Automated Whole Cochlear T2 Signal Demonstrates Weak Correlation with Hearing Loss in Observed Vestibular Schwannoma.

INTRODUCTION: We sought to evaluate the correlation between whole cochlear T2 signal changes obtained with a novel automated segmentation method and hearing levels, both at diagnosis and over time, in patients with observed vestibular schwannoma. METHODS: This retrospective correlation study within an academic medical center neurotology practice evaluated 127 patients with vestibular schwannoma observed over time, each with ≥2 MRI scans (367 total) and ≥2 audiograms (472 total). 86 patients had T2-weighted sequences with sufficient resolution for cochlear signal analysis, yielding 348 unique timepoint intervals. The main outcome measure was correlation of the ipsilateral-to-contralateral ratio of whole cochlear T2 signal with hearing outcomes as measured by pure tone average (PTA) and word recognition score (WRS). RESULTS: Whole cochlear T2 signal ratios did not show a correlation with hearing levels at diagnosis. Change in signal ratio over time showed weak correlation with changes in PTA, but not WRS, over time. Cochlear signal ratio did not precede changes in hearing but did follow changes in both PTA and WRS. CONCLUSION: Whole cochlear T2 signal ratios were weakly correlated with changes in hearing in patients with observed vestibular schwannoma. The technology of automated segmentation and signal processing holds promise for future evaluation of clinical entities causing cochlear signal changes.

Advances in understanding of presbycusis.

The pathophysiology of age-related hearing loss (ARHL), or presbycusis, involves a complex interplay between environmental and genetic factors. The fundamental biomolecular mechanisms of ARHL have been well described, including the roles of membrane transport, reactive oxygen species, cochlear synaptopathy, vascular insults, hormones, and microRNA, to name a few. The genetic basis underlying these mechanisms remains under-investigated and poorly understood. The emergence of genome-wide association studies has allowed for the identification of specific groups of genes involved in ARHL. This review highlights recent advances in understanding of the pathogenesis of ARHL, the genetic basis underlying these processes and suggests future directions for research and potential therapeutic avenues.

Inner ear manifestations in CHARGE: Abnormalities, treatments, animal models, and progress toward treatments in auditory and vestibular structures.

The inner ear contains the sensory organs for hearing and balance. Both hearing and balance are commonly affected in individuals with CHARGE syndrome (CS), an autosomal dominant condition caused by heterozygous pathogenic variants in the CHD7 gene. Semicircular canal dysplasia or aplasia is the single most prevalent feature in individuals with CHARGE leading to deficient gross motor skills and ambulation. Identification of CHD7 as the major gene affected in CHARGE has enabled acceleration of research in this field. Great progress has been made in understanding the role of CHD7 in the development and function of the inner ear, as well as in related organs such as the middle ear and auditory and vestibular neural pathways. The goals of current research on CHD7 and CS are to (a) improve our understanding of the pathology caused by CHD7 pathogenic variants and (b) to provide better tools for prognosis and treatment. Current studies utilize cells and whole animals, from flies to mammals. The mouse is an excellent model for exploring mechanisms of Chd7 function in the ear, given the evolutionary conservation of ear structure, function, Chd7 expression, and similarity of mutant phenotypes between mice and humans. Newly recognized developmental functions for mouse Chd7 are shedding light on how abnormalities in CHD7 might lead to CS symptoms in humans. Here we review known human inner ear phenotypes associated with CHD7 pathogenic variants and CS, summarize progress toward diagnosis and treatment of inner ear-related pathologies, and explore new avenues for treatment based on basic science discoveries.

The imaging appearance of crayons.

BACKGROUND: A crayon fragment was determined to be the source of a foreign body inflammatory process in the masticator space of a 15-month-old boy. The appearance of the crayon on CT and MR imaging was unexpected, leading to a further analysis of the imaging features of crayons. OBJECTIVE: To investigate and characterize the imaging appearance of crayons at CT and MRI. MATERIALS AND METHODS: The authors obtained CT and MR images of 22 crayons from three manufacturers and three non-pigmented crayons cast by the authors. CT attenuation of the crayons and diameter of the MRI susceptibility signal dropout were plotted versus brand and color. RESULTS: All crayons demonstrated a longitudinal central hypo-attenuating tract. Crayon attenuation varied by brand and color. All of the crayons demonstrated a signal void on T1 and T2 imaging and signal dropout on susceptibility-weighted imaging, the diameter of which varied by brand and color. CONCLUSION: Understanding the imaging appearance of crayons could help in the correct identification of a crayon as a foreign body on imaging studies, even when it is located in unusual places.

Trends in Inpatient Pediatric Polysomnography for Laryngomalacia and Craniofacial Anomalies.

OBJECTIVE: Increasingly, laryngomalacia and craniofacial anomalies are recognized as risk factors for obstructive sleep apnea. We sought to determine whether children with these diagnoses have become more likely to undergo inpatient polysomnogram (PSG) over time and to identify evolving trends in PSG utilization. METHODS: Retrospective analysis of the Kids' Inpatient Database from 2003 to 2012. Children <21 years who underwent PSG were included. Weighted comparisons of clinical/demographic characteristics of patients undergoing PSG were performed, as were associations between clinical and demographic patient characteristics and performance of inpatient PSG. RESULTS: Between 2003 and 2012, PSG procedures decreased from 1266 to 829 (P < .001). Among children who underwent PSG, mean age decreased from 3.9 ± 5.1 to 3.1 ± 5.2 years (P = .001), and the frequency of age <1 year increased from 47.8% to 59.5% (P < .001). The frequency of laryngomalacia increased from 2.5% to 14.3% (P < .001), while the frequency of craniofacial anomalies increased from 6.2% to 19.4% (P < .001). Laryngomalacia and craniofacial anomalies were predictive of undergoing inpatient PSG in both timeframes. CONCLUSION: Despite decreasing PSG volumes, diagnoses of laryngomalacia and craniofacial anomalies comprised increasing fractions of children undergoing inpatient PSG between 2003 and 2012. Laryngomalacia and craniofacial anomalies were also predictive of inpatient PSG use in both timeframes.

Endoscopic Versus Microscopic Transcanal Resection of Glomus Tympanicum: A Retrospective Comparative Study.

OBJECTIVE: Comparison of outcomes of microscopic and endoscopic resection of glomus tympanicum (GT) tumors. STUDY DESIGN: Retrospective case review. SETTING: Single tertiary referral center. PATIENTS: All adult patients undergoing transcanal GT resection without mastoidectomy from 2007 to 2021. INTERVENTIONS: Surgical resection-endoscopic versus microscopic approach. MAIN OUTCOME MEASURES: Primary outcomes were tumor recurrence at 1 year and presence of residual tumor at conclusion of surgery. Secondary outcome measures included operative time, postoperative air-bone gap, postoperative symptom resolution, and surgical complications. RESULTS: Thirty-eight patients underwent resection of GT (74% female; mean age, 59 years). Twenty-nine cases were performed microscopically, and nine cases were performed endoscopically. Both endoscopic and microscopic approaches yielded high rates of complete tumor resection (27/29 microscopic cases, 7/9 endoscopic cases). There was no significant difference in mean operative time (2.3 hours for microscopic; 2.6 hours for endoscopic). On average, air-bone gaps (ABGs) decreased by 6.3 dB after endoscopic resection compared with 1.0 dB after microscopic resection ( p = 0.064). No patients were found to have tumor recurrence during an average follow-up interval of 21 months. CONCLUSIONS: These results suggest comparable outcomes with both endoscopic and microscopic approaches for GT resection, and decisions regarding preferred approach should be dictated by surgeon preference.

Comparison of Speech Recognition and Hearing Preservation Outcomes Between the Mid-Scala and Lateral Wall Electrode Arrays.

OBJECTIVE: To assess speech recognition and hearing preservation (HP) outcomes with the Advanced Bionics Mid-Scala and SlimJ electrodes. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: A total of 237 adult patients implanted between 2013 and 2020 (Mid-Scala, n = 136; SlimJ, n = 101). MAIN OUTCOME MEASURES: Consonant-nucleus-consonant (CNC) and AzBio (Arizona Biomedical) scores at 6 and 12 months; postoperative HP, defined as low-frequency pure-tone average ≤ 80 dB HL; scalar position. RESULTS: Mean CNC scores did not significantly differ between Mid-Scala and SlimJ recipients at 6 (45.8% versus 46.0%, p = 0.962) and 12 (51.9% versus 48.8%, p = 0.363) months. Similarly, mean AzBio in quiet scores were equivalent for both groups at 6 (55.1% versus 59.2%, p = 0.334) and 12 (60.6% versus 62.3%, p = 0.684) months. HP rates were significantly higher with the SlimJ (48.4%) than the Mid-Scala (30.8%; p = 0.033). Scalar translocations were 34.8 and 16.1% for the Mid-Scala and SlimJ groups, respectively ( p = 0.019). Ears with postoperative HP had significantly fewer scalar translocations (16.7% versus 37.2%, p = 0.048), and postoperative HP was associated with higher AzBio in noise scores at the most recent follow-up interval (38.7% versus 25.1%, p = 0.042). CNC, AzBio in quiet and noise, low-frequency pure-tone average shifts, and PTA at 6 and 12 months were not significantly different between patients with scala tympani insertions of the SlimJ versus the Mid-Scala ( p > 0.05). CONCLUSIONS: Compared with the Mid-Scala, the lateral wall electrode has superior HP rates and fewer scalar translocations, whereas speech recognition scores are equivalent between both electrode arrays. These findings can help providers with electrode selection and patient counseling.

Clinical Applications for Spread of Excitation Functions Obtained Via Electrically Evoked Compound Action Potentials (eCAP).

OBJECTIVES: To assess the clinical utility of spread of excitation (SOE) functions obtained via electrically evoked compound action potentials (eCAP) to 1) identify electrode array tip fold-over, 2) predict electrode placement factors confirmed via postoperative computed tomography (CT) imaging, and 3) predict postoperative speech recognition through the first year post-activation in a large clinical sample. STUDY DESIGN: Retrospective case review. SETTING: Cochlear implant (CI) program at a tertiary medical center. PATIENTS: Two hundred seventy-two ears (238 patients) with Cochlear Ltd. CIs (mean age = 46 yr, range = 9 mo-93 yr, 50% female) implanted between August 2014 and December 2022 were included. MAIN OUTCOME MEASURES: eCAP SOE widths (mm) (probe electrodes 5, 11, and 17), incidence of electrode tip fold-over, CT imaging data (electrode-to-modiolus distance, angular insertion depth, scalar location), and speech recognition outcomes (consonant-nucleus-consonant [CNC], AzBio quiet, and +5 dB SNR) through the first year after CI activation. RESULTS: 1) eCAP SOE demonstrated a sensitivity of 85.7% for identifying tip fold-over instances that were confirmed by CT imaging. In the current dataset, the tip fold-over incidence rate was 3.1% (7 patients), with all instances involving a precurved electrode array. 2) There was a significant positive relationship between eCAP SOE and mean electrode-to-modiolus distance for precurved arrays, and a significant positive relationship between eCAP SOE and angular insertion depth for straight arrays. No relationships between eCAP SOE and scalar location or cochlea diameter were found in this sample. 3) There were no significant relationships between eCAP SOE and speech recognition outcomes for any measure or time point, except for a weak negative correlation between average eCAP SOE widths and CNC word scores at 6 months post-activation for precurved arrays. CONCLUSIONS: In the absence of intraoperative CT or fluoroscopic imaging, eCAP SOE is a reasonable alternative method for identifying electrode array tip fold-over and should be routinely measured intraoperatively, especially for precurved electrode arrays with a sheath.

Improved Postoperative Speech Recognition and Processor Use With Early Cochlear Implant Activation.

OBJECTIVE: To report speech recognition outcomes and processor use based on timing of cochlear implant (CI) activation. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: A total of 604 adult CI recipients from October 2011 to March 2022, stratified by timing of CI activation (group 1: ≤10 d, n = 47; group 2: >10 d, n = 557). MAIN OUTCOME MEASURES: Average daily processor use; Consonant-Nucleus-Consonant (CNC) and Arizona Biomedical (AzBio) in quiet at 1-, 3-, 6-, and 12-month visits; time to peak performance. RESULTS: The groups did not differ in sex ( p = 0.887), age at CI ( p = 0.109), preoperative CNC ( p = 0.070), or preoperative AzBio in quiet ( p = 0.113). Group 1 had higher median daily processor use than group 2 at the 1-month visit (12.3 versus 10.7 h/d, p = 0.017), with no significant differences at 3, 6, and 12 months. The early activation group had superior median CNC performance at 3 months (56% versus 46%, p = 0.007) and 12 months (60% versus 52%, p = 0.044). Similarly, the early activation group had superior median AzBio in quiet performance at 3 months (72% versus 59%, p = 0.008) and 12 months (75% versus 68%, p = 0.049). Both groups were equivalent in time to peak performance for CNC and AzBio. Earlier CI activation was significantly correlated with higher average daily processor use at all follow-up intervals. CONCLUSION: CI activation within 10 days of surgery is associated with increased early device usage and superior speech recognition at both early and late follow-up visits. Timing of activation and device usage are modifiable factors that can help optimize postoperative outcomes in the CI population.

Lumbar Drain Use during Middle Fossa Approaches for Nonneoplastic Pathology of the Skull Base.

Introduction The middle fossa craniotomy (MFCs) is commonly utilized for spontaneous cerebrospinal fluid (CSF) leaks, encephaloceles, and superior semicircular canal dehiscence (SSCD). This study compares postoperative outcomes of MFCs with and without LD use. Methods A retrospective cohort study of adults over the age of 18 years presenting for the repair of nonneoplastic CSF leak, encephalocele, or SSCD via MFC from 2009 to 2021 was conducted. The main exposure of interest was the placement of an LD. The primary outcome was the presence of postoperative complications (acute/delayed neurologic deficit, meningitis, intracranial hemorrhage, and stroke). Secondary outcomes included operating room (OR) time, length of stay, recurrence, and need for reoperation. Results In total, 172 patients were included, 96 of whom received an LD and 76 who did not. Patients not receiving an LD were more likely to receive intraoperative mannitol ( n = 24, 31.6% vs. n = 16, 16.7%, p = 0.02). On univariate logistic regression, LD placement did not influence overall postoperative complications (OR: 0.38, 95% confidence interval [CI]: 0.05-2.02, p = 0.28), CSF leak recurrence (OR: 0.75, 95% CI: 0.25-2.29, p = 0.61), or need for reoperation (OR: 1.47, 95% CI: 0.48-4.96, p = 0.51). While OR time was shorter for patients not receiving LD (349 ± 71 vs. 372 ± 85 minutes), this difference was not statistically significant ( p = 0.07). Conclusion No difference in postoperative outcomes was observed in patients who had an intraoperative LD placed compared to those without LD. Operative times were increased in the LD cohort, but this difference was not statistically significant. Given the similar outcomes, we conclude that LD is not necessary to facilitate safe MCF for nonneoplastic skull base pathologies.

Facial Paralysis in Skull Base Osteomyelitis - Comparison of Surgical and Nonsurgical Management.

TITLE: Facial Paralysis in Skull Base Osteomyelitis - Comparison of Surgical and Nonsurgical Management. OBJECTIVE: To compare outcomes of surgical and nonsurgical management in cases of facial paresis secondary to skull base osteomyelitis. METHODS: A 14 patients presenting with skull base osteomyelitis complicated by facial nerve paresis at a single tertiary referral center from 2009 to 2019 were retrospectively reviewed. Patients were treated with medical therapy with or without surgical intervention, consisting of mastoidectomy and debridement with or without facial nerve decompression. House-Brackmann (HB) Grade was the main outcome measure. RESULTS: A 14 patients (average age 68 years, range 58-82 years, 71% male) were analyzed, with 5 undergoing facial nerve decompression (36%), 5 undergoing mastoidectomy without facial nerve decompression (36%), and 4 undergoing medical management alone (28%). Of the 4 patients who underwent medical therapy alone, none experienced significant improvement in facial function. Of the 5 patients who underwent facial nerve decompression, 3 patients experienced improved facial function. Of the 5 patients who underwent mastoidectomy without decompression, 4 experienced improved facial function. There was no clear link between the severity of infection and the severity of facial paresis. When comparing HB score changes before and after treatment across groups, there was no statistically significant difference seen (p = 0.47). CONCLUSIONS: Mastoidectomy and debridement with or without facial nerve decompression may improve facial nerve outcomes when compared to isolated medical management, although differences were not of statistical significance. The best facial nerve recoveries occurred in patients undergoing surgery within 14 days of the onset of paralysis. LEVEL OF EVIDENCE: 4 - Case Series Laryngoscope, 133:179-183, 2023.

Endoscope-Assisted Visualization of the Internal Auditory Canal Using the Middle Fossa Approach.

HYPOTHESIS: Angled endoscopes have been postulated to increase visualization of the internal auditory canal (IAC); however, few studies have quantified the extent of IAC visualization using endoscopes of varying angles. BACKGROUND: Preservation of the bony labyrinth in middle fossa (MF) vestibular schwannoma surgery may limit visualization of the lateral IAC. We sought to determine the extent to which IAC visualization is increased with endoscopes in these situations. METHODS: Computed tomography (CT) scans were acquired before and after two cadaveric MF bony drill-outs. An atlas-based method was used to localize the IAC in the preprocedure CT and then registered with the postprocedure CT using standard image registration methods. Virtual microscope and endoscope positions and angles of approach were determined in a 3D rendering environment. Using ray casting techniques, the percentage of IAC surface area visible (unobscured by bony structures) with the microscope and 0°, 30°, and 45° endoscopes was calculated. RESULTS: For cadaver 1, the microscope led to visible IAC surface areas of 72%, whereas 0°, 30°, and 45° endoscopes visualized 58%, 79%, and 84%, respectively. For cadaver 2, the microscope led to visible surface areas of 67%, whereas the same endoscopes visualized 66%, 84%, and 84%, respectively. CONCLUSIONS: Using a microscope yields similar proportions of visible IAC surface area to a 0° endoscope in MF bony drill-outs. Increased visualization of the IAC is possible with more angled endoscopes. Using angled endoscopes may facilitate improved tumor dissection in the lateral IAC with neural and vascular preservation in vestibular schwannoma surgery aimed at hearing preservation.

Association of Postoperative Sigmoid Sinus Occlusion and Cerebrospinal Fluid Leak in Translabyrinthine Surgery.

OBJECTIVE: To characterize the incidence of sigmoid sinus occlusion (SSO) following translabyrinthine (TL) surgery for posterior fossa tumor resection and determine the association with cerebrospinal fluid (CSF) leak. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. METHODS: Patients undergoing TL surgery for vestibular schwannoma from 2012 to 2020 were included. Demographic data, medical history, preoperative tumor length and volume, and postoperative complications including CSF leak were recorded. Neuroradiology review of postoperative magnetic resonance imaging was used to determine the presence or absence of flow through the sigmoid sinus. RESULTS: Of 205 patients undergoing TL, 21 (10.2%) experienced CSF leak postoperatively. Overall 56 (27%) demonstrated SSO on immediate postoperative magnetic resonance imaging. CSF leaks were more likely in those with SSO (19.6%) than those without SSO (6.7%; odds ratio, 3.54 [95% CI, 1.25-10.17]). Tumor volume and body mass index were not significantly associated with CSF leak. In total, 105 (51%) patients had some degree of sigmoid sinus thrombosis, but nonocclusive thrombosis was not associated with CSF leak. CONCLUSION: SSO after TL approaches is common and appears to be significantly associated with postoperative CSF leak development. Minimizing manipulation of the sigmoid sinus during TL surgery and compression after surgery may have a role in preventing CSF leak.

Radiographic Sigmoid Sinus Wall Abnormalities and Pulsatile Tinnitus: A Case-Control Study.

OBJECTIVE: Compare incidence of sigmoid sinus wall abnormalities (SSWAs) and other radiographic abnormalities in patients with pulsatile tinnitus (PT) versus controls. STUDY DESIGN: Retrospective case-control. SETTING: Tertiary referral center. PATIENTS: Adults with PT and high-resolution computed tomography imaging were compared with adults undergoing cochlear implant workup including high-resolution computed tomography imaging. MAIN OUTCOME MEASURES: Incidence of SSWA in PT cohort (n = 141) compared with control (n = 149, n = 298 ears). Secondary outcome measures included differences in demographics and in other radiographic abnormalities between cohorts. RESULTS: Patients with PT had a higher incidence of SSWA (34% versus 9%, p < 0.001) and superior canal dehiscence (23% versus 12%, p = 0.017) than controls. Spearman product component correlations demonstrated that ipsilateral PT was weakly associated with SSWA ( r = 0.354, p < 0.001). When SSWA was present in the PT cohort (n = 48 patients, n = 59 ears), in 31 cases (64.6%), the SSWA correlated with PT laterality (e.g., left SSWA, left PT); in 12 (25.0%), SSWA partially correlated with PT laterality (e.g., bilateral SSWA, right PT); and in 5 (10.4%), the SSWA did not correlate with PT laterality (e.g., right SSWA, left PT). CONCLUSIONS: For our patients with both PT and SSWA, the SSWA is likely a contributing factor in approximately 65% of cases. For a third of patients with PT and concomitant SSWA, the association between the two is either not causative or not solely causative. Surgeons counseling patients with PT and SSWA may be optimistic overall regarding sigmoid resurfacing procedures but must appreciate the possibility of treatment failure, likely because of untreated comorbid conditions.

Presbycusis and Hearing Preservation in Observed Vestibular Schwannomas.

OBJECTIVE: We reviewed a cohort of patients with untreated sporadic vestibular schwannoma (VS) and examined the relationship between high-frequency hearing loss (HFHL) in the non-VS ear and long-term hearing outcomes in the VS-affected ear. We hypothesized that the progression of HFHL is associated with accelerated hearing decline in sporadic VS. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary center. PATIENTS: We studied 102 patients with sporadic VS diagnosed from 1999 to 2015 with ≥5 years of observation (median, 6.92; interquartile range, 5.85-9.29). Sixty-six patients had AAO-HNS class A/B hearing at presentation and were included in analysis. INTERVENTIONS: Audiometry, serial magnetic resonance imaging for observation of VS. MAIN OUTCOME MEASURES: Four-frequency pure tone average (PTA) and word recognition scores (WRS) in the VS-affected ear. Decline in high-frequency PTA (average of thresholds at 4000, 6000, and 8,000 Hz) was defined as ≥10 dB during the study period. Decline in WRS was defined as ≥10%. RESULTS: Compared with those without, patients with progressive HFHL in the non-VS ear were more likely to experience a decline in WRS in the VS ear (80% vs. 54%, p = 0.031). However, the same group showed no difference (52% vs. 41%, p = 0.40) in decline in PTA of the VS ear. CONCLUSIONS: Patients with observed VS who experience progressive HFHL in the non-VS ear are more likely to experience significant declines in speech understanding in the VS-affected ear over time. Patients with a history of presbycusis may have an increased risk of losing serviceable hearing because of sporadic VS.

Cochlear Implants for Single-Sided Deafness: Quality of Life, Daily Usage, and Duration of Deafness.

OBJECTIVE: To report our experience for adults undergoing cochlear implantation (CI) for single-sided deafness (SSD). METHODS: This is a retrospective case series for adults with SSD who underwent CI between January 2013 and May 2021 at our institution. CNC and AzBio speech recognition scores, Tinnitus Handicap Inventory (THI), Speech, Spatial, and Qualities of Hearing Scale (SSQ12), datalogging, and the Cochlear Implant Quality of Life (CIQOL)-10 Global measure were utilized. RESULTS: Sixty-six adults underwent CI for SSD (median 51.3 years, range 20.0-74.3 years), and 57 (86.4%) remained device users at last follow-up. Compared to pre-operative performance, device users demonstrated significant improvement in speech recognition scores and achieved peak performance at six months post-activation for CNC (8.0% increased to 45.6%, p < 0.0001) and AzBio in quiet (12.2% increased to 59.5%, p < 0.0001). THI was decreased at 6 months post-implantation (58.1-14.6, p < 0.0001), with 77% of patients reporting improved or resolved tinnitus. Patients demonstrated improved SSQ12 scores as well as the disease-specific CIQOL-10 Global questionnaire. Duration of deafness was not associated with significant differences in speech recognition performance. Average daily wear time was positively associated with CNC and AzBio scores as well as post-operative CIQOL-10 scores. CONCLUSIONS: Herein we present the largest cohort of adult CI recipients with SSD with data on speech recognition scores, tinnitus measures, and SSQ12. Novel insights regarding the correlation of datalogging, duration of deafness, and CI-specific quality of life (CIQOL-10) metrics are discussed. Data continue to support CI as an efficacious treatment option for SSD. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2362-2370, 2023.

Analysis of Hearing Preservation in Middle Cranial Fossa Resection of Vestibular Schwannoma.

OBJECTIVE: Describe the effect of preoperative hearing on the likelihood of hearing preservation after middle cranial fossa (MCF) approach for resection of vestibular schwannoma (VS) and the effect of hearing preservation on disease-specific quality of life (QOL). STUDY DESIGN: Retrospective chart review. SETTING: Academic tertiary care skull base surgery program. PATIENTS: Sixty three adult patients with preoperative word recognition score (WRS) ≥50% who underwent MCF resection of VS between 2017 and 2020. INTERVENTIONS: All patients underwent MCF VS resection with attempted hearing preservation. MAIN OUTCOME MEASURES: Hearing preservation (postoperative WRS ≥50%), hearing-related Penn Acoustic Neuroma Quality of Life (PANQOL) score. RESULTS: Sixty three patients with mean age 47.4 (±9.6) years and tumor size 11.5 (±0.5) mm were analyzed. Hearing was preserved (+HP) and lost (-HP) in 37 (58.7%) and 26 (41.3%) patients, respectively. Preoperatively, pure tone average audiometry was significantly lower among the +HP group (20.0 dB) versus -HP (31.0 dB, p < 0.003). WRS was higher among +HP versus -HP (94% vs. 84%, respectively; p < 0.002). Linear regression showed that intra- versus extra-canalicular tumor location, sudden hearing loss history, fundal fluid cap thickness, and tumor size had no relationship to hearing preservation outcomes. When evaluating postoperative QOL data (n = 37) hearing-related PANQOL score differed between +HP and -HP (t35 = 2.458, p = 0.0191) groups. CONCLUSIONS: In this cohort of patients undergoing MCF resection of VS, rates of HP were higher for patients with excellent preoperative hearing. Postoperatively, +HP patients reported improved hearing-related PANQOL scores compared to -HP patients.

Machine Learning for Automated Calculation of Vestibular Schwannoma Volumes.

HYPOTHESIS: Machine learning-derived algorithms are capable of automated calculation of vestibular schwannoma tumor volumes without operator input. BACKGROUND: Volumetric measurements are most sensitive for detection of vestibular schwannoma growth and important for patient counseling and management decisions. Yet, manually measuring volume is logistically challenging and time-consuming. METHODS: We developed a deep learning framework fusing transformers and convolutional neural networks to calculate vestibular schwannoma volumes without operator input. The algorithm was trained, validated, and tested on an external, publicly available data set consisting of magnetic resonance imaging images of medium and large tumors (178-9,598 mm 3 ) with uniform acquisition protocols. The algorithm was then trained, validated, and tested on an internal data set of variable size tumors (5-6,126 mm 3 ) with variable acquisition protocols. RESULTS: The externally trained algorithm yielded 87% voxel overlap (Dice score) with manually segmented tumors on the external data set. The same algorithm failed to translate to accurate tumor detection when tested on the internal data set, with Dice score of 36%. Retraining on the internal data set yielded Dice score of 82% when compared with manually segmented images, and 85% when only considering tumors of similar size as the external data set (>178 mm 3 ). Manual segmentation by two experts demonstrated high intraclass correlation coefficient (0.999). CONCLUSION: Sophisticated machine learning algorithms delineate vestibular schwannomas with an accuracy exceeding established norms of up to 20% error for repeated manual volumetric measurements-87% accuracy on a homogeneous data set, and 82% to 85% accuracy on a more varied data set mirroring real world neurotology practice. This technology has promise for clinical applicability and time savings.

Auditory Brain Stem Response Predictors of Hearing Outcomes after Middle Fossa Resection of Vestibular Schwannomas.

Objectives To analyze the relationship between preoperative and intraoperative auditory brain stem response (ABR) characteristics and hearing outcomes in patients with vestibular schwannomas (VS) undergoing hearing preservation (HP) surgery via a middle cranial fossa (MCF) approach. Design Prospective study. Setting Academic tertiary skull base referral center. Methods Pre- and postoperative pure-tone average (PTA) and word recognition score (WRS) were examined. Intraoperative ABR wave III latency, wave V latency, and amplitude were recorded. HP was defined as postoperative WRS ≥50%. Participants Adult patients with VS and WRS ≥50% who underwent MCF tumor resection between November 2017 and September 2019. Main Outcome Measures Postoperative hearing outcomes. Results Sixty patients were included. Mean tumor size was 9.2 mm (range, 3-17). HP rates were 56.7% for the cohort and 69.7% for tumors <10 mm. A complete loss of wave V was associated with an 82.9% increase in postoperative PTA ( p < 0.001) and 97.2% decrease in WRS ( p < 0.001), whereas a diminished wave V was correlated with 62.7% increase in PTA ( p < 0.001) and 55.7% decrease in WRS ( p = 0.006). A diminished or absent wave V, but not increased wave III/V latency or decreased wave V amplitude, was correlated with a decline in postoperative hearing class ( r = 0.735, p < 0.001). Receiver-operating characteristic analysis demonstrated that a stable wave V has the highest accuracy in predicting HP (sensitivity of 82.6%, specificity of 84.8%). Conclusion Of the examined preoperative and intraoperative ABR characteristics, a stable wave V intraoperatively was the strongest predictor of HP after MCF resection of VS. Level of Evidence Level III.

Delayed Facial Nerve Palsy Following Resection of Vestibular Schwannoma: Clinical and Surgical Characteristics.

OBJECTIVE: Analyze delayed facial nerve palsy (DFNP) following resection of vestibular schwannoma (VS) to describe distinct characteristics and facial nerve (FN) functional course. STUDY DESIGN: Prospective cohort with retrospective review. SETTING: Academic medical center. PATIENTS: Consecutive patients undergoing VS resection 11/2017 to 08/2020. Exclusion criteria: preoperative House-Brackmann (HB) ≥ III, postoperative HB ≥ III without delayed palsy, <30 days follow-up. INTERVENTIONS: VS resection with intraoperative electromyographic monitoring. MAIN OUTCOME MEASURES: FN outcomes utilizing the HB scale; comparison between patients with DFNP (deterioration greater than one HB grade 24 hours to 30 days postoperatively) vs. those with HBI-II throughout. RESULTS: Two hundred eighty-eight patients met criteria: mean age 47.6 years, 36.1% male; 24.0% middle cranial fossa, 28.5% retrosigmoid, 47.6% translabyrinthine. DFNP occurred in 31 (10.8%) patients with average time to onset of 8.1 days. Of these, 22 (71.0%) recovered HBI-II and 3 (9.7%) recovered HBIII. Patients who experienced DFNP, on average, had larger maximum tumor diameter (23.4 vs. 18.7 mm, p = 0.014), lower rate of gross-total resection (54.8% vs. 75.5%, p = 0.014), and lower rate of ≥100 µV FN response to 0.05 mA stimulus intraoperatively (80.6% vs. 94.9%, p = 0.002). Compared to overall incidence of DFNP, translabyrinthine approach demonstrated higher incidence (15.3%, p = 0.017) while retrosigmoid lower (3.7%, p = 0.014). In multivariable logistic regression, patients with FN response ≥100 µV to 0.05 mA stimulus were 72.0% less likely to develop DFNP (p = 0.021). CONCLUSIONS: Intraoperative electromyographic facial nerve response, tumor size, surgical approach, and extent of resection may play a role in development of DFNP following resection of VS. Most patients who develop DFNP recover near-normal function.