Neurosurgical Education Using Cadaver-Free Brain Models and Augmented Reality: First Experiences from a Hands-On Simulation Course for Medical Students.

Background and Objectives: Neurosurgery has been underrepresented in the medical school curriculum. Advances in augmented reality and 3D printing have opened the way for early practical training through simulations. We assessed the usability of the UpSurgeOn simulation-based training model and report first experiences from a hands-on neurosurgery course for medical students. Materials and Methods: We organized a two-day microneurosurgery simulation course tailored to medical students. On day one, three neurosurgeons demonstrated anatomical explorations with the help of life-like physical simulators (BrainBox, UpSurgeOn). The surgical field was projected onto large high-definition screens by a robotic-assisted exoscope (RoboticScope, BHS Technologies). On day two, the students were equipped with microsurgical instruments to explore the surgical anatomy of the pterional, temporal and endoscopic retrosigmoid approaches. With the help of the RoboticScope, they simulated five clipping procedures using the Aneurysm BrainBox. All medical students filled out a digital Likert-scale-based questionnaire to evaluate their experiences. Results: Sixteen medical students participated in the course. No medical students had previous experience with UpSurgeOn. All participants agreed that the app helped develop anatomical orientation. They unanimously agreed that this model should be part of residency training. Fourteen out of sixteen students felt that the course solidified their decision to pursue neurosurgery. The same fourteen students rated their learning experience as totally positive, and the remaining two rated it as rather positive. Conclusions: The UpSurgeOn educational app and cadaver-free models were perceived as usable and effective tools for the hands-on neuroanatomy and neurosurgery teaching of medical students. Comparative studies may help measure the long-term benefits of UpSurgeOn-assisted teaching over conventional resources.

Basal cisternostomy for traumatic brain injury: A case report of unexpected good recovery.

In subarachnoid hemorrhage following traumatic brain injury (TBI), the high intracisternal pressure drives the cerebrospinal fluid into the brain parenchyma, causing cerebral edema. Basal cisternostomy involves opening the basal cisterns to atmospheric pressure and draining cerebrospinal fluid in an attempt to reverse the edema. We describe a case of basal cisternostomy combined with decompressive craniectomy. A 35-year-old man with severe TBI following a road vehicle accident presented with acute subdural hematoma, Glasgow coma scale score of 6, fixed pupils and no corneal response. Opening of the basal cisterns and placement of a temporary cisternal drain led to immediate relaxation of the brain. The patient had a Glasgow coma scale score of 15 on postoperative day 6 and was discharged on day 10. We think basal cisternostomy is a feasible and effective procedure that should be considered in the management of TBI.

Synergistic Toll-like Receptor 3/9 Signaling Affects Properties and Impairs Glioma-Promoting Activity of Microglia.

In murine experimental glioma models, TLR3 or TLR9 activation of microglial/macrophages has been shown to impair glioma growth, which could, however, not been verified in recent clinical trials. We therefore tested whether combined TLR3 and TLR9 activation of microglia/macrophages would have a synergistic effect. Indeed, combined TLR3/TLR9 activation augmented the suppression of glioma growth in organotypic brain slices from male mice in a microglia-dependent fashion, and this synergistic suppression depended on interferon ß release and phagocytic tumor clearance. Combined TLR3/TLR9 stimulation also augmented several functional features of microglia, such as the release of proinflammatory factors, motility, and phagocytosis activity. TLR3/TLR9 stimulation combined with CD47 blockade further augmented glioma clearance. Finally, we confirmed that the coactivation of TLR3/TLR9 also augments the impairment of glioma growth in vivo Our results show that combined activation of TLR3/TLR9 in microglia/macrophages results in a more efficient glioma suppression, which may provide a potential strategy for glioma treatment.SIGNIFICANCE STATEMENT Glioma-associated microglia/macrophages (GAMs) are the predominant immune cells in glioma growth and are recently considered as antitumor targets. TLRs are involved in glioma growth, but the TLR3 or TLR9 ligands were not successful in clinical trials in treating glioma. We therefore combined TLR3 and TLR9 activation of GAMs, resulting in a strong synergistic effect of tumor clearance in vitro, ex vivo, and in vivo Mechanisms of this GAM-glioma interaction involve IFNß signaling and increased tumor clearance by GAMs. Interfering with CD47 signaling had an additional impact on tumor clearance. We propose that these signaling pathways could be exploited as anti-glioma targets.

YouTube as a source of patient information on awake craniotomy: Analysis of content quality and user engagement.

•Most YouTube videos on awake craniotomy are of poor educational value.•Intraoperative musical performances by patients are the strongest driver of video popularity.•User engagement of awake craniotomy videos is not linked to their educational quality.•Patients must be aware of the high prevalence of misleading content on YouTube.•Patients may require guidance in choosing the best resources online.

Tumor associated microglia/macrophages utilize GPNMB to promote tumor growth and alter immune cell infiltration in glioma.

Tumor-associated microglia and blood-derived macrophages (TAMs) play a central role in modulating the immune suppressive microenvironment in glioma. Here, we show that GPNMB is predominantly expressed by TAMs in human glioblastoma multiforme and the murine RCAS-PDGFb high grade glioma model. Loss of GPNMB in the in vivo tumor microenvironment results in significantly smaller tumor volumes and generates a pro-inflammatory innate and adaptive immune cell microenvironment. The impact of host-derived GPNMB on tumor growth was confirmed in two distinct murine glioma cell lines in organotypic brain slices from GPNMB-KO and control mice. Using published data bases of human glioma, the elevated levels in TAMs could be confirmed and the GPNMB expression correlated with a poorer survival.

Expanding access to microneurosurgery in low-resource settings: Feasibility of a low-cost exoscope in transforaminal lumbar interbody fusion.

Objectives: Less than a quarter of the world population has access to microneurosurgical care within a range of 2 h. We introduce a simplified exoscopic visualization system for low-resource settings. Materials and Methods: We purchased a 48 megapixels microscope camera with a c-mount lens and a ring light at a total cost of US$ 125. Sixteen patients with lumbar degenerative disk disease were divided into an exoscope group and a microscope group. In each group, we performed four open and four minimally invasive transforaminal lumbar interbody fusions (TLIF). We conducted a questionnaire-based assessment of the user experience. Results: The exoscope achieved similar outcomes with comparable blood loss and operating time as the microscope. It provided similar image quality and magnification. Yet, it lacked stereoscopic perception and the adjustability of the camera position was cumbersome. Most users strongly agreed the exoscope would significantly improve surgical teaching. Over 75% reported that they would recommend the exoscope to colleagues and all users saw its great potential for low-resource environments. Conclusion: Our low-budget exoscope is safe and feasible for TLIF and purchasable at a fraction of the cost of conventional microscopes. It may thus help expand access to neurosurgical care and training worldwide.

Surgical Management of Temporal Lobe Epilepsy Secondary to Epidermoid Cysts: A Case Report With Review of the Literature.

Epidermoid cysts represent roughly 1% of all intracranial tumors. They are frequently located in the cerebellopontine angle but rarely extend to the supratentorial brain. Epilepsy is an extremely uncommon manifestation of this neoplasm. We suggest the surgical management of a 35-year-old male who presented with a six-month history of intractable temporal lobe epilepsy. His seizures were characterized by a focal onset in the form of déjà vu experiences, followed by a secondarily generalized tonic-clonic seizure. Imaging revealed a heterogeneous cystic mass in the right cerebellopontine angle, extending supratentorially causing a mass effect on the mesial temporal region. Gross total resection was achieved through a combined subtemporal-retrosigmoid approach. Histopathology revealed an epidermoid cyst. The patient was entirely seizure-free at the three-month follow-up. Epidermoid cysts may present with epileptic seizures. Seizure freedom can be achieved with surgical management in most cases. The patient's symptoms, imaging findings, and epileptogenic focus must be considered to select the appropriate surgical strategy.

Neurofibromin 1 mutations impair the function of human induced pluripotent stem cell-derived microglia.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition caused by germline mutations in the neurofibromin 1 (NF1) gene. Children with NF1 are prone to the development of multiple nervous system abnormalities, including autism and brain tumors, which could reflect the effect of NF1 mutation on microglia function. Using heterozygous Nf1-mutant mice, we previously demonstrated that impaired purinergic signaling underlies deficits in microglia process extension and phagocytosis in situ. To determine whether these abnormalities are also observed in human microglia in the setting of NF1, we leveraged an engineered isogenic series of human induced pluripotent stem cells to generate human microglia-like (hiMGL) cells heterozygous for three different NF1 gene mutations found in patients with NF1. Whereas all NF1-mutant and isogenic control hiMGL cells expressed classical microglia markers and exhibited similar transcriptomes and cytokine/chemokine release profiles, only NF1-mutant hiMGL cells had defects in P2X receptor activation, phagocytosis and motility. Taken together, these findings indicate that heterozygous NF1 mutations impair a subset of the functional properties of human microglia, which could contribute to the neurological abnormalities seen in children with NF1.

A Low-Cost Three-Dimensional Printed Retractor for Transforaminal Lumbar Interbody Fusion.

The authors developed a low-cost surgical retractor to improve surgeon's comfort and facilitate pedicle screw insertion in transforaminal lumbar interbody fusion surgery. The retractor was designed using three-dimensional (3D) modeling software and produced with the help of a 3D printer. It was attached to a mechanic retractor arm. The retractor was anchored to the transverse process through a concave notch at its tip, visualizing the junction between the transverse process and the superior articular process. The gutter-shaped body of the retractor helped stay within the ideal trajectory during screw insertion. The retractor was tested in 20 patients undergoing transforaminal lumbar interbody fusion with satisfactory results. Future models will be generated suitable for surgery of the cervical and thoracic spine.

Gender Differences in Perceptions and Attitudes of Medical Students Toward Neurosurgery: A German Nationwide Survey.

BACKGROUND: Despite advances in gender equity, the paucity of women neurosurgeons remains. In Germany, women accounted for only 24% of the specialists who completed their neurosurgical training in 2019. We sought to explore the perceptions of medical students in Germany toward a neurosurgical career, focusing on gender-specific differences. METHODS: A digital 26-item questionnaire with a Likert 4-point scale and open-ended questions was distributed to the German medical school student bodies. Data were analyzed to determine statistically significant intragroup variability between women and men. RESULTS: Two hundred ten medical students participated in the survey. Women and men were equally interested in brain pathologies (38% vs. 47%, strongly agreed), whereas interest in neurosurgery was significantly greater in men (12% vs. 26%, strongly agreed). Men were less likely to believe that women neurosurgery residents would face inequality at work. They were also less likely to support a gender quota in neurosurgery. Yet, both women and men were convinced that a rise in the number of women would positively impact the field. No gender dependency was seen in students' strive for success and prestige. Men felt discouraged from pursuing neurosurgery because they feared an unpleasant work environment, whereas women were concerned about neurosurgery not being family-friendly. Regardless of gender, the greatest factor deterring students from neurosurgery was poor work-life balance. CONCLUSIONS: Awareness must be raised concerning gender inequity and discrimination in our specialty. A multifaceted approach is imperative to develop neurosurgery into a profession where gender no longer hinders access to training and success in the field.

Microsurgical Wiltse Paraspinal Approach Using a Low-Budget Exoscope.

Access to microneurosurgical care in low- and middle-income countries remains limited mainly due to a lack of equipment. High purchasing and maintenance costs hinder the use of operating microscopes in low-resource facilities. The authors present an improved version of their previously introduced low-cost exoscope to achieve high magnification and illumination in low-resource environments. The setup included a 48-megapixel two-dimensional digital microscope camera, a wide field C-mount lens, ring light, and a two-link cantilever with a screw terminal. The surgical field was projected to a portable 17.3-inch 2K resolution monitor. Ten patients underwent exoscope-assisted transforaminal lumbar interbody fusion via the Wiltse paraspinal approach. The simple construction allowed a fast and intuitive preoperative setup. The in-plane switching type display provided a clear and bright image regardless of the viewing angle. The two-link arm of the cantilever allowed smooth positioning of the camera, overcoming the cumbersome up and down movements needed to zoom in and out with the previous prototype. Industrial microscope cameras are effective low-budget alternatives to conventional operating microscopes in lumbar microdiscectomy. The improved system is superior compared to the authors' previous prototype with regard to affordability, image quality, and adjustability of position and angle.

Development of a Novel Low-Cost Exoscope to Expand Access to Microneurosurgical Care in Low- and Middle-Income Countries.

BACKGROUND: Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscope system to achieve magnification, illumination, and video recording in low-resource settings. METHODS: We combined an industrial microscope tube, a heavy-duty support arm, a wide-field c-mount digital microscope camera, and a light-emitting diode ring light. All parts were sterilized with ethylene oxide. We performed 13 spinal and 3 cranial surgeries with the help of the low-budget exoscope. RESULTS: The average preoperative setup time was 12.8 minutes. The exoscope provided similar magnification and illumination like a conventional binocular microscope. It allowed operating in a comfortable posture. The field of vision ranged from 30 mm-60 mm. The surgical field was captured by a 16-megapixel two-dimensional camera and projected to a 55-inch high-definition television screen in real time. Image quality was similar to that of a conventional microscope although our exoscope lacked stereoscopic view. Adjusting camera position and angle was time-consuming. Thus, the benefit of the exoscope was most notable in spine surgeries where the camera remained static for most of the time. The total cost of the exoscope was approximately U.S. $ 750. CONCLUSIONS: Our low-budget exoscope offers similar image quality, magnification, and illumination like a conventional binocular microscope. It may thus help expand access to neurosurgical care worldwide. Users may face difficulty adapting to the lack of depth perception in the beginning. Prospective studies are needed to assess its usability and effectiveness compared to the microscope.

Surgical Management of a Pediatric Infratentorial Subdural Empyema as a Complication of Parapharyngeal Abscess.

Infratentorial empyema is a rare medical emergency typically presenting secondary to a middle ear infection. Nonspecific symptoms, limited access to radiological facilities, and imaging artifacts render this pathology prone to misdiagnosis and delayed intervention. An 11-year-old girl presented to the emergency department with a high fever, cervicalgia, and a two-week history of frontal headache. Computed tomography revealed parapharyngeal abscess and polysinusitis. Pus drained from the parapharyngeal abscess showed Staphylococcus capitis and Streptococcus intermedius. Treatment with intravenous meropenem and vancomycin led to initial improvement. On day five post drainage, she suddenly deteriorated with severe headache, vomiting, and posturing. Repeat CT showed posterior fossa empyema with hydrocephalus. The patient underwent an emergency suboccipital craniotomy for empyema evacuation. Pus cultures from the empyema showed identical results as those from the parapharyngeal abscess. Antibiotic therapy was continued for 12 weeks. The patient was discharged on day 21 after craniotomy with no neurological deficits. Early diagnosis and prompt neurosurgical evacuation combined with antibiotic therapy are of utmost importance to reduce morbidity and mortality. Physicians should consider the possibility of subdural empyema in children with parapharyngeal abscess and polysinusitis.

Comparative survey study of the use of a low cost exoscope vs. microscope for anterior cervical discectomy and fusion (ACDF).

Background: Anterior cervical discectomy and fusion (ACDF) is an often performed procedure in spine neurosurgery. These are often performed using an operating microscope (OM) for better illumination and visualization. But its use is limited to the surgeon and the assistant. There is difficulty in maneuvering long surgical instruments due to the limited space available. Exoscope (EX) has been used as an alternative to microscopes and endoscopes. We used an EX in patients undergoing ACDF for cervical spondylotic myelopathy. Methods: A prospective comparative trial was conducted to test the safety and usability of a low-cost EX compared to a conventional surgical binocular OM in ACDF. Twenty-six patients with degenerative cervical myelopathy symptoms were operated by ACDF assisted by the EX and OM between December 2021 and June 2022. The authors collected and compared data on operative time, intraoperative hemorrhage, hospital admission, and complications in the two groups. Results: There were no statistically significant differences between the two groups in mean operative time, hospital stay, or postoperative complications. The average intraoperative blood loss was significantly more in the OM group. There were no surgical complications related to the use of the EX or OM. The comfort level, preoperative setup and intraoperative adjustment of position and angle of the EX were rated higher than the OM group. The image quality, depth perception, and illumination were rated as inferior to that of the OM. The low-cost EX was rated to be superior to that of the OM with regard to education and training purposes. Conclusion: Our study showed that the low-cost EX appears to be a safe and effective alternative for OM-assisted ACDF with great comfort and ergonomics and serves as an essential tool for education and training purposes. However, some limitations of our EX included slightly inferior image quality and illumination when compared with the OM.

Anatomical Variations of the Sciatic Nerve Exit from the Pelvis and Its Relationship with the Piriformis Muscle: A Cadaveric Study.

BACKGROUND: The sciatic nerve (SN) is the widest nerve of the human body that exits the pelvis through the greater sciatic foramen, usually below the piriformis muscle (PM), and descends between the greater trochanter of the femur and ischial tuberosity of the pelvis to the knee. The aim of this paper is to examine and identify the SN variations in relation to the PM, its prevalence, pattern, and course. METHODS: A prospective-descriptive cross-sectional study was carried out to determine the frequency of anatomical variations in the exit of the SN in relation with the PM in 20 anatomical bodies (corpses) of both genders, in equal numbers. RESULTS: The dissection of 40 SNs in corpses of both sexes in equal numbers showed that the SN exited inferior to the PM in 37 lower limbs (92.5%); between the fascicles of the PM and inferior to the PM in two lower limbs (5%); and in one thigh, between the fascicles of the PM and superior to the PM (2.5%). Our study reported that the SN divides in its terminal branches more commonly in the proximal part of the popliteal fossa in 55% of cases, in the gluteal region in 35% of cases, and in the middle third of the thigh in 10% of cases. CONCLUSIONS: Anatomical variations of the SN in relation to the PM are challenging for the diagnostic and therapeutic procedure in many clinical and surgical cases. Rapid recognition of the SN changes makes surgical approaches more accurate and effective. Our study confirmed that the SN exits the pelvis most commonly below the PM, although some anatomical variations may occur.

Surgical Management of Lumbar Hardware Failure Due to Recurrent Postoperative Spondylodiscitis: Case Report.

Spondylodiscitis is a rare bacterial infection of the vertebrae and intervertebral discs that causes inflammation and follows a destructive course. When conservative management fails, surgical management requires immediate debridement of the infective focus, with decompression and stabilization through a ventral approach. The most frequently involved locations are the lumbar spine (58%), thoracic (30%), and cervical (11%) regions. Gram-positive organisms such as Staphylococcus aureus and Streptococcus species are the most commonly isolated organisms (67% and 24%, respectively). Pathophysiologically, infectious spondylodiscitis begins in the anterior portion of the vertebral body, due to its rich vascular supply, and then spreads to the rest of the vertebral body and along the medullary spaces. In this study, we report the management of recurrent lumbar postoperative spondylodiscitis with transforaminal lumbar interbody fusion (TLIF) hardware failure in a 62-year-old female.

Three-Dimensional Plastic Modeling on Bone Frames for Cost-Effective Neuroanatomy Teaching.

Cadaveric models remain an essential part of medical training across all specialties. Due to their scarcity, high costs, and possible health hazards, there is a need for more accessible and affordable alternatives, especially in low-resource settings. We introduce cost-effective and easily replicable three-dimensional (3D) printed models to help democratize access to hands-on neuroanatomy education. Silicone-based glue is applied on the surface of a 3D-printed or cadaveric bone frame. Using plastiline on a 3 mm 3D acrylonitrile butadiene styrene pen, the desired anatomical structure is printed on the bone frame. A heat gun is used to smoothen the plastic edges. The structure can then be painted according to its appearance in the real anatomy. Using this technique, we successfully generated a variety of anatomical models to study the cerebrovascular anatomy, the course of the cranial nerves in relation to the skull base, and extracranial structures including the spine. Procurement and conservation of cadaveric specimens can be cumbersome. Our model may be an affordable and easily replicable approach to bridging the gap in anatomy education between low- and high-resource facilities.

Anatomical Variations of the Median Nerve: A Cadaveric Study.

OBJECTIVES: Variations in the morphological anatomy of the median nerve such as formation, distribution, and communication have been well documented. All these variations should be taken into account when practicing any surgical approach for the treatment of injuries affecting the median nerve. Furthermore, they are of the utmost importance for interpretation of the clinical presentation. METHODS: The objective of this investigation was to determine the anatomical variations in the formation of the median nerve in cadavers at the Forensic Pathology department in Central Clinical Hospital of the Academy of Sciences of the Russian Federation between January 2022 and April 2022. A descriptive, cross-sectional, and prospective information source study was conducted on 42 anatomical bodies (corpses) and 84 brachial plexuses. RESULTS: After analyzing the results obtained in this investigation, we concluded that the median nerve presented variation in its formation in 22.6% of the investigated cases. These variations were more common in males (81.8%) than females (18.2%). The anatomical variation was unilateral in 7.1% and bilateral in 19% of all anatomical bodies examined. CONCLUSIONS: The median nerve presented a great number of variations in its formation in roughly 23% of the anatomical bodies, with male being the predominant gender. Furthermore, the most frequent region of formation was the axillary region (92.9%). For clinicians, it is important to remember these variations during surgical procedures in this area and during brachial plexus block.

Surgical management of a penetrating drill bit injury to the skull base.

BACKGROUND: Low-energy penetrating brain injuries are rarely encountered in neurosurgical practice. Immediate surgical management remains the primary treatment strategy to control potential bleeding and prevents infectious complications. CASE DESCRIPTION: A 28-year-old man presented with an orbital injury with left-sided chemosis, amaurosis, and ophthalmoplegia following an assault. Cranial CT revealed an industrial drill bit causing a penetrating injury to the skull base. The tip of the object reached the petrous apex. CT angiography showed no signs of cerebrovascular damage. The drill bit was visualized through a frontotemporal craniotomy. It was then carefully removed under direct microscopic vision. Postoperative ceftriaxone was administered. The patient was discharged in good condition on postoperative day 6. His vision impairment remained. CONCLUSION: Timely access to neuroimaging diagnostics and microneurosurgical facilities allows for good outcomes in the surgical treatment of low-velocity penetrating brain injuries.