Optimization of Self-Double Emulsifying Drug Delivery System Using Design of Experiments for Enhanced Oral Bioavailability of Gentamicin: In-vitro, Ex-vivo and In-vivo Studies.

Water-in-oil-in-water (w/o/w) double emulsions have shown excellent capability in augmenting the enteral bioavailability of BCS class III drugs, besides being effective controlled-release formulations. However, the problem of thermodynamic instability has restrained their industrial applicability. The self-double emulsifying drug delivery system (SDEDDS) is one of several approaches used to improve the stability of double emulsions. SDEDDS is a mixture of primary emulsion and secondary surfactant that can spontaneously emulsify into double emulsions in an external aqueous environment with mild agitation. Here, we prepared SDEDDS of gentamicin sulfate by response surface methodology. Selected optimized formulations (ODS1 and ODS2) were evaluated for zeta potential (Y1), optical clarity (Y2), release at 420 min (Y3), emulsion stability index (Y4) and self-emulsification time (Y5). For ODS1, Y1=-35.45 (±1.06)mV, Y2=53.19 (±0.35)%, Y3=75.79 (±0.60)%, Y4=93.97(±0.15)% and Y5=0.631 (±0.014)min, whereas for ODS2, Y1=-35.70 (±0.56)mV, Y2=48.09 (±0.64)%, Y3=76.61 (±0.99)%, Y4=93.00(±0.94)% and Y5=0.687(±0.02)min. Furthermore, ex-vivo studies on intestinal permeability revealed that SDEDDS improved membrane permeability compared to drug solution. Histopathology investigations revealed that SDEDDS promoted permeation without causing significant local membrane distortion. In addition, in-vivo studies revealed a 2.84 -fold increase in AUC0-∞ of optimized SDEDD compared to pure drug oral solution.

Outcome of Patients on Prolonged V-V ECMO at a Tertiary Care Center in India.

Introduction: Extracorporeal membrane oxygenation (ECMO) is a life-support system that provides cardiopulmonary support. With recent advances, the duration of ECMO has increased but data on the outcomes of prolonged V-V ECMO are limited and inconsistent. Materials and methods: It is a retrospective observational study done at a tertiary care center in Kolkata to study the outcome of patients receiving prolonged V-V ECMO defined as >14 days. Observation: A total of 22 patients received prolonged ECMO support. Fifteen patients (68.2%) had severe coronavirus disease-2019 (COVID-19). The mean duration of invasive mechanical ventilation (IMV) before ECMO was 5 days. Baseline PaO2/FiO2 (p/f) ratio was 82 and Murray score was 3.5. The mean duration of ECMO support was 27.18 days (SD: 11.59). Five patients (22.7%) had minor bleeding and one patient had oxygenator failure. Survival at hospital discharge was seven patients (31.8%). Conclusion: Duration of ECMO support alone should not represent a basis for decision making to decide futility or continuation of ECMO support. Prolonged ECMO in acute respiratory distress syndrome (ARDS) has minor complications and can lead to recovery in almost one-third of the patients. How to cite this article: Goel K, Chakraborty A, Goel A. Outcome of Patients on Prolonged V-V ECMO at a Tertiary Care Center in India. Indian J Crit Care Med 2023;27(11):790-794.

Extracorporeal Membrane Oxygenation for Severe COVID-19 in Indian Scenario: A Single Center Retrospective Study.

Background: Initial reports from Wuhan (China) suggested poor outcomes for severe COVID-19 patients treated with Extracorporeal Membrane Oxygenation (ECMO). Extracorporeal Life Support Organization (ELSO) interim 2019 guidelines also recommended using ECMO only when all conventional therapies are exhausted. However, later studies showed that delayed ECMO initiation may lead to longer ECMO runs, offsetting any benefit from resource conservation by delaying the initiation. Hence, this study was intended to analyze the sociodemographic characteristics, type of ECMO, and complications of its outcome in the Indian scenario. Materials and methods: Demographic and patient clinical outcome data of all the patients of severe ARDS due to COVID-19 being treated with ECMO from 1st June 2020 to 31st May 2021 at Medica Super-specialty Hospital (Kolkata, India), were retrospectively compiled and analyzed. Results: Total number of patients treated was 79 with 10% female representation. The mean age was 43 ± 3.2 years and the mean body mass index 37 ± 4.3. Fifty percent of the patient survived. The mean duration of the ECMO run was 17 ± 5.2 days. Sepsis (65%) was the commonest complication observed followed by acute kidney injury (39%). Conclusion: This study provides significant insight into the outcomes of patients of COVID-19 treated by ECMO in the Indian scenario. Mortality rates of COVID-19 patients on ECMO were comparable to the non-COVID-19 patients, although the ECMO run time was relatively longer. Our study concluded that ECMO should be considered as a treatment option in appropriate COVID-19 cases. However, if the capacity diminishes in a pandemic situation, ECMO consideration should be based on more stringent criteria. How to cite this article: Sulakshana S, Chatterjee D, Chakraborty A. Extracorporeal Membrane Oxygenation for Severe COVID-19 in Indian Scenario: A Single Center Retrospective Study. Indian J Crit Care Med 2023;27(6):381-385.

Current Applications of Ablative Therapies for Trigeminal Neuralgia.

Trigeminal neuralgia (TN) is a syndrome consisting of episodic neuropathic facial pain. Although the precise symptoms vary across individuals, TN is typically described as lancinating electrical shocks triggered by sensory stimuli (light touch, talking, eating, and brushing teeth) that improve with antiepileptic medication (especially carbamazepine), remit spontaneously for weeks to months (pain-free intervals), and do not involve any changes in baseline sensation. The etiology of TN has not been definitively established, but many cases are associated with compression of the trigeminal nerve by a blood vessel at the trigeminal root entry zone adjacent to the brainstem. Patients who do not respond to medical management and who are not candidates for microvascular decompression often benefit from focal therapeutic injury to the trigeminal nerve at some point along its course. Many lesions have been described, including peripheral neurectomies that target distal branches of the trigeminal nerve, rhizotomies of the Gasserian ganglion of the nerve within Meckel's cave, radiosurgery of the trigeminal nerve at its root entry zone, partial sensory rhizotomy at the root entry zone, tractotomy of the spinal nucleus of the trigeminal nerve, and DREZotomy of the trigeminal nucleus caudalis, Though the latter two interventions are seldom done for TN and more commonly performed for trigeminal neuropathic pain. This article reviews the relevant anatomy and lesioning procedures for the treatment of trigeminal neuralgia.

Discontinuation of ECMO-a review with a note on Indian scenario.

Extracorporeal membrane oxygenation (ECMO) has strikingly progressed over the last 20 years in the management of adult and pediatric severe respiratory and cardiac dysfunctions refractory to conventional management. In this review, we will discuss the weaning strategies of veno-venous and veno-arterial ECMO including the bridge to recovery and bridge to transplant along with post-ECMO care. We will also discuss the futility and the management of bridge to nowhere from Indian perspectives.

Occipital condyle screw fixation after posterior decompression for Chiari malformation: Technical report and application.

BACKGROUND: Surgical techniques for stabilization of the occipital cervical junction have traditionally consisted of screw-based techniques applied in conjunction with occipital plating and rods connected to subaxial instrumentation in the form of pars, pedicle, or lateral mass screws. In patients with type 1 Chiari malformation (CM-1) and evidence of occipital cervical junction instability who have undergone posterior decompression, the occipital condyle (OC) represents a potential alternative cranial fixation point. To date, this technique has only been described in pediatric case reports and morphometric cadaver studies. METHODS: Patients underwent posterior fossa decompression for treatment of CM. Subsequently, patients received occipital cervical stabilization using OC screws. RESULTS: Patients were successfully treated with no post-operative morbidity. Patient 2 was found to have pseudoarthrosis and underwent revision. Both patients continue to do well at 1-year follow-up. CONCLUSION: Placement of the OC screw offers advantages over traditional plate-based occipital fixation in that bone removal for suboccipital decompression is not compromised by the need for hardware placement, screws are hidden underneath ample soft tissue in patients with thin skin which prevents erosion, and the OC consists of primarily cortical bone which provides for robust tricortical fixation. These cases demonstrate the novel application of the OC screw fixation technique to the treatment of occipital cervical junction instability in adult patients undergoing simultaneous posterior fossa decompression.

Optimal timing of post-operative enoxaparin after neurosurgery: A single institution experience.

PURPOSE: Venous thromboembolism (VTE) is a well-known problem in patients with intracranial tumors, especially high-grade gliomas. Optimal management of VTE complications is critical given that the development of deep vein thrombosis (DVT) and/or pulmonary embolism can exacerbate medical comorbidities and increase mortality. However, little is known about the optimum time to initiate post-operative anticoagulant prophylaxis. Therefore, there is a keen interest amongst neurosurgeons to develop evidence-based protocols to prevent VTE in post-operative brain tumor patients. METHODS: We retrospectively identified adult patients who underwent elective craniotomy for intracranial tumor resection between 2012 and 2017. Patients were categorized according to the time at which they began receiving prophylactic enoxaparin in the immediate post-operative period, within one day (POD 1), two days (POD 2), three days (POD 3), five days (POD 5), or seven days (POD 7). RESULTS: A total of 1087 patients had a craniotomy for intracranial tumor resection between 2012 and 2017. Multivariate binomial logistic regression analysis demonstrated that initiation of prophylactic enoxaparin within 72 h of surgery was protective against the likelihood of developing a lower extremity DVT (OR: 0.32; CI: 0.10-0.95; p = 0.049) while controlling for possible risk factors for DVTs identified on univariate analysis. Furthermore, complication rates between the anticoagulation and non-anticoagulation groups were not statistically significant. CONCLUSION: Initiating anticoagulant prophylaxis with subcutaneous enoxaparin sodium 40 mg once per day within 72 h of surgery can be done safely while reducing the risk of developing lower extremity DVT.

Dynamic Occlusion of Distal Ventriculoperitoneal Shunt Catheter after Infusion Port Placement: A New Shunt Malfunction.

Shunt failure requiring reintervention remains a common complication of hydrocephalus treatment. Here, we report a novel cause of mechanical shunt obstruction in an adult patient: position-dependent intermittent occlusion via an infusion port catheter. A 51-year-old woman with a grade II oligodendroglioma presented in a delayed fashion following surgery with a pseudomeningocele. She underwent ventriculoperitoneal shunt placement due to communicating hydrocephalus, resolving her pseudomeningocele. Shortly thereafter, she underwent placement of a subclavian infusion port at an outside institution. Her pseudomeningocele returned. Imaging demonstrated close proximity of her port catheter to the shunt catheter overlying the clavicle. Her shunt was tapped demonstrating a patent ventricular catheter with normal pressure. She underwent shunt exploration after her pseudomeningocele did not respond to valve adjustment. Intraoperative manometry demonstrated head position-dependent distal catheter obstruction. Repeat manometry following distal catheter revision demonstrated normal runoff independent of position. Her pseudomeningocele was resolved on follow-up. To our knowledge, this is the only reported case of intermittent, position-dependent distal catheter obstruction. Shunted patients with concern for malfunction following subclavian infusion port placement should be evaluated for possible dynamic obstruction of their distal catheter when the two catheters are in close proximity along the clavicle.

Implementation of new ECMO centers during the COVID-19 pandemic: experience and results from the Middle East and India.

PURPOSE: Extracorporeal membrane oxygenation (ECMO) use for severe coronavirus disease 2019 (COVID-19) patients has increased during the course of the pandemic. As uncertainty existed regarding patient's outcomes, early guidelines recommended against establishing new ECMO centers. We aimed to explore the epidemiology and outcomes of ECMO for COVID-19 related cardiopulmonary failure in five countries in the Middle East and India and to evaluate the results of ECMO in 5 new centers. METHODS: This is a retrospective, multicenter international, observational study conducted in 19 ECMO centers in five countries in the Middle East and India from March 1, 2020, to September 30, 2020. We included patients with COVID-19 who received ECMO for refractory hypoxemia and severe respiratory acidosis with or without circulatory failure. Data collection included demographic data, ECMO-related specific data, pre-ECMO patient condition, 24 h post-ECMO initiation data, and outcome. The primary outcome was survival to home discharge. Secondary outcomes included mortality during ECMO, survival to decannulation, and outcomes stratified by center type. RESULTS: Three hundred and seven COVID-19 patients received ECMO support during the study period, of whom 78 (25%) were treated in the new ECMO centers. The median age was 45 years (interquartile range IQR 37-52), and 81% were men. New center patients were younger, were less frequently male, had received higher PEEP, more frequently inotropes and prone positioning before ECMO and were less frequently retrieved from a peripheral center on ECMO. Survival to home discharge was 45%. In patients treated in new and established centers, survival was 55 and 41% (p = 0.03), respectively. Multivariable analysis retained only a SOFA score < 12 at ECMO initiation as associated with survival (odds ratio, OR 1.93 (95% CI 1.05-3.58), p = 0.034), but not treatment in a new center (OR 1.65 (95% CI 0.75-3.67)). CONCLUSIONS: During pandemics, ECMO may provide favorable outcomes in highly selected patients as resources allow. Newly formed ECMO centers with appropriate supervision of regional experts may have satisfactory results.

The Unique Fiber Anatomy of Middle Temporal Gyrus Default Mode Connectivity.

BACKGROUND: The middle temporal gyrus (MTG) is understood to play a role in language-related tasks such as lexical comprehension and semantic cognition. However, a more specific understanding of its key white matter connections could promote the preservation of these functions during neurosurgery. OBJECTIVE: To provide a detailed description of the underlying white matter tracts associated with the MTG to improve semantic preservation during neurosurgery. METHODS: Tractography was performed using diffusion imaging obtained from 10 healthy adults from the Human Connectome Project. All tracts were mapped between cerebral hemispheres with a subsequent laterality index calculated based on resultant tract volumes. Ten postmortem dissections were performed for ex vivo validation of the tractography based on qualitative visual agreement. RESULTS: We identified 2 major white matter bundles leaving the MTG: the inferior longitudinal fasciculus and superior longitudinal fasciculus. In addition to long association fibers, a unique linear sequence of U-shaped fibers was identified, possibly representing a form of visual semantic transfer down the temporal lobe. CONCLUSION: We elucidate the underlying fiber-bundle anatomy of the MTG, an area highly involved in the brain's language network. Improved understanding of the unique, underlying white matter connections in and around this area may augment our overall understanding of language processing as well as the involvement of higher order cerebral networks like the default mode network in these functions.

Anatomy and White Matter Connections of the Middle Frontal Gyrus.

BACKGROUND: The middle frontal gyrus (MFG) is involved in attention, working memory, and language-related processing. A detailed understanding of the subcortical white matter tracts connected within the MFG can facilitate improved navigation of white matter lesions in and around this gyrus and explain the postoperative morbidity after surgery. We aimed to characterize the fiber tracts within the MFG according to their connection to neuroanatomic structures through the use of diffusion spectrum imaging-based fiber tractography and validate the findings by gross anatomic dissection for qualitative visual agreement. METHODS: Tractography analysis was completed using diffusion imaging data from 10 healthy, adult subjects enrolled in the Human Connectome Project. We assessed the MFG as a whole component according to its fiber connectivity with other neural regions. Mapping was completed on all tracts within both hemispheres, with the resultant tract volumes used to calculate a lateralization index. A modified Klingler technique was used on 10 postmortem dissections to demonstrate the location and orientation of the major tracts. RESULTS: Two major connections of the MFG were identified: the superior longitudinal fasciculus, which connects the MFG to parts of the inferior parietal lobule, posterior temporal lobe, and lateral occipital cortex; and the inferior fronto-occipital fasciculus, which connected the MFG to the lingual gyrus and cuneus. Intra- and intergyral short association, U-shaped fibers were also identified. CONCLUSIONS: Subcortical white matter pathways integrated within the MFG include the superior longitudinal fasciculus and inferior fronto-occipital fasciculus. The MFG is implicated in a variety of tasks involving attention and memory, making it an important cortical region. The postoperative neurologic outcomes related to surgery in and around the MFG could be clarified in the context of the anatomy of the fiber bundles highlighted in the present study.

Venous Sinus Stenosis Treatment in Pediatric Idiopathic Intracranial Hypertension: Illustrative Case and Literature Review.

OBJECTIVE: To review the literature of venous sinus stenosis (VSS) treatment in children for idiopathic intracranial hypertension (IIH) and present our own institutional case. METHODS: A literature review was conducted using the PubMed and MEDLINE databases up to June 2020. From 134 studies that were screened, 6 studies were chosen for analysis that included patients <18 years old, a diagnosis of IIH that fit Dandy diagnostic criteria, and angiogram obtained to assess for VSS. IIH symptoms experienced in the pediatric population and efficacy of venous sinus stenting were analyzed. RESULTS: Eleven patients identified in the literature and 1 patient from our institution were included in the analysis. There was no statistically significant difference in pressure gradient response to stenting between male and female patients (P = 0.424) or patients with body mass index >90th percentile (P = 0.626). Larger decreases in pressure gradient after stent placement correlated with headache resolution (P = 0.0005). Patients who underwent unilateral stenting showed greater reduction in pressure gradient compared with patients who underwent bilateral stenting (average change 24 mm Hg vs. 5.75 mm Hg, P = 0.003). CONCLUSIONS: Our analysis showed that VSS treatment has the potential to be a safe option for IIH in pediatric patients. VSS treatment has shown similar results to traditional cerebrospinal fluid diversion procedures, with a lower complication rate and need for revision. More studies should be conducted to analyze the long-term efficacy and safety of VSS treatment in pediatric patients with IIH.

Anatomy and White Matter Connections of the Parahippocampal Gyrus.

BACKGROUND: The parahippocampal gyrus is understood to have a role in high cognitive functions including memory encoding and retrieval and visuospatial processing. A detailed understanding of the exact location and nature of associated white tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging-based fiber tracking validated by gross anatomic dissection as ground truth, we have characterized these connections based on relationships to other well-known structures. METHODS: Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. We evaluated the parahippocampal gyrus as a whole based on connectivity with other regions. All parahippocampal gyrus tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. RESULTS: We identified 2 connections of the parahippocampal gyrus: inferior longitudinal fasciculus and cingulum. Lateralization of the cingulum was detected (P < 0.05). CONCLUSIONS: The parahippocampal gyrus is an important center for memory processing. Subtle differences in executive functioning following surgery for limbic tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

An Evaluation of Neurosurgical Practices During the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: We sought to understand how the coronavirus disease 2019 pandemic has affected the neurosurgical workforce. METHODS: We created a survey consisting of 22 questions to assess the respondent's operative experience, location, type of practice, subspecialty, changes in clinic and operative volumes, changes to staff, and changes to income since the pandemic began. The survey was distributed electronically to neurosurgeons throughout the United States and Puerto Rico. RESULTS: Of the 724 who opened the survey link, 457 completed the survey. The respondents were from throughout the United States and Puerto Rico and represented all practices types and subspecialties. Nearly all respondents reported hospital restrictions on elective surgeries. Most reported a decline in clinic and operative volume. Nearly 70% of respondents saw a decrease in the work hours of their ancillary providers, and almost one half (49.1%) of the respondents had had to downsize their practice staff, office assistants, nurses, schedulers, and other personnel. Overall, 43.6% of survey respondents had experienced a decline in income, and 27.4% expected a decline in income in the upcoming billing cycle. More senior neurosurgeons and those with a private practice, whether solo or as part of a group, were more likely to experience a decline in income as a result of the pandemic compared with their colleagues. CONCLUSION: The coronavirus disease 2019 pandemic will likely have a lasting effect on the practice of medicine. Our survey results have described the early effects on the neurosurgical workforce. Nearly all neurosurgeons experienced a significant decline in clinical volume, which led to many downstream effects. Ultimately, analysis of the effects of such a pervasive pandemic will allow the neurosurgical workforce to be better prepared for similar events in the future.

Rosette-forming glioneuronal tumor: an illustrative case and a systematic review.

BACKGROUND: Rosette-forming glioneuronal tumors (RGNTs) are rare, low-grade, primary CNS tumors first described in 2002 by Komori et al. RGNTs were initially characterized as a World Health Organization (WHO) grade I tumors typically localized to the fourth ventricle. Although commonly associated with an indolent course, RGNTs have the potential for aggressive behavior. METHODS: A comprehensive search of PubMed and Web of Science was performed through November 2019 using the search term "rosette-forming glioneuronal tumor." Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. English, full-text case reports and series with histopathological confirmation were included. Patient demographics, presentations, MRI features, tumor location, treatment, and follow-up of all 130 cases were extracted. RESULTS: A 19-year-old man with a history of epilepsy and autism presented with acute hydrocephalus. MRI scans from 2013 to 2016 demonstrated unchanged abnormal areas of cortex in the left temporal lobe with extension into the deep gray-white matter. On presentation to our clinic in 2019, the lesion demonstrated significant progression. The patient's tumor was identified as RGNT, WHO grade I. One hundred thirty patients were identified across 80 studies. CONCLUSION: RGNT has potential to transform from an indolent tumor to a tumor with more aggressive behavior. The results of our systematic review provide insight into the natural history and treatment outcomes of these rare tumors.

Resting-state functional magnetic resonance imaging with independent component analysis for presurgical seizure onset zone localization: A systematic review and meta-analysis.

OBJECTIVE: One of the greatest challenges of achieving successful surgical outcomes in patients with epilepsy is the ability to properly localize the seizure onset zone (SOZ). Many techniques exist for localizing the SOZ, including intracranial electroencephalography, magnetoencephalography, and stereoelectroencephalography. Recently, resting-state functional magnetic resonance imaging (rs-fMRI) in conjunction with independent component analysis (ICA) has been utilized for presurgical planning of SOZ resection, with varying results. In this meta-analysis, we analyze the current role of rs-fMRI in identifying the SOZ for presurgical planning for patients with drug-resistant epilepsy. Specifically, we seek to demonstrate its current effectiveness compared to other methods of SOZ localization. METHODS: A literature review was conducted using the PubMed, MEDLINE, and Embase databases up to May of 2020. A total of 253 articles were screened, and seven studies were chosen for analysis. Each study was analyzed for SOZ localization by ground truth, SOZ localization by rs-fMRI with ICA, principal component analysis, or intrinsic connectivity contrast, and outcomes of surgery. A meta-analysis was performed to analyze how ground truth compares to rs-fMRI in SOZ localization. RESULTS: The odds ratio comparing ground truth to rs-fMRI was 2.63 (95% confidence interval = 0.66-10.56). Average concordance of rs-fMRI SOZ localization compared with ground truth localization across studies was 71.3%. SIGNIFICANCE: In the hunt for less invasive presurgical planning for epilepsy surgery, rs-fMRI with ICA provides a promising avenue for future standard practice. Our preliminary results show no significant difference in surgical outcomes between traditional standards of SOZ localization and rs-fMRI with ICA. We believe that rs-fMRI could be a step forward in this search. Further investigation comparing rs-fMRI to traditional methods of SOZ localization should be conducted, with the hope of moving toward relying solely on noninvasive screening methods.

Anatomy and White Matter Connections of the Inferior Temporal Gyrus.

BACKGROUND: The inferior temporal gyrus (ITG) is known to be involved in high-cognitive functions, including visual and language comprehensions and emotion regulation. A detailed understanding of the nature of association fibers could significantly improve postoperative morbidity related to declining capacity. Through diffusion spectrum imaging-based fiber tracking, we have characterized these connections on the basis of their relationships to other cortical areas. METHODS: Diffusion spectrum images from 10 healthy adults of the Human Connectome Project were randomly selected and used for tractography analysis. We evaluated the ITG as a whole based on connectivity with other regions. All ITG tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. RESULTS: We identified 5 major connections of the ITG: U-fiber, inferior longitudinal fasciculus, vertical occipital fasciculus, arcuate fasciculus, and uncinate fasciculus. There was no fiber lateralization detected. CONCLUSIONS: This study highlights the principal white-matter pathways of the ITG and demonstrates key underlying connections. We present a summary of the relevant clinical anatomy for this region of the cerebrum as part of a larger effort to understand it in its entirety.

An Evaluation of Neurosurgical Resident Education and Sentiment During the Coronavirus Disease 2019 Pandemic: A North American Survey.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had a tremendous impact on the healthcare system. Owing to restrictions in elective surgery and social distancing guidelines, the training curriculum for neurosurgical trainees has been rapidly evolving. This evolution could have significant long-term effects on the training of neurosurgery residents. The objective of the present study was to assess the effects of COVID-19 on neurosurgical training programs and residents. METHODS: A survey consisting of 31 questions assessing changes to resident clinical and educational workload and their sentiment regarding how these changes might affect their careers was distributed electronically to neurosurgery residents in the United States and Canada. RESULTS: The survey respondents were from 29 states and Canada and were relatively evenly spread across all levels of residency. Nearly 82% reported that the inpatient and outpatient volumes had been either greatly (44.0%) or moderately (37.8%) reduced. Greater than 91% reported that their work responsibilities or access to the hospital had been reduced, with a significant reduction in work hours and a significant increase in resident didactics (P < 0.001). Senior residents expressed concern about their educational experience and their future career prospects as a result of the pandemic. CONCLUSION: Universally, residents have experienced reduced work hours and a reduction in their operative case volumes. Programs have adapted by increasing didactic time and using electronic platforms. It is quite possible that this remarkable period will prompt a critical reappraisal of the pre-COVID-19 adequacy of educational content in our training programs and that the enhanced educational efforts driven by this pandemic could be lasting.

An Eyebrow, Supracarotid Triangle Approach for Lesions at the Ventral Thalamopeduncular Junction: A Technical Report.

BACKGROUND: Lesions arising at the ventral thalamopeduncular junction are difficult to resect. In addition to being relatively inaccessible, these lesions are located in one of the most sensitive areas of the brain. A critical question is whether new approaches could be developed to allow surgeons to adequately resect these lesions with reasonable outcomes. In the present report, we describe our approach to resect lesions in this region of the brain using an eyebrow craniotomy approach with a trajectory through the supracarotid triangle. METHODS: Through retrospective data collection, we present a small series of patients who had undergone an eyebrow, supracarotid triangle approach to resect lesions located at the thalamopeduncular junction. We describe our surgical technique and report patient outcomes using this approach. RESULTS: Three patients had undergone an eyebrow, supracarotid approach for resection of a lesion arising at the ventral thalamopeduncular junction. Two patients had presented with a cavernoma and one with a pilocytic astrocytoma. Complete resection of all 3 lesions was achieved during surgery without any intraoperative complications. No patient developed permanent contralateral weakness despite entering the peduncle during surgery. One patient developed permanent paresthesia in his left hand. CONCLUSIONS: Lesions arising at the ventral thalamopeduncular junction can be adequately resected with reasonable outcomes using an eyebrow, supracarotid triangle approach. This operative technique establishes another potential operative corridor by which neurosurgeons can resect lesions arising within this relatively inaccessible part of the brain.

Beyond eloquence and onto centrality: a new paradigm in planning supratentorial neurosurgery.

PURPOSE: Minimizing post-operational neurological deficits as a result of brain surgery has been one of the most pertinent endeavours of neurosurgical research. Studies have utilised fMRIs, EEGs and MEGs in order to delineate and establish eloquent areas, however, these methods have not been utilized by the wider neurosurgical community due to a lack of clinical endpoints. We sought to ascertain if there is a correlation between graph theory metrics and the neurosurgical notion of eloquent brain regions. We also wanted to establish which graph theory based nodal centrality measure performs the best in predicting eloquent areas. METHODS: We obtained diffusion neuroimaging data from the Human Connectome Project (HCP) and applied a parcellation scheme to it. This enabled us to construct a weighted adjacency matrix which we then analysed. Our analysis looked at the correlation between PageRank centrality and eloquent areas. We then compared PageRank centrality to eigenvector centrality and degree centrality to see what the best measure of empirical neurosurgical eloquence was. RESULTS: Areas that are considered neurosurgically eloquent tended to be predicted by high PageRank centrality. By using summary scores for the three nodal centrality measures we found that PageRank centrality best correlated to empirical neurosurgical eloquence. CONCLUSION: The notion of eloquent areas is important to neurosurgery and graph theory provides a mathematical framework to predict these areas. PageRank centrality is able to consistently find areas that we consider eloquent. It is able to do so better than eigenvector and degree central measures.