neuroGPT-X: toward a clinic-ready large language model.

OBJECTIVE: The objective was to assess the performance of a context-enriched large language model (LLM) compared with international neurosurgical experts on questions related to the management of vestibular schwannoma. Furthermore, another objective was to develop a chat-based platform incorporating in-text citations, references, and memory to enable accurate, relevant, and reliable information in real time. METHODS: The analysis involved 1) creating a data set through web scraping, 2) developing a chat-based platform called neuroGPT-X, 3) enlisting 8 expert neurosurgeons across international centers to independently create questions (n = 1) and to answer (n = 4) and evaluate responses (n = 3) while blinded, and 4) analyzing the evaluation results on the management of vestibular schwannoma. In the blinded phase, all answers were assessed for accuracy, coherence, relevance, thoroughness, speed, and overall rating. All experts were unblinded and provided their thoughts on the utility and limitations of the tool. In the unblinded phase, all neurosurgeons provided answers to a Likert scale survey and long-answer questions regarding the clinical utility, likelihood of use, and limitations of the tool. The tool was then evaluated on the basis of a set of 103 consensus statements on vestibular schwannoma care from the 8th Quadrennial International Conference on Vestibular Schwannoma. RESULTS: Responses from the naive and context-enriched Generative Pretrained Transformer (GPT) models were consistently rated not significantly different in terms of accuracy, coherence, relevance, thoroughness, and overall performance, and they were often rated significantly higher than expert responses. Both the naive and content-enriched GPT models provided faster responses to the standardized question set than expert neurosurgeon respondents (p < 0.01). The context-enriched GPT model agreed with 98 of the 103 (95%) consensus statements. Of interest, all expert surgeons expressed concerns about the reliability of GPT in accurately addressing the nuances and controversies surrounding the management of vestibular schwannoma. Furthermore, the authors developed neuroGPT-X, a chat-based platform designed to provide point-of-care clinical support and mitigate the limitations of human memory. neuroGPT-X incorporates features such as in-text citations and references to enable accurate, relevant, and reliable information in real time. CONCLUSIONS: The present study, with its subspecialist-level performance in generating written responses to complex neurosurgical problems for which evidence-based consensus for management is lacking, suggests that context-enriched LLMs show promise as a point-of-care medical resource. The authors anticipate that this work will be a springboard for expansion into more medical specialties, incorporating evidence-based clinical information and developing expert-level dialogue surrounding LLMs in healthcare.

Quality of life and broader experiences of those with acoustic neuroma: a mixed methods approach.

Background Acoustic neuromas (ANs) are consistently associated with decreased quality of life (QOL) related to the physical and psychosocial impacts of symptoms experienced from the tumour and its treatment. This study explored patient-reported experiences of ANs in New Zealand, with a focus on the impact on QOL and the provision of information, support and services. Methods A mixed methods approach was taken, conducting an online community survey that included the Penn Acoustic Neuroma Quality of Life Scale (N = 52). Those who indicated interest were offered semi-structured interviews after the survey (N = 17), which were analysed using content analysis. Results A negative impact on QOL was found, highlighting five key themes in the experiences of people: (1) ongoing physical, social and psychological impacts; (2) information and support from the medical system; (3) autonomy and decision-making; (4) the importance of peer support; and (5) remaining positive - life goes on. Conclusions Our findings indicate areas for improvement that may benefit people's healthcare experience and QOL. Both quantitative and qualitative results identified gaps associated with person-centred care and the need for information, education, emotional support and access to services. Recommendations include a need for more information (verbal and written) during all stages of diagnosis and treatment, shared decision-making and increased access to allied health, including psychological services and support groups.

Refining the predictive value of preoperative apparent diffusion coefficient (ADC) by whole-tumor analysis for facial nerve outcomes in vestibular schwannomas.

BACKGROUND: Apparent diffusion coefficient (ADC) in MRI has been shown to correlate with postoperative House-Brackmann (HB) scores in patients with vestibular schwannoma despite limited methodology. To rectify limitations of single region of interest (ROI) sampling, we hypothesize that whole-tumor ADC histogram analysis will refine the predictive value of this preoperative biomarker related to postoperative facial nerve function. METHODS: Of 155 patients who underwent resection of vestibular schwannoma (2014-2020), 125 patients were included with requisite clinical and radiographic data. After volumetric analysis and whole-tumor ADC histogram, regression tree analysis identified ADC cutoff for significant differences in HB grade. Outcomes were extent of resection, facial nerve function, hospital length of stay (LOS), and complications. RESULTS: Regression tree analysis defined three quantitative ADC groups (× 10-6 mm2/s) as high (> 2248.77; HB 1.7), mid (1468.44-2248.77; HB 3.1), and low (< 1468.44; HB 2.3) range (p 0.04). The mid-range ADC group had significantly worse postoperative HB scores and longer hospital LOS. Large tumor volume was independently predictive of lower rates of gross total resection (p <0.0001), higher postoperative HB score (p 0.002), higher rate of complications (p 0.04), and longer LOS (p 0.003). CONCLUSIONS: Whole-tumor histogram yielded a robust regression tree analysis that defined three ADC groups with significantly different facial nerve outcomes. This likely reflects tumor heterogeneity better than solid-tumor ROI sampling. Whole-tumor ADC warrants further study as a useful radiographic biomarker in patients with vestibular schwannoma who are considering surgical resection.

Incidence of vestibular schwannoma in Finland, 1990-2017.

BACKGROUND: An increasing trend in incidence of vestibular schwannomas (VS) has been reported, though not consistently, across populations.  Materials and methods: We obtained data from the Finnish Cancer Registry on 1,149 VS cases diagnosed in 1990-2017 with tabular data up to 2022. We calculated age-standardised incidence rates (ASR) overall, by sex, and for 10-year age groups. We analysed time trends using Poisson and joinpoint regression. RESULTS: The average ASR of VS in Finland during 1990-2017 was 8.6/1,000,000 person-years for women and 7.5/1,000,000 for men. A declining trend was found with an average annual percent change of -1.7% (95% confidence interval [CI]: -2.8%, -0.6%) for women, -2.2% (95% CI: -3.6%, -0.7%) for men, and -1.9% (95% CI: -2.9%, -1.0%) for both sexes combined. The ASR in women was 11.6/1,000,000 person-years in 1990 and it decreased to 8.2/1,000,000 by 2017. Correspondingly, the incidence in men was 7.1/1,000,000 in 1990 and decreased to 5.1/1,000,000 by 2017. Some decline in incidence over time was found in all age groups below 80 years, but the decline (2.3-3.1% per year) was statistically significant only in age groups 40-49, 50-59, and 60-69 years. In the oldest age group (80+ years), the incidence of VS increased by 16% per year. For 2018-2022, the ASR was 7.6/1,000,000 for both sexes combined, with a decline by -1.7% (95% CI: -2.3%, -1.2%) annually for the entire period 1990-2022. CONCLUSION: In contrast to the increasing incidence reported in some studies, we found a decreasing trend in VS incidence for both sexes in Finland.

Temporal lobe injury with middle fossa approach to intracanalicular vestibular schwannomas: a systematic review.

There are several surgical approaches for vestibular schwannoma (VS) resection. However, management has gradually shifted from microsurgical resection, toward surveillance and radiosurgery. One of the arguments against microsurgery via the middle fossa approach (MFA) is the risk of temporal lobe retraction injury or sequelae. Here, we sought to evaluate the incidence of temporal lobe retraction injury or sequela from a MFA via a systematic review of the existing literature. This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Relevant studies reporting temporal lobe injury or sequela during MFA for VS were identified. Data was aggregated and subsequently analyzed to evaluate the incidence of temporal lobe injury. 22 studies were included for statistical analysis, encompassing 1522 patients that underwent VS resection via MFA. The overall rate of temporal lobe sequelae from this approach was 0.7%. The rate of CSF leak was 5.9%. The rate of wound infection was 0.6%. Meningitis occurred in 1.6% of patients. With the MFA, 92% of patients had good facial outcomes, and 54.9% had hearing preservation. Our series and literature review support that temporal lobe retraction injury or sequelae is an infrequent complication from an MFA for intracanalicular VS resection.

Guía de práctica clínica sobre el manejo del schwannoma vestibular / Clinical practice guideline on the management of vestibular schwannoma

Introducción: El schwannoma vestibular (SV) es el tumor más frecuente del ángulo pontocerebeloso. La mayor accesibilidad a las pruebas radiológicas ha incrementado su diagnóstico. Teniendo en cuenta las características del tumor, la clínica y la edad del paciente se han propuesto tres estrategias terapéuticas, observación, cirugía o radioterapia. La elección de la más adecuada para cada paciente es un motivo de controversia frecuente. Material y métodos: El presente trabajo incluye una revisión exhaustiva sobre cuestiones relativas al SV que pueden servir de guía clínica en el manejo de pacientes con estas lesiones. La presentación se ha orientado en forma de preguntas que el clínico se hace habitualmente y las respuestas están redactadas y/o revisadas por un panel de expertos nacionales e internacionales consultados por la Comisión de Otología de la SEORL-CCC. Resultados: Se ha elaborado un listado con los 13 bloques temáticos más controvertidos sobre el manejo del SV en forma de 50 preguntas y se han buscado las respuestas a todas ellas mediante una revisión sistemática de la literatura (artículos publicados en PubMed y Cochrane Library entre 1992 y 2023 sobre cada bloque temático). Treinta y tres expertos, liderados por la Comisión de Otología de la SEORL-CCC, han analizado y discutido todas las respuestas. En el Anexo 1 pueden encontrarse 14 preguntas adicionales divididas en cuatro bloques temáticos. Conclusiones: Esta guía de práctica clínica sobre el manejo del SV ofrece respuestas consensuadas a las preguntas más habituales que se plantean sobre este tumor. La ausencia de suficientes estudios prospectivos hace que los niveles de evidencia sobre el tema sean en general medios o bajos. Este hecho incrementa el interés de este tipo de guías de práctica clínica elaboradas por expertos.(AU)

IntroductionVestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. Material and methods: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. Results: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. Conclusions: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.(AU)

[Neurofibromatosis type 2 in the otorhinolaryngological practice]. / Neirofibromatoz 2-go tipa v praktike vracha-otorinolaringologa.

Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disease (frequency 1 in 25-90 000) characterized by the formation of tumors of the central nervous system due to a mutation in the NF2 gene on chromosome 22q12. Bilateral vestibular schwannomas are recognized as absolute diagnostic criteria of NF2 and occur in 95% of patients, are accompanied by hearing impairment, manifest at the age of 18-24 years. Skin manifestations can precede vestibular schwannomas for several years and predict the course of the disease: neurofibromas, cafe-au-lait macules, hypopigmented spots, recently described mesh capillary malformations. Despite the benign nature of schwannomas, they can lead to hearing loss, vestibular dysfunction, facial nerve paralysis, gait disorders, pain and convulsions, there is a risk of early death from compression of the brain stem. The probability of progressive hearing loss is partly determined by the type of mutation. We described a clinical case of NF2 in a 21-year-old patient with bilateral vestibular schwannomas without hearing loss, whose skin examination by ENT specialist revealed this disease. The importance of the presented observation is that the doctor should assume neurofibromatosis type 2 in a young patient with bilateral vestibular schwannomas. It is necessary to undertake a further examination of this patient, including: skin examination for the identification of characteristic neurofibromas and cafe-au-lait macules, consultation with an ophthalmologist, neurologist, MRI of the brain and spinal cord with contrast, genetic analysis - for timely initiation of therapy that prevents hearing loss and vestibular disorders.

[To the origins of surgery for acoustic neuromas]. / K istokam khirurgii nevrinom slukhovogo nerva.

Acoustic neuroma is one of the most common tumors of the posterior cranial fossa. Its removal is always a challenge for the neurosurgeon and the patient. The history of surgery for acoustic neuromas is inextricably linked with the history of neurosurgery in general. The modern surgical community must know history and be able to use it. Only then will the development of surgery lead to the preservation of the quality of life of patients. In the history of surgery for acoustic neuromas, the stages of its development are clearly visible from the description of the clinical picture through the study of the anatomy of the cerebellopontine angle to modern microsurgical removal.

Transcanal transpromontorial approach for vestibular schwannoma: experience of a single center.

BACKGROUND: The expanded transpromontorial transcanal approach (ExpTTA) represents a recent addition to the surgical approaches available for the treatment of vestibular schwannoma. An initial purely endoscopic version has been complemented by the use of the microscope and it is now one of the possible surgical options for small to medium-sized vestibular schwannomas with a predominantly intracanalar development. METHODS: This is a series of 54 patients who underwent microsurgical resection of sporadic, unilateral vestibular schwannoma, mainly Koos I-II with non-serviceable hearing, between January 2016 and January 2023 using the expanded transcanal transpromontorial approach. We describe the surgical technique, focusing on anatomical landmarks, and analyzing its advantages and shortcomings. Retrospective analysis of clinical outcomes is presented, including early and late complications. The mean follow-up was 46.7 months. RESULTS: We achieved gross total resection of the lesion in all cases, confirmed on the first follow-up MRI at least 6 months after each procedure. We did not record any intraoperative complication nor disease recurrence. We recorded two postoperative severe facial nerve palsies, one of which was permanent. No cases of disabling vertigo or imbalance were reported, and all patients reported full recovery of autonomy in daily activities. Three cases of otoliquorrhea were managed conservatively successfully. CONCLUSIONS: The transcanal transpromontorial approach combines the advantages of endoscopy with the possibilities provided by microsurgery. Our experience confirms its safety in terms of surgical complications and facial nerve outcome. This approach is amongst the treatment options for small-medium schwannomas in patients with impaired hearing, especially in young patients, ensuring radical resection, disease control, and minimal morbidity.

Mobile phone use and brain tumour risk - COSMOS, a prospective cohort study.

BACKGROUND: Each new generation of mobile phone technology has triggered discussions about potential carcinogenicity from exposure to radiofrequency electromagnetic fields (RF-EMF). Available evidence has been insufficient to conclude about long-term and heavy mobile phone use, limited by differential recall and selection bias, or crude exposure assessment. The Cohort Study on Mobile Phones and Health (COSMOS) was specifically designed to overcome these shortcomings. METHODS: We recruited participants in Denmark, Finland, the Netherlands, Sweden, and the UK 2007-2012. The baseline questionnaire assessed lifetime history of mobile phone use. Participants were followed through population-based cancer registers to identify glioma, meningioma, and acoustic neuroma cases during follow-up. Non-differential exposure misclassification was reduced by adjusting estimates of mobile phone call-time through regression calibration methods based on self-reported data and objective operator-recorded information at baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for glioma, meningioma, and acoustic neuroma in relation to lifetime history of mobile phone use were estimated with Cox regression models with attained age as the underlying time-scale, adjusted for country, sex, educational level, and marital status. RESULTS: 264,574 participants accrued 1,836,479 person-years. During a median follow-up of 7.12 years, 149 glioma, 89 meningioma, and 29 incident cases of acoustic neuroma were diagnosed. The adjusted HR per 100 regression-calibrated cumulative hours of mobile phone call-time was 1.00 (95 % CI 0.98-1.02) for glioma, 1.01 (95 % CI 0.96-1.06) for meningioma, and 1.02 (95 % CI 0.99-1.06) for acoustic neuroma. For glioma, the HR for ≥ 1908 regression-calibrated cumulative hours (90th percentile cut-point) was 1.07 (95 % CI 0.62-1.86). Over 15 years of mobile phone use was not associated with an increased tumour risk; for glioma the HR was 0.97 (95 % CI 0.62-1.52). CONCLUSIONS: Our findings suggest that the cumulative amount of mobile phone use is not associated with the risk of developing glioma, meningioma, or acoustic neuroma.

Postoperative Herpes Viral Infections in Neurosurgery - An Experience and Arguments for and against the Plausible Hypotheses.

BACKGROUND: The literature contains several reports of herpes recrudescence after neurosurgery. We analyze our experience by vindicating or refuting the existing plausible hypotheses. MATERIAL AND METHODS: This is a retrospective review of all neurosurgical cases that developed postoperative herpes infection between January 2016 and June 2020. RESULTS: Six patients developed herpes infection after vestibular schwannoma (VS) surgery. Other neurosurgical cases did not develop herpes infection. There were five females and one male, with a mean age of 44.1 years. Four out of six patients developed delayed facial palsy (DFP) and did not improve after antiviral treatment. Postoperative herpes infections were 0.2% among all operated patients, 3.07% among all cerebellopontine (CP) angle surgeries, and 5.6% among VS surgeries. CONCLUSIONS: To date, none of the plausible hypotheses satisfactorily addresses all aspects of viral recrudescence. The etiology may be multi-factorial, and in all cases of unexplained clinical deterioration, herpes infection needs consideration in the differential diagnosis.

Transmastoid Approach to Repair Iatrogenic Cerebrospinal Fluid Otorhinorrhea After Cerebellopontine Angle Tumor Resection.

BACKGROUND: The precise treatment of iatrogenic cerebrospinal fluid (CSF) otorhinorrhea has been poorly studied. The purpose of the study was to investigate the clinical manifestation, surgical results, and management of CSF leak. METHODS: Electronic medical record database of iatrogenic CSF leaks after erebellopontine angle(CPA) surgery from 2019 to 2022 was retrospectively analyzed. Three patients returned to the hospital with the complication of CSF leak. After failed attempts of conservative strategies or reverse surgical repair, adipose tissue was applied to the mastoid cracks repair. RESULTS: With the techniques described above, the CSF leaks were successfully settled. The identified patients were observed for at least 10 months. and there was no recurrence or other complications. CONCLUSION: Conservative treatment and initial surgical methods for occult postoperative CSF leaks are prone to delay effective results, particularly in patients with well-evaporated temporal bone. This complication can be minimized with transmastoid closure utilizing autologous fat.

Coordinated Same- or Next-Day Radiosurgery and Cochlear Implantation for Vestibular Schwannoma.

OBJECTIVE: To describe the experience and results from coordinated and closely scheduled radiosurgery and cochlear implantation (CI) in a vestibular schwannoma (VS) cohort. PATIENTS: Patients with VS who underwent radiosurgery followed by CI on the same or next day. INTERVENTIONS: Interventions included sequential radiosurgery and CI. MAIN OUTCOME MEASURES: Tumor control defined by tumor growth on posttreatment surveillance and audiometric outcomes including consonant-nucleus-consonant words and AzBio sentences in quiet. RESULTS: In total, six patients were identified that met the inclusion criteria, with an age range of 38 to 69 years and tumor sizes ranging from 2.0 to 16.3 mm. All patients successfully underwent radiosurgery and CI on the same or immediately successive day. Postoperatively, all patients obtained open-set speech recognition. Consonant-nucleus-consonant word scores ranged from 40 to 88% correct, and AzBio scores ranged from 44 to 94% correct. During posttreatment magnetic resonance imaging surveillance, which ranged from 12 to 68 months, all tumors were noted to be adequately visualized, and no tumor progression was noted. CONCLUSION: Coordinated radiosurgery and CI can be safely performed in patients with VS on the same or next day, serving to decrease burden on patients and increase access to this vital rehabilitative strategy.

Sliding transformer with uncertainty estimation for vestibular schwannoma automatic segmentation.

Objective.Automated segmentation of vestibular schwannoma (VS) using magnetic resonance imaging (MRI) can enhance clinical efficiency. Though many advanced methods exist for automated VS segmentation, the accuracy is hindered by ambivalent tumor borders and cystic regions in some patients. In addition, these methods provide results that do not indicate segmentation uncertainty, making their translation into clinical workflows difficult due to potential errors. Providing a definitive segmentation result along with segmentation uncertainty or self-confidence is crucial for the conversion of automated segmentation programs to clinical aid diagnostic tools.Approach.To address these issues, we propose a U-shaped cascade transformer structure with a sliding window that utilizes multiple sliding samples, a segmentation head, and an uncertainty head to obtain both the segmentation mask and uncertainty map. We collected multimodal MRI data from 60 clinical patients with VS from Xuanwu Hospital. Each patient case includes T1-weighted images, contrast-enhanced T1-weighted images, T2-weighted images, and a tumor mask. The images exhibit an in-plane resolution ranging from 0.70 × 0.70 to 0.76 × 0.76 mm, an in-plane matrix spanning from 216 × 256 to 284 × 256, a slice thickness varying between 0.50 and 0.80 mm, and a range of slice numbers from 72 to 120.Main results.Extensive experimental results show that our method achieves comparable or higher results than previous state-of-the-art brain tumor segmentation methods. On our collected multimodal MRI dataset of clinical VS, our method achieved the dice similarity coefficient (DSC) of 96.08% ± 1.30. On a publicly available VS dataset, our method achieved the mean DSC of 94.23% ± 2.53.Significance.The method efficiently solves the VS segmentation task while providing an uncertainty map of the segmentation results, which helps clinical experts review the segmentation results more efficiently and helps to transform the automated segmentation program into a clinical aid diagnostic tool.

Salvage Microsurgery Following Failed Primary Radiosurgery in Sporadic Vestibular Schwannoma.

Importance: Management of sporadic vestibular schwannoma with radiosurgery is becoming increasingly common globally; however, limited data currently characterize patient outcomes in the setting of microsurgical salvage for radiosurgical failure. Objective: To describe the clinical outcomes of salvage microsurgery following failed primary stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) among patients with sporadic vestibular schwannoma. Design, Setting, and Participants: This was a cohort study of adults (≥18 years old) with sporadic vestibular schwannoma who underwent salvage microsurgery following failed primary SRS/FSRT in 7 vestibular schwannoma treatment centers across the US and Norway. Data collection was performed between July 2022 and January 2023, with data analysis performed between January and July 2023. Exposure: Salvage microsurgical tumor resection. Main Outcomes and Measures: Composite outcome of undergoing less than gross total resection (GTR) or experiencing long-term facial paresis. Results: Among 126 patients, the median (IQR) age at time of salvage microsurgery was 62 (53-70) years, 69 (55%) were female, and 113 of 117 (97%) had tumors that extended into the cerebellopontine angle at time of salvage. Of 125 patients, 96 (76%) underwent primary gamma knife SRS, while 24 (19%) underwent linear accelerator-based SRS; the remaining patients underwent FSRT using other modalities. Postoperative cerebrospinal fluid leak was seen in 15 of 126 patients (12%), hydrocephalus in 8 (6%), symptomatic stroke in 7 (6%), and meningitis in 2 (2%). Each 1-mm increase in cerebellopontine angle tumor size was associated with a 13% increased likelihood of foregoing GTR (64 of 102 patients [63%]) or long-term postoperative House-Brackmann grade higher than I (48 of 102 patients [47%]) (odds ratio, 1.13; 95% CI, 1.04-1.23). Following salvage microsurgery, tumor growth-free survival rates at 1, 3, and 5 years were 97% (95% CI, 94%-100%), 93% (95% CI, 87%-99%), and 91% (95% CI, 84%-98%), respectively. Conclusions: In this cohort study, more than half of patients who received salvage microsurgery following primary SRS/FSRT underwent less than GTR or experienced some degree of facial paresis long term. These data suggest that the cumulative risk of developing facial paresis following primary SRS/FSRT by the end of the patient's journey with treatment approximates 2.5% to 7.5% when using published primary SRS/FSRT long-term tumor control rates.

Navigating Uncharted Waters: Comparative Analysis of Clinical Progression and Outcomes in Vestibular Schwannoma Patients with Papilledema and without Hydrocephalus, Versus Those without Papilledema and Hydrocephalus: A Comprehensive Institutional Insight.

BACKGROUND: Papilledema's association with hydrocephalus (HCP)-linked larger vestibular schwannoma (VS) is established but cases lacking concurrent HCP require further investigation. METHODS: This retrospective comparative observational study, conducted from July 2018 to July 2023, examined 120 VS patients undergoing surgery. Patients were categorized into Group 1 (papilledema without HCP) and Group 2 (no papilledema or HCP), with comprehensive data analyzed. RESULTS: In this study, Group 1 (14 patients with papilledema) and Group 2 (106 patients without papilledema or HCP) were compared. Group 1 was younger (mean age 27.21 ± 11.73 years) than Group 2 (mean age 54.66 ± 11.44 years). Both groups had similar symptom durations and tumor detection times. Group 1 had increased vascularity (P = 0.001), elevated cisterna magna protein levels (P = 0.001), and a higher incidence of neurofibromatosis 2 (P = 0.003). They also experienced longer surgeries (P = 0.001) and more blood loss (P = 0.001), leading to extended postoperative complications. Group 2 showed improved postsurgery visual outcomes (P = 0.001), better Glasgow Outcome Scores (P = 0.001), enhanced facial nerve preservation (P = 0.002), and improved hearing on follow-up (P = 0.003). Logistic regression analysis highlighted prolonged surgery duration (P = 0.057) and papilledema (P = 0.0001) as significant factors influencing visual improvement. CONCLUSIONS: Patients with VS require preoperative fundoscopy evaluation due to potential visual loss and papilledema, even without HCP. Early treatment initiation enhances visual and hearing outcomes. Meticulous surgery is vital given the lesion's hypervascular nature and adherence to surrounding structures. Preoperative embolization may aid in preserving neurovascular structures. In developing countries with higher blindness rates, judicious noncontrast computed tomography brain evaluation is crucial for timely detection and treatment initiation of lesions like VS.

How I do it: hearing preservation in large vestibular schwannomas using vestibular nerve fiber preservation technique.

BACKGROUND: To improve hearing function after resection of large vestibular schwannomas, we describe a strategy of vestibular-nerve-fiber preservation. Anatomical considerations and stepwise dissection are described. METHOD: Steps include locating the vestibular nerve at the brainstem and identifying a dissection plane between nerve fibers and tumor capsule. Using this plane to mobilize and resect tumor reduced manipulation and maintained vascularity of underlying cochlear and facial nerves. CONCLUSION: Preservation of hearing function is feasible in large vestibular schwannomas with vestibular-nerve-fiber preservation. Reducing manipulation and ischemic injury of underlying cochlear and facial nerves thereby helped facilitate hearing preservation, even in large tumors.

Development of a vestibular schwannoma tumor slice model for pharmacological testing.

BACKGROUND: Our goal was to develop a 3D tumor slice model, replicating the individual tumor microenvironment and for individual pharmaceutical testing in vestibular schwannomas with and without relation to NF2. METHODS: Tissue samples from 16 VS patients (14 sporadic, 2 NF2-related) were prospectively analyzed. Slices of 350 µm thickness were cultured in vitro, and the 3D tumor slice model underwent thorough evaluation for culturing time, microenvironment characteristics, morphology, apoptosis, and proliferation rates. Common drugs - Lapatinib (10 µM), Nilotinib (20 µM), and Bevacizumab (10 µg/ml) - known for their responses in VS were used for treatment. Treatment responses were assessed using CC3 as an apoptosis marker and Ki67 as a proliferation marker. Standard 2D cell culture models of the same tumors served as controls. RESULTS: The 3D tumor slice model accurately mimicked VS ex vivo, maintaining stability for three months. Cell count within the model was approximately tenfold higher than in standard cell culture, and the tumor microenvironment remained stable for 46 days. Pharmacological testing was feasible for up to three weeks, revealing interindividual differences in treatment response to Lapatinib and intraindividual variability in response to Lapatinib and Nilotinib. The observed effects were less pronounced in tumor slices than in standard cell culture, indicating the model's proximity to in vivo tumor biology and enhanced realism. Bevacizumab had limited impact in both models. CONCLUSION: This study introduces a 3D tumor slice model for sporadic and NF2-related VS, demonstrating stability for up to 3 months, replication of the schwannoma microenvironment, and utility for individualized pharmacological testing.