avulsion (BPA). We provide evidence that following BPA and immediate reimplantation, transplantation of LINGO-1 shRNA lentiviral vectors encapsulated by PF-127 rescued the injured motoneurons, enhanced axonal outgrowth and myelination, rebuilt motor endplates, facilitated the reinnervation of terminal muscles, improved angiogenesis, and promoted recovery of avulsed forelimbs. Altogether, these data suggest that delivery of LINGO-1 shRNA by a gel scaffold is a potential therapeutic approach for root avulsion. Impact Statement In this study, we attempted transplantation of lentivirus (LV)/leucine-rich repeat and immunoglobulin-like domain-containing Nogo receptor-interacting protein 1 (LINGO-1)-short hairpin interfering RNA (shRNA) encapsulated by the Pluronic F-127 (PF-127) hydrogel into a brachial plexus avulsion (BPA)-reimplantation model. We found that administration of LV/LINGO-1 shRNA facilitates neuron survival and axonal regeneration, attenuates muscle atrophy and motor endplate (MEP) loss, enhances neovascularization, and promotes functional recovery in BPA rats. Co-transplantation of LV/LINGO-1 shRNA and gel reinforces the survival-promoting effect, axonal outgrowth, and angiogenesis in comparison with LV/LINGO-1 shRNA application alone. Our research provides evidence that LV /LINGO-1 shRNA delivered by PF-127 represents a new treatment strategy for BPA repair.

Double Fascicular Nerve Transfer to Musculocutaneous Branches for Restoration of Elbow Flexion in Brachial Plexus Injury.

BackgroundRestriction of elbow flexion significantly limits upper extremity function following brachial plexus injuries. In recent years, the double fascicular nerve transfer procedure utilizing ulnar and median nerve transfer to musculocutaneous branches has shown promising functional outcomes.ObjectiveTo evaluate restoration of elbow flexion following a double fascicular transfer in patients with brachial plexus injuries and identify predictors of poor outcomes.MethodsThis retrospective review included 10 consecutive patients with brachial plexus injuries involving C5-C6 root avulsions who underwent the double nerve transfer procedure. The mean follow-up was 12 months and the primary outcome was assessment of elbow flexion with the use of the Medical Research Council (MRC) scale.ResultsThis procedure achieved elbow flexion of MRC grade M3 or higher in 50% of our cohort. Time interval from injury to surgery showed a statistically significant inverse association with functional recovery (r = -0.73, p = 0.016). Patients who had the surgery within six months of the injury, demonstrated higher MRC grades during the follow-up (p = 0.048). There was no association between elbow flexion recovery and age, body mass index (BMI), gender, hypertension, diabetes or smoking status.ConclusionsThe double fascicular transfer to musculocutaneous may be a safe and effective treatment for restoration of elbow flexion. The procedure is associated with superior functional outcomes when performed within the first six months from the injury.

Microglia exit the CNS in spinal root avulsion.

Microglia are central nervous system (CNS)-resident cells. Their ability to migrate outside of the CNS, however, is not understood. Using time-lapse imaging in an obstetrical brachial plexus injury (OBPI) model, we show that microglia squeeze through the spinal boundary and emigrate to peripheral spinal roots. Although both macrophages and microglia respond, microglia are the debris-clearing cell. Once outside the CNS, microglia re-enter the spinal cord in an altered state. These peripheral nervous system (PNS)-experienced microglia can travel to distal CNS areas from the injury site, including the brain, with debris. This emigration is balanced by two mechanisms—induced emigration via N-methyl-D-aspartate receptor (NMDA) dependence and restriction via contact-dependent cellular repulsion with macrophages. These discoveries open the possibility that microglia can migrate outside of their textbook-defined regions in disease states.

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

Neuregulin-1 Accelerates Functional Motor Recovery by Improving Motoneuron Survival After Brachial Plexus Root Avulsion in Mice

Brachial plexus root avulsion (BPRA) results in the complete loss of motor function in the upper limb, mainly due to the death of spinal motoneurons (MNs). The survival of spinal MNs is the key to the recovery of motor function. Neuregulin-1 (Nrg1) plays fundamental roles in nervous system development and nerve repair. However, its functional role in BPRA remains unclear. On the basis of our findings that Nrg1 is down-regulated in the ventral horn in a mouse model of BPRA, Nrg1 may be associated with BPRA. Here, we investigated whether recombinant Nrg1β (rNrg1β) can enhance the survival of spinal MNs and improve functional recovery in mice following BPRA. In vitro studies on primary cultured mouse MNs showed that rNrg1β increased the survival rate in a dose-dependent manner, reaching a peak at 5 nM, which increased the survival rate and enhanced the pERK levels in MNs under H2O2-induced oxidative stress. In vivo studies revealed that rNrg1β improved the functional recovery of elbow flexion, promoted the survival of MNs, enhanced the re-innervation of biceps brachii, and decreased the muscle atrophy. These results suggest that Nrg1 may provide a potential therapeutic strategy for root avulsion.

Clinical significance of cervical MRI in brachial plexus birth injury

Background and purpose — Patient selection for nerve surgery in brachial plexus birth injury (BPBI) is difficult. Decision to operate is mostly based on clinical findings. We assessed whether MRI improves patient selection.Patients and methods — 157 BPBI patients were enrolled for a prospective study during 2007–2015. BPBI was classified at birth as global plexus injury (GP) or upper plexus injury (UP). The global plexus injury was subdivided into flail upper extremity (FUE) and complete plexus involvement (CP). Patients were seen at set intervals. MRI was scheduled for patients that had either GP at 1 month of age or UP with no antigravity biceps function by 3 months of age. Type (total or partial avulsion, thinned root), number and location of root injuries and pseudomeningoceles (PMC) were registered. Position of humeral head (normal, subluxated, dislocated) and glenoid shape (normal, posteriorly rounded, pseudoglenoid) were recorded. Outcome was assessed at median 4.5 years (1.6–8.6) of age.Results — Cervical MRI was performed on 34/157 patients at median 3.9 months (0.3–14). Total root avulsions (n = 1–3) were detected on MRI in 12 patients (8 FUE, 4 CP). Reconstructive surgery was performed on 10/12 with total avulsions on MRI, and on all 10 with FUE at birth. Sensitivity and specificity of MRI in detecting total root avulsions was 0.88 and 1 respectively. Posterior shoulder subluxation/dislocation was seen in 15/34 patients (3.2–7.7 months of age).Interpretation — Root avulsion(s) on MRI and flail upper extremity at birth are both good indicators for nerve surgery in brachial plexus birth injury. Shoulder pathology develops very early in permanent BPBI.

Contralateral C7 transfer to lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck for total brachial plexus root avulsion: a cadaveric study

BackgroundRestoration of hand function after total brachial plexus root avulsion (tBPRA) is a difficult problem in surgical management. A new modified approach in repairing tBPRA is to use a subcutaneous tunnel across the anterior surface of the chest and neck, and then transfer the contralateral C7 root (cC7) to the lower trunk. However, the anatomical details of this method have not yet been fully described and assessed. The objective of this study was to quantitatively describe the nerve transfer using a cadaveric surgical simulation.Materials and methodsBrachial plexuses were dissected from 12 adult cadavers, producing 24 sides of brachial plexuses for nerve transfer experiments. We performed simulated cC7 transfers to the lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck. Measurements of the nerves were made and transfers quantitatively documented.ResultsWith the affected shoulder and arm in a neutral position, cC7 and C8-T1 could be sutured directly together in 75% of the cadavers. A nerve graft length of 4.6 ± 1.18 cm was needed to bridge the gap in the remaining cadavers. For cadavers where distal cC7 was directly connected with the lower trunk, 54.17% could be sutured, and an average nerve graft length of 3.9 cm was needed in the remains.ConclusionsFor surgical management of total tBPRA, transfer of the cC7 nerve to the C8-T1 or lower trunk via a subcutaneous tunnel across the chest and neck will likely be superior to a conventional cC7 root transfer in the clinic. This approach shortens the nerve graft needed and nerve regeneration distance, decreases the number of neurorrhaphy sites, and makes full use of the donor nerves, which may benefit hand flexion restoration.

Magnetic Resonance Imaging for Detecting Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A Systematic Review and Meta-Analysis of Diagnostic Accuracy

Background: Traumatic brachial plexus injuries (BPI) affect 1% of patients involved in major trauma. Magnetic resonance imaging (MRI) is the best indicator of traumatic BPIs although its ability to differentiate root avulsions (which require urgent reconstructive surgery) from other types of nerve injury remains unknown. Methods: Medline and Embase were searched from inception to August 20th 2018, with no restrictions. Studies of adults with traumatic non-penetrating unilateral brachial plexus injuries were included. The target condition was root avulsion. The index test was pre-operative MRI and the reference standard was operative exploration of the roots of the brachial plexus. Results: Eleven studies of 275 adults were included. Most patients were males (94%) injured in motorcycle collisions (84%). The majority of studies were at unclear or high risk of bias and there were high applicability concerns for the index test (MRI) given the lack of diagnostic criteria for root avulsion, inadequate descriptions of pulse sequences and multiplicity of reporting radiologists. At least one root of the brachial plexus was avulsed in 72% of patients (IQR 53%, 86%) but meta-analysis of patient-level data was not performed due to sparse and heterogeneous data. With the nerve as the unit of analysis, 583 out of 918 roots were avulsed (median 55%; IQR 38%, 71%); the mean sensitivity of MRI for root avulsion was 93% (95% CI 77%, 98%) with a mean specificity of 72% (95% CI 42%, 90%). Conclusions: Based on the limited data, MRI has modest accuracy for diagnosing root avulsions following traumatic BPI and operative exploration should remain the diagnostic option. Funding Statement: Ryckie Wade is a Doctoral Research Fellow funded by the National Institute for Health Research (NIHR, DRF-2018-11-ST2-028). This research is supported by NIHR infrastructure at Leeds, Oxford and Birmingham. The views expressed are those of the author(s) and not necessarily those of the United Kingdom’s National Health Service, NIHR or Department of Health. Declaration of Interests: The authors state: none. Ethics Approval Statement: The authors state: Not required.

Split-Cord Malformation of the Cervical Spinal Cord Following Dorsal Root Entry Zone Lesioning Surgery

The authors report a rare case of a 54-year-old man who developed an asymptomatic cleft within the cervical spinal cord at C7-T1 following Dorsal Root Entry Zone (DREZ) lesioning surgery. The patient presented to the authors’ institution with neuropathic pain from a left brachial plexopathy resulting from a lower trunk avulsion. The initial MRI at 6 months post-injury confirmed preganglionic avulsions of the left C7, C8 and T1 nerve roots. Of note, there was a prominent anterior median fissure at the C7-T1 spinal level. He underwent a DREZ lesion 8 months after the injury. Subsequent MRI studies showed a progressive near complete split within the cervical cord at C7- T1. The patient did not develop any new neurological deficits. It remains unclear whether this observation was a sequela of the root avulsion or the DREZ surgery.

A Clinical Analysis of Repairing the Whole Brachial Plexus Nerve Root Avulsion by Transferring C7 Nerve Root from the Uninjured Side

Objective to perform a C7 transfer from the uninjured side for the patients with whole brachial plexus nerve root avulsion, conduct follow-up observations of the recovery conditions of the affected limb, and discuss the degree of the effect on the limb on the uninjured side and the mechanism. Method The 36 patients with whole brachial plexus nerve avulsion who received a C7 transfer from the uninjured side for repair by stages from January 2011-December 2011 in our hospital were selected as the objects to analyse the data of cases, carry out follow-up visits, evaluate of the limb functions on the uninjured side, and make comprehensive assessment in accordance with U.K. MRC scale for sensation and U.K. amended MRC scale for muscular strength. Result The follow-up visit results regarding the motor functions of the affected limb have indicated that there were 2 patients with effective recovery of supraspinatus muscular strength, 2 patients with effective recovery of deltoid muscular strength, 6 patients with effective recovery of biceps brachii muscular strength, 7 patients with effective recovery of triceps brachii muscular strength, 4 patients with effective recovery of extensor carpi muscular strength, and 5 patients with effective recovery of flexor carpi and flexor digitorum muscular strength. There were 7 patients whose latissimus dorsi muscular strength reached M5-, 7 patients whose triceps brachii muscular strength reached M5-, and 10 patients whose extensor digitorum muscular strength reached M5- 6 months after operation. There were 3 patients whose limb on the uninjured side reached Sensation Grade S4, 12 patients whose limb on the uninjured side reached Sensation Grade S3+, 11 patients whose limb on the uninjured side reached Sensation Grade S3, and 10 patients whose limb on the uninjured side reached Sensation Grade S2 3 days after operation. The sensory functions of the majority of the patients recovered to S4 and their two-point discrimination approximately recovered to normal at the follow-up visit 1 year after operation. Conclusion Repair with C7 transfer from the uninjured side is currently an effective and feasible method to repair the functions of the affected limb in brachial plexus nerve root avulsion.

Treatment of neuropathic pain after peripheral nerve and brachial plexus traumatic injury.

Peripheral nerve and brachial plexus injuries typically cause severe impairment in the affected limb. The incidence of neuropathic pain is high, reaching up to 95% of cases, especially if cervical root avulsion has occurred. Neuropathic pain results from damage to the somatosensory system, and its progression towards chronicity depends upon disruptions affecting both the peripheral and central nervous system. Managing these painful conditions is complex and must be accomplished by a multidisciplinary team, starting with first-line pharmacological therapies like tricyclic antidepressants and calcium channel ligands, combined physical and occupational therapy, transcutaneous electrical stimulation and psychological support. For patients refractory to the initial measures, several neurosurgical options are available, including nerve decompression or reconstruction and ablative/modulatory procedures.

Rewiring the upper limb: Motor nerve transfer surgery in the reconstruction of paralysis

Surgery to rewire a paralysed limb is now possible using motor nerve transfer surgery. The technique has been adapted from brachial plexus surgery and applied to other causes of paralysis with remarkable results, providing function to patients left paralysed from spinal cord injury, inflammatory neuropathy, tumour surgery and degenerative spinal disease. Adapting the techniques to peripheral nerve injury offers improved outcomes compared to anatomical reconstruction of an injured nerve. Nerve transfer surgery involves harvest of an expendable motor branch or redundant motor fascicle from a peripheral nerve and direct, tension-free coaptation to the distal motor branch of a paralysed muscle close to the motor point. Rapid re-innervation of the denervated muscle results in reliable motor recovery. Originally popularised for the reconstruction of nerve root avulsion, the technique has been adapted for use in other peripheral nerve injuries resulting in motor outcomes that are superior to those achieved through grafting of mixed motor-sensory nerve gaps. Nerve transfer surgery may be used to salvage late presenting cases, failed proximal reconstructions or as an adjunct for key motor functions in proximal nerve repairs where the time-distance phenomenon of peripheral nerve regeneration results in poor distal motor recovery, even following acute direct repair. The extension of the technique to other paralysing conditions demonstrates promise.

The evolution of nerve transfer restoration of shoulder function

Loss of shoulder abduction and external rotation reduces the working space for the upper limb and hand. Paralysis may follow C5 nerve root avulsion, upper trunk rupture or isolated injuries to the suprascapular and axillary nerves. Motor nerve transfer surgery involves a direct transfer of an expendable motor branch from a muscle in the vicinity of the paralyzed muscle and direct transfer with microsurgical end-to-end coaptation to the nerve to the denervated muscle close to its motor point. Reinnervation is rapid and robust. The technique was described for the restoration of deltoid function more than a century ago but was not adopted into wide spread use until the past two decades. This article explores the various options of nerve transfer surgery to restore function of shoulder function and reviews the evidence. Refinements in the procedure have resulted with the current algorithm for management, which will be described with its rationale and a review of clinical outcomes.