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

Application of olfactory ensheathing cells in peripheral nerve injury and its complication with pathological pain

Direct or indirect injury of peripheral nerve can lead to sensory and motor dysfunction, which can lead to pathological pain and seriously affect the quality of life and psychosomatic health of patients. While the internal repair function of the body after peripheral nerve injury is limited. Nerve regeneration is the key factor hindering the recovery of nerve function. At present, there is no effective treatment. Therefore, more and more attention have been paid to the development of foreground treatment to achieve functional recovery after peripheral nerve injury, including relief of pathological pain. Cell transplantation strategy is a therapeutic method with development potential in recent years, which can exert endogenous alternative repair by transplanting exogenous functional bioactive cells to the site of nerve injury. Olfactory ensheathing cells (OECs) are a special kind of glial cells, which have the characteristics of continuous renewal and survival. The mechanisms of promoting nerve regeneration and functional repair and relieving pathological pain by transplantation of OECs to peripheral nerve injury include secretion of a variety of neurotrophic factors, axonal regeneration and myelination, immune regulation, anti-inflammation, neuroprotection, promotion of vascular growth and improvement of inflammatory microenvironment around nerve injury. Different studies have shown that OECs combined with biomaterials have made some progress in the treatment of peripheral nerve injury and pathological pain. These biomaterials enhance the therapeutic effect of OECs. Therefore, the functional role of OECs in peripheral nerve injury and pathological pain was discussed in this paper.Although OECs are in the primary stage of exploration in the repair of peripheral nerve injury and the application of pain, but OECs transplantation may become a prospective therapeutic strategy for the treatment of peripheral nerve injury and pathological pain.

Abnormal genes and pathways that drive muscle contracture from brachial plexus injuries: Towards machine learning approach

In order to clarify the pathways closely linked to denervated muscle contracture, this work uses IoMT-enabled healthcare stratergies to examine changes in gene expression patterns inside atrophic muscles following brachial plexus damage. The gene expression Omnibus (GEO) database searching was used to locate the dataset GSE137606, which is connected to brachial plexus injuries. Strict criteria (|logFC|≥2 & adj.p < 0.05) were used to extract differentially expressed genes (DEGs). To identify dysregulated activities and pathways in denervated muscles, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and Gene Set Enrichment Analysis (GSEA) were used. Hub genes were found using Cytoscape software's algorithms, which took into account parameters like as proximity, degree, and MNC. Their expression, enriched pathways, and correlations were then examined. The results showed that 316 DEGs were predominantly concentrated in muscle-related processes such as tissue formation and contraction pathways. Of these, 297 DEGs were highly expressed in denervated muscles, whereas 19 DEGs were weakly expressed. GSEA showed improvements in the contraction of striated and skeletal muscles. In addition, it was shown that in denervated muscles, Myod1, Myog, Myh7, Myl2, Tnnt2, and Tnni1 were elevated hub genes with enriched pathways such adrenergic signaling and tight junction. These results point to possible therapeutic targets for denervated muscular contracture, including Myod1, Myog, Myh7, Myl2, Tnnt2, and Tnni1. This highlights treatment options for this ailment which enhances the mental state of patient.

Electrical burn-induced vocal cord injury: insights from a case report and literature review

We report a rare case of vocal cord injury from an electrical burn, managed successfully with conservative, non-invasive treatment. This unique case illustrates potential complications of electrical trauma and underscores the need for vigilance and consideration of conservative management approaches.

Combat-related peripheral nerve injuries

Active-duty service members (ADSM) and military Veterans represent a population with increased occupational risk for nerve injuries sustained both during training operations and wartime. Mechanisms of war-related nerve injuries have evolved over time, from the musket ball-related traumas described by S.W. Mitchell to complex blast injuries and toxic exposures sustained during Middle East conflicts in the 21st century. Commonly encountered nerve injury etiologies in this population currently include compression, direct trauma, nutritional deficits, traumatic limb amputation, toxic chemical exposures, or blast-related injuries. Expeditious identification and comprehensive, interdisciplinary treatment of combat-associated neuropathies, as well as prevention of these injuries whenever possible is critical to reduce chronic morbidity and disability for service members and to maintain a well-prepared military. However, diagnosis of a combat-associated nerve injury may be particularly challenging due to comorbid battlefield injuries or delayed presentation of neuropathy from military toxic exposures. Advances in imaging for nerve injury, including MRI and ultrasound, provide useful tools to compliment EMG in establishing a diagnosis of combat-associated nerve injury, particularly in the setting of anatomic disruption or edema. Surgical techniques can improve pain control or restoration of function. In all cases, comprehensive interdisciplinary rehabilitation provides the best framework for optimization of recovery. Further work is needed to prevent combat-associated nerve injuries and promote nerve recovery following injury.

Dental Pulp Stem Cell-Derived Exosomes Promote Sciatic Nerve Regeneration via Optimizing Schwann Cell Function

Repair strategies for injured peripheral nerve have achieved great progresses in recent years. However, the clinical outcomes remain unsatisfactory. Recent studies have found that exosomes secreted by dental pulp stem cells (DPSC-exos) have great potential for applications in nerve repair. In this study, we evaluated the effects of human DPSC-exos on improving peripheral nerve regeneration. Initially, we established a coculture system between DPSCs and Schwann cells (SCs) in vitro to assess the effect of DPSC-exos on the activity of embryonic dorsal root ganglion neurons (DRGs) growth in SCs. We extracted and labeled human DPSC-exos, which were subsequently utilized in uptake experiments in DRGs and SCs. Subsequently, we established a rat sciatic nerve injury model to evaluate the therapeutic potential of DPSC-exos in repairing sciatic nerve damage. Our findings revealed that DPSC-exos significantly promoted neurite elongation by enhancing the proliferation, migration, and secretion of neurotrophic factors by SCs. In vivo, DPSC-exos administration significantly improved the walking behavior, axon regeneration, and myelination in rats with sciatic nerve injuries. Our study underscores the vast potential of DPSC-exos as a therapeutic tool for tissue-engineered nerve construction.

The Role of Early Rehabilitation and Functional Electrical Stimulation in Rehabilitation for Cats with Partial Traumatic Brachial Plexus Injury: A Pilot Study on Domestic Cats in Portugal

This prospective observational cohort pilot study included 22 cats diagnosed with partial traumatic brachial plexus injury (PTBPI), aiming to explore responses to an early intensive neurorehabilitation protocol in a clinical setting. This protocol included functional electrical stimulation (FES), locomotor treadmill training and kinesiotherapy exercises, starting at the time with highest probability of nerve repair. The synergetic benefits of this multimodal approach were based on the potential structural and protective role of proteins and the release of neurotrophic factors. Furthermore, FES was parametrized according to the presence or absence of deep pain. Following treatment, 72.6% of the cats achieved ambulation: 9 cats within 15 days, 2 cats within 30 days and 5 cats within 60 days. During the four-year follow-up, there was evidence of improvement in both muscle mass and muscle weakness, in addition to the disappearance of neuropathic pain. Notably, after the 60 days of neurorehabilitation, 3 cats showed improved ambulation after arthrodesis of the carpus. Thus, early rehabilitation, with FES applied in the first weeks after injury and accurate parametrization according to the presence or absence of deep pain, may help in functional recovery and ambulation, reducing the probability of amputation.

Effects of rTMS combined with rPMS on stroke patients with arm paralysis after contralateral seventh cervical nerve transfer: a case-series

OBJECTIVE

We conducted this study to evaluate the effect of rTMS combined with rPMS on stroke patients with arm paralysis after CSCNTS.

METHODS

A case-series of four stroke patients with arm paralysis, ages ranging from 39 to 51 years, that underwent CSCNTS was conducted. Patients were treated with 10 HZ rTMS on the contralesional primary motor cortex combined with 20 HZ rPMS on groups of elbow and wrist muscles for 15 days.

RESULTS

The muscle tone of elbow flexor muscle (EFM), elbow extensor muscle (EEM), wrist flexor muscle (WFM) and flexor digitorum (FD) reduced immediately after operation followed by increasing gradually. After rehabilitation, the muscle tone of EEM and EFM reduced by 14% and 11%, respectively. There was a 13% and 45% change ratio in WFM and FD. The numeric rating scale (mean = 5.75 ± 1.71) was significantly lower (mean = 3.25 ± 1.90, t = 8.66, p = .00). Grip and pinch strength (mean = 23.65 ± 4.91; mean = 4.9 ± 0.59) were significantly higher (mean = 34.63 ± 5.23, t = -61.07, p = .00; mean = 7.1 ± 0.73, t = -13.91, p = .00).

CONCLUSIONS

The rehabilitation of stroke patients with arm paralysis after CSCNTS is a long, complicated process which includes great change of neuropathic pain, muscle tone, and muscle strength. In order to enhance the neural connection between the contralesional hemisphere and the hemiplegic limb, alleviate postoperative complications, as well as accelerate the rehabilitation process, we can consider to use rTMS combined with rPMS.

CDK5R1 promotes Schwann cell proliferation, migration, and production of neurotrophic factors via CDK5/BDNF/TrkB after sciatic nerve injury

Cyclin-dependent kinase 5 regulatory subunit 1 (CDK5R1) is necessary for central nervous system development and neuronal migration. At present, there are few reports about the role of CDK5R1 in peripheral nerve injury, and these need to be further explored. The CCK-8 and EdU assay was performed to examine cell proliferation. The migration ability of Schwann cells was tested by the cell scratch test. The apoptosis of Schwann cells was detected by flow cytometry. Sciatic nerve injury model in rats was established by crush injury. The sciatic function index (SFI) and the paw withdrawal mechanical threshold (PWMT) were measured at different time points. The results revealed that overexpression of CDK5R1 promoted the proliferation and migration of Schwann cells, and inhibited the apoptosis. Further studies found that pcDNA3.1-CDK5R1 significantly upregulated the expression of CDK5, BDNF and TrkB. More importantly, CDK5R1 promoted the recovery of nerve injury in rats. In addition, the CDK5 mediated BDNF/TrkB pathway was involved in the molecular mechanism of CDK5R1 on Schwann cells. It is suggested that the mechanism by which CDK5R1 promotes functional recovery after sciatic nerve injury is by CDK5 mediated activation of BDNF/TrkB signaling pathways.

Long-term functional recovery in C5-C6 avulsions treated with distal nerve transfers

BACKGROUND

In patients suffering from traction lesions of the brachial plexus, complete C5 and/or C6 root avulsion patients with C7 root preservation are relatively uncommon occurrences, but represent excellent candidates for surgical treatment, with satisfactory results. Shoulder abduction and extra-rotation, elbow flexion and forearm supination are lost functions restorable with surgical treatment.

METHODS

This single-center, prospective observational study involved a series of 27 young adults with C5 and/or C6 root complete avulsion and C7 preservation, which underwent surgical repair with double or triple nerve transfer.

RESULTS

Patients recovered a useful elbow flexion. Electromyographic and clinical signs of biceps reinnervation were observed in each UN-MC nerve transfer. The abduction strength recovery was M5 in 10 patients, M4 in 14 patients and M3 in 3 patients. The external rotation strength recovery was M5 in 4 patients, M4 in 18 patients, M3 in 3 patients and M2 in 2 patients. The elbow flection strength was M5 in 5 patients, M4 in 15 patients and M3 in 7 patients. Elbow extension was preserved in all cases.

CONCLUSIONS

The concept of 'peripheral rewiring procedures' represents an advance in the repair of the peripheral nerve injuries. Triple nerve transfer can be nowadays considered a standard treatment for isolated C5-C6 avulsions. We report our experience with the second-biggest casuistry in the literature on patients treated with this technique. We consider our outcome concerning functional recovery to be satisfying and comparable to data reported in the literature.

G protein-coupled P2Y12 receptor is involved in the progression of neuropathic pain

The pathological mechanism of neuropathic pain is complex, which seriously affects the physical and mental health of patients, and its treatment is also difficult. The role of G protein-coupled P2Y12 receptor in pain has been widely recognized and affirmed. After nerve injury, stimulated cells can release large amounts of nucleotides into the extracellular matrix, act on P2Y12 receptor. Activated P2Y12 receptor activates intracellular signal transduction and is involved in the development of pain. P2Y12 receptor activation can sensitize primary sensory neurons and receive sensory information. By transmitting the integrated information through the dorsal root of the spinal cord to the secondary neurons of the posterior horn of the spinal cord. The integrated information is then transmitted to the higher center through the ascending conduction tract to produce pain. Moreover, activation of P2Y12 receptor can mediate immune cells to release pro-inflammatory factors, increase damage to nerve cells, and aggravate pain. While inhibits the activation of P2Y12 receptor can effectively relieve pain. Therefore, in this article, we described P2Y12 receptor antagonists and their pharmacological properties. In addition, we explored the potential link between P2Y12 receptor and the nervous system, discussed the intrinsic link of P2Y12 receptor and neuropathic pain and as a potential pharmacological target for pain suppression.

Olfactory ensheathing cells and neuropathic pain

Damage to the nervous system can lead to functional impairment, including sensory and motor functions. Importantly, neuropathic pain (NPP) can be induced after nerve injury, which seriously affects the quality of life of patients. Therefore, the repair of nerve damage and the treatment of pain are particularly important. However, the current treatment of NPP is very weak, which promotes researchers to find new methods and directions for treatment. Recently, cell transplantation technology has received great attention and has become a hot spot for the treatment of nerve injury and pain. Olfactory ensheathing cells (OECs) are a kind of glial cells with the characteristics of lifelong survival in the nervous system and continuous division and renewal. They also secrete a variety of neurotrophic factors, bridge the fibers at both ends of the injured nerve, change the local injury microenvironment, and promote axon regeneration and other biological functions. Different studies have revealed that the transplantation of OECs can repair damaged nerves and exert analgesic effect. Some progress has been made in the effect of OECs transplantation in inhibiting NPP. Therefore, in this paper, we provided a comprehensive overview of the biology of OECs, described the possible pathogenesis of NPP. Moreover, we discussed on the therapeutic effect of OECs transplantation on central nervous system injury and NPP, and prospected some possible problems of OECs transplantation as pain treatment. To provide some valuable information for the treatment of pain by OECs transplantation in the future.

Time-course gait pattern analysis in a rat model of foot drop induced by ventral root avulsion injury

Foot drop is a common clinical gait impairment characterized by the inability to raise the foot or toes during walking due to the weakness of the dorsiflexors of the foot. Lumbar spine disorders are common neurogenic causes of foot drop. The accurate prognosis and treatment protocols of foot drop are not well delineated in the scientific literature due to the heterogeneity of the underlying lumbar spine disorders, different severities, and distinct definitions of the disease. For translational purposes, the use of animal disease models could be the best way to investigate the pathogenesis of foot drop and help develop effective therapeutic strategies for foot drops. However, no relevant and reproducible foot drop animal models with a suitable gait analysis method were developed for the observation of foot drop symptoms. Therefore, the present study aimed to develop a ventral root avulsion (VRA)-induced foot drop rat model and record detailed time-course changes of gait pattern following L5, L6, or L5 + L6 VRA surgery. Our results suggested that L5 + L6 VRA rats exhibited changes in gait patterns, as compared to sham lesion rats, including a significant reduction of walking speed, step length, toe spread, and swing phase time, as well as an increased duration of the stance phase time. The ankle kinematic data exhibited that the ankle joint angle increased during the mid-swing stage, indicating a significant foot drop pattern during locomotion. Time-course observations displayed that these gait impairments occurred as early as the first-day post-lesion and gradually recovered 7-14 days post-injury. We conclude that the proposed foot drop rat model with a video-based gait analysis approach can precisely detect the foot drop pattern induced by VRA in rats, which can provide insight into the compensatory changes and recovery in gait patterns and might be useful for serving as a translational platform bridging human and animal studies for developing novel therapeutic strategies for foot drop.

Potential mechanisms of acupuncture for neuropathic pain based on somatosensory system

Neuropathic pain, caused by a lesion or disease of the somatosensory system, is common and distressing. In view of the high human and economic burden, more effective treatment strategies were urgently needed. Acupuncture has been increasingly used as an adjuvant or complementary therapy for neuropathic pain. Although the therapeutic effects of acupuncture have been demonstrated in various high-quality randomized controlled trials, there is significant heterogeneity in the underlying mechanisms. This review aimed to summarize the potential mechanisms of acupuncture on neuropathic pain based on the somatosensory system, and guided for future both foundational and clinical studies. Here, we argued that acupuncture may have the potential to inhibit neuronal activity caused by neuropathic pain, through reducing the activation of pain-related ion channels and suppressing glial cells (including microglia and astrocytes) to release inflammatory cytokines, chemokines, amongst others. Meanwhile, acupuncture as a non-pharmacologic treatment, may have potential to activate descending pain control system via increasing the level of spinal or brain 5-hydroxytryptamine (5-HT), norepinephrine (NE), and opioid peptides. And the types of endogenously opioid peptides was influenced by electroacupuncture-frequency. The cumulative evidence demonstrated that acupuncture provided an alternative or adjunctive therapy for neuropathic pain.

Comparison of three different strategies to treat sciatic nerve regeneration: an experimental study

PURPOSE

To compare the effect of vein conduit filled with adipose tissue stem cells (ASC) on peripheral nerve injury regeneration.

METHODS

We analyzed 30 male Wistar rats surgically submitted to a 5-mm gap on the sciatic nerve. Then, the animals were divided into three groups: nerve autografting (AG, n=10), autogenous inverted glycerol-conserved vein (VG, n=10), and autogenous inverted glycerol-conserved vein + ASC (VASCG, n=10). The study endpoints were neuromotor functional analysis, gastrocnemius muscle weight, and sciatic nerve graft histomorphometry analysis. In the histologic analysis, we added a control group (naïve nerve).

RESULTS

Regarding functional analysis (Walking tract- score), the findings at week 3 showed a difference between the AG and the VG (-96.6 vs. -59.6, p=0.01, respectively) and between the VG and the inverted vein + VASCG (-59.9 vs. -88.92, p=0.02). At week 12, this study showed a difference between the AG and the VG (-64.8 vs. -47.3, p=0.004, respectively), and also a difference between the VG and the VASCG (-47.3 vs. -57.4, p=0.02, respectively). There was no difference in the histomorphometry analysis (nerve diameter, Schwann cells counting). The gastrocnemius muscles on the intervention side were more atrophic when compared to the gastrocnemius muscles on the control side.

CONCLUSIONS

Our results suggested better functional recovery in the inverted vein group when compared to control group, and inverted vein + ASC group.

Electron Microscope Observation of Acupuncture and Nerve Repair in the Treatment of Peripheral Facial Paralysis

The repair of peripheral facial paralysis is a long-term problem in neurosurgery, and nerve repair is often needed. Due to the high differentiation of nerve tissue and the slow regeneration of peripheral nerve fibers, the repair effect after peripheral nerve injury is not ideal. In recent years, studies have found that the inflammatory response after peripheral nerve injury also has an important impact on the repair of peripheral nerve defects. This study depends on the utilization of traditional needle therapy in the treatment of fringe facial loss of motion, and the clinical adequacy of needle therapy in addition to nerve fix in the intense period of fringe facial loss of motion was seen with an electron magnifying lens. Endeavor to give significant exploration results to the clinical treatment of fringe facial loss of motion gives a straightforward, simple, protected, and successful new treatment innovation for the clinical treatment of the infection and enriches the treatment plan for peripheral facial paralysis. Transmission electron microscopy observations showed that 21 days after the artificial nerve was repaired, the nerve injury showed different degrees of recovery, and the myelin sheath was forming and gradually wrapping the new axons, which was similar to the catheter group (NC) and hydrogel group (HC). In contrast, the myelin layer of the fibroblast group (FHC) is more obvious, and the repair effect is better. In the maintenance of fringe nerve surrenders, irritation is an unavoidable interaction, and moderate needle therapy is useful to advance the maintenance of fringe nerve abandons. Talking about the law of nerve fix reaction in fringe nerve imperfection fix is helpful to the examination of fringe nerve deformity fix. Tests have shown that utilizing needle therapy and moxibustion joined with nerve fixes has accomplished great outcomes in the treatment of fringe facial loss of motion, and the patient's recuperation rate has expanded by over 30%.

Site of Nerve Division Affects Pain-Related Behavior and Spinal Cord Glial Proliferation after C7 Neurotomy in a Rat Stroke Model

Objective

This study aimed to evaluate whether the site of C7 neurotomy affects spinal cord glial cell activation and pain-related behavior on the paralyzed side in a rat stroke model.

Methods

After middle cerebral artery occlusion (MCAO) was induced in male Sprague-Dawley rats, they underwent C7 neurotomy 0, 2, and 4 mm distal to the intervertebral foramen on the paralyzed side. Pain-related behavior and immunofluorescence examination of spinal cord glial cell activation in the ipsilateral C7 dorsal horn were evaluated.

Results

Mechanical paw withdrawal threshold (MPWT) was lower, and the number of microglia and astrocytes (/mm²) was higher as the distance between the site of C7 neurotomy and the intervertebral foramen decreased from 4 mm to 0.

Conclusion

The site of C7 neurotomy affects MPWT and spinal cord glial proliferation in rats with MCAO. Nerve division closer to intervertebral foramen resulted in lower MPWT and higher degree of glial proliferation in the spinal cord.

Early Intervention of Cold-Water Swimming on Functional Recovery and Spinal Pain Modulation Following Brachial Plexus Avulsion in Rats

Brachial plexus avulsion (BPA) causes peripheral nerve injury complications with motor and sensory dysfunction of the upper limb. Growing evidence has shown an active role played by cold-water swimming (CWS) in alleviating peripheral neuropathic pain and functional recovery. This study examined whether CWS could promote functional recovery and pain modulation through the reduction of neuroinflammation and microglial overactivation in dorsal horn neurons at the early-stage of BPA. After BPA surgery was performed on rats, they were assigned to CWS or sham training for 5 min twice a day for two weeks. Functional behavioral responses were tested before and after BPA surgery, and each week during training. Results after the two-week training program showed significant improvements in BPA-induced motor and sensory loss (p < 0.05), lower inflammatory cell infiltration, and vacuole formation in injured nerves among the BPA-CWS group. Moreover, BPA significantly increased the expression of SP and IBA1 in dorsal horn neurons (p < 0.05), whereas CWS prevented their overexpression in the BPA-CWS group. The present findings evidenced beneficial rehabilitative effects of CWS on functional recovery and pain modulation at early-stage BPA. The beneficial effects are partially related to inflammatory suppression and spinal modulation. The synergistic role of CWS combined with other management approaches merits further investigation.

Kinematic Changes in the Uninjured Limb After a Traumatic Brachial Plexus Injury

Background: Traumatic brachial plexus injury (TBPI) typically causes sensory, motor and autonomic deficits of the affected upper limb. Recent studies have suggested that a unilateral TBPI can also affect the cortical representations associated to the uninjured limb.

Objective: To investigate the kinematic features of the uninjured upper limb in participants with TBPI.

Methods: Eleven participants with unilateral TBPI and twelve healthy controls matched in gender, age and anthropometric characteristics were recruited. Kinematic parameters collected from the index finger marker were measured while participants performed a free-endpoint whole-body reaching task and a cup-to-mouth task with the uninjured upper limb in a standing position.

Results: For the whole-body reaching task, lower time to peak velocity (p = 0.01), lower peak of velocity (p = 0.003), greater movement duration (p = 0.04) and shorter trajectory length (p = 0.01) were observed in the TBPI group compared to the control group. For the cup-to-mouth task, only a lower time to peak velocity was found for the TBPI group compared to the control group (p = 0.02). Interestingly, no differences between groups were observed for the finger endpoint height parameter in either of the tasks. Taken together, these results suggest that TBPI leads to a higher cost for motor planning when it comes to movements of the uninjured limb as compared to healthy participants. This cost is even higher in a task with a greater postural balance challenge.

Conclusion: This study expands the current knowledge on bilateral sensorimotor alterations after unilateral TBPI and should guide rehabilitation after a peripheral injury.

Subcutaneous Peripheral Nerve Stimulation for Treatment of Acute/Subacute Herpes Zoster-related Trigeminal Neuralgia: A Retrospective Research

OBJECTIVES

The purpose of this study was to observe the effect of subcutaneous stimulation of the peripheral nerve on acute or subacute zoster occurring in trigeminal nerve branches, and to evaluate the preventive effect of prior temporary implant of a peripheral stimulation electrode in the acute or subacute phase of herpes zoster (HZ) (from 30 to 90 d after zoster onset) before postherpetic neuralgia (PHN) presents.

METHODS AND MATERIALS

A total of 26 patients' medical records were analyzed. All of patients had received temporary subcutaneous peripheral nerve stimulation (PNS). The clinical efficacy of treatment was evaluated on a visual analog scale (VAS), and dosages of pain medication were recorded before and at 1 to 6 months after the temporary stimulation. The rate of PHN was reevaluated at a 6 months follow-up.

RESULTS

There was a significant decrease in VAS values after PNS. Medication doses decreased significantly after TPNS. The rate of clinically meaningful PHN (VAS >3) dropped below 4%.

DISCUSSION

This study revealed that PNS is an effective treatment for trigeminal herpetic neuralgia following acute or subacute HZ. As a extend neuromodulation method, subcutaneous peripheral nerve-field stimulation might be a useful option to reduce the progression of neuropathic changes caused by persistent transmission of pain signals in the trigeminal nerve branches after the acute or subacute phase of HZ.

The efficacy of wrapping the neurorrhaphy site utilizing dura substitute: A case series

BACKGROUND

Different procedures have been developed to improve the surgical outcome of peripheral nerve injuries. The purpose of this study was to evaluate the efficacy of wrapping the neurorrhaphy site utilizing dura substitute graft as an alternative conduit in the management of peripheral nerve injury.

METHODS

This retrospective clinical case series included 42 patients with a single peripheral nerve injury. The mean age was 26.8 ± 11 years, and the mean duration of symptoms was 3 ± 1.8 months. The visual analogue score (VAS) for pain and the Medical Research Council's (MRC) grading for motor power were used to evaluate the functional outcome among our patients. All patients were operated on for primary microscopic end-to-end repair, followed by wrapping the neurorrhaphy site with dura substitute graft as a conduit. Patients were followed in the outpatient clinic with regular visits for average of 6 months.

RESULTS

Thirty-seven patients (83%), showed functional improvement in all aspects, the VAS for pain and the MRC for motor power, as well as the functional state. One patient (2.3%) developed a postoperative hematoma collection, which needed immediate evacuation. Superficial wound infection, reported in two patients (4.7%), was treated conservatively. No postoperative neuroma was observed among our patients during the follow-up period.

CONCLUSION

Wrapping the neurorrhaphy site utilizing dura substitute as conduit appears to be safe and might prove effective in managing peripheral nerve injury.

The influence of shoulder arthrodesis on the function of the upper limb in adult patients after a brachial plexus injury: a systematic literature review with elements of meta-analysis

Based on the literature, 294 shoulder arthrodeses after brachial plexus injury in adults were assessed, mostly male; the mean age of the patients was 33 years, and the mean follow-up time was 5.5 years. The most common cause of injury was a traffic accident, especially on a motorcycle.

Arthrodesis position ranged from 15 to 40 degrees of flexion, 15 to 60 degrees of abduction, and 0 to 50 degrees of internal rotation with the predominance of position by the 30-30-30 rule. Plates, screws, and external fixation were used for stabilization. The complication rate was at the level of 28%, the most common complication being delayed union or nonunion.

Active movements of flexion and abduction averaged 61 and 56 degrees, respectively, while reaching the hand to the mouth, front pocket, and buttock was feasible for 69%, 71%, and 38%, respectively, after surgery. Shoulder pain was present in 77% of patients, and 28% experienced no relevant pain reduction after surgery. The subjective satisfaction rate was 82% based on significant improvement and satisfaction reported by patients after arthrodesis.

Arthrodesis of the shoulder, in adult patients after brachial plexus palsy, can reduce shoulder pain, increase stability, and result in a range of motion that increases the possibility of carrying out everyday activities. This affects the high level of subjective patient satisfaction after surgery.

Cite this article: EFORT Open Rev 2021;6:797-807. DOI: 10.1302/2058-5241.6.200114

Microscissor DREZotomy for post brachial plexus avulsion neuralgia: A single center experience

INTRODUCTION

Brachial neuralgia is a dreaded sequelae which substantially impairs the quality of life in patients with brachial plexus avulsion (BPA) injuries. Dorsal Root Entry Zone (DREZ) lesioning of the cervical spinal cord is the most utilized procedure for alleviating this painful condition. In this study, we share a single center experience of surgically managing post BPA neuropathic pain. The efficacy, results and complications of the modified technique of DREZ, called the Microscissor DREZotomy (MDZ) are discussed along with the review of relevant literature.

METHODS

This retrospective analysis included all the patients undergoing MDZ for post BPA brachialgia over 5 years period (2012-2018) at our institution. The pain was quantified using the Numeric rating Scale (NRS) between 0 and 10 scale and was graded as 'Excellent' in patients with more than 75% pain relief, 'Good' with 50-75% relief, 'Fair' between 25% and 50% and 'Poor' if less than 25%.

RESULTS

A total of 56 patients underwent MDZ and a mean follow up of 32 months (range 18-69 months) available for 47 patients. Thirty three patients (70.4%) judged pain relief as Excellent, Five (10.6%) as Good, 3 (7%) as Fair and 6 (12%) having poor pain relief. Overall, in 38 (81%) patients long term analgesic effect (> 50%) was noted and 3 (7%) patients had more than 25% pain relief, making up an overall 41 (87%) of patients with some relief from pain.

CONCLUSION

MDZ is a safe, efficacious technique with good long term pain relief and quality of life. This technique entails utilization of routine surgical instruments and can be performed with ease even in resource limited settings.

Pain Study in X-Linked Adrenoleukodystrophy in Males and Females

INTRODUCTION

X-linked adrenoleukodystrophy (ALD) is a metabolic disorder in which very long chain fatty acids (VLCFAs) are accumulated in the nervous system and adrenal cortex, impairing their functions. Three main variants are described in males: adrenomyeloneuropathy (AMN), a cerebral form (cALD or cAMN) and Addison's disease only (AD), while for females no classification is used. To evaluate pain and the functional state of afferent fibers, a series of tests was carried out in male and female patients.

METHODS

Chronic pain occurrence and sensory phenotype profile were assessed in 30 patients (20 male: 10 AMN, 1 cAMN, 1 cALD, 8 AD; and 10 female). A set of instruments assessed the intensity, quality and extent of pain, while a battery of quantitative sensory testing (QST) procedures examined the functional status of Aβ and Aδ fibers. Principal component analysis and hierarchical clustering with sensory responses input were used to identify distinct clusters.

RESULTS

Nearly half of the subjects reported pain, with a high prevalence in females and male AMN patients. No sex differences in pain dimensions were found. The sensory responses were heterogeneous, differing among the clinical variants and between genders. Male AMN/cAMN/cALD patients showed the worst impairment. Aβ and Aδ fibers were affected in males and females, but Aβ fibers appeared undamaged in females when tactile sensitivity was tested. Abnormal responses were localized in the lower body district, according to the dying-back pattern of the neuropathy. Cluster analysis showed discrete clusters for each function examined, with well-interpretable sensory and clinical phenotypes.

CONCLUSION

The study of pain and of the sensory profile appears to indicate a difference in the mechanisms underlying the AMN/cAMN/cALD and AD clinical forms and in the treatment of the respective generated pain types.

Management of CRPS secondary to preganglionic C8 nerve root avulsion: A case report and literature review

Background:

Cervical nerve root avulsion is a well-documented result of high-velocity motor vehicle accidents (MVAs). In up to 21% of cases, preganglionic cervical root avulsion can result in a complex regional pain syndrome (CRPS) impacting the quality of life for patients already impaired by motor, sensory, and autonomic dysfunction. The optimal treatment strategies include repeated stellate ganglion blocks (SBGs).

Case Description:

A 43-year-old male sustained a high-velocity MVA resulting in the left C8 nerve root avulsion. This resulted in weakness in the C8 distribution, tactile allodynia, and dysesthesias. The magnetic resonance imaging demonstrated an abnormal signal ventral to the C8–T1 level. As the patient was not considered a candidate for surgical intervention secondary to the attendant brachial plexus injury, a C7–C8 epidural steroid injection was performed; this did not provide improvement. Before placing a spinal cord stimulator, the patient underwent a series of six ultrasound-guided SBGs performed 2 weeks apart; there was 75% improvement in pain and strength. Six years later, the patient continues to do well while receiving SBGs 4 times a year.

Conclusion:

A preganglionic cervical nerve root avulsion should not be a contraindication for a stellate ganglion block in a patient with established CRPS.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions

The brachial plexus represents a complex anatomical structure in the upper limb. This "network" of peripheral nerves permits the rearrangement of motor efferent fibers, coming from different spinal nerves, in several terminal branches directed to upper limb muscles. Moreover, afferent information coming from different cutaneous regions in upper limb are sorted in different spinal nerves through the brachial plexus. Severe brachial plexus injuries are a rare clinical condition in the general population and in sport medicine, but with dramatic consequences on the motor and sensory functions of the upper limb. In some sports, like martial arts, milder injuries of the brachial plexus can occur, with transient symptoms and with a full recovery. Clinical evaluation represents the cornerstone in the assessment of the athletes with brachial plexus injuries. Electrodiagnostic studies and imaging techniques, like magnetic resonance and high-frequency ultrasound, could be useful to localize the lesion and to define an appropriate treatment and a functional prognosis. Several conservative and surgical techniques could be applied, and multidisciplinary rehabilitative programs could be performed to guide the athlete toward the recovery of the highest functional level, according to the type of injury.

Spinal Cord Stimulation for Neuropathic Pain Treatment in Brachial Plexus Avulsions: A Literature Review and Report of Two Cases

BACKGROUND

At least 50% of individuals who suffer a brachial plexus avulsion (BPA) will develop chronic pain, frequently more debilitating than their functional limitations. Similar to other neuropathic pain states, BPA pain is often refractory to pharmacological agents. Despite spinal cord stimulation (SCS) first being used for BPA in 1974, there have been no published literature reviews examining the current evidence of SCS for the treatment of neuropathic pain following BPA. In addition to a clinical review of the literature for this indication, we also share our experience with high-frequency SCS (HF-SCS) for BPA-related pain.

METHODS

MEDLINE and EMBASE databases were searched. All published articles including at least one BPA individual treated with SCS for pain treatment were included.

RESULTS

The initial search identified 288 articles, of which 13 met inclusion criteria for a total of 41 patients. These patients were primarily male and underwent SCS with reported improved pain scores.

CASE REPORTS

HF-SCS leads were percutaneously placed in two male patients who suffered BPA from traumatic injuries. At follow-ups of 13 and eight months, respectively, both patients continued to report an improvement in their pain.

CONCLUSIONS

Despite published reports showing benefit for pain control in patients with BPA, the overall low quality, retrospective evidence included in this review highlights the need for a rigorous prospective study to further address this indication.

Mechanisms for Reducing Neuropathic Pain

Injury typically results in the development of neuropathic pain, but the pain normally decreases and disappears in paralleled with wound healing. The pain results from cells resident at, and recruited to, the injury site releasing pro-inflammatory cytokines and other mediators leading to the development of pro-inflammatory environment and causing nociceptive neurons to develop chronic ectopic electrical activity, which underlies neuropathic pain. The pain decreases as some of the cells that induce pro-inflammation, changing their phenotype leading to the blocking the release of pro-inflammatory mediators while releasing anti-inflammatory mediators, and blocking nociceptive neuron chronic spontaneous electrical activity. Often, despite apparent wound healing, the neuropathic pain becomes chronic. This raises the question of how chronic pain can be eliminated. While many of the cells and mediators contributing to the development and maintenance of neuropathic pain are known, a better understanding is required of how the injury site environment can be controlled to permanently eliminate the pro-inflammatory environment and silence the chronically electrically active nociceptive neurons. This paper examines how methods that can promote the transition of the pro-inflammatory injury site to an anti-inflammatory state, by changing the composition of local cell types, modifying the activity of pro- and anti-inflammatory receptors, inducing the release of anti-inflammatory mediators, and silencing the chronically electrically active nociceptive neurons. It also examines the hypothesis that factors released from platelet-rich plasma applied to chronic pain sites can permanently eliminate chronic inflammation and its associated chronic pain.

Microscissor DREZotomy - A New Way for 'Atraumatic Lesioning' of DREZ

Background and Aims

Dorsal root entry zone (DREZ) lesioning is a widely-used procedure for neuropathic pain which is refractory to other modes of treatment. However, all current techniques depend on thermal or radiofrequency (RF) lesioning of the DREZ. The authors describe a new technique in which mechanical lesioning of DREZ using microscissors.

Methods

The authors describe their technique of only using straight microscissors for the whole procedure of DREZotomy. No cautery is used except for hemostasis.

Results

Our technique is a continuing evolution of the original DREZotomy described by Nashold and Sindou, and appears more atraumatic and simpler.

Conclusion

Microscissor DREZotomy appears to be the most atraumatic way of carrying out DREZ lesioning and overcomes the disadvantages of other methods like thermal and RF lesioning.