Surgical Management of Large (≥3 cm) Trigeminal Schwannomas: Functional Outcomes and Approach Selection in Multicompartmental Schwannomas.

Introduction Trigeminal schwannoma surgery has shown a remarkable improvement in functional recovery and tumor resection. In the era of radiosurgery, these outcomes need to be characterized for tumors which are outside the realm of being treated with radiosurgery. We present a series of trigeminal schwannomas larger than 3 cm, surgical approaches used, and outcomes with an emphasis on functional recovery in a high-volume center with radiosurgery facilities. Method All consecutive cases of trigeminal schwannoma from January 2012 to May 2021 which were more than 3 cm in size and underwent microsurgery were included in this series. The surgical approach, neurological outcomes, and extent of resection were defined objectively with pre/postoperative magnetic resonance imaging. Results A total of 83 such cases (>3 cm) were found, with cranial nerve symptoms (5th most common) being the commonest. Twenty three percent cases had blindness due to secondary optic atrophy and eighteen percent had long tract motor symptoms signifying the tumor burden in our series. Radiological gross total excision was achieved in 75.9% cases. Conclusion Large-volume schwannomas present with cranial nerve involvement and may need extensive skull base approaches. Functional outcomes need to be prioritized and can be achieved albeit with lesser gross resection rates. Hearing and facial preservation in addition to relief of trigeminal symptoms should be the goal of resection with minimal additional morbidity.

Krause approach to pineal tumour with intraoperative oculomotor nerve monitoring.

Background: The supra-cerebellar infratentorial approach to pineal region tumours is versatile and safe corridor to lesions located below the deep veins. Monitoring of the extra-ocular muscle pathways using the evoked compound muscle action potential can lead to safer resections. Technical note: To describe the use of electrooculography and a three handed retractor less method for pineal region tumour surgeries. Material and methods: Intraoperative electrooculography uses recording done from two channels (horizontal and vertical)by inserting disposable subdermal needle electrodes along the periorbital area. The oculomotor nerve is being monitored as it exits the midbrain. Retractor-less three-handed-technique allows for minimal handling of the cerebellum while maximizing the operative corridor. Result: The oculomotor nerve was stimulated post resection and correspondingly led to improved symptoms post-operatively. Discussion and conclusion: We demonstrate a method for the intraoperative monitoring of the continuity of the oculomotor tracts and a three handed retractor-less method of resection of pineal region tumours. The placement of electrodes and area of stimulation need sound knowledge of anatomy of the region. Haemostasis at every step is absolutely essential to be able to visualize in the narrow corridor.

An Illustrative Review of the Pathomechanisms of Symptomatic Developmental Venous Anomalies.

OBJECTIVE: Symptomatic developmental venous anomalies (DVAs) are rare. Here, we illustrate the varied clinicoradiologic profiles of symptomatic DVAs and contemplate the mechanisms that render these (allegedly) benign entities symptomatic supported by a review of literature. METHODS: Institutional databases were searched to identify cases of symptomatic DVAs. Clinical and imaging (angiographic and cross-sectional) data of 9 cases with 11 neurovascular symptoms consequent to inflow/outflow perturbations and mechanical obstruction that manifested because of the strategic topography of underlying DVAs were analyzed. A review of the existing literature on DVAs in agreement with our case series was performed on publications retrieved from the PubMed database. RESULTS: Symptoms secondary to venous hypertension arising from flow-related perturbations were broadly divided into those arising from restricted outflow and increased inflow. Restricted outflow occurred because of collector vein stenosis (n = 2) and collector vein/DVA thrombosis (n = 3), whereas the latter pathomechanism was initiated by arterialized/transitional DVAs (n = 2). A mechanical/obstructive pathomechanism culminating in moderate supratentorial ventriculomegaly was noted in 1 case. One patient was given a diagnosis of hemorrhage associated with a cavernoma. CONCLUSIONS: Awareness and contextualization of potential flow-related perturbations and mechanical insults that render DVAs symptomatic aid in accurate diagnosis, management, and prognostication.

Topical Vancomycin for Prevention of Surgical Site Infection in Cranial Surgeries: Results of an Updated Systematic Review, Meta-Analysis and Meta-Regression.

Background: Surgical site infection (SSI) rates (1-9%) remain high despite the widespread adoption of infection control bundles. Topical vancomycin has emerged as an effective strategy to reduce the rate of SSI in patients undergoing spinal surgery including instrumentation. However, its use and efficiency in cranial neurosurgery is not well established. The aim of this study is to study the efficacy of topical vancomycin in cranial neurosurgery. Methods: A systematic search was performed according to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Data regarding type of surgery, use of implants, the dose of vancomycin, technique of administration in each study, outcomes, rate of SSI, and the interval between surgery and SSI; possible complications related to antibiotic use were collected. Results: A total of 12 studies were included in the qualitative analysis with 3,446 patients. SSI developed in 1.6% of the patients in the vancomycin group as compared to 5.28% in the control group. The pooled risk ratio was 0.24 with 95% CI: 0.12-0.51 (P-value: <0.00001). The difference between the subgroups was significant (P-value: < 0.00001). The number needed to treat (NNT) was 27.2. The studies showed low heterogeneity with an I2 of 24%. Meta-regression analysis showed that the number of patients in a study, duration of follow-up, and year of publication did not contribute significantly to effect size. Conclusion: The limited systemic absorption of vancomycin and broad-spectrum led to its widespread applicability in the prevention of SSI in all types of cranial neurosurgery. Cases with implantable pulse generators, cranioplasty, and cerebrospinal fluid (CSF) diversion procedures have all demonstrated their unequivocal effectiveness.

Minimally invasive resection of cervical schwannoma (C1-C2 level) using tubular retractors.

Cervical schwannoma excision usually involves laminectomy and violation of the facet joints that necessitates the need for fusion with consequent loss of cervical mobility. The authors present the first video demonstration of an excision of the cervical schwannoma at the C1-2 level using minimally invasive spine tubular retractors, which allows direct access to the lesion and prevents the need for any bony removal. It also preserves the paraspinal muscles, which are important for spinal stability, especially at the C2 level. Special attention is given to incision planning and preoperative image analysis for preventing injury to critical neurovascular structures at this level.

An assessment of the variation in the practice of lumbar discectomy and its role in axial back pain.

Background: Lumbar discectomy is performed for symptomatic lumbar disc herniation and is one of the most widely performed spinal surgical procedures worldwide in a variety of ways. This survey aimed at providing an overview/perspective of different practice patterns and the impact of lumbar discectomy on axial back pain with or without sciatica. Methods: An online survey was performed using the application "Google Forms." The link to the questionnaire was distributed to neurosurgeons through personal E-mail and social media platforms. Results: We received 333 responses. The largest percentage of responses across five continents was from Asia (66.97%, n = 223). The mean age of the respondents was 40.08 ± 10.5 years. A total of 66 respondents (20%) had a spine practice of 7%-90%, and 28 respondents had a spine practice of 90%-100% (8.4%). The number of respondents who practiced microscopic discectomy using a tubular retractor (n = 143 respondents, 42.9%) was nearly equal to the number of respondents who practiced open discectomy (n = 142 respondents, 42.6%). An almost equal proportion of respondents believed discectomy does not help in relieving axial back pain. Only 20.4% (n = 68) of respondents recommend bed rest for a longer duration postoperatively. Conclusions: Our survey revealed that only 22.2% of spine surgeons recommended discectomy in patients with radiological disc herniation with axial back pain alone and preferred a minimally invasive method of discectomy. Almost half of them believed discectomy to be ineffective for axial low back pain and only a few recommended prolonged bed rest postoperatively.

Self-Citation Rates Among Neurosurgery Journals and Authors: Unethical or Misunderstood?

OBJECTIVE: The role of self-citation has not been discussed in the neurosurgery literature, although citations, citation indices, and impact of research may enhance funding opportunities, academic positions, fellowship opportunities, employment, and professional identity development. We sought to assess the magnitude and role of self-citation in academic neurosurgery. METHODS: We performed a retrospective analysis of the citation and self-citation rates of articles published in 2001-2020 in 7 major neurosurgery journals: Acta Neurochirurgica, Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, Neurosurgery, Neurosurgical Review, and World Neurosurgery. RESULTS: The total number of citations was highest for Journal of Neurosurgery and lowest for Neurosurgical Review. Journal of Neurosurgery: Spine had the highest average number of citations per article, followed closely by Journal of Neurosurgery. The self-citation rate increased for all journals over the time period 2001-2020. The highest number of self-citations per article during 2016-2020 was seen in Journal of Neurosurgery: Pediatrics and World Neurosurgery. Neurosurgical Review had the lowest number of self-citations per article. CONCLUSIONS: Academic neurosurgeons must understand the ecosystem around self-citation. In our study, we found overall low levels of self-citations in neurosurgery journals with a few outliers. We have, however, noticed an increasing trend in self-citation rates. Self-citation rates should be considered while evaluating the impact of an author and research productivity. Contrary to popular belief, self-citation is not always unethical and must be understood within its circumstances.

Torsion of giant occipital encephalocoele in a 2-day-old infant: emergent surgery and outcome.

INTRODUCTION: Torsion of a giant occipital encephalocele leading to necrosis is an extremely rare complication found in neonates with only two such cases reported in literature previously. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocele showing progressive necrosis during the first day of his life. CASE REPORT: A new-born baby, delivered vaginally, with no antenatal imaging was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the first day of his life, the sac started becoming ulcerated accompanied with a rapid colour change in the skin, gradually turning darker and then black. The pedicle of the encephalocele was twisted with progressive necrosis of the encephalocele. MRI showed a giant encephalocele with single vein draining into the torcula and dysplastic occipital lobe herniating into the defect. The neonate was taken up for urgent excision and repair of the encephalocele. The encephalocele was excised 'in-total' with 'figure-of-8' repair of the meninges. One year after the operation, she appears to be well-developed without any neurological problems. CONCLUSION: Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocele may be another predisposing factor. In view of the risk of meningitis and rupture, immediate surgery with repair with minimal blood loss is indicated.

History and Evolution of Radiosurgery in India: Strength to Strength.

Stereotactic radiosurgery (SRS) has been well received by the neurosurgical community since its introduction in India. Knowledgeable radiosurgeons and visionary neurosurgeons have contributed to its success. At present, we have five functional and busy gamma knife centers, one proton radiosurgery center, and seven CyberKnife centers in India. However, there is a need for more such centers and formal training facilities, especially in the unorganized private sector. Radiosurgery has expanded its horizon from its initial indications of vascular and benign disorders to functional ailments and metastasis. Here, we take a look at the seminal points in its development in India along with the centers of excellence that contributed to the same. While we have tried to cover all the facets of its development, it is natural to miss some undocumented events not available in public domain. Nonetheless, the future of radiosurgery seems promising in India with the assurance of minimally invasive, safe, and effective treatment delivery.

Anesthetic Concerns during Gamma-Knife Radiosurgery.

Background: Gamma-knife radiosurgery (GKRS) has emerged as one of the mainstream modalities in the treatment of many neurosurgical conditions. The indications for Gamma knife are ever-increasing and presently more than 1.2 million patients have been treated with Gamma knife worldwide. Objective: A neurosurgeon usually leads the team of radiation oncologists, medical physicists, nursing staff, and radiation technologists. Seldom, help from anesthetist colleagues is required in managing patients, who either require sedation or anesthesia. Methods: In this article, we try to elucidate anesthetic considerations in Gamma-knife treatment for different age groups. With the collective experience of authors involved in Gamma-Knife Radiosurgery of 2526 patients in 11 years with a frame-based technique, authors have tried to elucidate an effective and operational management strategy. Results: For pediatric patient (n = 76) population and mentally challenged adult patients (n = 12), GKRS merits special attention given its noninvasive nature but problems of frame fixation, imaging, and claustrophobia during radiation delivery become an issue. Even among adults, many patients have anxiety, fear, or claustrophobia, who require medications either to sedate or anesthetize during the procedure. Conclusion: A major goal in treatment would be a painless frame fixation, avoid inadvertent movement during dose delivery, and a fully wake, painless, and smooth course after frame removal. The role of anesthesia is to ensure patient immobilization during image acquisition and radiation delivery while ensuring an awake, neurologically accessible patient at the end of the radiosurgery.

Gamma Knife Radiosurgery in Partially Embolised Arteriovenous Malformations: Management Dilemmas and Outcomes.

Introduction: The role of Gamma Knife radiosurgery (GKRS) in partially embolized arteriovenous malformations (AVMs) has always remained a subject of debate. The aim of this study was to evaluate the efficacy of GKRS in partially embolized AVMs and to analyze factor that influence its obliteration. Methods: This was a retrospective study from a single institute performed over a period of 12 years (2005-2017). It included all patients who underwent GKRS for partially embolized AVMs. Demographic characteristics, treatment profiles, and clinical and radiological data were obtained during treatment and follow-up. Obliteration rates and factors affecting the same were sought and analyzed. Results: A total of 46 patients with a mean age of 30 years (range: 9-60 years) were included in the study. Follow-up imaging was available for 35 patients either by digital subtraction angiography (DSA) or magnetic resonance imaging (MRI). We found complete AVM obliteration in 21 patients (60%): one had near total obliteration (>90% obliteration), 12 had subtotal obliteration (<90%), and one had no change in the volume following GKRS. Following embolization alone, an average of 67% of the AVM volume was obliterated which resulted in an average 79% final obliteration rate after Gamma Knife radiosurgery. Mean duration to complete obliteration was found to be 3.45 years (range: 1-10 years). There was a significant difference (P = 0.04) in the mean interval between embolization and GKRS among cases with complete obliteration (12 months) and those with incomplete obliteration (36 months). There was no significant difference (P = 0.49) in the average obliteration rate between the ARUBA-eligible unruptured AVMs (79.22%) and ruptured AVMs (79.04%). Bleeding after GKRS during the latency period had a negative impact on obliteration (P = 0.05). Other factors like age, sex, Spetzler-Martin (SM)-grade, Pollock Flickinger score (PF-score), nidus volume, radiation dose, or presentation before embolization had no significant influence on obliteration. Three patients had permanent neurological deficits after embolization and none after radiosurgery. Six out of nine patients (66%) presenting with seizures were seizure-free after the treatment. Hemorrhage was noted in three patients following combined treatment and were managed non-surgically. Conclusion: Obliteration rates in partially embolized AVM after Gamma Knife are inferior when compared to Gamma Knife alone; moreover with volume staging and/or dose staging being increasingly plausible due to the new ICON machine, embolization may be completely replaced. However we have shown that in complicated and carefully chosen AVMs, embolization followed by GKRS is a valid modality of management. This study represents a real-world picture of individualized AVM treatment depending on patient choices and resources available.

The Legal Void Outside Brain Death in India: The Legislative Need of 'DNR' in Brain Death.

Objective: The legal definitions of brain death are tantamount for legal dogmas and sometimes criminal intimidation of the treating doctors. The tests for brain death are only applicable to patients planned for organ transplantation. We intend to discuss the necessity of the "Do Not Resuscitate (DNR)" legislature in cases of brain death patients and applicability of tests for brain death irrespective of the intention for organ donation. Methods: A comprehensive review of the literature was performed till May 31, 2020 from the MEDLINE (1966 to July 2019) and Web of Science (1900 to July 2019). Search criteria included all publications with the MESH terms: "Brain Death/legislation and jurisprudence"[Mesh] OR "Brain Death/organization and administration"[Mesh] AND "India" [Mesh]. We also discuss the different opinions and implications of brain death versus brain stem death in India with the senior author (KG) who was responsible for South Asia's first multi-organ transplant after certifying brain death. Additionally, a hypothetical scenario of a DNR case is discussed in the current legal paradigm of India. Results: The systematic search yielded only five articles reporting a series of brain stem death cases with an acceptance rate of organ transplant among brain stem deaths being 34.8%. The most common solid organs transplanted were the kidney (73%) and liver (21%). A hypothetical scenario of a DNR and possible legal implications of the same under the current 'Transplantation of Human Organs Act (THOA)' of India remains unclear. A comparison of brain death laws in most Asian countries shows a similar pattern regarding the declaration of brain death and the lack of knowledge or legislature regarding DNR cases. Conclusion: After the determination of brain death, discontinuation of organ support requires the consent of the family. The lack of education and the lack of awareness have been major impediments in this medico-legal battle. There is also an urgent need to make laws for cases that do not qualify for brain death. This would help in not only realistic realization but also better triage of the health care resources while legally safeguarding the medical fraternity.

Factors Affecting the Choice of Neurosurgery Subspecialty: A Geographic and Gender-Wise Analysis.

OBJECTIVE: To understand the factors that affect decision-making when choosing a specific subspecialty while exploring gender and geographic variables. METHODS: A cross-sectional, 13-item, nonrandomized online survey was created and shared over various social media platforms of the Neurosurgery Cocktail. Data were collected between January and April 2022. The survey focused on the amount of exposure to subspecialties during training, along with factors affecting the decision in choosing a specific subspecialty. RESULTS: A total of 207 respondents, predominantly from Asian and European countries, with an 83.6% dominance of male respondents, completed the survey. The most common subspecialties with maximum exposure were neurosurgical oncology, spine, and neurocritical care and trauma, whereas peripheral nerve surgery and stereotactic and functional neurosurgery were the least exposed. In total, 70% of the respondents had no training or degree in a subspecialty, which was the greatest in Asian and African countries (P = 0.0205). Respondents found the prestige and lifestyle of a skull base neurosurgeon very attractive (P = 0.027, 0.034 respectively), whereas the lifestyle and salary of spine neurosurgeons made it a popular subspecialty (P < 0.001, 0.008, respectively). Personal interest in neurosurgical oncology established its popularity among the respondents (P = 0.028). CONCLUSIONS: Stereotactic and functional neurosurgery and peripheral nerve surgery are the emerging subspecialties and hence their exposure and access are highly limited to the developed world whereas spine and neurosurgical oncology branches had a homogenous geographic presence. Pediatric neurosurgery had the most female representation, thereby necessitating the need to uplift women in other subspecialties.

An update of predictors of cerebral infarction after aneurysmal subarachnoid hemorrhage: systematic review and meta-analysis.

INTRODUCTION: Evidence about predictors of poor outcomes such as cerebral infarction (CI) after aneurysmal subarachnoid hemorrhage (aSAH) has not been fully elucidated. EVIDENCE ACQUISITION: We performed a systematic review and meta-analysis on studies with adults with aSAH considering RCT and non-RCT, prospective, and retrospective cohort studies describing clinical, imaging as well as angiographic studies in patients with aSAH. EVIDENCE SYNTHESIS: After reviewing the complete text, 11 studies were considered eligible, out of which four were ruled out. Degree of clinical severity was the most predictive factor with a higher degree at the presentation on different severity scales being associated with a statistically significant increasing the risk of suffering a CI following aSAH (OR 2.49 [95% CI 1.38-4.49] P=0.0003). Aneurysm size increased the risk of CI (OR 1.49 [95% CI 1.20-1.85] P=0.0003; I2=4%). In six studies analyzed, it was found that an important factor for the subsequent development of CI is vasospasm (OR 7.62 [2.19, 26.54], P=0.0001). CONCLUSIONS: The development of vasospasm is a risk factor for CI development after aSAH. In our review, three factors were associated with an increased risk of CI: clinical severity at presentation, vasospasm, and aneurysm size. The major limitation of this meta-analysis is that included studies were conducted retrospectively or were post hoc analyses of a prospective trial.