Root Avulsion Research Articles

Diagnostic Accuracy of MRI for Detecting Nerve Injury in Brachial Plexus Birth Injury.

To determine the diagnostic accuracy of MRI for diagnosing nerve injury in brachial plexus birth injury (BPBI). Electronic databases were searched from inception to 15th February 2023 for studies reporting the accuracy of MRI (index test) compared to surgical exploration (reference standard) in detecting the target conditions of: root avulsion; any nerve abnormality; and pseudomeningocele (as a marker of root avulsion) in children with BPBI. Meta-analysis using a bivariate model was performed where data allowed. 8 studies met the inclusion criteria. In total, 116 children with BPBI were included. All included studies were at risk of bias. The mean sensitivity and mean specificity of MRI for detecting root avulsion was 68% (95% CI: 55%, 79%) and 89% (95% CI: 78%, 95%) respectively. Pseudomeningocele was not a reliable marker of avulsion. Data was too sparse to determine the diagnostic accuracy of MRI for any nerve abnormality. At present, surgical exploration should remain as the diagnostic modality of choice for BPBI due to the modest diagnostic accuracy of MRI in detecting root avulsion. The diagnostic accuracy of MRI needs to be close to 100% as the results may determine whether a child undergoes invasive surgery. Previous research regarding MRI in detecting BPBI is highly variable and prior to our study the overall diagnostic accuracy was unclear. Through conducting a systematic review and meta-analysis, we were able to reliably determine the overall sensitivity and specificity of MRI for detecting root avulsion.

Partial weight-bearing and range of motion limitation significantly reduce the loads at medial meniscus posterior root repair sutures in a cadaveric biomechanical model.

The aim of this study was to investigate the influence of medial meniscus posterior root avulsion (MMPRA) before and after surgical treatment on the biomechanics of the knee joint, including suture repair forces during daily and crutch-assisted gait movements. MMPRA were investigated in eight human cadaver knee joint specimens by a dynamic knee joint simulator with daily (normal gait, gait with additional rotational movement, standing up, sitting down) and rehabilitation-associated movements (crutch-assisted gait with limited flexion range of motion [30°] and 30% [toe-touch weight-bearing, TTWB] and 50% of body weight [partial weight-bearing, PWB]) with simulated physiologic muscle forces. Each specimen was tested in intact, torn and repaired (transtibial suture) state. The biomechanical parameters were: medial mean contact pressure and area, knee joint kinematics, medial displacement of the posterior meniscus horn and loading on the anchoring suture. Significant reduction of the contact area due to the avulsion was observed in all movements except for PWB and sitting down. MMPRA repair significantly increased the contact areas during all movements, bringing them to levels statistically indistinguishable from the initial state. MMPRA resulted in a medial displacement up to 12.8 mm (sitting down) and could be reattached with a residual displacement ranging from 0.7 mm (PWB) to 5.7 mm (standing up), all significantly (p < 0.001) reduced compared to the torn state. The mean peak anchoring suture load increased from TTWB (77 N), PWB (91 N) to normal gait (194 N), gait rotation (207 N), sitting (201 N; p < 0.01) and to standing up (232 N; p = 0.03). Surgical treatment of MMPRA allows restoration of physiological knee joint biomechanics. Crutch-assisted movements reduce the loading of the repair suture, thus likewise the risk for failure. From a biomechanical point of view, crutch-assisted movements are recommended for the early rehabilitation phase after MMPRA repair. Level V.

Intra-Tunnel Knotless Anchor Fixation for Lateral Meniscus Posterior Root Tears: A Novel Technique.

Lateral meniscus posterior root tears (LMPRTs) are radial tears that occur within 10mm of the posterior root tibial connection, also known as lateral meniscus posterior root avulsions. A common surgical approach for LMPRT (2) that contributes to positive biomechanical outcomes is independent transtibial pullout repair.(6,7,8) If this treatment is performed on people who need both LMPRT repair and ACL restoration, an extra tibial tunnel is required. The installation of a tibial tunnel increases surgical challenges and lengthens operation time, as well as the danger of iatrogenic damage to the normal architecture of the knee. To circumvent these drawbacks, we have developed a novel technique for intra-tunnel LMPRT repair using a knotless anchor construct at the upper posterior edge of the tibial tunnel. A stab incision is made to create the standard antero lateral portal and after introducing the trochar and the scope, a round of diagnostic arthroscopy is performed and the posterior root of lateral meniscus tear is identified. After creating an anteromedial portal, With help of 1 fiber tape, a loaded bite is taken with the help of a first pass mini device (Smith & Nephew), via the antero medial portal, deep into the posterior root ( around 5mm), using a self winching technique, and reduction of the LMPRT is checked. The position for the anchor entry is visualized in the superior edge of the tibial tunnel along its posterior wall, and the tapes are passed through the knotless anchor extra-articulately outside the AM portal. Thereafter, the anchor is shuttled in through the AM portal and punched in the footprint on the posterior-superior edge of the tibial tunnel with visualization of the reduction of the LMPR to the footprint. This technique offers a simple solution to a complex problem in the form of a simple procedure. This technique is a good choice when a tear of the posterior root of the LM occurs.

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

Treatment priority in C5, C6, and C7 brachial plexus root avulsion is the recovery of shoulder function through reinnervation of shoulder muscles. The medial pectoral nerve is a potential donor for axillary nerve transfer, but outcomes are sparsely reported. This study reports the results of medial pectoral nerve transfer to the axillary nerve. We conducted a retrospective analysis of 12 patients with traumatic brachial plexus injury (C5, C6, and C7 root avulsion) who underwent medial pectoral nerve transfer to the axillary nerve. Sociodemographic and clinical characteristics, including electromyography findings, were documented. We assessed postoperative shoulder abduction strength and range of motion. Statistical analyses compared presurgery and postsurgery outcomes and contrasted our results with those from a study using spinal accessory nerve transfer to the suprascapular nerve. Postsurgery, the mean shoulder abduction range of motion was 65.45°, with a median strength of M2. Significant improvement was noted compared to preoperative values. However, outcomes did not significantly surpass those from spinal accessory nerve transfer. Electromyography showed a low incidence of motor unit action potentials in the deltoid. Medial pectoral nerve transfer to the axillary nerve did not yield superior results in shoulder abduction and deltoid reinnervation in our group of patients. At present, different nerve donors may also need to be considered for deltoid muscle reinnervation in patients with C5, C6, and C7 root avulsion to achieve better shoulder abduction recovery.

Tension Pneumocephalus Caused by a Communicating Pneumothorax via a Nerve Root Avulsion

Tension Pneumocephalus Caused by a Communicating Pneumothorax via a Nerve Root Avulsion

C286, an orally available retinoic acid receptor β agonist drug, regulates multiple pathways to achieve spinal cord injury repair.

Retinoic acid receptor β2 (RARβ2) is an emerging therapeutic target for spinal cord injuries (SCIs) with a unique multimodal regenerative effect. We have developed a first-in-class RARβ agonist drug, C286, that modulates neuron-glial pathways to induce functional recovery in a rodent model of sensory root avulsion. Here, using genome-wide and pathway enrichment analysis of avulsed rats' spinal cords, we show that C286 also influences the extracellular milieu (ECM). Protein expression studies showed that C286 upregulates tenascin-C, integrin-α9, and osteopontin in the injured cord. Similarly, C286 remodulates these ECM molecules, hampers inflammation and prevents tissue loss in a rodent model of spinal cord contusion C286. We further demonstrate C286's efficacy in human iPSC-derived neurons, with treatment resulting in a significant increase in neurite outgrowth. Additionally, we identify a putative efficacy biomarker, S100B, which plasma levels correlated with axonal regeneration in nerve-injured rats. We also found that other clinically available retinoids, that are not RARβ specific agonists, did not lead to functional recovery in avulsed rats, demonstrating the requirement for RARβ specific pathways in regeneration. In a Phase 1 trial, the single ascending dose (SAD) cohorts showed increases in expression of RARβ2 in white blood cells correlative to increased doses and at the highest dose administered, the pharmacokinetics were similar to the rat proof of concept (POC) studies. Collectively, our data suggests that C286 signalling in neurite/axonal outgrowth is conserved between species and across nerve injuries. This warrants further clinical testing of C286 to ascertain POC in a broad spectrum of neurodegenerative conditions.

AB041. The morphological changes of paraspinal muscles in adult brachial plexus injury.

Traumatic brachial plexus injury (BPI) is a debilitating injury that has a devastating impact. However, management of BPI remains a complex challenge, not only in diagnosis but also in treatment strategies for reconstructive microsurgeons. The aim of this study was to develop an additional assessment tool for root avulsion based on the volume of paraspinal muscle (PM) prior to surgical intervention, making the preoperative diagnosis more precise. This retrospective study was centered on adult patients with BPI who underwent surgical exploration and treatment, postoperative follow-up at the Chang Gung Hospital. Labeling of PMs was aided by semi-automated segmentation using 3D Slicer 5.2.2. Slices spanning from the lower end of the upper vertebral body endplate to the upper end of the lower vertebral body. The ratio of muscle volume on the lesion side to that on the normal side (L/N ratio), indicating the volume proportion between the injured and healthy areas, serves as the primary parameter for assessing the relationship in root avulsion. The L/N ratio for the deepest layers of PMs consistently predicted the level of root injury across C4 to C7 levels, with all reaching statistical significance. In terms of partial and total root avulsion, the L/N ratio of layer 4th at 0.78 significantly outperforms other methods. Concerning the timing of MRI, both partial avulsion (PA) and total avulsion (TA) groups of merge roots showed a statistically significant decrease in the L/N ratio over time. In conclusion, the L/N volume ratio of 4th layer in PMs reliably predicts the functional severity of avulsed roots and surpasses the performance of traditional diagnostic tools under specific conditions.

Functional outcomes after re-insertion of posterior root tear of medial meniscus using a simple economic technique

Background Root avulsions of the meniscus cause loss of hoop stresses and therefore loss of the meniscal function. This in return is associated with increased peak contact stresses and risk of osteoarthritis. Root repair is therefore crucial to preserve normal biomechanics and kinematics. Many techniques have been used and expensive fancy equipment made the procedure easier, however, cost is of great importance. Aim To demonstrate the results and functional outcomes after root re-insertion using simple economic tools. Patients and methods Between March 2022 and May 2023, 25 patients with root tears were operated upon and followed-up for a mean of 12 months. Patients with acute traumatic tears, degenerative tears with grade 1–2 osteoarthritis, associated genu varum less than 5º and a BMI less than or equal to 35 were included in the study. All patients underwent diagnostic arthroscopy as part of the procedure. Pie-crusting of the medial ligament was performed routinely to facilitate visualization and instrumentation in the medial compartment. Bed preparation was performed using a motorized shaver. This was followed by passing polydioxanone suture (PDS) shuttling sutures through a grey cannula and into the posterior root meniscal tissue, this was then used to shuttle heavy poly-braided nonabsorbable suture material. A tunnel was created through the anterior tibial cortex using the anterior cruciate ligament (ACL) guide. The sutures are then tied over a post (4.5 mm screw). Lysholm, International Knee Documentation Committee (IKDC), and Tegner activity scores were used to evaluate the patients at 6 and 12 months. Results The mean Lysholm score improved from 50.16 ± 12.51 preoperative to 82.08 ± 12.90 postoperative. The mean IKDC score improved from 51.24 ± 11.06 to 84.36 ± 10.18. The mean Tegner activity score improved from 3 ± 1.32 ranging from 1 to 5 to 5.20 ± 1.53. Traumatic tears showed greater improvement as compared with degenerative tears. Conclusion Simple outside techniques can be used to perform adequate reliable root repair. This yields comparable results to other techniques described in the literature.

Recovery of the Total Birth Brachial Plexus Palsy without Surgical Treatment: A Single-Center, Retrospective Study and Literature Review.

Background Spontaneous recovery of a birth brachial plexus disorder is difficult to predict. Although root avulsion and total plexus injury is indicated for surgical management, early nerve surgery is still doubtful. Hand motion is obviously an important indicator for predicting the function of an affected limb. However, the timing for diagnosing a transient or true total plexus injury from hand recovery is controversial. This study aimed to report the recovery time of total birth brachial plexus palsy in patients who did not undergo surgery due to various reasons. Methods In this 15-year retrospective chart review, 45 patients of total birth brachial plexus injury with a mean follow-up time of 34.5 months, were included. Although patients met surgical indications, surgical management was abandoned for a variety of reasons. Imaging was not performed routinely and, nerve conduction study and Horner's syndrome were not consistently recorded in the past. All patients were evaluated for clinical improvement by motor power grading. The recovery time was reported as the median and interquartile range. Results Forty-five patients were diagnosed with total birth brachial plexus injury. Out of 45 patients, 36 showed clinical evidence of recovering their hand motion within a median of 3 months. The median time for the recovery of elbow flexion and shoulder abduction was 4 months. The median for achieving antigravity or full motion recovery of elbow flexion, shoulder abduction, and hand flexion were 10, 10.5, and 7 months, respectively. Conclusion In this study, spontaneous recovery of shoulder, elbow and hand motion substantially occurred in the patient diagnosed with a total birth brachial plexus palsy. True total plexus palsy can be distinguished from transient palsy by the recovery of hand motion at 3 months. Most of the patients, who had spontaneous recovery, potentially achieved antigravity or full hand movement without surgery.

Anatomical damages in the spinal nerve roots and the spinal cord after brachial plexus injury: descriptive study from a cohort of consecutive patients who underwent DREZ-lesioning for pain-practical implications.

Systematic descriptions of anatomical damage after brachial plexus injury (BPI) at the intradural level have been scarcely reported in detail. However, considering these damages, not only in the spinal nerve roots but also in the spinal cord itself, is crucial in determining the appropriate surgical approach to restore upper limb function and address refractory pain. Therefore, the authors present a descriptive study focusing on intradural findings observed during microsurgical DREZ-lesioning. This study enrolled 19 consecutive patients under the same protocol. Microsurgical observation through exposure of C4 to Th1 medullary segments allowed to describe the lesions in spinal nerve roots, meninges, and spinal cord. Electrical stimulation of the ventral roots checked the muscle responses. Extensive damage was observed among the 114 explored roots (six roots per patient), with only 21 (18.4%) ventral (VR) and 17 (14.9%) dorsal (DR) roots retaining all rootlets intact. Damage distribution varied, with the most frequent impairments in C6 VRs (18 patients) and the least in Th1 VRs (14 patients), while in all the 19 patients for the C6 DRs (the most frequently impaired) and in 14 patients for Th1 DRs (the less impaired). C4 roots were found damaged in 12 patients. Total or partial avulsions affected 63.3% and 69.8% of DRs and VRs, respectively, while 15.8% and 14.0% of the 114 DRs and VRs were atrophic, maintaining muscle responses to stimulation in half of those VRs. Pseudomeningoceles were present in 11 patients but absent in 46% of avulsed roots. Adhesive arachnoiditis was noted in 12 patients, and dorsal horn parenchymal alterations in 10. Knowledge of intradural lesions post-BPI helps in guiding surgical indications for repair and functional neurosurgery for pain control.

Prognostic Factors of Mandibular Osteoradionecrosis Including Accurate Colocalization of Avulsions and Dosimetric Dental Mapping Software, a Case-control Study

IntroductionOsteoradionecrosis of the mandible (ORN) remains a significant complication in the intensity modulated radiotherapy (IMRT) era. Dental dose cannot be predicted from heterogeneous IMRT dose distributions; mandibular dose metrics cannot guide dentist avulsion decisions in high risk ORN situations. Using a mapping tool to report dental root dose, avulsions and ORN sites, we reexamined ORN risk factors in a case-control study. MethodsFrom 2008 to 2019, 897 consecutive patients with oral cavity/oropharynx (OC/OR) or unknown primary cancer (CUP) and undergoing IMRT were analyzed to identify ORN cases. These were matched (1 ORN/2 controls) retrospectively for tumor, surgery, tobacco in a monocentric case-control study. Univariate and multivariate analyses integrated ORN factors and accurate dental dose data (grouped into 4 mandibular sectors). Generalizability was investigated in a simulated population database. Results171 patients were included. Median follow-up was 5.2 and 4.5 years in the ORN and control groups, respectively. Median time to ORN was 12 months. In univariate analysis, post-IMRT avulsions at the ORN site (Hazard ratio (HR) = 3.6; 95% confidence interval (CI) = 1.5-8.9; p=0.005), tumor laterality (HR =4.4; 95% CI = 1.4-14, p = 0.01), mean mandibular dose (HR = 1.1; 95% CI = 1.01-1.1; p = 0.018) and mean dose to the ORN site (HR = 1.1; 95% CI = 1.1-1.2; p < 0.001) correlated with higher ORN risk. In multivariate analysis, mean dose to the ORN site (HR = 1.1; 95% CI = 1.1-1.2; p < 0.001) and post-IMRT avulsions at the ORN site (HR = 4.6; 95% CI = 1.5-14.7; p = 0.009) were associated with ORN. For each increase in Gray in dental dose, the ORN risk increased by 12%. Simulations confirmed study observations. ConclusionDental dose and avulsions are associated with ORN with a 12% increase in risk with each additional Gray. Accurate dose information can help dentists in their decisions after IMRT.

Neuromuscular Ultrasound in Cervical Nerve Root Avulsion.

Neuromuscular Ultrasound in Cervical Nerve Root Avulsion.

Embryonic stem cells overexpressing high molecular weight FGF2 isoform enhance recovery of pre-ganglionic spinal root lesion in combination with fibrin biopolymer mediated root repair

BackgroundSpinal ventral root avulsion results in massive motoneuron degeneration with poor prognosis and high costs. In this study, we compared different isoforms of basic fibroblast growth factor 2 (FGF2), overexpressed in stably transfected Human embryonic stem cells (hESCs), following motor root avulsion and repair with a heterologous fibrin biopolymer (HFB).MethodsIn the present work, hESCs bioengineered to overexpress 18, 23, and 31 kD isoforms of FGF2, were used in combination with reimplantation of the avulsed roots using HFB. Statistical analysis was conducted using GraphPad Prism software with one-way or two-way ANOVA, followed by Tukey’s or Dunnett’s multiple comparison tests. Significance was set at *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.ResultsFor the first set of experiments, rats underwent avulsion of the ventral roots with local administration of HFB and engraftment of hESCs expressing the above-mentioned FGF2 isoforms. Analysis of motoneuron survival, glial reaction, and synaptic coverage, two weeks after the lesion, indicated that therapy with hESCs overexpressing 31 kD FGF2 was the most effective. Consequently, the second set of experiments was performed with that isoform, so that ventral root avulsion was followed by direct spinal cord reimplantation. Motoneuron survival, glial reaction, synaptic coverage, and gene expression were analyzed 2 weeks post-lesion; while the functional recovery was evaluated by the walking track test and von Frey test for 12 weeks. We showed that engraftment of hESCs led to significant neuroprotection, coupled with immunomodulation, attenuation of astrogliosis, and preservation of inputs to the rescued motoneurons. Behaviorally, the 31 kD FGF2 - hESC therapy enhanced both motor and sensory recovery.ConclusionTransgenic hESCs were an effective delivery platform for neurotrophic factors, rescuing axotomized motoneurons and modulating glial response after proximal spinal cord root injury, while the 31 kD isoform of FGF2 showed superior regenerative properties over other isoforms in addition to the significant functional recovery.

Boundary cap neural crest stem cells promote angiogenesis after transplantation to avulsed dorsal roots in mice and induce migration of endothelial cells in 3D printed scaffolds

Dorsal root avulsion injuries lead to loss of sensation and to reorganization of blood vessels (BVs) in the injured area. The inability of injured sensory axons to re-enter the spinal cord results in permanent loss of sensation, and often also leads to the development of neuropathic pain. Approaches that restore connection between peripheral sensory axons and their CNS targets are thus urgently need. Previous research has shown that sensory axons from peripherally grafted human sensory neurons are able to enter the spinal cord by growing along BVs which penetrate the CNS from the spinal cord surface. In this study we analysed the distribution of BVs after avulsion injury and how their pattern is affected by implantation at the injury site of boundary cap neural crest stem cells (bNCSCs), a transient cluster of cells, which are located at the boundary between the spinal cord and peripheral nervous system and assist the growth of sensory axons from periphery into the spinal cord during development. The superficial dorsal spinal cord vasculature was examined using intravital microscopy and intravascular BV labelling. bNCSC transplantation increased vascular volume in a non-dose responsive manner, whereas dorsal root avulsion alone did not decrease the vascular volume. To determine whether bNCSC are endowed with angiogenic properties we prepared 3D printed scaffolds, containing bNCSCs together with rings prepared from mouse aorta. We show that bNCSC do induce migration and assembly of endothelial cells in this system. These findings suggest that bNCSC transplant can promote vascularization in vivo and contribute to BV formation in 3D printed scaffolds.

Contralateral C7 Nerve Transfer

Complex brachial plexus injuries with multiple or complete root avulsions make intraplexic reconstruction impossible in some cases. Such cases necessitate the use of extraplexic nerve donors such as the spinal accessory nerve or intercostal nerves. The contralateral C7 root represents a donor with a high axon count and can be used as an axon source in such cases. We summarise current indications, surgical technique and functional results after a contralateral C7 transfer in cases of brachial plexus injury, describing some of our own cases and including a selective literature review.

Adult traumatic brachial plexus injuries: advances and current updates.

Nerve grafting, tendon transfer and joint fusion are routinely used to improve the upper limb function in patients with brachial plexus palsies. Newer techniques have been developed that provide additional options for reconstruction. Nerve transfer is a tool for restoring upper limb function in total root avulsions where nerve grafting is not possible. In partial brachial plexus injuries, nerve transfers can greatly improve shoulder, elbow, wrist and hand function. Intraoperative electrical stimulation can be used to diagnose precisely which nerve is injured and to choose which nerve fascicles should be transferred. Finally, measuring the postoperative outcome can improve the evaluation of our techniques. The aim of this article was to present the current techniques used to treat patients with brachial plexus injury.

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.

Effects of local and systemic treatment with human natural killer-1 mimetic peptide (HNK-1) after ventral root avulsion and reimplantation in mice.

Spinal ventral root injuries generate significant motoneuron degeneration, which hinders full functional recovery. The poor prognosis of functional recovery can be attributed to the use or combination of different therapeutic approaches. Several molecules have been screened as potential treatments in combination with surgical reimplantation of the avulsed roots, the gold standard approach for such injuries. Among the studied molecules, human natural killer-1 (HNK-1) stands out as it is related to the stimulation of motor axon outgrowth. Therefore, we aimed to comparatively investigate the effects of local administration of an HNK-1 mimetic peptide (mp-HNK-1) and systemic treatment with ursolic acid (UA), another HNK-1 mimetic, after ventral root avulsion and reimplantation with heterologous fibrin biopolymer (HFB). Female mice of the isogenic strain C57BL/6JUnib were divided into five experimental groups: Avulsion, Reimplantation, mp-HNK-1 (in situ), and UA (systemic treatment). Mice were evaluated 2 and 12 weeks after surgery. Functional assessment was performed every four days using the Catwalk platform. Neuronal survival was analyzed by cytochemistry, and glial reactions and synaptic coverage were evaluated by immunofluorescence. Treatment with UA elicited long-term neuroprotection, accompanied by a decrease in microglial reactions, and reactive astrogliosis. The neuroprotective effects of UA were preceded by increased glutamatergic and GABAergic inputs in the ventral spinal cord two weeks after injury. However, a single application of mp-HNK-1 had no significant effects. Functional analysis showed that UA treatment led to an improvement in motor and sensory recovery. Overall, the results indicate that UA is neuroprotective, acting on glial cells and synaptic maintenance, and the combination of these findings led to a better functional recovery.

Cervical spinal cord compression from subdural hematoma caused by traumatic nerve root avulsion: illustrative case.

Posttraumatic intradural hematomas of the cervical spine are rare findings that may yield significant neurological deficits if they compress the spinal cord. These compressive hematomas require prompt surgical evacuation. In certain instances, intradural hematomas may form from avulsion of cervical nerve roots. The authors present the case of a 29-year-old male who presented with right upper-extremity weakness in the setting of polytrauma after a motor vehicle accident. He had no cervical fractures but subsequently developed right lower-extremity weakness. Magnetic resonance imaging (MRI) demonstrated a compressive hematoma of the cervical spine that was initially read as an epidural hematoma. However, intraoperatively, it was found to be a subdural hematoma, eccentric to the right, stemming from an avulsion of the right C6 nerve root. Posttraumatic cervical subdural hematomas require rapid surgical evacuation if neurological deficits are present. The source of the hematoma may be an avulsed nerve root, and the associated deficits may be unilateral if the hematoma is eccentric to one side. Surgeons should be prepared for the possibility of an intradural hematoma even in instances in which MRI appears consistent with an epidural hematoma.

Quercetin Ameliorates Neuropathic Pain after Brachial Plexus Avulsion via Suppressing Oxidative Damage through Inhibition of PKC/MAPK/ NOX Pathway.

Brachial plexus avulsion (BPA) animally involves the separation of spinal nerve roots themselves and the correlative spinal cord segment, leading to formidable neuropathic pain of the upper limb. The right seventh cervical (C7) ventral and dorsal roots were avulsed to establish a neuropathic pain model in rats. After operation, rats were treated with quercetin (QCN) by intragastric administration for 1 week. The effects of QCN were evaluated using mechanical allodynia tests and biochemical assay kits. QCN treatment significantly attenuated the avulsion-provoked mechanical allodynia, elevated the levels of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and total antioxidant capacity (TAC) in the C7 spinal dorsal horn. In addition, QCN administration inhibited the activations of macrophages, microglia and astrocytes in the C6 dorsal root ganglion (DRG) and C6-8 spinal dorsal horn, as well as attenuated the release of purinergic 2X (P2X) receptors in C6 DRG. The molecular mechanism underlying the above alterations was found to be related to the suppression of the PKC/MAPK/NOX signal pathway. To further study the anti-oxidative effects of QCN, we applied QCN on the H2O2-induced BV-2 cells in vitro, and the results attested that QCN significantly ameliorated the H2O2-induced ROS production in BV-2 cells, inhibited the H2O2-induced activation of PKC/MAPK/NOX pathway. Our study for the first time provided evidence that QCN was able to attenuate pain hypersensitivity following the C7 spinal root avulsion in rats, and the molecular mechanisms involve the reduction of both neuro-inflammatory infiltration and oxidative stress via suppression of P2X receptors and inhibition of the activation of PKC/MAPK/NOX pathway. The results indicate that QCN is a natural compound with great promise worthy of further development into a novel therapeutic method for the treatment of BPA-induced neuropathic pain.