Faculty Bibliography

OBJECTIVE:We sought to apply a previously developed transimpedance (TIM) heatmap pattern classification scheme in patients with no known risk factors for cochlear anomalies, in addition to patients implanted in the revision setting, to better understand the incidence of pattern variants, and potential clinical implications. STUDY DESIGN/METHODS:Single-center retrospective review. SETTING/METHODS:Tertiary referral centre. PATIENTS/METHODS:Patients older than 6 months of age who underwent cochlear implantation between June 2020 and June 2024 with normal gross cochlear anatomy and no concern for fibrosis that had intraoperative TIM testing completed. Patients undergoing revision implantation were also included as a separate cohort. INTERVENTION/METHODS:None. MAIN OUTCOME MEASURES/METHODS:The number of patients with normal and variant TIM patterns was evaluated for each cohort. TIM patterns were subsequently compared with the electrode position found on intraoperative x-ray. RESULTS:There were 321 ears that underwent implantation and subsequent intraoperative TIM assessment meeting inclusion criteria. Of these, 310 (96.6%) were in the primary surgery setting, and 11 (3.4%) were in the revision surgical setting. In the primary surgical setting, 86.4% (n=268) of the implants demonstrated a normal TIM heatmap. Compared with the primary surgical setting, where only 45.5% (n=5) of revision surgery TIM heatmaps were interpreted as normal. One patient in the revision setting had a newly identified "double X" pattern corresponding to a normal electrode position on x-ray. CONCLUSIONS:There is a decreased incidence of previously developed TIM heatmap pattern variants in CI recipients with normal gross cochlear anatomy.

OBJECTIVE:To characterize patient outcomes after primary stereotactic radiosurgery (SRS) for the management of sporadic facial nerve schwannoma. STUDY DESIGN/METHODS:Retrospective cohort study. SETTING/METHODS:Six tertiary referral centers across the United States and United Kingdom. PATIENTS/METHODS: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/METHODS:Stereotactic radiosurgery. MAIN OUTCOME MEASURE/METHODS: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.

OBJECTIVE:NF2-related schwannomatosis (NF2-SWN) is an autosomal dominant genetic disorder characterized by the development of schwannomas, meningiomas, and spinal ependymomas. Treatment with bevacizumab, a monoclonal antibody against VEGF, has been shown to result in decreased vestibular schwannoma size and hearing improvement in ~50% of NF2-SWN patients. It is unknown whether the same degree of benefit is seen in younger patients compared with older patients. The objective of this study is to determine the association between age and bevacizumab treatment outcomes in NF2-SWN. STUDY DESIGN/METHODS:Retrospective cohort study. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:Thirty-seven patients with NF2-SWN. INTERVENTIONS/METHODS:Bevacizumab. MAIN OUTCOME MEASURES/METHODS:Change in tumor size of 20% or more. RESULTS:This study includes 37 patients with NF2-SWN who were treated with bevacizumab at our institution between 2014 and 2024. They were divided into 2 groups: 22 adults over the age of 25 (26 to 71 y) and 15 adolescent and young adult (AYA) patients under the age of 25 (12 to 24 y). The median treatment duration was 2.1 years. A significantly higher proportion of AYA schwannomas (37.5%, n=9) exhibited radiographic tumor progression during the treatment period compared with those of the older patient group (11.9%, n=5) (P=0.026), despite similar pre-treatment growth rates. There was no significant difference in the proportion of older and younger patients with hearing decline, improvement, or stability (P>0.05). CONCLUSIONS:AYA patients were significantly more likely to exhibit progression of tumor growth during bevacizumab treatment compared with older patients, though no significant differences were detected in hearing outcomes.

Hearing loss is a highly prevalent disease state affecting almost 1 in 5 individuals globally. Growing research shows that untreated or undertreated hearing loss carries significant long-term sequelae, including increased risk of social isolation, depression, and cognitive decline, among other ramifications. Limited awareness and common misperceptions among the general US adult population and primary care providers contribute to low rates of referral to hearing specialty clinics and underutilization of hearing aids, cochlear implants, and other rehabilitative devices. Comprised of diverse membership, the Hearing Health Collaborative (HHC) was formed in May 2021 to identify and overcome challenges impacting good health care practices and public policy on hearing care in connection with healthy aging. This editorial documents a recent outcome of the HHC derived from a structured A3 process. Specifically, initiative 2, a proposal to develop a simple, clinically anchored staging system primarily for use by frontline providers and patients, is presented. Unlike other common disorders that harbor long-term health sequelae, a corresponding pragmatic clinical staging system-leveraging precedent disease staging convention, based on clinically meaningful outcomes and prognosis for acquired hearing loss-does not exist. The development of this staging system will potentially allow for improved communication across providers and patients, facilitate referral pathways, and ultimately enable patient access to timely and appropriate care.

INTRODUCTION/UNASSIGNED:Skull base surgery is a highly innovative, multidisciplinary field that brings together teams of neurosurgeons, otolaryngology-head and neck surgeons (OHNS), plastic surgeons, ophthalmologists, radiation oncologists, and others. However, not long ago, the nascent field was instead characterized by isolated individual brilliance. METHODS/UNASSIGNED:This paper explores the contributions of several key players toward breaking silos and transforming the field into what it is today. Our analysis centers on the formation of the North American Skull Base Society (NASBS), and the instrumental role that it played in the development of skull base surgery. We interviewed 12 past presidents of the NASBS and 2 prominent figures in skull base surgery. The contents of those 20 hours and 38 minutes of interviews and documents from initial NASBS meetings were analyzed. Key moments were segmented into short video clips, which complement this manuscript and are available on the NASBS website. RESULTS/UNASSIGNED:A compelling narrative of collaboration, mentorship, and tenacity emerged from our analysis. In the 20th century, the field of skull base surgery was characterized mainly by courageous but isolated efforts by neurosurgeons and OHNS surgeons. Through mentorship, collaboration, and incredible innovation, it has since grown into a multidisciplinary, cutting-edge specialty that utilizes the strengths of several medical specialties. This transformation was largely facilitated by the formation of the NASBS in 1989, which enabled worldwide communication and collaboration among those dedicated to advancing the field. CONCLUSION/UNASSIGNED:The growth of skull base surgery in North America and the instrumental role of the NASBS highlight the power of collaboration and innovation. It is important to recognize and celebrate the key players who facilitated the creation and success of the NASBS, which continues to unite young members across countless disciplines under one banner.

Despite the poor sound quality provided by cochlear implants (CIs), single-sided deaf (SSD) CI users prefer to listen to music with the acoustic hearing (AH) and CI ears together rather than with the AH ear alone. The source of this binaural benefit remains unclear. In the present study, sound quality ratings were collected in SSD CI users for music excerpts from different genres (pop, rock, and classical). A novel vocoder-to-the-CI (VCI) approach was used to control the spectral and temporal information delivered to the CI ear. Custom sine-wave vocoders were designed for each participant according to the frequency allocation in their clinical map. Sound quality ratings were collected with CI-only, AH-only, and CI+AH listening. CI+AH ratings were significantly higher than AH-only ratings when unprocessed stimuli or vocoded stimuli with spectro-temporal information were delivered to the CI ear. There were no significant differences among CI+AH ratings for the unprocessed stimuli, vocoded stimuli with spectro-temporal information, and vocoded stimuli with greatly reduced temporal cues, suggesting that the binaural benefit was largely driven by similar spectral information across ears. Effects of genre were minimal. CI+AH ratings for unprocessed music were significantly correlated with CI-only ratings (r = 0.57, p < 0.001), with the slope (0.97) suggesting that the binaural benefit was largely additive between the AH and CI ears. VCI appears to be a fruitful approach to control the spectral and temporal information delivered to the CI ear without directly manipulating CI users' clinical processors.

Speech production entails several processing steps that encode linguistic and articulatory structure, but whether these computations correspond to spatiotemporally discrete patterns of neural activity is unclear. To address this issue, we use electrocorticography to directly measure the brains of neurosurgical participants performing an interactive speech paradigm. We observe a broad range of cortical modulation profiles, and subsequent clustering analyses establish that responses comprised distinct classes associated with sensory perception, planning, motor execution, and task-related suppression. These activity classes are also localized to separate neural substrates, indicating their status as specialized networks. We then parse dynamics in the planning and motor networks using unsupervised dimensionality reduction, which reveals subnetworks that are sequentially active throughout preparation and articulation. These results therefore support and extend a localizationist model of speech production where cortical activity "flows" within and across discrete pathways during language use.