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Objectives Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscopic visualization system to achieve optical magnification, illumination, and video recording in low-resource settings. Materials and Methods We purchased a 48 megapixels industrial microscope camera with a heavy-duty support arm, a wide field c-mount lens, and an LED ring light at a total cost of US$ 125. Sixteen patients with lumbar degenerative disk disease were divided into an exoscope group and a conventional microscope group. In each group we performed four open and four minimally invasive transforaminal lumbar interbody fusion procedures. We further conducted a questionnaire-based assessment of the user experience. Results The overall user experience was positive. The exoscope achieved similar postoperative improvement with comparable blood loss and operating time as the conventional microscope. It provided a similar image quality, magnification and illumination. Yet, the lack of stereoscopic perception and the cumbersome adjustability of the camera position and angle resulted in a shallow learning curve. Most users strongly agreed that the exoscope would significantly improve surgical teaching. Over 75% reported they would recommend the exoscope to colleagues and all users saw its great potential for low-resource environments. Conclusion Our low-budget exoscope is technically non-inferior to the conventional binocular microscope and purchasable at a significantly lower price. It may thus help expand access to neurosurgical care and training worldwide.

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.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.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.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.

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.

PubMed: 32376377 Background: Cerebral cavernomas are vascular malformations characterized by networks of abnormally dilated capillaries. They typically present as nodules with mixed signal intensity and a surrounding hemosiderin rim on magnetic resonance imaging. They may occur as multiple lesions in the autosomal-dominant familial form. In rare cases, cavernomas may form cystic masses, mimicking other pathologies. Case Description: A 35-year-old man presented with recurrent seizures, aphasia, and gait disturbance with onset at age 14 years. He had previously undergone surgical drainage of multiple cysts across the brain with suspected parasitic infection. On magnetic resonance imaging, 22 cystic lesions were seen across the brain. A large cyst was located in the midline cerebellum, compressing the fourth ventricle. Occipital craniotomy and transvermian dissection allowed total resection of the cyst along with its wall. The postoperative course was uneventful and symptoms progressively improved. Histological analysis revealed cavernoma. Three more surgeries were performed for removal of large supratentorial cavernomas. Conclusions: In patients with cystic lesions of the brain, the neurosurgeon should consider the possibility of cavernoma. Total excision along with the cyst wall is crucial for timely diagnosis and therapy. © 2020 Elsevier Inc.

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.

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.

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.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.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.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.

Image-guidance has been the mainstay for most neurosurgical procedures to aid in accuracy and precision. Developments in visualization tools have brought into existence the current microscope and even sophisticated augmented reality devices providing a human–computer interface. The current microscope poses an ergonomic challenge particularly in scenarios like sitting position. Also, the cost associated with the present microscope hinders the accessibility of micro neurosurgery in most low-to-middle-income countries.

BACKGROUND The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH). OBJECTIVE To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots. METHODS Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla. RESULTS The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P

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.

Objectives 1) To provide neurosurgeons and radiologists with a new quantitative and anatomical method to describe spinal meningiomas (SM) consistently. 2) To provide a guide to the surgical approach needed and amount of bony resection required based on the proposed classification. 3) To report the distribution of our 58 cases of SM over different Stages and Subtypes in correlation to the surgical treatment needed for each case. 4) To briefly review the literature on the rare non-conventional surgical corridors to resect SM. Patients and methods We reviewed the literature to report on previously published cohorts and classifications used to describe the location of the tumor inside the spinal canal. We reviewed the cases that were published prior showing non-conventional surgical approaches to resect spinal meningiomas. We proposed our classification system composed of Staging based on maximal cross-sectional surface area of tumor inside canal, Typing based on number of quadrants occupied by tumor and Subtyping based on location of the tumor bulk to spinal cord. Extradural and extra-spinal growth were also covered by our classification. We then applied it retrospectively on our 58 cases. Results 12 articles were published illustrating overlapping terms to describe spinal meningiomas. Another 7 articles were published reporting on 23 cases of anteriorly located spinal meningiomas treated with approaches other than laminectomies/laminoplasties. 4 Types, 9 Subtypes and 4 Stages were described in our Classification System. In our series of 58 patients, no midline anterior type was represented. Therefore, all our cases were treated by laminectomies or laminoplasties (with/without facetectomies) except a case with a paraspinal component where a costotransversectomy was needed. Conclusion Spinal meningiomas can be radiologically described in a precise fashion. Selection of surgical corridor depends mainly on location of tumor bulk inside canal.

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 β 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 IFNβ 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.

PubMed: 32479911 Background: Reports on neurologic manifestations of coronavirus disease 2019 (COVID-19) have attracted broad attention. We present an unusual case of COVID-19?associated encephalitis mimicking a glial tumor. Case Description: A 35-year-old woman presented with headache and seizures. T2 fluid-attenuated inverse recovery imaging showed hyperintensities in the left temporal lobe. Magnetic resonance spectroscopy showed an elevated choline peak. Imaging findings were suggestive of high-grade glioma. Antiepileptic medication failed to achieve seizure control. A left anterior temporal lobectomy was performed. The patient had no postoperative deficits, and her symptoms completely improved. Histologic examination revealed encephalitis. Postoperatively, our patient tested positive for COVID-19. Conclusions: Our case raises awareness of neurologic manifestations of the disease and their potential to mimic glial tumors. For prompt diagnosis and prevention of transmission, clinicians should consider COVID-19 in patients with similar presentation. © 2020 Elsevier Inc. Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

BACKGROUND Glioma-associated microglia and blood-derived macrophages (GAMs) promote tumor growth in experimental mouse glioma models. Using microarray and RNA sequencing, we have previously shown that GAMs upregulate the expression of Glycoprotein NMB/Osteoactivin (GPNMB) when compared to naïve microglia. GPNMB is a type 1 transmembrane glycoprotein expressed intracellularly under healthy conditions. Malignancies such as glioma induce a translocation into the plasma membrane where the extracellular domain can be cleaved and released. METHODS We used qRT-PCR, immunocytochemistry, Western Blot and flow cytometry to determine the cellular localization of GPNMB expression in human and mouse glioblastoma. To test the impact of microenvironment-derived GPNMB on glioma growth, we inoculated GL261 and RCAS-PDGFb glioblastoma cells into organotypic brain slices obtained from wildtype and GPNMB-/- mice. In addition, we quantified glioma growth after injection of RCAS-PDGFb cells into wildtype and GPNMB-/- mice. The soluble extracellular domain of GPNMB was used to stimulate primary human glioblastoma and RCAS-PDGFb cells in vitro. SRB assays were performed to assess proliferation. RESULTS Our data indicate that GAMs are the predominant source of GPNMB in both human and mouse glioblastoma and that the levels of expression in GAMs in the tumor microenvironment is higher than in naïve microglia. In the organotypic brain slice model we found that tumors were significantly smaller in slices derived from GPNMB-/- mice as compared to wildtype. The tumor growth in vivo was nearly completely blocked in the absence of GPNMB. Stimulation of glioma cells with the extracellular domain of GPNMB did not increase proliferation. CONCLUSION Our results show that GPNMB is predominantly expressed in GAMs of human and murine samples. Loss of GPNMB impaired tumor growth ex vivo and glioblastoma progression in vivo. GPNMB seems to play a crucial role in the pro-tumorigenic activity of microglia and blood-derived macrophages in the tumor microenvironment.

Aim To better understand the indications and the impact of antidepressant drugs on the field of neurosurgery in terms of risks and benefits in Turkey. Material and methods A national survey was conducted among neurosurgeons in current practice in Turkey to report routine prescription trends of antidepressant drugs. Gender, neurosurgical subspecialty, city, type of practice, years of experience, antidepressant agent, indications and reasons not to prescribe were ascertained. A brief review of literature was done to show clinical and research evidence. Results A total of 336 neurosurgeons took the survey; 53% of them prescribe antidepressants routinely, whereas 47% of them do not. Of the 72% non-prescribers prefer to refer their patients to a psychiatrist and 22% of them believe that antidepressants have no role in neurosurgery. Vascular and pediatric neurosurgeons as well as neurosurgeons at research hospitals showed the lowest prescription proportion, while general and brain tumor neurosurgeons and ones in private practice showed the highest prescription proportion. Surgeons with more than 20 year-experience had the lowest prescription proportion (43%). Type of practice and years of experience showed a statistically significant association with the prescription of antidepressant drugs across (p=0.002 and p=0.025, respectively). Conclusion Type of practice and years of experience showed a statistically significant association with the proportion of antidepressants' prescribers in Turkish neurosurgery practice at the time of this survey. Non-prescriber neurosurgeons need to recognize the indications, whereas prescribers have to understand the risks of using antidepressants.

Background The cervicothoracic junction is a challenging anatomic transition in spine surgery. It is commonly affected by different types of diseases that may significantly impair stability in this region. The seventh cervical vertebra (C7) is an atypical cervical vertebra with unique anatomic features compared to subaxial cervical spine (C3 to C6). C7 has relatively broader laminae, larger pedicles, smaller lateral masses, and a long nonbifid spinous process. These features allow a variety of surgical methods for performing posterior rigid instrumentation in the form of different types of screws, such as lateral mass screws, pedicle screws, transfacet screws, and intralaminar screws. Many biomechanical studies on cadavers have evaluated and compared different types of implants at C7. Methods We reviewed PubMed/Medline by using specific combinations of keywords to summarize previously published articles that examined C7 posterior rigid instrumentation thoroughly in an experimental fashion on patients or cadavers with additional descriptive radiologic parameters for evaluation of the optimum surgical technique for each type. Results A total of 44 articles were reported, including 22 articles that discussed anatomic considerations (entry points, sagittal and axial trajectories, and features of screws) and another 22 articles that discussed the relevant biomechanical testing at this transitional region if C7 was directly involved in terms of receiving posterior rigid implants. Conclusions C7 can accommodate different types of screws, which can provide additional benefits and risks based on availability of bony purchase, awareness of surgical technique, biomechanics, and anatomic considerations.