Nerve Root Avulsion Research Articles

Traumatic Oculomotor Nerve Avulsion after Mild Head Injury

The authors describe a 37-year-old female who suffered a mild head injury after a car accident. She was found with an initial Glasgow coma scale score of 15. On further inspection, complete right ophthalmoplegia was observed. Initial computerized tomography (CT) scan of the head was normal, but magnetic resonance imaging showed right oculomotor nerve avulsion. The patient was discharged from the hospital without any improvement in complete ophthalmoplegia. To our knowledge, this is the first radiographically documented case of oculomotor nerve root avulsion with associated irreversible oculomotor nerve palsy after mild head injury. Considering the poor prognosis for recovery of the nerve function, an appropriate counseling should be provided to the patient and family. Neurosurgical techniques for attempting nerve reconstruction have yet to be investigated but could be a new area for clinical and surgical research.

Novel Drug Therapy Improved Nerve Regeneration and Function

Background: Injured peripheral nerves regenerate their lost axons but functional recovery in humans is frequently disappointing. This is particularly important when injuries require regeneration over long distances and/or over long time periods. In addition, neurotmesis caused by nerve root avulsion may lead to a progressive loss of axotomized motoneurons (MNs) which sometimes avert warranty for surgical nerve repair. Using a bottom-up experimental approach using rat models of peripheral nerve injuries and sophisticate molecular biology and computational tools we ended up with a selected combination of FDA-approved drugs repurposed for its unexpected use in traumatology. In previous studies, using experimental models of nerve root avulsion, we validated that the drug combination (C1) exerted neuroprotection of almost 60% of spinal motoneurons (MNs) and exhibited anti-inflammatory properties reducing glial reactivity. Currently, we aim to verify the regenerative potential of C1. Methods: We use a model of crush injury in rat (Sprague Dawley) sciatic nerve. To asses functional recovery of denervated muscles, the compound muscle action potentials (CMAP) evoked in response to sciatic nerve stimulation were recorded in gastrocnemius and plantar muscles during the follow up. The recovery of locomotion function was assessed by the walking track analysis. At end point, we analysed neuromuscular junction’s reinnervation by plantar muscle immunohistochemistry. Results: We are now presenting that in a crush model of the sciatic nerve, the animals treated with oral administrated C1 presented acceleration in nerve regeneration analysed by electrophysiological recordings. Treated rats presented around 40 and 60% of increased amplitude of the CMAP of the gastrocnemius and plantar muscles, respectively compared with vehicle group after 35 days post-injury. Consequently, C1 treated rats showed an improved sciatic nerve functional index of 50% respect to controls. Besides, the number of reinnervated end-plates at the plantar muscle was 20% higher in C1 treated rats than in controls. Finally, walking track assessment revealed that locomotor function was better achieved after the treatment with C1. Conclusion: Overall, we set up and validated a new platform for therapy discovery to treat nervous system traumatic injuries.

New Treatments for Spinal Nerve Root Avulsion Injury.

Further progress in the treatment of the longitudinal spinal cord injury has been made. In an inverted translational study, it has been demonstrated that return of sensory function can be achieved by bypassing the avulsed dorsal root ganglion neurons. Dendritic growth from spinal cord sensory neurons could replace dorsal root ganglion axons and re-establish a reflex arch. Another research avenue has led to the development of adjuvant therapy for regeneration following dorsal root to spinal cord implantation in root avulsion injury. A small, lipophilic molecule that can be given orally acts on the retinoic acid receptor system as an agonist. Upregulation of dorsal root ganglion regenerative ability and organization of glia reaction to injury were demonstrated in treated animals. The dual effect of this substance may open new avenues for the treatment of root avulsion and spinal cord injuries.

Pseudomeningocele as a result of traumatic nerve root avulsion

A 23-year-old man presented with weakness of shoulder abduction and elbow flexion on the right side, with numbness of the index finger and thumb, after a bike accident. On examination, he had grade II/V power of the deltoid and biceps, with absent biceps jerk and sensory impairment in the C5–C6 dermatomes. Considering a traumatic cervical radiculopathy or brachial plexus injury, magnetic resonance imaging of the cervical spine and brachial plexus was taken, which showed cerebrospinal fluid collection lateral to the spinal cord and extending to the neural foramina, with denervation changes in the right paraspinal muscles, such as the multifidus muscle, suggestive of C6 root avulsion with pseudomeningocele (Fig. 1a,b). Pseudomeningocele is an extravasated collection of extradural cerebrospinal fluid that results from a dural tear, which unlike true meningocele, is not lined by arachnoid cells. Traumatic pseudomeningocele occurs after injuries to the brachial or lumbosacral plexus. Magnetic resonance imaging is the diagnostic modality of choice, which shows cerebrospinal fluid density adjacent to and in connection with the thecal sac.1 The prognosis of this type of nerve injury is poor. Nerve transfer techniques using spinal accessory or intercostal nerves are effective in such cases.2 The authors declare no conflict of interest.

Magnetic resonance imaging atlas of the cervical spine musculature.

The anatomy of the cervical spine musculature visible on magnetic resonance (MR) images is poorly described in the literature. However, the correct identification of individual muscles is clinically important because certain conditions of the cervical spine, for example whiplash associated disorders, idiopathic neck pain, cervical nerve root avulsion and cervical spondylotic myelopathy, are associated with different morphological changes in specific muscles visible on MR images. Knowledge of the precise structure of different cervical spine muscles is crucial when comparisons with the contralateral side or with normal are required for accurate description of imaging pathology, management and assessment of treatment efficacy. However, learning the intricate arrangement of 27 muscles is challenging. A multi-level cross-sectional depiction combined with three-dimensional reconstructions could facilitate the understanding of this anatomically complex area. This paper presents a comprehensive series of labeled axial MR images from one individual and serves as a reference atlas of the cervical spine musculature to guide clinicians, researchers, and anatomists in the accurate identification of these muscles on MR imaging. Clin. Anat. 29:643-659, 2016. © 2016 Wiley Periodicals, Inc.

The current role of diagnostic imaging in the preoperative workup for refractory neonatal brachial plexus palsy.

Despite recent improvements in perinatal care, the incidence of neonatal brachial plexus palsy (NBPP) remains relatively common. CT myelography is currently considered to be the optimal imaging modality for evaluating nerve root integrity. Recent improvements in MRI techniques have made it an attractive alternative to evaluate nerve root avulsions (preganglionic injuries). We demonstrate the utility of MRI for the evaluation of normal and avulsed spinal nerve roots. We also show the utility of ultrasound in providing useful preoperative evaluation of the postganglionic brachial plexus in patients with NBPP.

Diagnosis of nerve root avulsion injuries in adults with traumatic brachial plexopathies: MRI compared with CT myelography

Background: Computed tomography myelography (CTM) has been broadly adopted as the ‘gold standard’ imaging technique in the diagnosis of nerve root avulsion injuries in traumatic brachial plexopathies. CTM has the distinct advantage of better spatial resolution than magnetic resonance imaging (MRI); however, this technique is invasive and can result in significant patient discomfort. MRI, therefore, seems relatively more advantageous as it is less invasive (requires no lumbar puncture), lacks radiation exposure, has no adverse reactions related to intrathecal contrast agents and confers excellent soft-tissue contrast. Objectives: To compare the sensitivity and specificity of MRI with CTM in the diagnosis of preganglionic nerve root avulsion injuries in adults with traumatic brachial plexopathies at the Inkosi Albert Luthuli Central Hospital.Method: A retrospective comparative analysis was performed on 16 adult patients with traumatic preganglionic brachial plexopathies who underwent both MRI and CTM at Inkosi Albert Luthuli Central Hospital. Radiologists experienced in both CTM and MRI interpreted the data and a comparison was made using CTM as the gold standard. Results: The sensitivity and specificity for MRI detecting preganglionic nerve root avulsion injuries and pseudomeningoceles was 82% and 100% respectively. The interobserver agreement between CTM and MRI for the detection of preganglionic nerve root avulsion injuries was 81.25% (Kappa = 0.77) and 87.5% (Kappa = 0.84) for the detection of pseudomeningoceles. Conclusion: MRI was as sensitive as CTM at detecting preganglionic nerve root avulsion injuries and pseudomeningoceles of spinal nerve roots C7–T1 of the brachial plexus. Some mild discrepancies existed at the C5 and C6 nerve root levels. Owing to the invasiveness of the procedure and resultant patient discomfort, CTM should be reserved for complicated cases or for patients with contraindications to MRI.

The neuroprotective effect of erythropoietin on spinal motor neurons after nerve root avulsion injury in rats.

The rapid death of many spinal motor neurons after nerve root avulsion injury results in limited functional recovery following replantation surgery of avulsed nerves into the spinal cord. Therefore, we investigated the neuroprotective effect of erythropoietin (EPO) on motor neurons after nerve root avulsion injury using a rat model. After C6 nerve root avulsion injury, EPO (2680 U/kg) was injected subcutaneously once a day for 3 consecutive days with various starting time points. At 28 and 56 days after injury, histological and immunohistological investigations were performed. EPO-treated rats showed a significant increase in the number of surviving motor neurons at day 28 when the initial dose was started within 96 h after injury. In EPO-treated rats, superoxide formation in the motor neurons and proliferation of microglia were markedly suppressed in the acute phase. GAP-43-positive surviving motor neurons were significantly increased in EPO-treated rats at day 28. However, at 56 days after surgery, EPO-treated rats showed a much greater decrease of surviving motor neurons compared with those at day 28. The neuroprotective effect of EPO is not long lasting, but may prolong the time before replantation surgery.

Isolated C5–C6 avulsion in obstetric brachial plexus palsy treated by ipsilateral C7 neurotization to the upper trunk: outcomes at a mean follow-up of 9 years

Cervical root avulsions are the worst pattern of injury in obstetrical brachial plexus injury (OBPI). The prognosis is poor and the treatment is mainly surgical with extraplexual neurotizations or muscle transfers. We present the outcomes of a technique performed in our institution to treat C5-C6 avulsion in obstetrical brachial plexus injury. This technique consists of a total ipsilateral C7 neurotization to the upper trunk. Ten babies with isolated C5-C6 root avulsion were operated on; we were able to review nine of them at over 12 months follow-up. The shoulder and the elbow function were assessed, as well as the Mallet Score. The mean follow-up was 9.2 years (SD 5.7). After a follow-up of 6 years, elbow flexion was restored with a range of motion ⩾130° and a motor function ⩾M3 in all patients. The average Mallet score was 18.1 (SD 1.2). This approach appears to be a viable alternative to extraplexual neurotizations for the treatment of C5-C6 nerve root avulsion.

Post-traumatic cervical nerve root avulsion: direct and indirect magnetic resonance myelography findings

Post-traumatic cervical nerve root avulsion: direct and indirect magnetic resonance myelography findings

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

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

A new cervical nerve root avulsion model using a posterior extra-vertebral approach in rats

BackgroundThe nerve root avulsion injury causes decrease of motor neurons in the spinal ventral horn. To investigate the motoneuron death after avulsion injury in rats, the intradural root avulsion procedure is usually used, although it is technically demanding and associated with a risk of unexpected spinal cord damage. We have developed a new cervical nerve root avulsion procedure in rats and investigated the validity of our procedure.MethodsOur procedure is using a posterior approach and pulling the C6 nerve root outside the vertebral foramen without intradural procedures. The lateral third of the lateral mass is needed to be resected before pulling the nerve root. The accomplishment of our procedure is judged by confirmation of the bifurcated stump of the avulsed nerve root and the leakage of the spinal fluid from vertebral foramen. At first, four Sprague–Dawley (SD) rats were used for the examination of C6 motor neuron distribution in the normal spinal cord. Then, 40 SD rats were divided into following four groups and the survival rate of motor neuron was examined. (A) an intradural avulsion group, (B) an intradural rhizotomy group, (C) our extravertebral avulsion group, and (D) an extravertebral rupture group. Another 26 SD rats were used for the examination of histomorphorogic changes in the spinal cord after our extra-vertebral avulsion procedure.ResultsAt 28 days after injury, the percentage of surviving motor neurons in groups A (39.0 ± 2.1%) and C (47.5 ± 7.1%) were significantly lower than those in groups B (77.1 ± 12.3%) and D (98.9 ± 9.9%). Compared with other groups, our procedure was easier and associated with less unexpected spinal cord damage. Although the length of the distal stump of the extravertebrally avulsed ventral rootlets was varied between 1.5 and 3.2 mm, this difference did not affect motoneuron death. The extravertebral avulsion injury showed intraspinal bleeding along the motoneuron axons, glial reaction and macrophage infiltration in the lesioned side of the ventral horn.ConclusionsOur extravertebral avulsion procedure is simple and reproducible. It would become a useful tool for the study of cervical nerve root avulsion injury.

Computerized tomography myelography with coronal and oblique coronal view for diagnosis of nerve root avulsion in brachial plexus injury

BackgroundThe authors describe a new computerized tomography (CT) myelography technique with coronal and oblique coronal view to demonstrate the status of the cervical nerve rootlets involved in brachial plexus injury. They discuss the value of this technique for diagnosis of nerve root avulsion compared with CT myelography with axial view.MethodsCT myelography was performed with penetration of the cervical subarachnoid space by the contrast medium. Then the coronal and oblique coronal reconstructions were created. The results of CT myelography were evaluated and classified with presence of pseudomeningocele, intradural ventral nerve rootlets, and intradural dorsal nerve rootlets. The diagnosis was by extraspinal surgical exploration with or without spinal evoked potential measurements and choline acetyl transferase activity measurement in 25 patients and recovery by a natural course in 3 patients. Its diagnostic accuracy was compared with that of CT myelography with axial view, correlated with surgical findings or a natural course in 57 cervical roots in 28 patients.ResultsCoronal and oblique coronal views were superior to axial views in visualization of the rootlets and orientation of the exact level of the root. Sensitivity and specificity for coronal and oblique coronal views of unrecognition of intradural ventral and dorsal nerve root shadow without pseudomeningocele in determining pre-ganglionic injury were 100% and 96%, respectively. There was no statistically significant difference between coronal and oblique coronal views and axial views.ConclusionThe information by the coronal and oblique coronal slice CT myelography enabled the authors to assess the rootlets of the brachial plexus and provided valuable data for helping to decide whether to proceed with exploration, nerve repair, primary reconstruction.

High noon back pain- severe pseudoradicular pain as a lead symptom of superficial siderosis: a case report.

A superficial siderosis of the central nervous system following a traumatic cervical nerve root avulsion usually leads to gait difficulties and hearing loss, whereas back pain is described only rarely. Here we report on the first case with circadian occurrence of severe back pain as the only symptom of a superficial siderosis. We present a case with the most severe pseudoradicular lumbosacral pain occurring daily at noon for the past 5 weeks. The 48-year-old male white patient did not complain of pain in the morning. A traumatic root avulsion 26 years earlier led to a brachial plexus palsy and Horner's syndrome in this patient. Superficial hemosiderosis in cranial MRI and examination of the cerebrospinal fluid revealing massive red blood cells as well as xanthochromia and elevated protein levels (742 mg/l) led to the diagnosis of a superficial siderosis. A pseudomeningocele caused by a cervical nerve root avulsion is described as a rare reason for superficial siderosis. Surgery on a pseudomeningocele, diagnosed by MRI, led to an immediate disappearance of complaints in our case. Regular neurological investigation and possibly repeated lumbar puncture to exclude superficial siderosis should be considered in cases with severe back pain and a history of traumatic root avulsion. Modern susceptibility weighted MR imaging (SWI) techniques, sensible to the detection of superficial hemosiderosis, might be helpful in the making of a diagnosis.

Case Scenario: Postoperative Brachial Plexopathy Associated with Infraclavicular Brachial Plexus Blockade

Case Scenario: Postoperative Brachial Plexopathy Associated with Infraclavicular Brachial Plexus Blockade

Nerve Transfers for an Upper Brachial Plexus Injury: A Case Report

Objective: To demonstrate multiple nerve transfers as primary surgical management for an upperplexus injury.Methods: A 6-year-old boy who suffered a preganglionic upper brachial plexus injury following a motor vehicle accident, exhibited complete biceps, deltoids, suprapinatus, and infraspinatus palsies.Multiple nerve transfers, which consist of spinal accessory nerves to suprascapular nerve transfer, median and ulnar motor fascicles to biceps and brachialis motor branches transfers, and long head oftriceps motor branch to axillary nerve transfer were performed 6 months after injury.Results: 13 months post multiple nerve transfer, the patient has regained M4+/5 elbow flexion, M4/5 external rotation, and M4/5 shoulder abduction.Conclusion: Nerve transfer is a viable option for upper plexus palsy management. With a sound surgical technique and good case selection, the results can be very rewarding. This case showedquite robust re-innervation with significant functional recovery at a one-year follow-up following multiple nerve transfers.Keywords: Brachial Plexus Injury, Upper Plexus Injury, Nerve Root Avulsion, Nerve Transfers, Functional Recovery.

Anterior cornual motoneuron regression pattern after sacral plexus avulsion in rats.

Sacral plexus avulsions lead to severe disability in patients and remain a thorny clinical problem due to the lack of anatomical, experimental and clinical studies. Attempts have been made to treat lumbosacral plexus injuries with such operations as direct anastomosis of the ends of injured sacral plexuses, and certain therapeutic effects were achieved. To further explore the degeneration pattern of anterior cornual motoneurons and determine the best time for treatment, we carried out this study. We randomly assigned 60 SD rats into six groups (group A-F), with ten rats per group. The A, B, C, D, E, F groups included animals that received operation for L4-L6 nerve root avulsion at 2, 4, 6, 8, 10 and 12 weeks respectively. We measured the apoptosis of motor neurons in the anterior corn through hematoxylin-eosin (HE) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and found that after sacral plexus avulsions, motor neurons in the anterior horn of the spinal cord gradually reduced and the apoptosis index gradually increased as the time went by. Survival rates of motoneurons at 2, 4, 6, 8, 10, and 12 weeks after avulsion were (92.1 ± 4.7)%, (83.6 ± 3.7)%, (43.6 ± 4.2)%, (32.1 ± 3.5)%, (18.4 ± 3.7)% and (12.1 ± 3.3)%, respectively. The difference was most significant at week 6. Week 6 after injury is probably the deadline for surgical repair of sacral plexus avulsions.

High-Resolution Ultrasonography for the Diagnosis of Brachial Plexus Root Lesions

The aim of this study was to investigate the feasibility of using high-resolution ultrasonography in the diagnosis of brachial plexus (BP) root lesions. A prospective study of ultrasonographic evaluation of BP nerve roots was performed in 37 patients with BP root lesions (29 with root injuries, 8 with tumors). The pre-operative ultrasonographic findings were compared with the surgical and pathohistological findings. All C5–7 roots were detected by ultrasonography in all patients, whereas 92% (68/74) of C8 and 51% (38/74) of T1 nerve roots were visualized. Among 29 patients with BP root avulsion, partial injuries or totally interrupted BP roots were detected in all patients. Cystic masses and neuromas were detected in 16 and 23 patients, respectively. In 8 patients with BP root tumors, 8 hypo-echoic masses were detected inside or partly outside of intervertebral foramina connecting to nerve roots. Surgical exploration revealed that there were 57 BP root avulsions in 29 patients. However, 2 T1 nerve root avulsions had been missed by pre-operative ultrasonography. Pathohistology revealed that all 8 BP root tumors pre-operatively diagnosed by ultrasonography were schwannomas. High-resolution ultrasonography can provide a convenient and accurate imaging modality for quick diagnosis and location of BP root lesions.

Cervical Spinal Cord Stimulation for the Management of Pain from Brachial Plexus Avulsion

Dear Editor, Almost 80% of patients with brachial plexus avulsion develop chronic pain. The pain can be treated medically or with more invasive surgical procedures. However, in most cases, the pain is resistant to medical treatment and has a high-recurrence rate after invasive procedures like dorsal root entry zone (DREZ) lesioning. Cervical spinal cord stimulation (SCS) is one of the underutilized treatment modalities with several reports of good outcome. We report a case of significant improvement in pain from brachial plexus avulsion injury after implanting a cervical SCS. A 25-year-old male patient was involved in a motor vehicle accident 5 years ago. He suffered from multiple injuries including injury to his right brachial plexus. Magnetic resonance imaging (MRI) showed complete nerve root avulsion from C6 to T1. He lost sensation and motor function below the deltoid in his right upper extremity, however his main debilitating problem was severe chronic pain. He described his pain as burning, stabbing, and sometime like an electric shock, starting at the shoulder and radiating to the arm and his five fingers, with an intensity of 7/10 on a numeric pain rating scale. On examination, he had no sensation or motor function below the deltoid. He was not interested in functional recovery and was only concerned about relieving the pain. Medical management with a combination of an antidepressant, an anticonvulsant, a …

Nerve Transfers to Restore upper Extremity Function: A Paradigm Shift.

Nerve Transfers to Restore upper Extremity Function: A Paradigm Shift.