Cases Of Vestibular Schwannoma Research Articles

AutoCorNN: An Unsupervised Physics-Aware Deep Learning Model for Geometric Distortion Correction of Brain MRI Images Towards MR-Only Stereotactic Radiosurgery.

Geometric distortions in brain MRI images arising from susceptibility artifacts at air-tissue interfaces pose a significant challenge for high-precision radiation therapy modalities like stereotactic radiosurgery, necessitating sub-millimeter accuracy. To achieve this goal, we developed AutoCorNN, an unsupervised physics-aware deep-learning model for correcting geometric distortions. Two publicly available datasets, the MPI-Leipzig Mind-Brain-Body with 318 subjects, and the Vestibular Schwannoma-SEG dataset, encompassing 242 patients were utilized. AutoCorNN integrates two 2D convolutional encoder-decoder neural networks with the forward physical model of MRI signal generation to predict undistorted MR and field map images from distorted MR input. The network is trained in an unsupervised manner by minimizing the mean absolute error between the measured and estimated k-space data, without requiring ground truth images during training or deployment. The model was evaluated on vestibular schwannoma cases. AutoCorNN achieved a peak signal-to-noise ratio (PSNR) of 41.35 ± 0.02dB, a root mean square error (RMSE) of 0.02 ± 0.003, and a structural similarity index (SSIM) of 0.99 ± 0.02 outperforming uncorrected and B0-mapping correction methods. Geometric distortions of about 1.6mm were observed at the air-tissue interfaces at the air canal and nasal cavity borders. Geometrically, distortion correction increased the target volume from 3.12 ± 0.52cc to 3.84 ± 0.54cc. Dosimetrically, AutoCorNN improved target coverage (0.96 ± 0.01 to 0.97 ± 0.02), conformity index (0.92 ± 0.03 to 0.94 ± 0.03), and reduced dose gradients outside the target. AutoCorNN achieves accurate geometric distortion correction comparable to conventional iterative methods while offering substantial computational acceleration, enabling precise target delineation and conformal dose delivery for improved radiation therapy outcomes.

Factors affecting facial nerve outcome in vestibular Schwannoma surgery

Background: Preservation of facial nerve injury is a key important factor in vestibular schwannoma surgery as facial paralysis has devastating functional and psychological consequences for patients. Objective: To correlate different factors resulting in facial nerve preservation in vestibular schwannoma surgery by retro mastoid retro sigmoid approach. Method: This is a retrospective analysis of facial nerve status of 212 cases of vestibular schwannoma microsurgery through Retrosigmoid Retromastoid (RSRM) approach. This study was carried out in National Neurosurgical Referral Center(NNRC), National Academy Of Medical Sciences (NAMS), Bir hospital between January 2016 to December 2022.Preoperative and post operative details of facial nerve function status compared according to House and Brackmann (H and B) grading system, and factors influencing outcome in facial nerve preservation were analyzed. Recurrent and residual tumors were excluded. Results: A total of 212 cases of vestibular schwannoma were operated during the study period. The average age of presentation was 47 years. Most common affected age group was 51-60 years. Female to male ratio was 3:2.5. The most common clinical symptoms for vestibular schwannoma were sensorineural hearing loss followed by headache and difficulty in limb coordination. Tumor size and consistency was most important indicator of facial nerve function outcome. Conclusion: The incidence of post operative facial palsy is found to be correlated to tumor size and consistency. Improvement of the facial nerve outcome is detected in patients undergone simultaneous intraoperative monitoring (IONM).

Multimodal intraoperative neurophysiological monitoring with special emphasis on facial MEPs for facial nerve preservation in vestibular schwannoma surgeries: Surgical nuances and outcome predictability

Objectives: The objective of this study was to evaluate the utility of facial motor-evoked potentials (FMEPs) as a significant part of multimodal intraoperative neurophysiological monitoring (IONM) for preserving facial nerve (FN) function in vestibular schwannoma surgery guiding the resection, and predicting outcome. Materials and Methods: This prospective observational study included 35 cases of vestibular schwannomas operated under multimodal IONM using free-running electromyography (EMG), triggered EMG (with both monopolar probe and suction stimulator), FMEPs, electroencephalography and its spectral derivatives and train-of-four testing. Direct stimulation using a monopolar probe helped in the identification of FN and guiding tumour resection. The suction stimulator probe was used for quasi-continuous stimulus delivery and FN mapping. FMEPs helped in the assessment of the integrity of FN. Results: In 14 cases, there was a single instance, and in 11 cases, there was more than one instance of a significant drop in FMEPs. Sixteen cases had >50% fall in FMEPs during surgery. In 28 cases, the proximal stimulation threshold for FN was ≤0.1 mA at the end of the tumour resection. At the end of the first week following surgery, only 42.9% of the cases had good functional preservation (House–Brackmann [HB] Grade I or II) of FN, which increased to 78.8% at the end of one year. The remaining 21.2% had HB Grade III weakness. Percentage drop in FMEP amplitude and final FMEP amplitude correlated significantly (P < 0.01) with the post-operative HB Grade at 1st week, 3, 6 and 12 months following surgery. Conclusion: FMEPs, as a significant component of multimodal IONM, provide a real-time assessment of FN function during surgery, facilitate safe maximal resection, predict immediate post-operative FN outcomes, and improve long-term FN function by minimising the cumulative insult inflicted on the FN during surgery.

Vestibular schwannoma unveiled by pregnancy: A case report and literature review

BackgroundVestibular schwannomas – benign tumours originating from the vestibular nerve – are rare during pregnancy. The intricate interplay between the gravid uterus, maternal physiology and neoplastic growth imposes complexities that demand a careful and tailored approach. Case reportThis article reports a case of a pregnant woman in her 30 s diagnosed with a large vestibular schwannoma exhibiting brainstem compression, peritumoral oedema and cranial nerve encasement at 36 + 5 weeks of gestation. A multi-disciplinary team collaborated to devise a treatment plan considering the delicate balance between fetal well-being and the urgent need for intervention. A conservative approach involving close monitoring, corticosteroid therapy to manage peritumoral oedema, and detailed fetal assessments was initially employed. As the patient neared full term, a carefully planned caesarean section was performed, followed by a successful craniotomy to resect the vestibular schwannoma. Both the mother and the newborn showed favourable outcomes postoperatively. In addition, a literature review of cases of vestibular schwannoma in pregnancy was undertaken to inform optimal management strategies and enhance understanding of this complex scenario. ConclusionThis case highlights the complexity of managing vestibular schwannomas in pregnant women, and underscores the importance of a tailored, collaborative approach. The condition was resolved successfully, emphasizing the significance of timely diagnosis, meticulous planning and a patient-centred approach in these rare and intricate cases.

Comparative Analysis on Vestibular Schwannoma Surgery with and without Intraoperative Fluorescein Sodium Enhancement

Background: Vestibular schwannoma (VS), also known as acoustic neuroma, is a benign, well-encapsulated, and slow-growing tumor that originates from Schwann cells, which form the myelin sheath around the vestibulocochlear nerve (VIII cranial nerve). The surgical treatment of this condition presents a challenging task for surgeons, as the tumor’s location and size make it difficult to remove without causing damage to the surrounding structures. In recent years, fluorescein sodium (FS) has been proposed as a tool to enhance surgical outcomes in VS surgery. This essay will provide an analytical comparison of the use of FS in VS surgery, evaluating its benefits and limitations and comparing surgical outcomes with and without FS-assisted surgery. Methods: In a retrospective study conducted at San Filippo Neri Hospital, we examined VS cases that were operated on between January 2017 and December 2023. The patients were divided into two groups: group A, which consisted of patients who underwent surgery without the use of FS until January 2020 (102 cases), and group B, which included patients who underwent surgery with FS after January 2020 (55 cases). All operations were performed using the retrosigmoid approach, and tumor size was classified according to the Koos, et al. classification system. The extent of surgical removal was evaluated using both the intraoperative surgeon’s opinion and postoperative MRI imaging. Preoperatively and postoperatively, facial nerve function and hearing were assessed. In group B, FS was used to assist the surgical procedures, which were performed using a surgical microscope equipped with an integrated fluorescein filter. Postoperative clinical and MRI controls were performed at six months and annually, with no patients lost to follow-up. Results: This study investigated the impact of intraoperative fluorescein exposure on tumor resection and clinical outcomes in patients with VS. The study found a statistically significant difference in the tumor resection rates between patients who received fluorescein intraoperatively (p = 0.037). Further analyses using the Koos classification system revealed a significant effect of fluorescein exposure, particularly in the Koos 3 subgroup (p = 0.001). Notably, no significant differences were observed in hearing loss or facial nerve function between the two groups. A Spearman correlation analysis revealed a positive correlation between tumor size and Koos, age, and size, but no significant correlation was found between facial nerve function tests. Conclusions: FS-assisted surgery for VS may potentially enhance tumor resection, allowing for more comprehensive tumor removal.

Applying the Full Endoscopic Keyhole Technique to CPA Lesions: A Single-Center Study.

In recent years, endoscopy has become an increasingly common tool used during neurosurgical procedures. However, its application in treating cerebellopontine angle (CPA) lesions has not progressed as rapidly. In this study, the authors present their initial experience with surgically treating CPA lesions using a fully endoscopic keyhole retrosigmoid approach. They conducted a retrospective analysis of clinical data from patients who underwent endoscopic keyhole CPA surgery at their center between May 2017 and April 2022. They provide a comprehensive explanation of this method and an overview of the strategies that have been developed to achieve better clinical outcomes. The study included 107 patients, consisting of 10 cases of vestibular schwannoma, 21 cases of epidermoid cyst, 32 cases of trigeminal neuralgia, and 44 cases of hemifacial spasm. The authors analyzed the clinicodemographic details of the patients. Among the 31 tumor cases, gross total resection was achieved in 25 patients (80.6%), while near-total resection was performed in 6 patients (19.4%). In patients with trigeminal neuralgia, facial pain resolved in 31 out of 32 patients (96.9%). Similarly, facial convulsions disappeared or were relieved in all 44 patients (100%) with hemifacial spasms after the operation. Postoperative complications included facial nerve paresis (n=9, 8.4%), with improvement observed in 6 cases during follow-up, transient facial hypoesthesia (n=3, 2.8%), cerebrospinal fluid rhinorrhea (n=3, 2.8%), transient abducens paresis (n=1, 0.9%), and postoperative hemorrhage (n=1, 0.9%). Endoscopy provides improved deep illumination and, combined with close-up observation, enhances the visualization of structures within the CPA region. The fully endoscopic keyhole technique is a safe and effective method for managing CPA lesions.

Stereotactic radiosurgery for vestibular schwannomas: evolution of the philosophy of treatment

Vestibular schwannomas are the most common tumors in the cerebellopontine angle. Stereotactic radiosurgery is included in the armamentarium of methods for treating these tumors along with surgical treatment. Given the annual incidence of more than 15 radiosurgical cases of vestibular schwannomas per 1 million population, the expected need for stereotactic radiosurgery of these tumors in Russia is more than 2000 cases annually.Stereotactic radiosurgery is located at the intersection of several clinical specialties: neuroradiology, neurosurgery and radiation therapy, each of which has made a significant contribution to the development of this treatment method. The most commonly used for this is the cobalt‑based Leksell Gamma Knife, specifically intended for the treatment of intracranial neoplasms. Treatment is also possible with modern linear accelerators and proton accelerators, which provide high accuracy and conformity of irradiation. The experience gained since the first application of this method in the treatment of vestibular schwannomas has made it possible not only to optimize the radiation doses to the tumor and adjacent critical structures (brain stem, inner ear), but also to study the features of post‑radiation micro‑ and macro‑ changes, their impact on the clinical course, to develop recommendations for radiosurgery with schwannomas of various sizes. All this contributes to high control of tumor growth and a low level of functional disorders, which, along with easy tolerability and minimal hospitalization time, determines lower cost of this treatment compared to the traditional surgical approach and significant social and economic effect.This lecture is intended for neurosurgeons and radiation therapists and focuses on the most significant factors that influenced the development, promotion and active use of stereotactic radiosurgery of vestibular schwannomas in cli nical practice.

Incidence of vestibular schwannoma in Finland, 1990-2017.

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. 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. In contrast to the increasing incidence reported in some studies, we found a decreasing trend in VS incidence for both sexes in Finland.

Extended Vestibular Schwannoma Presenting as an External Auditory Canal Mass: Two New Cases and Review of the Literature

This article describes two rare cases of vestibular schwannoma extending to the external auditory canal (EAC). Vestibular schwannomas typically arise from the internal acoustic canal and have a slow growth rate, rarely extending to the middle ear extension and even rarer EAC. The article highlights the importance of considering vestibular schwannoma as a differential diagnosis in patients with masses in the EAC and the need for early diagnosis and treatment to prevent potential complications.

Spontaneous Bleeding in Vestibular Schwannoma in Patients on Oral Anticoagulant Therapy: Report of Two Cases and Review of Literature.

Anticoagulant therapy is a risk factor for repeated intratumoral hemorrhage and acute enlargement of a vestibular schwannoma (VS) with neurological deficits. Therefore, we describe two cases of patients on oral anticoagulant therapy with intratumoral hemorrhage in which anticoagulant therapy prior to surgical resection was discontinued. We also discuss other similar cases from the literature since this is a rare event. We described the two cases of intratumoral hemorrhage in acoustic neurinoma and conducted a literature review of similar cases of patients with intratumoral hemorrhage in acoustic neurinoma who were also on oral anticoagulants. Both patients presented with CN-VII palsy prior to surgery; both also fully re-covered after surgery except for hearing loss on the tumor side. Our literature review found 50 cases of VS (reported as vestibular schwannomas in the literature) with intratumoral hemorrhage. From this total, 11 patients used oral anticoagulant therapy with reported poor outcomes and high mortality; 9 of these 11 cases were reported in the past 20 years. The incidence is expected to rise due to increased use of anticoagulant therapy due to onset of atrial fibrillation, atherosclerosis, and thromboembolism from longer human lifespan. Anticoagulant therapy represents a risk factor for intratumoral hemorrhage and acute enlargement of VS tumor mass with neurological deficits.

Automated, fast, robust brain extraction on contrast-enhanced T1-weighted MRI in presence of brain tumors: an optimized model based on multi-center datasets

ObjectivesExisting brain extraction models should be further optimized to provide more information for oncological analysis. We aimed to develop an nnU-Net–based deep learning model for automated brain extraction on contrast-enhanced T1-weighted (T1CE) images in presence of brain tumors.MethodsThis is a multi-center, retrospective study involving 920 patients. A total of 720 cases with four types of intracranial tumors from private institutions were collected and set as the training group and the internal test group. Mann–Whitney U test (U test) was used to investigate if the model performance was associated with pathological types and tumor characteristics. Then, the generalization of model was independently tested on public datasets consisting of 100 glioma and 100 vestibular schwannoma cases.ResultsIn the internal test, the model achieved promising performance with median Dice similarity coefficient (DSC) of 0.989 (interquartile range (IQR), 0.988–0.991), and Hausdorff distance (HD) of 6.403 mm (IQR, 5.099–8.426 mm). U test suggested a slightly descending performance in meningioma and vestibular schwannoma group. The results of U test also suggested that there was a significant difference in peritumoral edema group, with median DSC of 0.990 (IQR, 0.989–0.991, p = 0.002), and median HD of 5.916 mm (IQR, 5.000–8.000 mm, p = 0.049). In the external test, our model also showed to be robust performance, with median DSC of 0.991 (IQR, 0.983–0.998) and HD of 8.972 mm (IQR, 6.164–13.710 mm).ConclusionsFor automated processing of MRI neuroimaging data presence of brain tumors, the proposed model can perform brain extraction including important superficial structures for oncological analysis.Clinical relevance statementThe proposed model serves as a radiological tool for image preprocessing in tumor cases, focusing on superficial brain structures, which could streamline the workflow and enhance the efficiency of subsequent radiological assessments.Key Points• The nnU-Net–based model is capable of segmenting significant superficial structures in brain extraction.• The proposed model showed feasible performance, regardless of pathological types or tumor characteristics.• The model showed generalization in the public datasets.

Incidence of Vestibular Schwannoma in Patients with Unilateral Tinnitus: A Systematic Review and Meta-Analysis.

Vestibular schwannoma (VS) is a tumor of the vestibulocochlear nerve. Current literature indicates that 1.6% of patients undergoing magnetic resonance imaging of the internal auditory meatus (MRI IAM) for audiovestibular symptoms are diagnosed with a VS. However, there is limited research reporting on patients who present with unilateral tinnitus without asymmetrical hearing loss. This study is a systematic review and meta-analysis evaluating how many of those patients had a VS diagnosed on MRI IAM. Online searches of PubMed, Medline, and Embase databases were performed up to October 2022. This meta-analysis was undertaken aligning with PRISMA guidelines. Articles reporting on patients having MRI IAM for unilateral tinnitus without asymmetrical hearing loss were included. Outcomes measures were patient demographics, VS cases, incidental findings, size, and management of tumor. A meta-analysis of proportions was performed using a random-effects model with the restricted maximum likelihood method. Quality assessment was performed using the Joanna Briggs Institute critical appraisal checklist. Seven case series were included in the review: a total of 1,394 patients. Seven patients had a VS, with a median size of 4 mm. The pooled detection rate for VS was 0.08% (95% confidence interval = 0.00-0.45). Subsequent management was reported in six cases of which four were actively monitored and two surgically excised. The most common incidental finding was sinus disease (49 patients). Our findings indicate that MRI IAM has a low diagnostic yield for VS detection in patients presenting with unilateral tinnitus without asymmetrical hearing loss, with mostly small tumors that are conservatively managed.

Incidence and presentation of vestibular schwannoma: a 3-year cohort registry study.

Vestibular schwannoma (VS) is the most common benign tumour arising in the lateral skull base. Reported incidence rates of VS vary across geographical locations and over time. There is scarce updated evidence over the past decade on the epidemiology and mode of presentation of VS. To describe the epidemiology and mode of presentation of VS in the East of England between 2013 and 2016. A retrospective epidemiological analysis of data from a national VS registry and electronic patient records was conducted, including all newly diagnosed adult patients in a UK tertiary referral centre, between April 1st, 2013, and March 31st, 2016. There were 391 new cases identified resulting in an overall mean incidence of 2.2 VS cases per 100,000 person-year. The incidence rate for all patients in the <40 age group ranged between 0.3 and 0.7 per 100,000 person-year, increasing to a range of 5.7 to 6.1 per 100,000 person-year in the 60-69 age group. The top three combinations of symptoms on presentation per patient were hearing loss and tinnitus (97, 24.8%), hearing loss alone (79, 20.2%) and hearing loss, tinnitus, and balance symptoms (61, 15.6%). The median duration of symptoms was 12 months, with a wide range from 1.4 to 300 months. Age was negatively correlated with tumour size (r = -0.14 [-0.24 to -0.04], p=0.01) and positively correlated with symptom duration (r = 0.16 [0.03-0.29], p=0.02). The incidence of vestibular schwannoma has increased compared to previous studies in the UK and is similar to incidence rates reported in other countries during the past decade. It peaks in the seventh decade of life, mainly because of an increase in the diagnosis of small tumours with a long duration of audio-vestibular symptoms in older patients, compared to earlier studies.

Bilateral vision loss as first presentation of vestibular schwannoma

Abstract Vestibular schwannoma is a benign, slow-growing tumor of the vestibular nerve, located at cerebellopontine angle. It is derived from the Schwann cells of the myelin sheath of cranial nerve eight. We present here a unique case of vestibular schwannoma, who visited us with a primary complaint of bilateral decreased vision. Detailed examination revealed bilateral papilloedema associated with right-sided cranial nerve five and eight involvements. Patient was operated for the right-sided cerebellopontine angle tumor under intraoperative neuromonitoring. Postoperatively, patient showed significant improvement, both symptomatically and clinically.

Patient-specific geometrical distortion corrections of MRI images improve dosimetric planning accuracy of vestibular schwannoma treated with gamma knife stereotactic radiosurgery.

To investigate the impact of MRI patient-specific geometrical distortion (PSD) on the quality of Gamma Knife stereotactic radiosurgery (GK-SRS) plans of the vestibular schwannoma (VS) tumors. Three open access datasets including the MPI-Leipzig Mind-Brain-Body (318 patients), the slow event-related fMRI designs dataset (62 patients), and the VS dataset (242 patients) were used. We used first two datasets to train a 3D convolution network to predict the distortion map of third dataset that were then used to calculate and correct the PSD. GK-SRS plans of VS dataset were used to evaluate dose distribution of PSD-corrected MRI images. GK-SRS prescription dose of VS cases was 12Gy. Geometric and dosimetric discrepancies were assessed between the dose distributions and contours before and after the PSD corrections. Geometry indices were center of the contours, Dice coefficient (DC), Hausdorff distance (HD), and dosimetric indices were , , , and doses, target coverage (TC), Paddick's conformity index (PCI), Paddick's gradient index (GI), and homogeneity index (HI). Geometric distortions of about 1.2mm were observed at the air-tissue interfaces at the air canal and nasal cavity borders. Average center of the targets was significantly distorted along the frequency encoding direction after the PSD-correction. Average DC and HD metrics were 0.90 and 2.13mm. Average , and in Gy significantly increased after PSD correction from 16.85 to 17.25, 12.30 to 12.77, and from 8.98 to 9.92. did not significantly change after the correction. Average TC and PCI significantly increased from 0.97 to 0.98, and 0.94 to 0.96. Average GI decreased significantly from 2.24 to 2.15 after PSD correction. However, HI did not significantly change after the correction. The proposed method could predict and correct the PSD that indicates the importance of PSD correction before GK-SRS plans of the VS patients.

Cerebellopontine angle tumours: clinico-radiological features and surgical outcome

Object. Our aim is to demonstrate the various aspects of clinical-Radiological presentation and surgical Outcome with association to the tumour size concerning cerebellopontine angle (CPA) tumours.&#x0D; Materials and method. This is a prospective study of 40 patients at the Department of Neurosurgery, Jayarogya Group of Hospitals, GRMC Gwalior, M.P. India. All of the patients were pre-operatively evaluated with either non-enhanced and enhanced computerized tomography (CT) or Magnetic-resonance (MR) imaging or both.CPA tumours (predominantly acoustic neuroma) that underwent surgical removal using a suboccipital retro sigmoid approach over a 2-year period (June 2019 to May 2021).&#x0D; Results. There was a female preponderance. The most common presentation was Sensorineural hearing loss (90%) followed by Headache (67.5%). The majority of cases of Vestibular Schwannoma have heterogenous enhancement with cystic component.65% of patients have large (26-40mm) size tumours and facial nerve preservation is 86.4% in medium size tumours (10-25 mm).and Incidence of post-postoperative of facial nerve palsy is more in Giant size tumour (&gt; 40mm) so Positive association between size of lesion and Incidence of Post-operative facial nerve palsy. CSF leak occurs in 6 patients and postoperative Hydrocephalus occur in 2 patients and Mortality occurs in 3 patients.&#x0D; Conclusion. CP angle Tumor was common in middle age group, with the incidence in females slightly more than in males. The majority of lesions were of large size (26-40mm). Most of the patients on admission had a non-serviceable hearing. Heterogeneous enhancement with cystic components was found in most of the lesions. Gross-total excision was one in the majority of cases and vestibular schwannoma was the most common histopathological lesion obtained. Facial nerve palsy was the most complication and as the size of the lesion increased, the possibility of facial nerve palsy also increased post-operatively. Overall mortality is 7.5%.

Association Between Facility Surgical Volume and Excess Time in the Hospital After Surgical Resection of Vestibular Schwannomas

High surgical vestibular schwannoma case volume in a medical institution may decrease the risk of adverse outcomes among patients undergoing vestibular schwannoma surgery. To study the association between surgical vestibular schwannoma case volume and excess time in the hospital after vestibular schwannoma surgery. This cohort study evaluated data from the National Cancer Database from January 1, 2004, through December 31, 2019, on Commission on Cancer-accredited facilities in the US. The hospital-based sample comprised adult patients aged 18 years or older with a vestibular schwannoma treated with surgery. Facility case volume, defined as the mean number of surgical vestibular schwannoma cases per year in the 2 years preceding the index case. The primary outcome was a composite of prolonged hospital stay (>90th percentile) or 30-day readmission. Risk-adjusted restricted cubic splines were used to model the probability of the outcome according to facility volume. The inflection point (in cases per year) when the declining risk of excess time in the hospital began to plateau was selected as the threshold to define high- and low-volume facilities. Outcomes were compared among patients treated at high- and low-volume facilities, with mixed-effects logistic regression models adjusting for patient sociodemographic characteristics, comorbidities, tumor size, and clustering within facilities. Collected data were analyzed between June 24 and August 31, 2022. Among 11 524 eligible patients (mean [SD] age, 50.2 [12.8] years; 53.5% female; 46.5% male) who underwent surgical resection of vestibular schwannoma at 66 reporting facilities, the median length of stay was 4 (IQR, 3-5) days, and 655 patients (5.7%) were readmitted within 30 days. The median case volume was 16 (IQR, 9-26) cases per year. An adjusted restricted cubic spline model identified a downtrending probability of excess time in the hospital with increasing volume. The declining risk of excess time in the hospital began to plateau at a facility volume of 25 cases per year. Surgery at a facility with an annual case volume at or above this threshold was independently associated with a 42% reduction in the odds of excess time in the hospital compared with surgery at a low-volume center (odds ratio, 0.58; 95% CI, 0.44-0.77). This cohort study found that among adults undergoing vestibular schwannoma surgery, a higher facility case volume was associated with a reduced risk of prolonged hospital stay or 30-day readmission. A facility case volume of 25 cases per year may represent a risk-defining threshold.

Genome-wide association analysis identifies a susceptibility locus for sporadic vestibular schwannoma at 9p21.

Vestibular schwannomas are benign nerve sheath tumours that arise on the vestibulocochlear nerves. Vestibular schwannomas are known to occur in the context of tumour predisposition syndromes NF2-related and LZTR1-related schwannomatosis. However, the majority of vestibular schwannomas present sporadically without identification of germline pathogenic variants. To identify novel genetic associations with risk of vestibular schwannoma development, we conducted a genome-wide association study in a cohort of 911 sporadic vestibular schwannoma cases collated from the neurofibromatosis type 2 genetic testing service in the North West of England, UK and 5,500 control samples from the UK Biobank resource. One risk locus reached genome-wide significance in our association analysis (9p21.3, rs1556516, P = 1.47e-13, odds ratio = 0.67, allele frequency = 0.52). 9p21.3 is a genome-wide association study association hotspot, and a number of genes are localised to this region, notably CDKN2B-AS1 and CDKN2A/B, also referred to as the INK4 locus. Dysregulation of gene products within the INK4 locus have been associated with multiple pathologies and the genes in this region have been observed to directly impact the expression of one another. Recurrent associations of the INK4 locus with components of well described oncogenic pathways provides compelling evidence that the 9p21.3 region is truly associated with risk of vestibular schwannoma tumourigenesis.

Is There an Inherited Contribution to Risk for Sporadic Unilateral Vestibular Schwannoma? Evidence of Familial Clustering.

Unlike the autosomal dominant inheritance of neurofibromatosis 2, there are no known inherited risk factors for sporadic, unilateral vestibular schwannoma (VS), which comprise most VS cases. The authors tested a hypothesis positing a genetic contribution to predisposition to these lesions by analyzing familial clustering of cases. Familial clustering of individuals with unilateral VS was analyzed in two independent genealogical resources with linked diagnosis data: the Veterans Health Administration Genealogy Resource and the Utah Population Database. Tests for excess relatedness, estimation of relative risks (RRs) in close and distant relatives, and identification of pedigrees with a significant excess of unilateral VS among descendants were performed. The average pairwise relatedness of the Veterans Health Administration Genealogy Resource VS cases significantly exceeded the expected relatedness ( p = 0.016), even when close relationships were ignored ( p = 0.002). RR for third- and fifth-degree relatives developing VS were significantly elevated (RR, 60.83; p = 0.0005; 95% confidence interval [CI], 7.37-219.73) and (RR, 11.88; p = 0.013; 95% CI, 1.44-42.90), respectively. No VS-affected first-, second-, or fourth-degree relatives were observed. In the Utah Population Database population, no first- or second-degree relatives with VS were observed. RR for fifth-degree relatives developing VS was significantly elevated (RR, 2.23; p = 0.009; 95% CI, 1.15-3.90). These results provide strong evidence for an inherited predisposition to sporadic, unilateral VS. This study exhibits the value of genealogical resources with linked medical data for examining hypotheses regarding inherited predisposition. The high-risk unilateral VS pedigrees identified in two independent resources provide a powerful means of pursuing predisposition gene identification.

An Unusual Bifurcated Proximal Facial Nerve Found During Excision of a Vestibular Schwannoma: Clinical Imaging with a Surgical Video

Carefully preserving facial nerve function is crucial when using the translabyrinthine approach for vestibular schwannoma surgery. Nerve preservation can only be accomplished by employing rigorous surgical methods and having a thorough understanding of the relevant anatomy, including any variations. Anatomical variations in the path of the facial nerve are infrequent but are most commonly encountered in association with congenital abnormalities of the temporal bone or ossicles. We present a rare case of vestibular schwannoma with a bifurcated facial nerve having 2 origins at the brainstem. The patient underwent a right-sided microsurgical excision using the right translabyrinthine approach. Postoperative recovery went smoothly, resulting in a House-Brackmann scale of Grade I. This case emphasizes the importance of identifying and preserving the facial nerve during vestibular schwannoma resection. To avoid injury, intraoperative neurostimulation should be used to positively identify the facial nerve and its anatomical variations along its entire course.