Auditory brainstem implants for hearing rehabilitation in NF2-schwannomatosis: A systematic review and single-arm meta-analysis.

BACKGROUND: NF2-schwannomatosis (NF2) is an autosomal dominant disorder prone to hearing loss. Auditory brainstem implants (ABIs) offer a promising solution for hearing rehabilitation in NF2. OBJECTIVE: To synthesize existing literature on ABI implantation in NF2, focusing on audiological outcomes and ABI-related complications. METHODS: The systematic review followed PRISMA guidelines and was registered in the PROSPERO database (CRD42022362155). Relevant studies were identified by searching PubMed, EMBASE, CENTRAL, CMB, and CNKI from inception to August 2023. Data on environmental sound discrimination, open-set discrimination, closed-set discrimination, and ABI-related complications were extracted and subjected to meta-analysis. Publication bias was evaluated using funnel plots and Egger's test. RESULTS: Thirty-three studies were included. The pooled estimate was 58% (95% CI 49-66%) for environmental sound discrimination and 55% (95% CI 40-69%) for closed-set discrimination. Regarding open-set discrimination, the pooled estimates were 30% (95% CI 19-42%) for sound only, 46% (95% CI 37-54%) for lip-reading only, and 63% (95% CI 55-70%) for sound plus lip-reading. The pooled occurrence of ABI-related complications was 33% (95% CI 15-52%). CONCLUSION: This meta-analysis underscores the effectiveness and safety of ABIs in NF2, providing valuable insights for evidence-based decision-making and hearing rehabilitation strategies.

[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.

Imaging as an early biomarker to predict sensitivity to everolimus for progressive NF2-related vestibular schwannoma.

PURPOSE: NF2-related schwannomatosis (NF2) is characterized by bilateral vestibular schwannomas (VS) often causing hearing and neurologic deficits, with currently no FDA-approved drug treatment. Pre-clinical studies highlighted the potential of mTORC1 inhibition in delaying schwannoma progression. We conducted a prospective open-label, phase II study of everolimus for progressive VS in NF2 patients and investigated imaging as a potential biomarker predicting effects on growth trajectory. METHODS: The trial enrolled 12 NF2 patients with progressive VS. Participants received oral everolimus daily for 52 weeks. Brain imaging was obtained quarterly. As primary endpoint, radiographic response (RR) was defined as ≥ 20% decrease in target VS volume. Secondary endpoints included other tumors RR, hearing outcomes, drug safety and quality of life (QOL). RESULTS: Eight participants completed the trial and four discontinued the drug early due to significant volumetric VS progression. After 52 weeks of treatment, the median annual VS growth rate decreased from 77.2% at baseline to 29.4%. There was no VS RR and 3 of 8 (37.5%) participants had stable disease. Decreased or unchanged VS volume after 3 months of treatment was predictive of stabilization at 12 months. Seven of eight participants had stable hearing during treatment except one with a decline in word recognition score. Ten of twelve participants reported only minimal changes to their QOL scores. CONCLUSIONS: Volumetric imaging at 3 months can serve as an early biomarker to predict long-term sensitivity to everolimus treatment. Everolimus may represent a safe treatment option to decrease the growth of NF2-related VS in patients who have stable hearing and neurological condition. TRN: NCT01345136 (April 29, 2011).

Patient-reported measures of tinnitus for individuals with neurofibromatosis type 2-related schwannomatosis: Recommendations for clinical trials.

BACKGROUND: Neurofibromatosis type 2-related schwannomatosis is a genetic disease characterized by the development of bilateral vestibular schwannomas, ependymomas, meningiomas, and cataracts. Mild to profound hearing loss and tinnitus are common symptoms reported by individuals with neurofibromatosis type 2. While tinnitus is known to have a significant and negative impact on the quality of life of individuals from the general population, the impact on individuals with neurofibromatosis type 2 is unknown. Consensus regarding the selection of suitable patient-reported outcome measures for assessment could advance further research into tinnitus in neurofibromatosis type 2 patients. The purpose of this work is to achieve a consensus recommendation by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration for patient-reported outcome measures used to evaluate quality of life in the domain of tinnitus for neurofibromatosis type 2 clinical trials. METHODS: The Response Evaluation in Neurofibromatosis and Schwannomatosis Patient-Reported Outcomes Communication Subgroup systematically evaluated patient-reported outcome measures of quality of life in the domain of tinnitus for individuals with neurofibromatosis type 2 using previously published Response Evaluation in Neurofibromatosis and Schwannomatosis rating procedures. Of the 19 identified patient-reported outcome measures, 3 measures were excluded because they were not validated as an outcome measure or could not have been used as a single outcome measure for a clinical trial. Sixteen published patient-reported outcome measures for the domain of tinnitus were scored and compared on their participant characteristics, item content, psychometric properties, and feasibility for use in clinical trials. RESULTS: The Tinnitus Functional Index was identified as the most highly rated measure for the assessment of tinnitus in populations with neurofibromatosis type 2, due to strengths in the areas of item content, psychometric properties, feasibility, and available scores. DISCUSSION: Response Evaluation in Neurofibromatosis and Schwannomatosis currently recommends the Tinnitus Functional Index for the assessment of tinnitus in neurofibromatosis type 2 clinical trials.

Characteristics of MicroRNA Expression Depending on the Presence or Absence of Meningioma in Patients with Neurofibromatosis Type 2: A Secondary Analysis.

Meningioma is the second most frequent tumor in patients with neurofibromatosis type 2 (NF2). The presence of meningioma is believed to be a negative prognostic marker in these patients. However, the molecular mechanisms involved in the tumorigenesis of NF2-associated meningioma are not well characterized. Epigenetic regulation, including microRNAs (miRNAs), may be involved in the development of different tumor types in patients with NF2. The objective of this study is to explore the different characteristics of serum miRNA expression depending on the presence or absence of meningioma in patients with NF2. Nine patients with NF2 who were treated at the Department of Neurosurgery, Hiroshima University Hospital, were included. Total RNA (including small RNAs) was extracted from serum samples for the preparation of a small RNA library for next-generation sequencing analysis. Differentially expressed miRNAs (DEMs) were analyzed using the DESeq2 package to compare the characteristic miRNA expression profiles of patients with and without meningioma. In small RNA sequencing analysis, out of a total of 1,879 miRNAs registered in the database, the expressions of 657 miRNAs were observed. In DEM analysis, the expressions of four miRNAs, namely, hsa-miR-664b, hsa-miR-7706, hsa-miR-590, and hsa-miR-6513, were downregulated in patients with NF2 with meningioma compared with patients with NF2 without meningioma. Hsa-miR-193a was identified as the only upregulated miRNA in patients with NF2 with meningioma. In conclusion, we identified different circulating miRNA expression characteristics depending on the presence or absence of meningioma in patients with NF2.

Neurofibromatosis Type II and Facial Paralysis: Clinical Evaluation and Management.

BACKGROUND: Facial paralysis secondary to neurofibromatosis type 2 (NF2) presents the reconstructive surgeon with unique challenges because of its pathognomonic feature of bilateral acoustic neuromas, involvement of multiple cranial nerves, use of antineoplastic agents, and management. Facial reanimation literature on managing this patient population is scant. METHODS: A comprehensive literature review was performed. All patients with NF2-related facial paralysis who presented in the past 13 years were reviewed retrospectively for type and degree of paralysis, NF2 sequelae, number of cranial nerves involved, interventional modalities, and surgical notes. RESULTS: Twelve patients with NF2-related facial paralysis were identified. All patients presented after resection of vestibular schwannoma. Mean duration of weakness before surgical intervention was 8 months. On presentation, one patient had bilateral facial weakness, 11 had multiple cranial nerve involvement, and seven were treated with antineoplastic agents. Two patients underwent gracilis free functional muscle transfer, five underwent masseteric-to-facial nerve transfer (of whom two were dually innervated with a crossfacial nerve graft), and one patient underwent depressor anguli oris myectomy. Trigeminal schwannomas did not affect reconstructive outcomes if trigeminal nerve motor function on clinical examination was normal. In addition, antineoplastic agents such as bevacizumab and temsirolimus did not affect outcomes if stopped in the perioperative period. CONCLUSIONS: Effectively managing patients with NF2-related facial paralysis necessitates understanding the progressive and systemic nature of the disease, bilateral facial nerve and multiple cranial nerve involvement, and common antineoplastic treatments. Neither antineoplastic agents nor trigeminal nerve schwannomas associated with normal examination affected outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Cases of Mixed Schwannoma-Meningioma With and Without Neurofibromatosis 2 with Emphasis on Tumorigenesis.

Concurrent occurrence of schwannoma and meningiomas are rare, and are found especially in association with neurofibromatosis type 2 (NF2). Occurrence of mixed tumor without the aforementioned conditions is extremely rare. We present three cases of mixed tumor in different locations, including two with NF2 and one without NF2. We analyse the relationship of mixed tumor with NF2 and its clinical implications. Presence of mixed schwannoma-meningioma should prompt screening for NF2. Thus aids in early diagnosis of unsuspected NF2 cases. We observed that irrespective of different locations, cases with NF2 showed frequent recurrence of schwannoma as compared to case who did not fit in the existing clinical criteria for NF2. Collision tumor and thereby NF2 mutations indicates the prognosis and recurrence of the tumor, thereby guides in deciding the management.

Longitudinal Performance of Cochlear Implants in Neurofibromatosis Type 2.

OBJECTIVE: Cochlear implants (CIs) are a well-established treatment modality for hearing loss due to neurofibromatosis type 2 (NF2). Our aim is to investigate variables that affect longitudinal performance of CIs among patients with NF2. STUDY DESIGN: Retrospective review at a single academic institution consisting of patients who have received cochlear implants following hearing loss due to NF2. METHODS: The primary outcome examined was CI disuse or explantation. Associated clinical and surgical variables were analyzed using descriptive statistics. These included postoperative pure tone average (PTA) at 500, 1000, and 2000 Hz, tumor size, previous surgery, and comorbid depression. RESULTS: A total of 12 patients and 14 cochlear implants received at our institution from 2001 to 2022 were included. Notably, 35.7% of CIs (5 out of 14 cases) resulted in disuse or explantation. The average interval until explant was 9.4 years (range 3-14 years). In explanted CI cases, 20% had previous surgery and 80% had a diagnosis of comorbid depression as compared to 22.2% and 22.2%, respectively, in intact CI cases. Maximum tumor diameter was the only variable found to impact CI usage outcome (p = 0.028). Long-term data showed that on average, patients benefit from 13.85 years of CI utility and a maximum PTA improvement of 45.0 ± 29.0 dB. CONCLUSION: Despite the recurrent nature of NF2, patients continue to receive audiological benefit from cochlear implants. We found that larger tumor size may be associated with longitudinal CI failure. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1847-1853, 2024.

Comparing Speech Recognition Outcomes Between Cochlear Implants and Auditory Brainstem Implants in Patients With NF2-Related Schwannomatosis.

OBJECTIVE: To compare cochlear implant (CI) and auditory brainstem implant (ABI) performance in patients with NF2-related schwannomatosis (NF2). STUDY DESIGN: Historical cohort. SETTING: Tertiary academic center. PATIENTS: A total of 58 devices among 48 patients were studied, including 27 ABIs implanted from 1997 to 2022 and 31 CIs implanted from 2003 to 2022. Three patients had bilateral ABIs, three had bilateral CIs, three had an ABI on one side and a CI on the other, one had a CI that was later replaced with an ipsilateral ABI, and one had an ABI and CI concurrently on the same side. INTERVENTIONS: CI or ABI ipsilateral to vestibular schwannoma. MAIN OUTCOME MEASURES: Open-set speech perception, consonant-nucleus-consonant word scores, and AzBio sentence in quiet scores. RESULTS: Among all patients, 27 (47%) achieved open-set speech perception, with 35 (61%) daily users at a median of 24 months (interquartile range [IQR], 12-87 mo) after implantation. Comparing outcomes, CIs significantly outperformed ABIs; 24 (77%) CIs achieved open-set speech perception compared with 3 (12%) ABIs, with median consonant-nucleus-consonant and AzBio scores of 31% (IQR, 0-52%) and 57% (IQR, 5-83%), respectively, for CIs, compared with 0% (IQR, 0-0%) and 0% (IQR, 0-0%), respectively, for ABIs. Patients with ABIs were younger at diagnosis and at implantation, had larger tumors, and were more likely to have postoperative facial paresis. CONCLUSION: Many patients with NF2-associated vestibular schwannoma achieved auditory benefit with either a CI or an ABI; however, outcomes were significantly better in those patients who were able to receive a CI. When disease and anatomy permit, hearing rehabilitation with a CI should be considered over an ABI in these patients. Tumor management strategies that increase the ability to successfully use CIs should be strongly considered given the high risk of losing bilateral functional acoustic hearing in this population.

Long-term outcomes of stereotactic radiosurgery for intracranial schwannoma in neurofibromatosis type 2: a genetic analysis perspective.

PURPOSE: Neurofibromatosis type 2 (NF2) is intractable because of multiple tumors involving the nervous system and is clinically diverse and genotype-dependent. Stereotactic radiosurgery (SRS) for NF2-associated schwannomas remains controversial. We aimed to investigate the association between radiosurgical outcomes and mutation types in NF2-associated schwannomas. METHODS: This single-institute retrospective study included consecutive NF2 patients with intracranial schwannomas treated with SRS. The patients' types of germline mutations ("Truncating," "Large deletion," "Splice site," "Missense," and "Mosaic") and Halliday's genetic severity scores were examined, and the associations with progression-free rate (PFR) and overall survival (OS) were analyzed. RESULTS: The study enrolled 14 patients with NF2 with 22 associated intracranial schwannomas (median follow-up, 102 months).　The PFRs in the entire cohort were 95% at 5 years and 90% at 10-20 years. The PFRs tended to be worse in patients with truncating mutation exons 2-13 than in those with other mutation types (91% at 5 years and 82% at 10-20 years vs. 100% at 10-20 years, P = 0.140). The OSs were 89% for patients aged 40 years and 74% for those aged 60 years in the entire cohort and significantly lower in genetic severity group 3 than in the other groups (100% vs. 50% for those aged 35 years; P = 0.016). CONCLUSION: SRS achieved excellent PFR for NF2-associated intracranial schwannomas in the mild (group 2A) and moderate (group 2B) groups. SRS necessitates careful consideration for the severe group (group 3), especially in cases with NF2 truncating mutation exons 2-13.

Extraordinary Speech and Language Outcomes After Auditory Brainstem Implantation: Guidance From a Case Study.

PURPOSE: Large individual differences and poor speech recognition outcomes are routinely observed in most patients who have received auditory brainstem implants (ABIs). A case report of an ABI recipient with exceptionally good speech recognition outcomes presents an opportunity to better understand the core information processing mechanisms that underlie variability and individual differences in outcomes. METHOD: A case study is reported of an adult ABI recipient (ID-006) with postlingually acquired, Neurofibromatosis Type 2 (NF2)-related hearing loss who displayed exceptional postoperative speech recognition scores. A novel battery of assessment measures was used to evaluate ID-006's auditory, cognitive, and linguistic information processing skills. RESULTS: Seventeen years following ABI activation, ID-006 scored 77.6% correct on the AzBio Sentences in quiet. On auditory processing tasks, ID-006 scored higher on tasks with meaningful sentences and much lower on tasks that relied exclusively on audibility. ID-006 also demonstrated exceptionally strong abilities on several cognitive and linguistic information processing tasks. CONCLUSIONS: Results from a novel battery of information processing tests suggest that ID-006 relies extensively on top-down predictive processing and cognitive control strategies to efficiently encode and process auditory information provided by his ABI. Results suggest that current measures of outcomes and benefits should be expanded beyond conventional speech recognition measures to include more sensitive and robust measures of speech recognition as well as neurocognitive measures such as executive function, working memory, and lexical access.

Bilateral intracochlear schwannomas: histopathological confirmation and outcomes following tumour removal and cochlear implantation with lateral wall electrodes.

Intracochlear schwannomas (ICS) are very rare benign tumours of the inner ear. We present histopathological proof of the extremely rare bilateral occurrence of intracochlear schwannomas with negative blood genetic testing for neurofibromatosis type 2 (NF2). Bilateral schwannomas are typically associated with the condition NF2 and this case is presumed to have either mosaicism for NF2 or sporadic development of bilateral tumours. For progressive bilateral tumour growth and associated profound hearing loss, surgical intervention via partial cochleoectomy, tumour removal, preservation of the modiolus, and simultaneous cochlear implantation with lateral wall electrode carrier with basal double electrode contacts was performed. The right side was operated on first with a 14-month gap between each side. The hearing in aided speech recognition for consonant-nucleus-consonant (CNC) phonemes in quiet improved from 57% to 83% 12 months after bilateral cochlear implantation (CI). Bilateral intracochlear schwannomas in non-NF2 patients are extremely rare but should be considered in cases of progressive bilateral hearing loss. Successful tumour removal and cochlear implantation utilizing a lateral wall electrode is possible and can achieve good hearing outcomes.

Meningiomas in patients with neurofibromatosis type 2 predominantly comprise 'immunogenic subtype' tumours characterised by macrophage infiltration.

Although recent molecular analyses revealed that sporadic meningiomas have various genetic, epigenetic, and transcriptomic profiles, meningioma in patients with neurofibromatosis type 2 (NF2) have not been fully elucidated. This study investigated meningiomas' clinical, histological, and molecular characteristics in NF2 patients. A long-term retrospective follow-up (13.5 ± 5.5 years) study involving total 159 meningiomas in 37 patients with NF2 was performed. Their characteristics were assessed using immunohistochemistry (IHC), bulk-RNA sequencing, and copy number analysis. All variables of meningiomas in patients with NF2 were compared with those in 189 sporadic NF2-altered meningiomas in 189 patients. Most meningiomas in NF2 patients were stable, and the mean annual growth rate was 1.0 ± 1.8 cm3/year. Twenty-eight meningiomas (17.6%) in 25 patients (43.1%) were resected during the follow-up period. WHO grade I meningiomas in patients with NF2 were more frequent than in sporadic NF2-altered meningiomas (92.9% vs. 80.9%). Transcriptomic analysis for patients with NF2/sporadic NF2-altered WHO grade I meningiomas (n = 14 vs. 15, respectively) showed that tumours in NF2 patients still had a higher immune response and immune cell infiltration than sporadic NF2-altered meningiomas. Furthermore, RNA-seq/IHC-derived immunophenotyping corroborated this enhanced immune response by identifying myeloid cell infiltration, particularly in macrophages. Clinical, histological, and transcriptomic analyses of meningiomas in patients with NF2 demonstrated that meningiomas in NF2 patients showed less aggressive behaviour than sporadic NF2-altered meningiomas and elicited a marked immune response by identifying myeloid cell infiltration, particularly of macrophages.

Fractionated Stereotactic Radiotherapy Compared to Stereotactic Radiosurgery for Vestibular Schwannoma in Patients with Type 2 Neurofibromatosis.

BACKGROUND: The use of radiotherapy (RT) for the treatment of vestibulocochlear schwannomas is standard in patients with type 2 neurofibromatosis (NF2). In the general population, fractionated RT (FRT) can achieve good results compared to single-dose radiosurgery (SRS). We aimed to assess whether this is true for NF2 patients as well. METHODS: This retrospective cohort study included 34 patients and 54 lesions treated between 2010 and 2023 in a single university hospital. RESULTS: Thirty-four patient charts were assessed. The median follow-up was 62.6 months (range, 7.1-135.8 months). Lesion size (median larger diameter, 2.5 cm) was correlated with the use of FRT (P > 0.001). Younger age also was correlated with FRT (P = 0.006). Median overall survival and progression-free survival (PFS) were not reached. The overall control rate was 76.5%, and the mean PFS was 49.8 months, compared with . 90.5% and 57.2 months, respectively, for SRS and 66.7% and 44.9 months, respectively, for FRT. There were no differences between the 2 groups in hearing loss, tinnitus, and facial palsy. CONCLUSIONS: In the NF2 population, FRT may yield worse control rates than SRS. Whenever possible, it is preferable to not fractionate treatment for these patients. Nevertheless, the FRT results were still good. More and larger prospective trials are warranted.

Ischemic Cerebellar Stroke in a Young Patient With Neurofibromatosis Type 2: A Case Report.

BACKGROUND: Neurofibromatosis type 2 (NF2) is a multifaceted disease characterized primarily by benign CNS tumors, especially meningiomas and vestibular schwannomas. There have been several cases of brainstem ischemic stroke in young NF2 patients reported in the literature. To date, there is no unified theory about the connection between NF2 and pediatric stroke. METHODS: We present a case of ischemia in the left cerebellar peduncle of a young patient with NF2, as well as a narrative review of the literature of previous cases. RESULTS: Serial magnetic resonance images (MRIs) displayed an initial area of restricted diffusion in the left cerebellar peduncle with peripheral enhancement which did improve over several months, consistent with maturing infarct. CONCLUSIONS: Our case joins several others with similar presentations and findings. The primary theory for the cause of brainstem ischemia in juvenile NF2 is a microvascular cause due to deficiency of neurofibromin 2, a regulator of endothelial development. Multicenter studies with large NF2 cohorts are needed to better characterize this syndrome.

Hearing Rehabilitation in Patients With Neurofibromatosis Type 2: The Quebec's Experience With Auditory Implants.

OBJECTIVE: To review a single-center experience with hearing rehabilitation in patients with neurofibromatosis type 2 (NF2) and to describe the auditory outcomes of cochlear implants (CIs) and auditory brainstem implants (ABI) in this population. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Twelve adult patients with NF2 who received a CI (n = 10) and/or an ABI (n = 5) between 2000 and 2021. INTERVENTIONS: Insertion of a CI and/or an ABI in NF2 patients with bilateral vestibular schwannomas (VSs). MAIN OUTCOME MEASURES: Patients' demographic data, treatment history, hearing evolution, hearing rehabilitation methods, implant details, and auditory outcomes after implantation. RESULTS: Among those who received a CI, five patients had a stable untreated VS, one patient underwent a cochlear nerve preserving surgery, and four patients received radiotherapy treatments. Six patients became regular users of their device. The median open-set sentence recognition scores were as follows: 0.5% preoperatively, 60% at 1 year postoperatively, and 80% on the most recent audiological evaluation. All patients with an ABI were implanted concomitantly with VS surgical excision, and three of them also received radiotherapy treatments. The median open-set sentence recognition scores were as follows: 4% preoperatively, 26% at 1 year postoperatively, and 0% on the most recent evaluation. Three patients became regular ABI users. CONCLUSION: Despite major technological advances, auditory outcomes with ABIs remain deceiving. Considering the overall improvement in postoperative auditory performances provided by CIs compared with ABIs, cochlear implantation standouts as a primary mean of hearing rehabilitation in NF2 patients.

Sporadic and neurofibromatosis type 2-associated meningioma in children and adolescents.

PURPOSE: Pediatric meningioma differs not only in its rare incidence from the adult meningioma, but also in its clinical characteristics. Many treatment approaches of pediatric meningioma are based on the study results of adult meningioma studies. The aim of this study was to explore the clinical and epidemiological characteristics of pediatric meningioma. METHODS: Data on pediatric patients diagnosed between 1982 and 2021 with NF2-associated or sporadic meningioma and recruited in the trials/registries HIT-ENDO, KRANIOPHARYNGEOM 2000/2007 and KRANIOPHARYNGEOM Registry 2019 were retrospectively analyzed for clinical characteristics, etiology, histology, therapy, and outcome. RESULTS: One hundred fifteen study participants were diagnosed with sporadic or NF2-associated meningioma at a median age of 10.6 years. There was a 1:1 sex ratio, with 14% of study participants suffering from NF2. 46% of the meningiomas were located hemispherically, 17% at the optic nerve/ intraorbital and 10% ventricularly. Multiple meningiomas were detected in 69% of NF2 patients and in 9% of sporadic meningiomas. 50% of the meningiomas were WHO grade I, 37% WHO grade II and 6% WHO grade III. Progressions or recurrences occurred after a median interval of 1.9 years. Eight patients (7%) died, 3 of them due to disease. The event-free survival was higher for WHO grade I than for WHO grade II meningioma patients (p = 0.008). CONCLUSIONS: The major difference to the preceding literature could be found in the distribution of different WHO grades and their influence on event-free survival. Prospective studies are warranted to assess the impact of different therapeutic regimens. CLINICAL TRIAL REGISTRATION NUMBERS: NCT00258453; NCT01272622; NCT04158284.

Cochlear Implant Outcomes between Patients with Sporadic and Neurofibromatosis Type 2-Associated Vestibular Schwannoma.

OBJECTIVE: Compare cochlear implant (CI) performance between patients with ipsilateral sporadic vestibular schwannoma (VS) and NF2-related schwannomatosis (NF2). Compare CI performance according to VS management modality. STUDY DESIGN: Historical cohort. SETTING: Tertiary academic center. PATIENTS: Forty-nine patients (52 ears) undergoing cochlear implantation in the setting of ipsilateral sporadic (n = 21) or NF2-associated VS (n = 28). INTERVENTIONS: CI ipsilateral to VS. MAIN OUTCOME MEASURES: Auditory thresholds, consonant-nucleus-consonant (CNC) word scores, and AzBio sentences in quiet scores. RESULTS: Among all patients, median post-CI pure tone average was 28 dB HL (interquartile range [IQR], 21-38), CNC word score was 39% (IQR, 6-62), and AzBio sentences in quiet score was 60% (IQR, 11-83) at a median of 12.5 months postimplantation. Despite the NF2 cohort having larger tumors, when comparing patients with sporadic versus NF2-associated VS, there were no statistically significant differences in CNC word (49% [30-70] vs. 31% [0-52]) or AzBio sentences in quiet (66% [28-80] vs. 57% [5-83]) scores. Regardless of NF2 status, all patients managed with observation, and radiosurgery achieved open-set speech. In patients who underwent microsurgery, 6 (46%) of 13 with NF2 achieved open-set speech recognition compared with 4 (67%) of 6 with sporadic disease. CONCLUSION: Select patients with VS achieve successful hearing rehabilitation with a CI. In this cohort, tumor management strategy significantly influenced CI performance, whereas differences in NF2 status exhibited less effect. Specifically, all patients managed with observation or radiosurgery achieved open-set speech perception, whereas approximately half of people with NF2-related VS and two-thirds of people with sporadic VS achieved this outcome after tumor microsurgery. When disease permits, observation and radiosurgery should be considered in patients who may later pursue a CI.