Skull base chordomas are rare, locally invasive tumors that remain a diagnostic and therapeutic challenge. We developed a machine-learning (ML) radiomics model to (i) distinguish chordoma from chondrosarcoma and skull base background, (ii) differentiate true postoperative residual tumor from treatment-related changes, and (iii) predict 2-year progression-free survival (PFS). In this retrospective, dual-center study, 61 patients underwent surgery between 1998 and 2023. Preoperative contrast-enhanced T1-weighted MRI images were pre-processed and segmented; data were augmented by 20%. ML models included nested cross-validated XGBoost and a 4-layer standard feedforward Multilayer Perceptron (MLP) (Python, Keras). The primary and secondary endpoints were diagnostic discrimination and residual-versus-treatment-related change classification; the exploratory endpoint was 2-year PFS prediction. XGBoost achieved diagnostic accuracy of 0.90 (95% CI: 0.84-0.96) in distinguishing chordoma from chondrosarcoma/skull base background, and residual-versus-change accuracy 0.91 (95% CI: 0.85-0.96). PFS prediction reached an accuracy of 0.87 (95% CI: 0.74-0.98). MLP showed comparable performance (diagnostic validation accuracy 0.89; residual classification 0.90; PFS 0.93). To our knowledge, this is the first dual-center MRI-based ML study to jointly address preoperative histologic discrimination, postoperative residual detection, and short-term PFS prediction in a small, heterogeneous cohort. These results support future clinical translation as a noninvasive decision-support tool for preoperative assessment, postoperative surveillance, and risk stratification.

OBJECTIVE:Surgical management of large vestibular schwannoma (VS; Koos grades III and IV) requires a balance between the maximum extent of resection and the best functional preservation. The primary objective of this study was to determine the volumetric threshold of the VS residual tumor at risk of progression after incomplete resection. The secondary objective was to identify other risk factors of regrowth after incomplete resection. METHODS:This retrospective study included patients who underwent incomplete resection of sporadic VS at a single center from January 2008 to December 2018. The inclusion criteria were: adult age, large single sporadic VS, incomplete resection, and follow-up of > 5 years. Quantitative 3D volumetry was assessed on pre- and postoperative contrast-enhanced T1-weighted MRI using semiautomated segmentation. The volumetric criteria for residual tumor were < 250 mm3 for near-total resection (NTR) and < 2 cm3 for subtotal resection (STR). Univariate and multivariate logistic regression analyses were performed to assess predictors of regrowth after incomplete resection. A residual volume cutoff for risk of regrowth was determined using the Youden index via area under the curve analysis. RESULTS:The cohort included 119 patients (60 female, median age 58 years) who were categorized into 3 subgroups based on the residual VS according to 3D volumetry: NTR, STR, and partial resection (PR). NTR achieved the best long-term tumor control. Kaplan-Meier progression-free survival rates at 2, 5, and 10 years were 98%, 97%, and 95% for the NTR group; 69%, 56%, and 56% for the STR group; and 20%, 0%, and 0% for the PR group, respectively (p < 0.0001). The cutoff residual volume at risk of growth was 200 mm3, with sensitivity of 95% (95% CI 74%-99%) and specificity of 77% (95% CI 68%-85%, p < 0.001). Moreover, good facial nerve outcomes (House-Brackmann grades I and II) were best achieved with PR (100%), followed by STR (96%) and NTR (90%). In the univariate analysis, the risk factors for regrowth of residual tumor were cystic morphology, residual volume, and residual location (internal auditory canal, cisternal segment, and brainstem combined). The multivariate model identified the volume and location of residual as risk factors (p < 0.0001). CONCLUSIONS:These findings suggest that limited NTR (< 250 mm3) offered an excellent compromise, with long-term tumor control comparable to that of radical resection while preserving superior functional preservation. The authors hope to stimulate discussion toward a unified volumetrically established classification of incomplete resections, allowing for cooperation in future multicenter studies.

BACKGROUND AND OBJECTIVES:Surveillance studies offer sparse knowledge of predictors of future growth in sporadic vestibular schwannomas (VS).Our aim was identification of these risk factors. We propose a scoring system to estimate the risk of growth in sporadic vestibular schwannoma. METHODS:This retrospective study is based on the demographic and radiological data of 615 adult patients under the surveillance for single VS in our center. Univariate analysis, multivariate regression, and Kaplan-Meier analysis were used when appropriate. The regression coefficient-based "VS score" was calculated based on Cox proportional-hazards regression. RESULTS:During surveillance, 285 tumors (46%) remained stable, 314 tumors (51%) grew, and 16 tumors (3%) shrank. The significant risks factors for future growth identified both in univariate and multivariate analyses were younger age at onset, cystic morphology, larger tumor volume, and cisternal location (as per Hannover grade). The proportion of growing tumors was 40%, 75%, and 96% among the homogeneous VS, primary cystic, and VS transformed to cystic, respectively. Moreover, tumor growth during the 1st year was significant predictor of continuous growth. Our "VS score" includes variables such as age, sex, morphology, and Hannover grade. The score extends between -3 and 6 points. Kaplan-Meier, confusion matrix, and receiver operating characteristic analysis proved high accuracy of our scoring model. CONCLUSION:Our retrospective study revealed that younger age, cystic morphology, cisternal extent, larger volume, and growth during 1st year were strong predictors of future growth. Moreover, we propose a scoring system that accurately estimates the risks of future tumor growth.

Importance:In the literature, there is a lack of data reporting tumor control rates after radiotherapy in actively growing vestibular schwannomas (VS). Data for this rarely studied population are needed. Objective:To estimate tumor control rates in radiologically growing VS treated with first-line radiotherapy. Design, Setting, and Participants:This international, multicenter cohort study used prospectively collected data from patients with growing unilateral VS treated first-line with radiotherapy between January 2000 and December 2023 from 8 tertiary referral skull base units. The data were analyzed in June 2025. Exposures:Radiotherapy as an initial treatment for VS. Main Outcomes and Measures:The primary outcome was treatment failure, ie VS growth postradiotherapy, which was predefined as an increase in maximum intracranial tumor diameter (ICTD) of 3 mm or greater within the first 2 years after radiotherapy or 2 mm or greater thereafter. Secondary outcomes were treatment failure based on different definitions of VS growth: (1) an increase in ICTD of 2 mm or greater, (2) an increase in ICTD of 3 mm or greater, and (3) conversion to surgery. Results:A total of 1883 patients (975 female individuals [51.8%]; median age at diagnosis, 63 years [IQR, 53-71 years]) were included in the study. Using the primary definition of treatment failure (an increase in ICTD of ≥3 mm within the first 2 years postradiotherapy or ≥2 mm thereafter), the Kaplan-Meier estimate yielded a 10-year tumor control rate of 76.1% (95% CI, 72.7%-79.2%). For secondary outcome definitions, 10-year tumor control rates were 60.1% (95% CI, 57.5%-64.3%) for an ICTD increase of 2 mm or greater, 78.3% (95% CI, 75.0%-81.2%) for an increase of 3 mm or greater, and 92.6% (95% CI, 90.4%-94.3%) for conversion to surgery. Neither pretreatment tumor size nor tumor location (intracanalicular vs extracanalicular) were significantly associated with treatment failure. Conclusions and Relevance:The results of this cohort study provide tumor control outcomes for radiologically growing VS treated with radiotherapy using several clinically relevant definitions of growth. By focusing exclusively on this rarely isolated subgroup, the findings offer targeted data to potentially inform treatment expectations and future research.

PURPOSE:Temporal bone osteoradionecrosis (ORN) is a severe complication that can occur when the temporal bone lies within the field of radiation therapy (RT), mainly for head and neck cancer. Currently, there is no universally accepted treatment approach, but both conservative and surgical management options have been proposed. We present the outcomes of surgically treated cases and propose our surgical strategy for complete management. METHODS:A retrospective study was conducted to identify temporal bone ORN cases that were primarily treated surgically at two centres between 2005 and January 2025. We recorded and analysed patients' demographics, the anatomic site of the primary tumors and assessed hearing and other postoperative outcomes. RESULTS:Fourteen cases of ORN of the temporal bone have been identified. Management for these cases varied: six were treated with canaloplasty, two had mastoidectomy with reconstruction, three had lateral temporal bone resection with blind sac closure, three were treated with petrosectomy and blind sac closure. The mean age at diagnosis was 63 years, and half of the cases involved males. The most common site of the primary tumor that received RT was the nasopharynx. CONCLUSION:Surgery is an effective management option for recalcitrant temporal bone ORN. The surgical strategy for temporal bone ORN is guided by disease extent and hearing status. As there are no standardised recommendations for its management, future research is necessary.

Rehabilitation of hearing loss is determined by both the nature and the severity of the loss. The past decades have seen a wide range of implantable hearing rehabilitation options develop. While air conduction hearing aids are the standard of care and provide excellent amplification for the majority of patients, there are occasions where they are not suitable. In this situation, there are a range of implantable auditory devices: these include bone conduction hearing devices, active middle ear implants, cochlear implants, and auditory brainstem implants. These implantable devices rehabilitate hearing by interacting with different components of the auditory pathway.

Osteomas of the internal auditory canal (IAC) are rare pathologies and diagnosis requires thin-slice computed tomography imaging of the skull or magnetic resonance imaging. We report a case of bilateral florid osteomas in the IAC resulting in tinnitus and vertigo. A literature review identified 29 publications, the majority case reports, meeting our criteria involving 40 patients. We examined symptomatology, laterality, diagnostic imaging, and management strategies. Regarding diagnosis, our findings affirm the importance of thorough clinical and radiological investigations. Of utmost importance, is the assessment of patient symptoms on an individual basis to determine treatment goals, as both conservative and surgical management options have risks and benefits. While conservative treatment remains appropriate for the majority of patients, those with more severe symptoms do experience benefit from a surgical strategy. Careful case selection and management of patient expectations continue to feature as a mainstay of successful treatment. This report aims to contribute to the growing body of literature on osteomas of the IAC and ultimately guide the establishment of evidence-based nationally recognized guidelines to improve care and outcomes in patients with this rare condition.

Objective: To characterize patient outcomes after primary stereotactic radiosurgery (SRS) for the management of sporadic facial nerve schwannoma. Study design: Retrospective cohort study. Setting: Six tertiary referral centers across the United States and United Kingdom. Patients: Adults undergoing SRS from 2000 through 2023 for sporadic facial nerve schwannoma along any segment of the facial nerve were included. Patients with NF2-related schwannomatosis were excluded. Intervention: Stereotactic radiosurgery. Main outcome measure: Long-term tumor control. Results: Among 60 patients meeting inclusion, the median age at SRS was 52 years (IQR: 41 to 64) with a median tumor size of 19.5 mm (IQR: 14.7 to 22.8). Tumors commonly involved the internal auditory canal (73%), cisternal (49%), geniculate/labyrinthine (47%), and tympanic segments (22%). Two patients experienced SRS failure and underwent salvage treatment; salvage-free survival rates (95% CI; number still at risk) at 1, 3, 5, and 10 years after SRS were 100% (100 to 100; 55), 100% (100 to 100; 36), 100% (100 to 100; 18), and 87% (72 to 100; 9), respectively. Among 31 (52%) patients with House-Brackmann (HB) grade I facial function at presentation, only 6 demonstrated worse facial function at a median of 3.2 years (IQR: 1.7 to 6.6) after SRS. Of 18 patients with serviceable hearing (AAO-HNS class A/B) at SRS, 13 maintained serviceable hearing at a median of 1.0 years (IQR: 0.5 to 4.9) of post-SRS audiometric follow-up. Conclusions: Durable tumor control after primary SRS for sporadic facial nerve schwannoma is achieved in most patients. Among those with HB grade I facial function at presentation, treatment with SRS harbors limited additional risk of facial paresis beyond observation alone.

Pulsatile tinnitus can be subjective or objective (OPT), with significant delay to diagnosis OPT aetiology is poorly characterised, and very little is known about the risk of serious pathology for patients with OPT, with diagnoses such as dural arteriovenous fistula (dAVF) having potentially life-threatening intracranial abnormalities. All patients with OPT at Addenbrooke’s, Cambridge, were prospectively studied between December 2004-March 2022 (n=59). We collected information on history, auscultation, IJV compression, myofascial triggers, otoscopy, pure tone audiometry, and CT arteriography and venography findings with concurrent Borden and Cognard classification. OPT has a very high chance of radiological somatic diagnosis (89.8%), with a high proportion of dAVFs (45.8%, n=27), and importantly, 16.7% of dAVFs were classified as Borden and Cognard Type 3 or above, indicating increased risk of intracranial haemorrhage, neurological deficit, or death. Mean age of OPT onset was 49.0±16.9, being significantly higher in patients with dAVF (58.9±9.5) or arterial abnormality (56.8±14.7) compared to idiopathic intracranial hypertension or venous origin (p<0.001). dAVFs also had a more equal gender split compared to female-predominant arterial, IIH and venous OPT (p=0.006). The significant QoL impact caused by dAVF-induced OPT is frequently treatable, typically by embolisation±styloidectomy, with 19 cases showing resolution/improvement. OPT must always undergo a thorough work-up for somatic causes given the high likelihood of diagnosis and critical risk of mortality and serious neurological complications if dAVFs causing OPT are missed. Treatment is often successful and should be undertaken at an appropriate centre of expertise.

OBJECTIVE:To examine the quality of information provided by artificial intelligence platforms ChatGPT-4 and Claude 2 surrounding the management of vestibular schwannomas. STUDY DESIGN:Cross-sectional. SETTING:Skull base surgeons were involved from different centers and countries. INTERVENTION:Thirty-six questions regarding vestibular schwannoma management were tested. Artificial intelligence responses were subsequently evaluated by 19 lateral skull base surgeons using the Quality Assessment of Medical Artificial Intelligence (QAMAI) questionnaire, assessing "Accuracy," "Clarity," "Relevance," "Completeness," "Sources," and "Usefulness." MAIN OUTCOME MEASURE:The scores of the answers from both chatbots were collected and analyzed using the Student t test. Analysis of responses grouped by stakeholders was performed with McNemar test. Stuart-Maxwell test was used to compare reading level among chatbots. Intraclass correlation coefficient was calculated. RESULTS:ChatGPT-4 demonstrated significantly improved quality over Claude 2 in 14 of 36 (38.9%) questions, whereas higher-quality scores for Claude 2 were only observed in 2 (5.6%) answers. Chatbots exhibited variation across the dimensions of "Accuracy," "Clarity," "Completeness," "Relevance," and "Usefulness," with ChatGPT-4 demonstrating a statistically significant superior performance. However, no statistically significant difference was found in the assessment of "Sources." Additionally, ChatGPT-4 provided information at a significant lower reading grade level. CONCLUSIONS:Artificial intelligence platforms failed to consistently provide accurate information surrounding the management of vestibular schwannoma, although ChatGPT-4 achieved significantly higher scores in most analyzed parameters. These findings demonstrate the potential for significant misinformation for patients seeking information through these platforms.

OBJECTIVES:This systematic review and meta-analysis aimed to estimate the rate of taste disturbance following cochlear implantation. METHODS:The review was designed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies psychophysically measured taste. DerSimonian and Laird random-effects models were used. An overall mean from studies reporting a single mean of taste strip performance was calculated using inverse variance method for pooling. RESULTS:Of 380 studies identified, 9 were included across which 55 cases of postoperative taste disturbance were reported in 498 patients. Taste was tested at variable timepoints, from <1 week to ≥6 months postoperatively. The overall rate of postoperative taste disturbance was 13.5% (95% CI, 7.6-20.7%) with high heterogeneity between studies (I2 = 62%). DISCUSSION:13.5% might indicate a higher prevalence of taste disturbance following cochlear implantation compared to the general population. However, the confidence we can assign to our calculated rate is limited by significant heterogeneity and potential publication bias. Studies reporting mean taste strip scores generally found reduced taste function on the side of the tongue ipsilateral to implantation, but this reduction wasn't statistically significant. CONCLUSION:Further research, employing more robust and standardised methodologies, is necessary to accurately ascertain the rate and nature of taste disturbance following cochlear implantation.

Cochlear implants (CIs) are prosthetic devices used to restore hearing sensation in people with severe to profound sensorineural hearing loss [1]. The success of the CI surgery relies on the surgical placement of the electrodes within the scala tympani. Electrode migration post placement is well documented and could significantly affect the overall CI performance [2]. Migration may result in extracochlear electrodes (EE). Notably, this is under-reported in the existing literature [3, 4]. Routine intraoperative measures, such as contact impedances, may not indicate misplacement or extrusion of electrodes, particularly if there is an electrically conductive blood, fluid, or soft tissue around the EEs, which may result in the normal contact impedances. If the EE are in air, the contact impedances will show an open circuit and so are easier to detect [5, 6]. Advanced measures such as the stimulation current induced non-stimulating electrode voltage (SCINSEV- termed differently in various clinical software as transimpedance matrix (TIM) by Cochlear Corp, electric field imaging (EFI) by Advanced Bionics(AB) and impedance field telemetry (IFT) by MEDEL), could potentially be used to detect the extrusion EE. The application of SCINSEV measurements in cadaveric studies demonstrates a comparable and well-defined role in the identification of electrode EE, as detailed in the existing literature [5, 6]. Here, we report three cases of intraoperative electrode extrusion detected using SCINSEV measures, subsequently performing corrective repositioning during the same surgical session which prevented the need for delayed revision surgery. This report further highlights the potential of SCINSEV as an important tool in intraoperative measures and enhancing CI surgical outcomes and reports for the first time their use in live patient surgery as determinants of EE and for intraoperative decision-making and correction. Three paediatric patients are reported, implanted either bilaterally or unilaterally on the basis of multidisciplinary team decisions. All the 3 patients were females, with a mean age of 11 ± 3 years (Table 1). Preoperative magnetic resonance imaging (MRI) was performed to evaluate cochlear anatomical structures and assess the integrity of the auditory nerve. All the patients were implanted with AB HiRes Ultra 3D implants using the round window approach. After periosteal closure, intraoperative electrical impedance and other measurements were performed. In our centre, the intraoperative test protocol follows a battery of tests including initial contact impedance measures, subsequent SCINSEV (termed EFI by AB) and Electrical Compound Action Potentials (ECAP). Following CI placement in the subperiosteal pocket and electrode insertion, the external coil is attached underneath the sterile surgical drapes and connected to a AB-AIM (active insertion monitoring) tablet system, and SCINSEV recordings are analysed by EFI analysis tool version 1.2 software (this software, currently experimental on the AIM tablet, is not commercially available at the moment). In instances where SCINSEV measures yielded inconclusive results regarding the presence of EE, ECAP assessments were also used to make determinations, particularly those from the basal end of the electrode array. It is important to note again that the contact impedances by themselves are not sensitive for detection of EE if the electrodes are surrounded by blood, saline or soft-tissue [5, 6]. If ECAP responses were absent in basal electrodes, such as for electrodes 16 or 15 for AB electrode arrays, adjacent electrode ECAP measurement were examined to determine the first electrode where robust responses were obtained. The ECAP profiles were subsequently compared with SCINSEV data to make a definitive determination of EE, indicated by a decreased intracochlear electrode voltage profile at the basal end of the array in the absence of ECAP response for the most basal electrodes. Where EE were expected, the wound was reopened, and the electrode repositioned. The entire battery of tests was then repeated. Post-operative x-rays were performed for all the patients approximately two to three weeks later to check for extrusion of the electrode array. The study followed the CARE reporting guidelines [7]. Written informed consent was collected from all the patients for anonymised data presentation. A 10-year-old female patient underwent a bilateral CI implantation surgery with full electrode insertion to the end-marker. Post-closure SCINSEV(EFI) was revealed by a heat map and line graph indicative of two potential EE in one ear, using the SCINSEV criteria from previous cadaveric studies [5, 6], with the unremarkable contact impedance measures (Figure 1A,B). Upon reopening of the periosteal closure, two EE were found, and the electrode was re-advanced into the cochlea. Immediately, repeated EFI confirmed the absence of EE post-repositioning. Post-closure ECAP measures presented with robust responses at electrodes 15 and 16, confirming the efficacy of the corrective intervention (see Figure 1C,D). A 9-year-old female patient underwent an unilateral reimplantation due to a soft device failure with full electrode insertion. Post-closure SCINSEV (EFI) indicated two EE (Figure 2A,B), a finding further supported by the absence of responses in electrode 16 and elevated ECAP thresholds in electrode 15. Surgical reopening confirmed 2 EE electrode displacement, prompting reinsertion. Post-closure SCINSEV (EFI) verified proper electrode positioning, and subsequent ECAP assessments at electrodes 15 and 16 demonstrated robust responses, validating the success of the corrective measures (Figure 2C,D). A 14-year-old female patient underwent a reimplantation with full insertion, following soft device failure. The post-closure SCINSEV (EFI) results were inconclusive but were suggestive of two potential EE (Figure 3A,B). ECAP measures at electrodes 15 and 16 were unresponsive, prompting surgical re-evaluation and reinsertion. Validation through repeat SCINSEV (EFI) confirmed normal transimpedance and the electrode positioning with subsequent ECAP responses across all electrode arrays (see Figure 3C,D). In this report we presented three cases of intraoperative electrode extrusion that occurred after the operating surgeon felt that full insertion of the electrode had been achieved. Intraoperative SCINSEV measurements subsequently identified EE and allowed for surgical correction, thereby averting the need for basal electrode inactivation during programming or delayed revision surgery for electrode repositioning. Electrode extrusion is an important factor that can significantly affect the overall outcome in the patients with CI [8]. A recently published report indicates that approximately 11.5% of CI recipients experience electrode extrusion of various numbers of electrodes within the first few weeks of post-surgery [3]. This is alarming, as it necessitates the deactivation of approximately one to two electrodes during the CI programming stage, thereby potentially limiting the overall benefits [9]. The effective application of SCINSEVs and timely intervention by the surgical team have proven to be a critical factor in immediate repositioning of the electrodes completely inside the cochlea in our three cases. In three cases, lack of ECAPs at the base might have led to suspicion and need for intraoperative x-ray, but the confirmatory SCINSEV avoided this. The salient marker for EE in the three cases presented here are that they show a notable decline in the intracochlear voltage profile especially at the basal electrode array. This is in keeping with what has been previously described as the marker for EE in cadaveric models [5, 6] but not, to date, reported in living human subjects. The SCINSEV measurements depicted in the heat map and in the line graph are essentially generated after the transimpedance measures by removing the contact impedances and plotting the 'tails' of the transimpedance measure [6, 10]. They basically document the electric field generated by each individual stimulated electrode by measuring the voltage generated on every other electrode in the array. These are generally available in all the CI manufacturers' clinical software in different versions. This enables clinicians to identify both the presence, and often the number of electrodes that are outside the cochlea. This study not only underscores the clinical significance of SCINSEV but also affirms its role as an important tool in intraoperative settings. Detecting and addressing the electrode extrusion during the same surgical session not only avoids radiation but also mitigates potential delays in waiting for radiographers. This could significantly enhance consistency and cost-effectiveness of CI surgical placement. Stimulation current induced non-stimulating electrode voltage measures from most companies take less than 5 min to perform and can be easily repeated for several times such as after insertion and after full closure of the wound. This might be useful, for instance if an electrode is felt to be unstable and shows tendencies for extrusion during the surgery. This case series reports the use of SCINSEVs for the intraoperative detection and correction of EE in live human patients. It validates the important role of SCINSEV measurements in ensuring optimal electrode array placement intraoperatively. Importantly, employing SCINSEV measures intraoperatively not only facilitates the corrective repositioning of electrode arrays within the same session but may also enhance operational efficiency for theatre utilization as these measures are rapid and do not use x-ray resources. Our clinical experience leads us to recommend the routine use of these measures in all CI surgeries. Muhammed Ayas, Manohar L Bance, Yu Cheun Tam designed the work. Muhammed Ayas acquired, analysed and drafted the manuscript. Yu Chuen Tam, Dakota Bysouth-Young, Susan T. Eitutis, Marina Salorio-Corbetto acquired the data, reviewed and provided critical revision of the manuscript. Patrick R. Axon, Manohar L. Bance, James R. Tysome, Neil P. Donnelly, Mathew E. Smith, Daniele Borsetto performed cochlear implant surgeries, reviewed and provided critical revision of the manuscript. The authors discussed the results and implications and commented on the work at all stages. Dr. James Tysome is Editor-in-Chief and Dr. Smith, Matthew is AE of the journal and co-author of this article. They were excluded from the peer-review process and all the editorial decisions related to the acceptance and publication of this article. The peer review history for this article is available at https://www.webofscience.com/api/gateway/wos/peer-review/10.1111/coa.14212. The authors confirm that the data supporting the findings of this study are available within the article.

ObjectivesNew diagnostic criteria for NF2-related schwannomatosis (NF2) were published in 2022. An updated UK prevalence was generated in accordance with these, with an emphasis on the rate of de novo NF2 (a 50% frequency is widely quoted in genetic counselling). The distribution of variant types among de novo and familial NF2 cases was also assessed.MethodsThe UK National NF2 database identifies patients meeting updated NF2 criteria from a highly ascertained population cared for by England’s specialised service. Diagnostic prevalence was assessed on 1 February 2023. Molecular analysis of blood and, where possible, tumour specimens forNF2, LZTR1andSMARCB1was performed.Results1084 living NF2 patients were identified on prevalence day (equivalent to 1 in 61 332). The proportion with NF2 inherited from an affected parent was only 23% in England. If people without a confirmed molecular diagnosis or bilateral vestibular schwannoma are excluded, the frequency of de novo NF2 remains high (72%). Of the identified de novo cases, almost half were mosaic. The most common variant type was nonsense variants, accounting for 173/697 (24.8%) of people with an established variant, but only 18/235 (7.7%) with an inheritedNF2pathogenic variant (p<0.0001). Missense variants had the highest proportion of familial association (56%). The prevalence ofLZTR1-related schwannomatosis andSMARCB1-related schwannomatosis was 1 in 527 000 and 1 in 1.1M, respectively, 8.4–18.4 times lower than NF2.ConclusionsThis work confirms a much higher rate of de novo NF2 than previously reported and highlights the benefits of maintaining patient databases for accurate counselling.

Objective:Surveillance plays a crucial role in managing patients with vestibular schwannomas (VSs). Consensus is lacking on the optimal duration, frequency, and modality of imaging. Standardizing this approach would ensure safe and effective care, reduce patient distress, and promote consistency in management decisions among clinicians. Methods:In July 2022, a multi-disciplinary Delphi consensus was conducted at the British Skull Base Society Meeting. Expert United Kingdom-based skull-base surgeons and neuroradiologists were presented semi-systematic literature reviews summarizing current evidence on VS management. Anonymized opinions were collated and discussed to reach a majority vote, which was deemed the final consensus opinion. Results:Recommendations for VS managed by surveillance are: (1) surveillance frequency should decrease over time; (2) surveillance may be discontinued when the remaining lifetime risk of VS growth is <0.5% (∼8.5 years); (3) factors such as age, VS size, VS location, and cystic components should be considered. Surveillance after surgery or radiotherapy has limited evidence but recommendations are: (4) surveillance should be adjusted based on residual tumor size or nodular enhancement. Imaging modality and sequences are recommended to be (5) high-resolution magnetic resonance imaging with T1, T2, FIESTA/CISS multiplanar sequences, contrast is not required in untreated cases, and linear reporting of measurements is pragmatically sufficient. Conclusion:This consensus and literature review provides an evidence and expert opinion-based guide to help clinicians with the surveillance of patients with VS. Further research should focus on better understanding the dynamic nature of growth risks and the growth characteristics of postintervention VS to enable personalized growth risk stratification.

Objective Pure tone audiometry (PTA) is the gold standard for hearing assessment. However, it requires access to specialized equipment. Smartphone audiometry applications (apps) have been developed to perform automated threshold audiometry and could allow patients to perform self‐administered screening or monitoring. This study aimed to assess the validity and feasibility of patients using apps to self‐assess hearing thresholds at home, with comparison to PTA. Methods A multi‐center, prospective randomized study was conducted amongst patients undergoing PTA in clinics. Participants were randomly allocated to one of four publicly‐available apps designed to measure pure tone thresholds. Participants used an app once in optimal sound‐treated conditions and a further three times at home. Ear‐specific frequency‐specific thresholds and pure tone average were compared using Pearson correlation coefficient. The percentage of app hearing tests with results within ±10 dB of PTA was calculated. Patient acceptability was assessed via an online survey. Results One hundred thirty‐nine participants submitted data. The results of two at‐home automated smartphone apps correlated strongly/very strongly with PTA average and their frequency‐specific median was within ±10 dB accuracy. Smartphone audiometry performed in sound‐treated and home conditions were very strongly correlated. The apps were rated as easy/very easy to use by 90% of participants and 90% would be happy/very happy to use an app to monitor their hearing. Conclusion Judicious use of self‐performed smartphone audiometry was both valid and feasible for two of four apps. It could provide frequency‐specific threshold estimates at home, potentially allowing assessments of patients remotely or monitoring of fluctuating hearing loss. Level of Evidence 2 Laryngoscope , 134:2864–2870, 2024