Management and outcomes of cerebrovascular injuries after gunshot wounds to the cervical spine.

STUDY DESIGN: This study was a multicenter retrospective analysis of cervical spine gunshot wound (GSW) patients. OBJECTIVE: The present study was conducted to evaluate the management and outcomes of vascular injuries following GSW involving the cervical spine. SUMMARY OF BACKGROUND DATA: Gunshot wounds (GSW) injuring the cervical spine are associated with high rates of vascular injury. METHODS: Charts of patients with GSW involving the cervical spine at two Level 1 trauma centers were reviewed from 2010 to 2021 for demographics, injury characteristics, management and follow-up. Statistical analysis included T tests and ANOVA for comparisons of continuous variables and chi-square testing for categorical variables, non-parametric tests were used when indicated. Beta-binomial models were used to estimate the probabilities outcomes. Bayesian regression models were utilized to compute risk ratios (RR) and their 95 % confidence intervals (CI) to enhance the inferential robustness. RESULTS: 40 patients with cervical spine GSW and associated cerebrovascular injury were included in our analysis. 15 % of patients had Biffl grade (BG) V injuries, 50 % grade IV, and 35 % grade III-I. Angiography was performed in 35 % of patients. 5 of these patients (BG V-III) required endovascular treatment for pseudoaneurysm obliteration or parent vessel sacrifice. 7 patients (22 %) showed evidence of progression. 70 % of patients were placed on antiplatelet therapy for stroke prevention. Bayesian regression models with a skeptical prior for cerebral ischemia revealed a mean RR of 4.82 (95 % CI 1.02-14.48) in the BG V group, 0.75 (95 % CI 0.13-2.26) in the BG IV group, and 0.61 (95 % CI 0.06-2.01) in the combined BG III-I group. For demise the mean RR was 3.41 (95 % CI 0.58-10.65) in the BG V group and 1.69 (95 % CI 0.29-5.97) in the BG IV group. In the high BG (V, IV) group, 54.55 % of patients treated with antiplatelet therapy had complications. None of the patients that were treated with antiplatelet therapy in the low BG (III-I) group had complications. CONCLUSIONS: Cervical spine GSWs are associated with high-grade vascular injuries and may require early endovascular intervention. Additionally, a high rate of injury progression was seen on follow up imaging, requiring subsequent intervention. Reintervention and demise were common and observed in high BG (V, IV) groups. The incidence of stroke was low, especially in low BG (I-III) groups, suggesting that daily aspirin prophylaxis is adequate for long-term stroke prevention.

Multi-institutional review of characteristics and management of gunshot wounds to the spine.

BACKGROUND CONTEXT: Gunshot wounds (GSWs) to the vertebral column represent an important cause of morbidity and mortality in the United States, constituting approximately 20% of all spinal injuries. The management of these injuries is an understudied and controversial topic, given its heterogeneity and lack of follow-up data. PURPOSE: To characterize the management and follow-up of GSWs to the spine. STUDY DESIGN/SETTING: A multi-institutional retrospective review of the experience of two urban Level 1 trauma centers. PATIENT SAMPLE: Patients with GSWs to the spine between 2010-2021. OUTCOME MEASURES: Measures included work status, follow-up healthcare utilization, and pain management were collected. METHODS: Charts were reviewed for demographics, injury characteristics, surgery and medical management, and follow-up. Statistical analysis included T-tests and ANOVA for comparisons of continuous variables and chi-square testing for categorical variables. All statistics were performed on SPSS v24 (IBM, Armonk, NY). RESULTS: A total of 271 patients were included for analysis. The average age was 28 years old, 82.7% of patients were black, 90% were male, and 76.4% had Medicare/Medicaid. The thoracic spine (35%) was most commonly injured followed by lumbar (33.9%) and cervical (25.6%). Cervical GSW was associated with higher mortality (p<.001); 8.7% of patients developed subsequent osteomyelitis/discitis, 71.3% received prophylactic antibiotics, and 56.1% of cervical GSW had a confirmed vertebral or carotid artery injury. ASIA scores at presentation were most commonly A (26.9%), D (20.7%), or E (19.6%), followed by C (7.4%) and B (6.6%). 18.8% of patients were unable to be assessed at presentation. ASIA score declined in only 2 patients, while 15.5% improved over their hospital stay. Those who improved were more likely to have ASIA B injury (p<.001). Overall, 9.2% of patients underwent spinal surgery. Of these, 33% presented as ASIA A, 21% as ASIA B, 29% as ASIA C, and 13% as ASIA D. Surgery was not associated with an improvement in ASIA score. CONCLUSIONS: Given the ubiquitous and heterogeneous experience with GSWs to the spine, rigorous attempts should be made to define this population and its clinical and surgical outcomes. Here, we present an analysis of 11 years of patients presenting to two large trauma centers to elucidate patterns in presentation, management, and follow-up. We highlight that GSWs to the cervical spine are most often seen in young black male patients. They were associated with high mortality and high rates of injury to vertebral arteries and that surgical intervention did not alter rates of discitis/osteomyelitis or propensity for neurologic recovery; moreover, there was no incidence of delayed spinal instability in the study population.

A Simple 3D Printed Model for Intracranial Vascular Anastomosis Practice and the Rochester Bypass Training Score.

BACKGROUND AND OBJECTIVES: Surgical simulation models in cranial neurosurgery are needed to allow affordable, accessible, and validated practice in resident education. Current bypass anastomosis practice models revolve around basic tube tying or complex animal and 3-dimensional models. This study sought to design and validate a 3-dimensional printed model for intracranial anastomosis training. METHODS: A computer-aided design (CAD) generic skull was uploaded into Meshmixer (v.3.5), and a 55-mm opening was created on the right side, mimicking a standard orbitozygomatic craniotomy. The model was rotated 15° upward and 35° left, before a 10-mm square frame was added 80-mm deep to the right orbit. The CAD model was uploaded to GrabCAD and printed using a J750 PolyJet 3D printer before being paired with a vascular anastomosis kit. The model was validated with standardized assessments of residents and attendings by simulating an "M2 to P2" bypass. The Rochester Bypass Training Score (RBTS) was created to assess bypass patency, back wall suturing, and suture quality. Postsimulation survey data regarding the realism and usefulness of the simulation were collected. RESULTS: Five junior residents (Postgraduate Year 1-4), 3 senior residents (Postgraduate Year 5-7), and 2 attendings were participated. The mean operative time in minutes was as follows: junior residents 78, senior residents 33, and attendings 50. The RBTS means were as follows: junior residents 2.4, senior residents 4.0, and attendings 5.0. Participants agreed that the model was realistic, useful for improving operative technique, and would increase comfort in bypass procedures. There are a few different printing options, varying in model infill and printing material used. For this experiment, a mix of Vero plastics were used totaling $309.09 per model; however, using the more common printing material polylactic acid brings the cost to $17.27 for a comparable model. CONCLUSION: This study presents an affordable, realistic, and educational intracranial vascular anastomosis simulator and introduces the RBTS for assessment.

Delayed myelopathy after remote C1-2 sublaminar wire fixation: illustrative case.

BACKGROUND: Atlantoaxial sublaminar wiring complications, both early and delayed, have been documented. However, delayed neurological compromise 27 years after successful fusion is a rare but possible occurrence. OBSERVATIONS: A 76-year-old male, who had undergone C1-2 sublaminar wire fusion for atlantoaxial instability in 1995, presented with symptoms of progressive right arm weakness, falls, and incontinence of bowel and bladder over a 1-week period. Initial imaging workup revealed bowing of the C1-2 sublaminar wires resulting in cervical spinal cord compression and T2-weighted signal changes. A C1-2 laminectomy was performed to remove the wires and decompress the spinal cord with improvement in the patient's neurological status. LESSONS: This rare case highlights the potential for delayed cervical myelopathy and cord compression from sublaminar wires, even after a successful fusion. In patients with a history of sublaminar wiring who experience new neurological deficits, it is essential to evaluate the hardware for migration.

Treatment of hydrocephalus in an ovine model with an intraparenchymal stent.

OBJECTIVE: While CSF diversion is highly effective at treating hydrocephalus, shunting is unfortunately associated with a very high revision rate. Studies have demonstrated that proximal catheter obstruction is a major cause of failure. A novel proximal access device was developed, and pilot testing was performed in a sheep model of hydrocephalus. METHODS: Hydrocephalus was induced in 8 sheep using a cisternal injection of 4 ml of 25% kaolin, and the sheep were randomized to either a standard ventricular catheter or a novel intraparenchymal stent (IPS). Both groups received identical valves and distal catheters. The novel device included a 3D-printed stainless steel port and a 6 × 40-mm covered peripheral vascular stent. Animals were euthanized for signs of hydrocephalus or at a time point of 2 months. MRI was performed to determine ventricular size. Time to failure and Evans indices were compared using the Wilcoxon rank-sum test. RESULTS: All 4 experimental devices were placed without difficulty into the right lateral ventricle. There was a trend toward longer survival in the experimental group (40 vs 26 days, p = 0.24). Within the IPS group, 3 of the 4 sheep did not experience clinical symptoms of shunt failure and had an average of 37% decrease in Evans index. While 3 of 4 traditional proximal catheters demonstrated debris within the inlet holes, there was no obstructive material found in the IPSs. CONCLUSIONS: An IPS was successfully used to treat hydrocephalus in a sheep model. While statistical significance was not achieved, there were clear benefits to using a stent, including a decreased clog rate and the ability to perform a percutaneous revision. Further testing is needed to ensure efficacy and safety prior to human application.

Meningitis due to intra-abdominal cerebrospinal fluid fistula following gunshot wound successfully treated with antibiotics and blood patch: A case report and literature review.

Background: Penetrating spinal cord injury (PSCI) represents an average of 5.5% of all SCIs among civilians in the United States. The formation of a cerebrospinal fluid (CSF) fistula following PSCI occurs in approximately 9% of cases. Intra-abdominal CSF fistulae are rarely reported. Case Description: We present the case of a 28-year-old Caucasian female who suffered a single gunshot wound to the abdomen with a missile fragment lodged within the left L2 pedicle and transverse process without obvious canal compromise. The patient developed bacterial meningitis 13 days after the initial injury, treated with IV antibiotics. CT myelogram demonstrated intra-abdominal ventral CSF fistula from the left L2-L3 neuroforamen. The patient was successfully treated with fluoroscopy-guided dorsal autologous blood patch graft. Conclusion: This case highlights a rare complication of PSCI successfully managed with the use of a blood patch graft.

Remote surgical education using synthetic models combined with an augmented reality headset.

Objective: The objective was to investigate the use of an augmented reality headset to remotely train clinicians on medical devices using anatomic models. Design: Disease-specific phantoms were developed to train physicians in mpMRI-guided fusion prostate biopsy, brachytherapy, and rectal spacer insertion. Training was remotely demonstrated using 1-way virtual video conferencing format. Participants responded to an educational content survey. A heads-up display with software and augmented reality was used for remote 2-way training with the proctor and student using on their own phantoms. Setting: The virtual video meeting took place during a prostate cancer conference in 2020, while the augmented reality training occurred in 2021. The proctor and student wore a heads-up display containing a projector and webcam where the ultrasound image was displayed onto a see-through optic along with the physician's hands. The heads-up display allowed the proctor to teach by line-of-sight while the student watched and repeated the steps. Participants: Faculty with expertise with the medical devices used in these procedures provided training to urologists unfamiliar with these techniques. Results: Participants responded that the 1-way training on the phantoms was realistic and mimicked human tissue. A total of 70.9% requested more training or training on the phantoms. The remote training platform was successfully beta tested at the 2 locations in transperineal prostate biopsy and rectal spacer insertion. Conclusion: Remote training using augmented reality eliminates the need for travel. For training programs and workshops, this technology may mitigate the risk of infectious exposures, reduce training cost, and increase proctor availability, allowing training from their own institution or clinic.This investigation qualifies for the Accreditation Council for Graduate Medical Education competency in medical knowledge.

Neuromuscular choristoma-associated desmoid-type fibromatosis: Establishing a nerve territory concept.

INTRODUCTION: Desmoid-type fibromatosis (DTF) frequently arises in patients with neuromuscular choristoma (NMC). We hypothesize that NMC-associated DTF occurs in soft tissues innervated by the NMC-affected nerve, and arises from CTNNB1-mutated (myo) fibroblasts within or directly adjacent to the NMC. MATERIALS AND METHODS: A retrospective review of patients treated at our institution was performed for patients with biopsy-confirmed diagnosis of NMC-DTF. Clinical presentation, physical examination, electrodiagnostic findings and radiological features (MR and FDG PET/CT images for each NMC-DTF) and pathologic re-review of available materials were analyzed. A literature review was also performed. RESULTS: Eight patients from our institution met the inclusion criteria. All patients presented with neuropathic symptoms and soft tissue or bone changes in the nerve territory innervated by the NMC. All MR images (N=8 cases) showed the characteristic features of NMC, and also showed direct contact between unifocal (N=5) or multifocal (N=3) DTF(s) and the NMC-affected nerve NMC. FDG PET/CT (N=2 cases) showed diffuse, increased FDG uptake along the entire affected nerve segment, contiguous with the FDG-avid DTF. In all cases, the DTFs arose in the soft tissues of the NMC-affected nerve's territory. No patient developed DTF at any other anatomic site. CONCLUSIONS: These data demonstrate that NMC-DTF arises solely within the NMC-affected nerve territory, and has direct contact with the NMC itself. Based on all these findings and the multifocality of NMC in several cases, we recommend imaging and surveillance of the entire NMC-affected nerve (from spine to distal extremity) to identify clinically-occult DTF in patients with NMC.

Go for the Gold: A "Plane" and Simple Technique for Resecting Benign Peripheral Nerve Sheath Tumors.

BACKGROUND: Intraneural dissection is a useful technique for achieving gross total resection and preserving functional fascicles for peripheral nerve tumors. Finding the correct tissue plane is the critical step for safe successful enucleation. The authors hypothesized that the yellow color of benign nerve tumors can be used to identify surgical planes. OBJECTIVE: To describe a technique to find the correct intraneural dissection plane based on a quantified yellow appearance during resection of benign peripheral nerve sheath tumors. METHODS: Intraoperative photographs were reviewed to determine the percentage of yellow that tumors appeared at different phases of surgery. A technique was developed to quantitatively measure the amount of yellow using Photoshop. Previously published journal articles containing color images of peripheral nerve tumor resections were also analyzed for yellow tumor color. RESULTS: There were 24 patients with suitable images to permit measurement of color for 3 steps of the procedure. The average percentages of yellow for tumor exposure, tumor resection, and removed specimen were 36.5%, 59.1%, and 80.4%, respectively (P < .001). Three publications were found that contained high-quality images of at least 2 phases of the surgery with average yellow content of 47.4% and 84% (P < .01). CONCLUSION: The simple observation that a benign nerve sheath tumor is yellow in color can be used to guide surgical resection and achieve excellent outcomes. Intraneural dissection through the pseudocapsule should be pursued layer by layer until a yellow true capsule is found. By sparing functional nervous tissue within the pseudocapsule, this technique may lead to improved neurological outcomes.

Joint Outcomes Following Surgery for Superior Tibiofibular Joint-Associated Peroneal Intraneural Ganglion Cysts.

BACKGROUND: Intraneural ganglion cysts are joint-connected, with the primary pathology residing in the associated joint. For peroneal intraneural ganglion cysts, the surgical strategy can include resection of the synovial surface of the superior tibiofibular joint (STFJ). However, the rate of instability postoperatively is unclear. OBJECTIVE: To evaluate the rate of STFJ instability, following surgery for peroneal intraneural ganglion cysts. The second goal of the study was to assess the relationship between volume of resection of the STFJ and risk of extraneural recurrence. METHODS: We performed a retrospective analysis of a cohort of patients with peroneal intraneural ganglion cysts. We analyzed clinical factors, including recurrence, and assessed the rate of postoperative STFJ instability. We created 3-dimensional models of the STFJ pre- and postoperatively to compare the volume of resection in recurrent cases and nonrecurrent cases using a case-control design. RESULTS: The total cohort consisted of 65 subjects. No patient had evidence of radiological or clinical instability of the STFJ postoperatively. Extraneural radiological recurrence occurred in 6 (9%) patients. No intraneural recurrences were observed. The average volume of resection for patients with recurrence was 1349 mm3 (SD = 1027 mm3) vs 3018 mm3 (SD = 1433 mm3) in controls that did not have a recurrence (P = .018). CONCLUSION: This study supports performing an aggressive STFJ resection to minimize the risk of extraneural recurrence. Superior tibiofibular joint resection is not associated with postoperative joint instability. A smaller volume resection is correlated with recurrence risk.

Design and Validation of a Cervical Laminectomy Simulator using 3D Printing and Hydrogel Phantoms.

BACKGROUND: The development of technical skills for a cervical laminectomy are traditionally acquired through intraoperative learning and cadaveric courses. These methods provide little objective assessment, involve financial and biohazard considerations, and may not incorporate desired pathology. OBJECTIVE: To develop an inexpensive cervical spine laminectomy simulator capable of measuring operative performance and to assess its face, content, and construct validity. METHODS: A virtual model was generated and 3D printed into negative molds. A multilayered surgical phantom was fabricating by filling molds with hydrogels, plaster, and fiberglass. A pressure transducer measured simulated spinal cord manipulation. Participants completed full-procedural laminectomy simulations. Post-simulation surveys assessed face and content validity. Construct validity was assessed by comparing expert and novice procedural metrics. RESULTS: Twelve surgeons participated. The simulator received median face and content validity ratings of 4/5. Differences between experts and novices were found in mean intrathecal pressure wave count (84 vs 153, P = .023), amplitude (4 vs 12% > 2SD above expert mean, P < .001), area under curve (4 vs 12% > 2SD above expert mean, P < .001), procedure time (35 vs 69 min P = .003), and complication rates (none vs 3 incorrect levels decompressed and 1 dural tear, P = .06). Insignificant differences were found in mean pressure wave slope and blood loss. CONCLUSION: This inexpensive cervical laminectomy simulator received favorable face and content validity ratings, and distinguished novice from expert participants. Further studies are needed to determine this simulator's role in the training and assessment of novice surgeons.

Interfascicular Resection of Benign Peripheral Nerve Sheath Tumors.

BACKGROUND: Interfascicular resection is a surgical technique used to safely treat benign peripheral nerve sheath tumors through careful dissection of functional neural elements off the tumor surface1,2. DESCRIPTION: Proper operative technique is essential to improving symptoms, preserving neurologic function, and minimizing the chance for recurrence. Accurate tumor localization, ideal patient positioning, and placement of a longitudinal incision permit adequate exposure. Prior to tumor resection, normal nerve should be identified proximally and distally and controlled with vessel loops. This allows functional fascicles streaming around the tumor in the pseudocapsule to be visualized during resection. A fascicle-free window is identified on the tumor surface through visual inspection and intraoperative neurophysiology monitoring if desired. The pseudocapsule layers are divided with a sharp instrument until a smooth and shiny true capsule layer is found. This plane should have minimal resistance and is developed circumferentially until the tumor can be enucleated in toto. At the poles of the tumor, a single nonfunctional nerve fascicle that courses into the tumor is typically found. If there is >1 fascicle running into the tumor, further pseudocapsule layers should be undermined to sweep fascicles off the true capsule surface. The entering-exiting fascicle can be tested for function and is cut sharply. The specimen should be sent to pathology for permanent sectioning. The sides of the pseudocapsule are spread in opposite directions to evaluate for residual tumor, and any remaining tumor is removed if it can be done safely. Meticulous hemostasis is achieved, and the surgical site is closed in anatomical layers. ALTERNATIVES: Pain is the most common presenting symptom, and neuroleptic medications should be used in escalating dosage prior to surgical intervention. Nonoperative medical therapy does not typically result in symptom freedom, and patients often opt for resection. For tumors that are suspected of being malignant, an image-guided percutaneous or open biopsy and staging (positron emission tomography and/or computed tomography scans of the chest, abdomen, and pelvis) are recommended prior to treatment planning. For symptomatic benign extremity lesions, surgical resection is the treatment of choice, and adjuvant therapies like radiation and/or chemotherapy are not recommended. For malignant lesions, more aggressive surgery (wide resection or amputation) and preoperative, intraoperative, or postoperative radiation with or without chemotherapy are often utilized. RATIONALE: The treatment approach depends on a variety of presenting features such as onset, progression, symptom severity, tumor size, location, imaging features, presence of a syndrome, and patient age. There is little benefit from the resection of an incidentally found, small, nongrowing lesion. The most common reasons for removal of extremity lesions are a painful mass and/or radiating "nerve" pain. There is a high likelihood of relieving the symptoms and minimizing the risk of recurrence, and a relatively low risk of causing neurologic injury. The procedure provides a definitive diagnosis. For patients with severe pain, progressive weakness, rapid tumor growth, or concerning imaging characteristics, biopsy should be considered to determine malignant potential.

Clinical and Magnetic Resonance Imaging Longitudinal Follow-up of Neuromuscular Choristomas.

INTRODUCTION: The natural history of growth and radiologic progression of neuromuscular choristomas (NMCs) remain unknown. The purpose of this study was to describe the radiologic growth pattern of NMCs and to determine how the pattern of growth relates to clinical progression. METHODS: A retrospective review was performed for patients with a confirmed diagnosis of NMC and at least 2 years of radiologic (magnetic resonance imaging [MRI]) follow-up. Medical records, including physical examinations and radiologic studies, were reviewed in detail. The NMC length and transverse dimensions were compared between serial MRI examinations. RESULTS: Eleven patients with a mean radiologic follow-up time of 5.6 years (range 2-19 years) were identified. Motor deficits occurred in 10 patients (90%), sensory deficits in 5 patients (45%), and neuropathic pain in 4 (36%) patients. Eight patients (73%) presented with manifestations of limb undergrowth, 2 (18%) with congenital hip dysplasia, and 1 with a cavus foot deformity. Progression of motor and sensory deficits was observed in 5 (45%) and 1 (9%) patients, respectively. The maximal length and height of the NMC was significantly (P < 0.05) longer (initial 218 ± 118 mm vs. follow-up 270 ± 135 mm) and larger (20 ± 10 mm vs. 24 ± 14 mm) on the follow-up scan. MRI demonstrated abnormalities that were in continuity along the longitudinal extent of the NMC. CONCLUSIONS: According to this small but relatively long-term follow-up cohort, the growth pattern of this lesion is slow but progressive. We found a longitudinal continuity pattern of growth in all MRI scans, often spanning a great distance.

Extended-release gabapentin for failed back surgery syndrome: results from a randomized double-blind cross-over study.

Persistent pain after lumbar surgery (failed back surgery syndrome [FBSS]) remains a leading indication for chronic analgesia. However, no analgesics have proven efficacious for this condition. Although trials have evaluated gabapentinoids for chronic low back pain, none of these trials focused solely on FBSS. This randomized, double-blind cross-over trial evaluated the efficacy of gabapentin (1800 mg/day) for FBSS. Eligible patients had a diagnosis of FBBS, an average daily pain score of at least 4 of 10, a neuropathic pain component (indicated by the PainDetect), and reported at least half of their pain radiating in their lower extremity. Participants were randomized to 2, 7-week study periods separated by a 10-day washout. The primary outcome measure was a 0 to 10 numeric rating scale (NRS) of average pain. Secondary measures included the McGill Pain Questionnaire and Patient Global Impression of Change. The treatment effect was analyzed using a mixed effect analysis of covariance with fixed effects for treatment, period, and baseline 7-day mean NRS pain score and a random effect for the participant. The outcome of the model was the mean 7-day NRS score for the last 7 days of each treatment period. Thirty-two participants were randomized and included in the primary analysis; 25 completed both study periods. No difference was detected between treatments on any outcome measure, including the primary (least square mean difference in NRS: -0.01 confidence interval: [-0.22 to 0.20]). Given the escalating rate of complex lumbar surgery, future research to develop novel therapies for this prevalent syndrome is needed.

Stimulation Contractility Gradient of a Neuromuscular Choristoma Within the Sciatic Nerve: 2-Dimensional Operative Video.

Neuromuscular choristoma (NMC) is a rare congenital nerve lesion that is classified by the presence of heterotopic muscle fibers intercalated within nerve fascicles.1 The presence of NMC typically causes progressive neuropathy and bony/soft tissue undergrowth, often leading to a shortened atrophic limb.2,3 The typical appearance of NMC on magnetic resonance imaging is an enlarged fusiform nerve that exhibits minimal gadolinium enhancement.4 While there is increasing documentation of pathognomonic clinical and radiographic features for various diffuse fusiform peripheral nerve lesions, nerve biopsy is still occasionally required for some patients given the rarity of these diseases and progressive neuropathic features.The intraoperative appearance of NMC and its unique electrical stimulation properties are quite interesting. Intrafascicular replacement of nerve by skeletal muscle gives the nerve a red beefy color and causes the fascicles to contract with electrical stimulation.5 In this video, we demonstrate the intraoperative appearance and contractile properties of NMC in a 60-yr-old woman with progressive sciatic neuropathy. Histologic and immunohistochemical studies identified a gradient of intralesional mature skeletal muscle within the NMC, with substantially fewer desmin-positive skeletal muscle fibers in the distal aspect. A gradient of contractility with intraoperative stimulation seemed to correlate with this pathology. These findings suggest that the lesional extent of NMC may not be clinically or grossly evident, reflecting a varying distribution of skeletal muscle within the affected nerve.The Mayo Clinic Institutional Review Board Office for Human Research Protection does not require approval for single participant case studies. The subject involved in this study was not identifiable and the general surgical consent form included permission for intraoperative photos and video.

Multimodal Imaging Aids in the Diagnosis of Perineural Spread of Prostate Cancer.

BACKGROUND: The perineural spread of prostate cancer into pelvic peripheral nerves is a rare, but increasingly recognized, entity. This form of metastasis invades the lumbosacral plexus via the splanchnic nerves innervating the prostate. The prevalence of perineural spread is likely underappreciated, and further imaging-based studies are needed to elucidate its true frequency. METHODS: A retrospective review was performed using an institutional radiology database. Medical reports from patients with prostate cancer who had undergone positron emission tomography (PET) imaging were queried for terms suggestive of perineural spread. PET and magnetic resonance imaging (MRI) from the identified patients were blindly reviewed for peripheral nerve involvement by 2 nuclear medicine and 2 musculoskeletal radiologists. RESULTS: A total of 22 patients were identified. After review by the radiologists, 16 patients had positive findings of perineural spread found on PET and 15 had abnormalities found on MRI involving lumbosacral plexus neural elements. All patients with biopsy-proven neoplastic perineural spread (including 1 patient with malignant peripheral nerve sheath tumor) had positive findings on both PET and MRI. All patients with biopsy-proven inflammatory lesions had negative PET and variable MRI findings. CONCLUSIONS: The perineural spread of prostate cancer might be more common than previously thought. The use of multimodal imaging for patients suspected of having perineural spread should be a part of the treatment algorithm. Targeted fascicular biopsy might be indicated for patients with progressive neurological deficit and an unclear diagnosis.

Preoperative Planning Using 3-Dimensional Printing for Complex Paraspinal Schwannoma Resection: 2-Dimensional Operative Video.

Schwannomas are benign peripheral nerve sheath tumors that are typically round, smooth, and straightforward to resect. Occasionally they are more complicated to resect because of their size, location, degree of bony erosion, and vascular or neural compression. These complex lesions frequently require multidisciplinary surgical teams in order to decrease surgical morbidity. Historically, surgical planning consisted of imaging review and verbal communication among team members. 3-dimensional (3D) printing offers a new method for preoperative planning and is becoming more popular in Neurosurgery. This video demonstrates the use of 3D printing for complex paraspinal tumors in the cervical, thoracic, and sacral regions. The Institutional Review Board Office for Human Research Protection does not require approval for single participant case studies, or a case series with multiple participants. The subjects involved in this study were not identifiable and the general surgical consent form included permission for intraoperative photos.

Delayed Myelopathy in Patients with Traumatic Preganglionic Brachial Plexus Avulsion Injuries.

BACKGROUND: Cervical and upper thoracic nerve root avulsions are preganglionic lesions that occur after extreme traction of the brachial plexus. The tearing of the roots from the spinal cord pia leads, not only to immediate and permanent deficits, but also to delayed neurologic complications. Symptomatic myelopathy can present in a late fashion owing to chronic sequelae from the inciting traumatic event. No unifying theory has yet been provided that can explain the causes of delayed spinal cord dysfunction after preganglionic brachial plexus injury. We have proposed a collective mechanism for the development of delayed spinal cord injury. METHODS: An institutional database search and a literature review were performed to find patients who had presented with delayed myelopathy after brachial plexus injury. RESULTS: We found 454 adult patients with traumatic brachial plexus injury and spinal cord injury from 1997 to 2018 in the institutional search. Of these patients, 74 had a delayed presentation of new myelopathic findings on physical examination that had developed ≥6 months after the initial presentation. In these 74 patients with delayed myelopathic symptoms, radiologic findings of spinal cord herniation, syringomyelia, superficial siderosis, or pathologic intradural or extradural cerebrospinal fluid collections from traumatic dural tears were present. Each of these pathologic entities was present in isolation or combination in our patient population. CONCLUSIONS: Four overlapping etiologies appeared to compose the primary foundation for delayed spinal cord dysfunction after brachial plexus injury. We have highlighted this continuum by providing institutional case examples and a review of the reported data.

Recurrent desmoid-type fibromatosis associated with underlying neuromuscular choristoma.

OBJECTIVE: Desmoid-type fibromatosis (DTF) presents a therapeutic dilemma. While lacking metastatic potential, it is a locally aggressive tumor with a strong propensity for occurrence near nerve(s) and recurrence following resection. In this study, the authors introduce the association of an occult neuromuscular choristoma (NMC) identified in patients with DTF. METHODS: After experiencing a case of DTF found to have an occult NMC, the authors performed a retrospective database review of all other cases of biopsy-proven DTF involving the extremities or limb girdles in patients with available MRI data. Two musculoskeletal radiologists with expertise in peripheral nerve imaging reviewed the MRI studies of the eligible cases for evidence of previously unrecognized NMC. RESULTS: The initial case of a patient with an occult sciatic NMC is described. The database review yielded 40 patients with DTF-18 (45%) in the upper limb and 22 (55%) in the lower limb. Two cases (5%) had MRI findings of NMC associated with the DTF, one in the proximal sciatic nerve and the other in the proximal tibial and sural nerves. CONCLUSIONS: The coexistence of NMC may be under-recognized in a subset of patients with extremity DTF. This finding poses implications for DTF treatment and the likelihood of recurrence after resection or biopsy. Further study may reveal crucial links between the pathogenesis of NMC and DTF and offer novel therapeutic strategies.

Analysis of Peripheral Nerve Schwannoma Pseudocapsule.

BACKGROUND: Using proper surgical technique, schwannomas can be resected safely, with a low recurrence rate and high likelihood of improvement in symptomatology. There are multiple peritumoral tissue layers, and finding the correct plane is critical to safe tumor enucleation. The contents of the pseudocapsule tissue surrounding a schwannoma are not well described, and the consequences of resecting or leaving pseudocapsules are unknown. METHODS: An institutional database was searched for any pathology reports that contained both of the words "schwannoma" and "capsule." Charts and histopathologic specimens were reviewed to determine the contents of various tissue layers and determine if there was any correlation between pseudocapsular contents and clinical outcomes. RESULTS: A pseudocapsule was separately sent for pathology in 36 patients during schwannoma resection. Ten pseudocapsule specimens contained microscopic foci of tumor. In a separate 6 patients, there was evidence of nerve fascicles. There were no correlations between the tumor or nerve in the pseudocapsule and postoperative neurologic deficits. After an average follow-up time of 3.1 years, no patients developed a recurrence either clinically or on follow-up imaging (imaging available in 52.7%). Histopathologically, the pseudocapsule was made of dense hypocellular collagen and occasionally contained arteries, veins, and nerve fascicles. CONCLUSIONS: The pseudocapsule surrounding a schwannoma occasionally contained nerve tissue and blood vessels. While a microscopic focus of tumor was often found in this tissue layer, recurrence is exceedingly rare and did not occur in this case series. The risk of undue pseudocapsule dissection likely outweighs any negligible benefit from microscopic cytoreduction.