Comparison of nylon, vicryl, and fibrin glue for nerve grafting in rats.

OBJECTIVES: For nerve injuries, not amendable to tensionless epineural coaptation of the nerve, autografts are the preferred treatment. Although absorbable sutures are not recommended for nerve repair, there is no evidence that non-absorbable sutures are superior to absorbable sutures. This study aims to assess the effectiveness of non-absorbable monofilament nylon sutures, absorbable monofilament vicryl sutures, and fibrin glue when used for nerve grafting. METHODS: Lewis rats (N = 32) were subjected to a sciatic nerve transection and randomly assigned to a group: graft with Nylon, graft with Vicryl, graft with Fibrin Glue, or no graft. Motor function, sensory function, and thermal pain were assessed during a 12-week recovery period, and immunohistochemistry was used to assess macrophage response. RESULTS: At 12 weeks, the Vicryl and Nylon groups had significantly larger ankle angles at to lift off, which is a measure of motor function, compared to injured controls (p < 0.05). Grafted rats displayed no difference in thermal response but hypersensitivity to mechanical stimuli compared to the uninjured hindlimb. The Nylon, Vicryl, and Fibrin Glue groups all had significantly less atrophy of the gastrocnemius muscle compared to injured controls (p < 0.0001). In the Fibrin Glue group, 3/9 grafts did not incorporate. The Nylon group had significantly less (p = 0.0004) axon growth surrounding the suture holes compared to the Vicryl group. There were no differences in the axon counts, motor neurons, or sensory neurons between all grafted rats. CONCLUSIONS: These results demonstrate that vicryl sutures work just as well as nylon for nerve recovery after injury and grafting.

Clavicular window for brachial plexus schwannoma removal.

Background: Schwannomas are benign nerve sheath tumors that can either be sporadic or part of neurofibromatosis type 2 (NF2). Tumors of the brachial plexus (BP) with both supra- and infraclavicular components are uncommon and represent a challenge to complete surgical resection. There are few reports on single clavicular osteotomies for BP exposure; however, there are currently no reports of utilization of a clavicular window for a large schwannoma resection. Case Description: We report a case of a patient with a schwannoma spanning the BP roots to the cords, with the majority involving the retro clavicular inferior trunk in the setting of NF2. The patient underwent previous subtotal resection and had postoperative enlargement of the residual mass. A gross total resection was made possible by the creation of a clavicular window to expose the BP. A 2 cm segment piece of the mid-clavicle was removed, allowing for roughly 6 cm of mediolateral exposure through clavicular distraction. This clavicular window facilitated complete exposure of the BP schwannoma underneath the clavicle as well as unobstructed exposure of supraclavicular and infraclavicular tumor. The segment was then refixed with a plate after resection of the tumor. Conclusion: The use of a clavicular window allowed for extensive exposure of the trunks and divisions of the BP to achieve a gross total resection in this case. The clavicular window approach may provide a benefit for optimizing exposure in the setting of lesions involving the trunks and divisions that the clavicle would traditionally obstruct.

Anatomical Proximity Between Sciatic Nerve and Ischial Spine and its Relationship to the Development of Deep Gluteal Pain Syndrome.

OBJECTIVE: Deep gluteal syndrome (DGS) is a medical diagnosis in which the pathoanatomy of the subgluteal space contributes to pain. The growing recognition that gluteal neuropathies can be associated with the presence of a bone-neural conflict with irritation or compression may allow us to shed some light on this pathology. This study aims to determine whether the location of the sciatic nerve (SN) in relation to the ischial spine (IS) contributes to the development of DGS. METHODS: The SN - IS relationship was analyzed based on magnetic resonance imaging (MRI) in 15 surgical patients (SPs), who underwent piriformis release, and in 30 control patients who underwent MRI of the pelvis for reasons unrelated to sciatica. The SN exit from the greater sciatic foramen was classified as either zone A (medial to the IS); zone B (on the IS); or zone C (lateral to the IS). RESULTS: The SN was significantly closer to the IS in SPs than in MRI controls (P = 0.014). When analyzing patients of similar age, SNs in SPs were significantly closer (P = 0.0061) to the IS, and located in zone B significantly more (P = 0.0216) as compared to MRI controls. Patients who underwent surgery for piriformis release showed a significant decrease in pain postoperatively (P < 0.0001). CONCLUSIONS: The results from this study suggest that the relationship between the IS and SN may play a role in the development of DGS. This may also help establish which patients would benefit more from surgical intervention.

Compressive median neuropathy caused by brachial artery pseudoaneurysm.

Background: Brachial artery pseudoaneurysms (PSAs) are a rare complication of trauma and medical intervention, estimated to constitute 0.3-0.7% of all PSAs. Although neurologic symptoms are common in patients undergoing hemodialysis, direct nerve compression by large PSAs is rare. Case Description: We report a case of median nerve compression by a brachial artery PSA treated by PSA resection and distal nerve transfer of the extensor carpi radialis brevis nerve to the anterior interosseous nerve. Conclusion: This case illustrates the successful use of distal nerve transfers for the treatment of median neuropathy secondary to brachial PSA. In addition, this case highlights the importance of imaging before any exploratory nerve surgery in the setting of a mass and/or prior vascular procedure. Embarking on a nerve release/ repair surgery in the absence of a vascular surgeon would be disastrous.

Preoperative Ultrasound-Guided Localization of the Lateral Femoral Cutaneous Nerve: From Guide Wire to Novel Clip.

BACKGROUND AND OBJECTIVE: Lateral femoral cutaneous nerve (LFCN) decompression and transposition are surgical treatment options for meralgia paresthetica. Identifying the LFCN during surgery may be challenging, and preoperative localization is a valuable adjunct in this case. The objective of this study was to explore a new technique using preoperative ultrasound-guided clip localization (USCL) of the LFCN. METHODS: After Institutional Review Board approval, data were collected on patients who underwent both preoperative ultrasound-guided wire localization (USWL) and USCL over the past 13 years. Skin-to-nerve time was calculated prospectively. RESULTS: Fifty-six patients were identified, 51 had USWL and 5 had USCL; the skin-to-nerve median time was 7.5 and 6 minutes, respectively. Six wires were misplaced, and this was at the beginning of utilization of the USWL technique. There were no nerve injury, infection, or bleeding complications related to either wire or clip placement. CONCLUSION: USWL or USCL is safe and time-efficient in LFCN surgeries.

Anatomical Relationships of the Sciatic Nerve and Pudendal Nerve to the Ischial Spine as They Exit the Greater Sciatic Foramen.

OBJECTIVE: Deep gluteal syndrome is a clinical condition in which discomfort may arise due to the pathoanatomy of the subgluteal space. We conducted an anatomical exploration to categorize the relationship of the piriformis muscle, sciatic nerve (SN), and pudendal nerve (PN) to the ischial spine (IS) and sacrospinous ligament. METHODS: We analyzed 22 cadavers. The piriformis muscle, SN, and PN were exposed through either a transgluteal approach or a gluteal flap. The relationship of the neural structures to the IS, sacrospinous ligament, and ischial bone as they exit the greater sciatic foramen was observed, and the exit zones were classified as zone A, medial to the IS (entirely on sacrospinous ligament); zone B, on the IS; and zone C, lateral to the IS (entirely on ischial bone). RESULTS: The SN was observed either in zone B or zone C in all specimens. The PN was found to be in either zone A or zone B in 97.6% of specimens. The most common combinations were SN in zone B and PN in zone A (type I), and SN in zone C and PN in zone B (type II). CONCLUSIONS: The results from this study show clear anatomical differences in the SN-PN relationship, which may play a role in pain seen in deep gluteal syndrome. Moreover, classification of the SN-IS and PN-IS relationships described in this article will help describe different pathologies affecting the deep gluteal area.

YouTube and pudendal neuralgia: Is it a good source of information for patients?

OBJECTIVE: This study aims to identify the shortcomings and quality content of YouTube videos and its effectiveness as a source of patient information on pudendal neuralgia treatment. METHODS: A search was conducted on YouTube using the words "pudendal neuralgia physical therapy," "medications for pudendal neuralgia," "pudendal nerve block," "pudendal neuralgia surgery," and "alternative treatments for pudendal neuralgia." The results were analyzed based on the source, general descriptive statistics, the intended audience, and five content areas. The DISCERN scoring system was used to evaluate the quality of videos. RESULTS: After the search, 73 videos met the inclusion criteria for further analysis. The majority of these videos (61.64%) were intended to target the general population, whereas a smaller percentage were identified as professional (41.10%) or targeted for physicians (35.62%). From the videos included, 10 (13.70%) described treatment options in a balanced and evidence-based manner. The higher DISCERN score positively correlated with the presence of this last content criterion. With a total DISCERN mean score of 35.42, a significant proportion of the videos (41.10%) were rated very poor. The remaining videos were classified as poor (23.29%), fair (19.18%), good (8.22%), and excellent (8.22%). CONCLUSION: The quality of the information included in YouTube videos regarding pudendal neuralgia treatment was considered generally poor. Healthcare providers must recognize the potential influence of this platform on patients' understanding of pudendal neuralgia treatment. There is a need for additional research and randomized studies regarding YouTube content about this condition.

Large vertebral artery pseudoaneurysm masquerading as a schwannoma: illustrative case.

BACKGROUND: Extracranial vertebral aneurysms or pseudoaneurysms are rare and result primarily from trauma. Large pseudoaneurysms can masquerade as mass lesions, making it challenging to identify the correct diagnosis. OBSERVATIONS: This is a case report in which a large vertebral pseudoaneurysm posed as a schwannoma and biopsy was attempted. It was later identified as a vascular lesion and treated appropriately with no complications. LESSONS: Vascular etiologies should always be included in the differential diagnosis of spine and nerve pathologies especially lesions that are in the vicinity of major vascular channels such as the transverse foramina of the cervical spine.

A combined, supraclavicular, infraclavicular, transaxillary, and posterior subscapular approaches for en bloc resection of giant myxofibrosarcoma.

Background: Myxofibrosarcoma (MFS) is a rare and locally infiltrative tumor that commonly occurs in extremities in older adults; however, truncal and head and neck cases have been reported. They are characterized by multinodular growth, incomplete fibrous septa, and myxoid stroma. Surgical resection is the mainstay of treatment. Case Description: The authors report a case of a combined, supraclavicular, infraclavicular, transaxillary, and posterior subscapular approaches for resection of giant MFS. Conclusion: The anatomical complexity and rarity of tumors involving the brachial plexus impose many challenges onto surgeons performing surgical resections. Treatment choices and surgical outcomes rely heavily on meticulous multidisciplinary planning, anatomical knowledge, careful dissection, and extent of resection. This case is unique in utilizing four different approaches to the brachial plexus to resect one tumor.

Peroneal Nerve Repair with Cross-Bridge Ladder Technique: Parallel End-to-Side Neurorrhaphies.

Background Multiple nerve transfer techniques are used to treat patients with nerve injuries when a primary repair is not possible. These techniques are categorized to end-to-end, end-to-side, and side-to-side neurorrhaphy. Our study aims to explore the utility of the cross-bridge ladder technique (H-shaped), which has shown promising results in animal models and probably underutilized clinically. Methods Four patients with significant loss of ankle dorsiflexion were seen in the clinic and underwent evaluation, including electrodiagnostic studies. A cross-bridge ladder repair technique was used between the tibial nerve as the donor and the common peroneal nerve as the recipient via one or two nerve grafts coapted in parallel with end-to-side neurorrhaphies. Dorsiflexion strength was measured preoperatively using the Medical Research Council (MRC) grading system and at each postoperative follow-up appointment. Results All four patients had suffered persistent and severe foot drop (MRC of 0) following trauma that had occurred between 6 and 15 months preoperatively. Three of the four patients improved to an MRC of 2 several months postoperatively. The last patient had an immediate improvement to an MRC of 2 by his first month and had a complete recovery of ankle dorsiflexion within 4 months from surgery. Conclusion We demonstrate the utility and clinical outcomes of the cross-bridge ladder technique in patients with persistent and prolonged foot drop following trauma. Both early and late recovery were seen while all patients regained motor function, with some patients continuing to improve up to the most recent follow-up. IRB Approval: Obtained 2013-1411-CP005.

Gait analysis in swine, sheep, and goats after neurologic injury: a literature review.

Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials. Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans. As a result, functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models. Comparatively, larger, more clinically relevant models have not been as well studied. To achieve similar locomotor testing standardization in larger animals, the models must be accessible to a wide array of researchers. Non-human primates are the most relevant animal model for translational research, however ethical and financial barriers limit their accessibility. This review focuses on swine, sheep, and goats as large animal alternatives for transitional studies between rodents and non-human primates. The objective of this review is to compare motor testing and data collection methods used in swine, sheep, and goats to encourage testing standardization in these larger animal models. The PubMed database was analyzed by searching combinations of swine, sheep, and goats, neurologic injuries, and functional assessments. Findings were categorized by animal model, data collection method, and assessment design. Swine and sheep were used in the majority of the studies, while only two studies were found using goats. The functional assessments included open pen analysis, treadmill walking, and guided free walking. Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software. Overall, swine and sheep were well-suited for a variety of assessment designs, with treadmill walking and guided free walking offering the most consistency across multiple trials. Data collection methods varied, but image-based gait analysis software provided the most robust analysis. Future studies should be conducted to standardize functional testing methods after neurologic impairment in large animals.

Lateral femoral cutaneous nerve transposition.

Lateral femoral cutaneous neuropathy, also known as meralgia paresthetica, is a pathology commonly encountered by neurosurgeons. Symptoms include numbness, tingling, and burning pain over the anterolateral thigh due to impingement on the lateral femoral cutaneous nerve (LFCN). Surgical treatment has traditionally involved nerve release or neurectomy. LFCN transposition is a relatively new approach that can provide excellent symptomatic relief. In this video, the authors highlight key operative techniques to ensure easy identification, adequate decompression, and transposition of the nerve. Key steps include ultrasound-guided wire localization, superficial decompression, opening of the inguinal ligament, deep decompression, and medial transposition. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID2289.

Can MR neurography of the common peroneal nerve predict a residual motor deficit in patients with foot drop?

OBJECTIVE: To determine if MR neurography of the common peroneal nerve (CPN) predicts a residual motor deficit at 12-month clinical follow-up in patients presenting with foot drop. MATERIALS AND METHODS: A retrospective search for MR neurography cases evaluating the CPN at the knee was performed. Patients were included if they had electrodiagnostic testing (EDX) within 3 months of imaging, ankle and/or forefoot dorsiflexion weakness at presentation, and at least 12-month follow-up. Two radiologists individually evaluated nerve size (enlarged/normal), nerve signal (T2 hyperintense/normal), muscle signal (T2 hyperintense/normal), muscle bulk (normal/Goutallier 1/Goutallier > 1), and nerve and muscle enhancement. Discrepancies were resolved via consensus review. Multivariable logistical regression was used to evaluate for association between each imaging finding and a residual motor deficit at 12-month follow-up. RESULTS: Twenty-three 3 T MRIs in 22 patients (1 bilateral, mean age 52 years, 16 male) met inclusion criteria. Eighteen cases demonstrated common peroneal neuropathy on EDX, and median duration of symptoms was 5 months. Six cases demonstrated a residual motor deficit at 12-month follow-up. Fourteen cases underwent CPN decompression (1 bilateral) within 1 year of presentation. Three cases demonstrated Goutallier > 1 anterior compartment muscle bulk. Multivariable logistical regression did not show a statistically significant association between any of the imaging findings and a residual motor deficit at 12-month follow-up. CONCLUSION: MR neurography did not predict a residual motor deficit at 12-month follow-up in patients presenting with foot drop, though few patients demonstrated muscle atrophy in this study.

Accessory head of flexor carpi radialis and abnormal course of the median nerve in the forearm.

Background: The median nerve anatomy and its clinical presentation are crucial for surgeons to consider avoiding iatrogenic injury and performing effective surgical interventions. Case Description: An atypical presentation of median nerve anatomy proximal to the carpal tunnel was found during cadaveric dissection. The median nerve was located deep to a uniquely double-headed flexor carpi radialis and curved medially around the tendons of the forearm to enter the carpal tunnel superficially. Conclusion: The atypical presentation of median nerve anatomy can assist surgeons in adverse event reduction during surgeries such as carpal tunnel and pronator teres syndrome releases.

Spinal fractures in the setting of diffuse idiopathic skeletal hyperostosis conservatively treated via orthosis: illustrative cases.

BACKGROUND: Fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH) are considered highly unstable injuries with high risk for neurological injury. Surgical intervention is the standard of care for these patients to avoid secondary spinal cord injuries. Despite this, certain cases may necessitate a nonoperative approach. Herein within, the authors describe three cases of cervical, thoracic, and lumbar fractures in the setting of DISH that were successfully treated via orthosis. OBSERVATIONS: The authors present three cases of fractures in patients with DISH. A 74-year-old female diagnosed with an acute fracture of a flowing anterior osteophyte at C6-C7 treated with a cervical orthosis. A 78-year-old male with an anterior fracture of the ankylosed T7-T8 vertebrae managed with a Jewett hyperextension brace. Finally, a 57-year-old male with an L1-L2 disc space fracture treated with a thoraco-lumbo-sacral orthosis. All patients recovered successfully. LESSONS: In certain cases, conservative treatment may be more appropriate for fractures in the setting of DISH as an alternative to the surgical standard of care. Most fractures in the setting of DISH are unstable, therefore it is necessary to manage these patients on a case-by-case basis.

Outcomes following conservative treatment of extension fractures in the setting of diffuse idiopathic skeletal hyperostosis: is external orthosis alone a reasonable option?

OBJECTIVE: Extension fractures in the setting of diffuse idiopathic skeletal hyperostosis (DISH) represent highly unstable injuries. As a result, these fractures are most frequently treated with immediate surgical fixation to limit any potential risk of associated neurological injury. Although this represents the standard of care, patients with significant comorbidities, advanced age, or medical instability may not be surgical candidates. In this paper, the authors evaluated a series of patients with extension DISH fractures who were treated with orthosis alone and evaluated their outcomes. METHODS: A retrospective review from 2015 to 2022 was conducted at a large level 1 trauma center. Patients with extension-type DISH fractures without neurological deficits were identified. All patients were treated conservatively with orthosis alone. Baseline patient characteristics and adverse outcomes are reported. RESULTS: Twenty-seven patients were identified as presenting with extension fractures associated with DISH without neurological deficit. Of these, 22 patients had complete follow-up on final chart review. Of these 22 patients, 21 (95.5%) were treated successfully with external orthosis. One patient (4.5%) who was noncompliant with the brace had an acute spinal cord injury 1 month after presentation, requiring immediate surgical fixation and decompression. No other complications, including skin breakdown or pressure ulcers related to bracing, were reported. CONCLUSIONS: Treatment of extension-type DISH fractures may be a reasonable option for patients who are not candidates for safe surgical intervention; however, a risk of neurological injury secondary to delayed instability remains, particularly if patients are noncompliant with the bracing regimen. This risk should be balanced against the high complication rate and potential mortality associated with surgical intervention in this patient population.

A Localized Materials-Based Strategy to Non-Virally Deliver Chondroitinase ABC mRNA Improves Hindlimb Function in a Rat Spinal Cord Injury Model.

Spinal cord injury often results in devastating consequences for those afflicted, with very few therapeutic options. A central element of spinal cord injuries is astrogliosis, which forms a glial scar that inhibits neuronal regeneration post-injury. Chondroitinase ABC (ChABC) is an enzyme capable of degrading chondroitin sulfate proteoglycan (CSPG), the predominant extracellular matrix component of the glial scar. However, poor protein stability remains a challenge in its therapeutic use. Messenger RNA (mRNA) delivery is an emerging gene therapy technology for in vivo production of difficult-to-produce therapeutic proteins. Here, mineral-coated microparticles as an efficient, non-viral mRNA delivery vehicles to produce exogenous ChABC in situ within a spinal cord lesion are used. ChABC production reduces the deposition of CSPGs in an in vitro model of astrogliosis, and direct injection of these microparticles within a glial scar forces local overexpression of ChABC and improves recovery of motor function seven weeks post-injury.