Citations

ObjectiveTo ascertain the relationship among vestibular schwannoma (VS) tumor volume, growth, and hearing loss.Study DesignRetrospective cohort study.SettingSingle tertiary center.Subjects and MethodsAdults with observed VS and serviceable hearing at diagnosis were included. The primary outcome was the development of nonserviceable hearing as estimated using the Kaplan‐Meier method. Associations of tumor volume with baseline hearing were assessed using Spearman rank correlation coefficients. Associations of volume and growth with the development of nonserviceable hearing over time were assessed using Cox proportional hazards models and summarized with hazard ratios (HRs).ResultsOf 230 patients with VS and serviceable hearing at diagnosis, 213 had serial volumetric tumor data for analysis. Larger tumor volume at diagnosis was associated with increased pure‐tone average (PTA) (P <. 001) and decreased word recognition score (WRS) (P =. 014). Estimated rates of maintaining serviceable hearing at 6 and 10 years following diagnosis were 67% and 49%, respectively. Larger initial tumor volume was associated with development of nonserviceable hearing in a univariable setting (HR for 1‐cm3 increase: 1.36, P =. 040) but not after adjusting for PTA and WRS. Tumor growth was not significantly associated with time to nonserviceable hearing (HR, 1.57; P =. 14), although estimated rates of maintaining serviceable hearing during observation were poorer in the group that experienced growth.ConclusionLarger initial VS tumor volume was associated with poorer hearing at baseline. Larger initial tumor volume was also associated with the development of nonserviceable hearing during observation in a univariable setting; however, this association was not statistically significant after adjusting for baseline hearing status.

Objective: Closely paralleling previous radiologic studies, recent population-based prevalence data suggest sporadic vestibular schwannoma (VS) affects over one in 2,000 adults and up to one in 500 in those aged 70 years or older. Attributable to increased utilization of magnetic resonance imaging and screening protocols for asymmetrical sensorineural hearing loss, the increasing detection rate of sporadic VS fundamentally changes the perception of VS as a whole. The primary objective of the current study was to contextualize modern epidemiological trends in neurofibromatosis type 2 (NF2) in light of these recent advancements in the understanding of sporadic VS. Study Design: Population-based study. Setting: Olmsted County, Minnesota. Population size on January 1, 2017: 159,689 people. Patients: All patients with NF2 diagnosed between Jan 1, 1966 and Dec 31, 2016, identified using the Rochester Epidemiology Project. Main Outcome Measures: Incidence, prevalence. Results: Six incident cases were identified over the past 50 years. From 1966 to 2016, the age- and sex-adjusted incidence rate was 0.10 per 100,000 person-years. The incidence rate remained at 0.12 over the most recent decade. Five cases met disease prevalence criteria, and the age- and sex-adjusted prevalence of NF2 on Jan 1, 2017 was 3.1 per 100,000 persons. All prevalent cases were women, and the resultant prevalence among women only was 6.0 per 100,000 persons. Conclusions: The modern age- and sex-adjusted incidence rate and prevalence of NF2 is 0.10 per 100,000 person-years and 3.1 per 100,000 persons, respectively. In contrast to trends in incidence rates of sporadic VS over the last half-century, this study demonstrates that the incidence of NF2 has remained relatively stable since 1966. This divergence in epidemiological trends is likely attributed to the nature of NF2, with early clinical manifestations resulting in diagnosis regardless of modern advances, whereas the increased incidence of sporadic VS is heavily influenced by improved detection in a greater population of patients with minimally symptomatic or asymptomatic tumors.

Objective: Several reports have suggested that the incidence of otosclerosis is declining. However, due to the limitations of epidemiologic databases within the United States, little is known about the incidence of congenital stapes footplate fixation (CSFF), much less epidemiological trends over the past 50 years. The current study was conceived to characterize the epidemiology of CSFF over the past five decades using the unique resources of the Rochester Epidemiology Project (REP). Study Design: Population-based study. Patients: The medical records of every resident of Olmsted County, Minnesota who was diagnosed with CSFF was reviewed from January 1, 1970 to December 12, 2017 using the REP. The population of Olmsted County on January 1, 2017 was 159,689 persons. Main Outcome Measure: Incidence of CSFF. Results: Sixteen cases of CSFF were identified at a median age at diagnosis of 8 years (IQR, 6–17), eight of whom confirmed by exploratory tympanotomy. Three of the 16 (19%) cases were bilateral, and the median pure-tone average (500, 1k, 2k, 3k Hz) at time of diagnosis was 37 dB (IQR, 31–48). Two (13%) cases were identified in patients bearing a syndromic condition and one (6%) case demonstrated a malformed external ear on physical examination. The incidence rate of surgically confirmed cases among residents of Olmsted County was 0.31 per 100,000 person-years from 1970 to 1979 and 0.28 from 2000 to 2009. No incident cases among residents of Olmsted County were identified since 2010. Conclusions: CSFF constitutes a rare disease. Unlike epidemiological trends in otosclerosis, the incidence of surgically confirmed cases of CSFF remained stable over the past 50 years.

Objective: Intraoperative far-field auditory brainstem response (ABR) and direct cochlear nerve action potential monitoring using neural response imaging (NRI) are techniques for monitoring the cochlear nerve during vestibular schwannoma (VS) surgery. A new paradigm has developed where the cochlear nerve is anatomically preserved during tumor removal to facilitate cochlear implantation in select circumstances. This report describes the use of an unmodified commercial cochlear implant (CI) to elicit electrically-evoked direct cochlear nerve and far-field ABR monitoring to evaluate the status of the cochlear nerve during tumor resection in real time. Patients: Adult female with unilateral, sporadic VS. Intervention(s): Cochlear implantation followed by translabyrinthine resection of VS in single operation. Main Outcome Measures: During tumor resection intra-cochlear electrodes were used to deliver electrical stimulation and measure NRI or the cochlear nerve action potential. Electrically-evoked ABR (eABR) was measured using surface electrodes and wave V was monitored (far-field ABR) during surgery. Results: A 61-year-old female was evaluated for a unilateral, enlarging intracanalicular VS with asymmetric SNHL. The patient opted for microsurgery and due to her bilateral hearing loss was a candidate for CI. Cochlear implantation with an unmodified, commercially available lateral wall electrode was performed. The remainder of the approach and tumor resection was performed under continuous eABR and NRI monitoring. Gross total resection was achieved with intact eABR and NRI at the conclusion of the case. Changes in ABR and NRI consistently recovered after modifying dissection strategy. The patient reported auditory percepts with her cochlear implant postoperatively. Conclusions: This report demonstrates the feasibility of using real-time NRI and eABR with a CI to facilitate preservation of the cochlear nerve during VS microsurgery. Using this method to mitigate cochlear nerve trauma during microsurgery may preserve the option of CI for hearing rehabilitation.

ObjectiveIgG4‐related disease (IgG4‐RD) is a recently recognized disease characterized by fibroinflammatory infiltrates rich in IgG4+ plasma cells that can present as isolated tumor‐like lesions of the head and neck. The objective of the current study was to describe the cranial base manifestations of IgG4‐RD.MethodsReview of all cases at three tertiary‐referral centers since disease description in 2003.ResultsEleven patients were identified at a median age at presentation of 58 years (IQR, 38–65; 55% male). Ten (91%) patients had isolated skull base masses without systemic disease. Cranial neuropathies were commonly observed in the abducens (45%), trigeminal (18%), and facial nerves (18%). Lesions frequently involved the cavernous sinus (55%; 6/11) with extension to the petroclival junction in 50% (3/6). Infiltration of the internal auditory canal was present in 27% (3/11) with one case demonstrating erosion of the bony labyrinth. Preliminary clinical diagnoses commonly included nasopharyngeal cancer, pituitary macroadenoma, cholesteatoma, and meningioma / multiple meningioma syndrome. Local biopsy demonstrated >30 IgG4‐positive plasma cells per high‐powered field or an IgG4:IgG ratio greater than 40% in all cases. Rapid and durable clinical improvement was seen in 91% following corticosteroid and rituximab therapy.ConclusionsIgG4‐RD nonspecifically presents as a rare cause of the skull base mass. Often presenting without concomitant systemic disease, local diagnostic biopsies are required. Obtaining adequate tissue specimen is complicated by densely fibrotic cranial base lesions that are frequently in close proximity to critical neurovascular structures. Primary medical therapy with corticosteroids and rituximab is effective in most patients.Level of Evidence4 Laryngoscope, 130:2574–2580, 2020

Objective: The majority of research influencing our understanding of vestibular schwannoma (VS) comes from large tertiary referral centers, and as a consequence, is inherently prone to referral bias. The objective of the current study was to characterize tertiary referral center bias in VS research. Study design: Single-institution retrospective clinical, audiometric, and radiologic review. Setting: One tertiary referral center. Patients: One hundred twenty-three patients with sporadic VS treated at our institution, consisting of a local cohort of all 41 VS patients residing in the same US county as our medical center and a referral cohort of 82 patients from outside counties matched 2:1 based on age, sex, and year of diagnosis. Intervention: Surgical resection, stereotactic radiosurgery (SRS), observation. Main outcome measures: Clinical manifestations, audiometric and radiologic findings, elected treatment modality. Results: Local patients had significantly longer follow-up after initial presentation compared to referral patients (median 4.0 vs 2.2 yr; p = 0.007). Referral patients were significantly less likely to have an incidental VS diagnosis (1% vs. 29%; p < 0.001) and presented with worse symptomatology such as hearing loss (80% vs. 54%; p = 0.002), dizziness (72% vs. 44%; p = 0.002), headache (29% vs. 15%; p = 0.075), and other cranial nerve dysfunction (11% vs. 0%; p = 0.029). Audiometrically, referral patients had significantly poorer word recognition scores at presentation (median 70% vs. 90%; p = 0.043). Local patients were more likely to have tumors confined to the IAC compared with referral patients, and had significantly smaller tumors when restricted to this region (median 4.0 vs 6.5 mm; p = 0.005). Referral patients were significantly more likely to undergo definitive management with either radiosurgery or microsurgery following primary evaluation compared to local patients (48% vs. 24%; p = 0.013). Conclusion: These data suggest that the majority of existing literature surrounding VS likely suffers from referral bias, whereby disease characteristics and management decisions are distinct from that of the general VS patient population.

Objective The aim of this study was to quantitatively demonstrate radiation dose reduction for sinus and temporal bone examinations using high-resolution photon-counting detector (PCD) computed tomography (CT) with an additional tin (Sn) filter. Materials and Methods A multienergy CT phantom, an anthropomorphic head phantom, and a cadaver head were scanned on a research PCD-CT scanner using ultra-high-resolution mode at 100-kV tube potential with an additional tin filter (Sn-100 kV) and volume CT dose index of 10 mGy. They were also scanned on a commercial CT scanner with an energy-integrating detector (EID) following standard clinical protocols. Thirty patients referred to clinically indicated sinus examinations, and two patients referred to temporal bone examinations were scanned on the PCD-CT system after their clinical scans on an EID-CT. For the sinus cohort, PCD-CT scans were performed using Sn-100 kV at 4 dose levels at 10 mGy (n = 9), 8 mGy (n = 7), 7 mGy (n = 7), and 6 mGy (n = 7), and the clinical EID-CT was performed at 120 kV and 13.7 mGy (mean CT volume dose index). For the temporal bone scans, PCD-CT was performed using Sn-100 kV (10.1 mGy), and EID-CT was performed at 120 kV and routine clinical dose (52.6 and 66 mGy). For both PCD-CT and EID-CT, sinus images were reconstructed using H70 kernel at 0.75-mm slice thickness, and temporal bone images were reconstructed using a U70 kernel at 0.6-mm slice thickness. In addition, iterative reconstruction with a dedicated sharp kernel (V80) was used to obtain high-resolution PCD-CT images from a sinus patient scan to demonstrate improved anatomic delineation. Improvements in spatial resolution from the dedicated sharp kernel was quantified using modulation transfer function measured with a wire phantom. A neuroradiologist assessed the H70 sinus images for visualization of critical anatomical structures in low-dose PCD-CT images and routine-dose EID-CT images using a 5-point Likert scale (structural detection obscured and poor diagnostic confidence, score = 1; improved anatomic delineation and diagnostic confidence, score = 5). Image contrast and noise were measured in representative regions of interest and compared between PCD-CT and EID-CT, and the noise difference between the 2 acquisitions was used to estimate the dose reduction in the sinus and temporal bone patient cohorts. Results The multienergy phantom experiment showed a noise reduction of 26% in the Sn-100 kV PCD-CT image, corresponding to a total dose reduction of 56% compared with EID-CT (clinical dose) without compromising image contrast. The PCD-CT images from the head phantom and the cadaver scans demonstrated a dose reduction of 67% and 83%, for sinus and temporal bone examinations, respectively, compared with EID-CT. In the sinus cohort, PCD-CT demonstrated a mean dose reduction of 67%. The 10- and 8-mGy sinus patient images from PCD-CT were significantly superior to clinical EID-CT for visualization of critical sinus structures (median score = 5 ± 0.82 and P = 0.01 for lesser palatine foramina, median score = 4 ± 0.68 and P = 0.039 for nasomaxillary sutures, and median score = 4 ± 0.96 and P = 0.01 for anterior ethmoid artery canal). The 6- and 7-mGy sinus patient images did not show any significant difference between PCD-CT and EID-CT. In addition, V80 (sharp kernel, 10% modulation transfer function = 18.6 cm −1 ) PCD-CT images from a sinus patient scan increased the conspicuity of nasomaxillary sutures compared with the clinical EID-CT images. The temporal bone patient images demonstrated a dose reduction of up to 85% compared with clinical EID-CT images, whereas visualization of inner ear structures such as the incudomalleolar joint were similar between EID-CT and PCD-CT. Conclusions Phantom and cadaver studies demonstrated dose reduction using Sn-100 kV PCD-CT compared with current clinical EID-CT while maintaining the desired image contrast. Dose reduction was further validated in sinus and temporal bone patient studies. The ultra-high resolution capability from PCD-CT allowed improved anatomical delineation for sinus imaging compared with current clinical standard.

Objective:To ascertain long-term hearing outcomes in patients with serviceable hearing following microsurgical resection of sporadic vestibular schwannoma (VS).Study Design:Retrospective cohort.Setting:Tertiary academic referral center.Patients:Forty-three adult subjects with unilateral sporadic VS who had serviceable hearing (American Academy of Otolaryngology–Head and Neck Surgery [AAO-HNS] class A or B) on initial postoperative audiogram following microsurgical resection between 2003 and 2016 with a minimum of two postoperative audiograms available for review.Intervention:Surgical treatment with a retrosigmoid or middle cranial fossa approach.Main Outcome Measure:Rate of maintaining serviceable hearing, as estimated using the Kaplan–Meier method, in accordance with the 1995 and 2012 AAO-HNS guidelines on reporting hearing outcomes.Results:The median immediate postoperative pure-tone average (PTA) and word recognition score (WRS) were 31 dB and 95%, respectively. At last follow-up, the median PTA was 38 dB with a median change of 5 dB from initial postoperative audiogram, and the median WRS was 90% with a median change of 0% from initial postoperative audiogram. Eight patients developed non-serviceable hearing at a median of 4.1 years following microsurgical resection (interquartile range, 2.9–7.0). The median duration of hearing follow-up for the 35 patients who maintained serviceable hearing was 3.1 years (interquartile range, 2.2–7.5). Tumor control was achieved in 41 (95%) patients. The rate of maintaining serviceable hearing at 5 years was 81%.Conclusion:Microsurgical resection provides excellent tumor control and durable long-term hearing in those with AAO-HNS class A or B hearing postoperatively. The paradigm of proactive microsurgical resection—when the tumor is small and hearing is good—hinges on the surgeon's ability to preserve residual hearing in a very high percentage of cases at or near preoperative hearing levels to maintain an advantage over conservative observation with regard to long-term hearing preservation.

Objective: To report the use of multi-frequency intra-cochlear electrocochleography (ECOG) in monitoring and optimizing electrode placement during cochlear implant surgery. An acoustic pure tone complex comprising of 250, 500, 1000, and 2000 Hz was used to elicit ECOG, or more specifically cochlear microphonics (CMs), responses from various locations in the cochlea. The most apical cochlear implant electrode was used as the recording electrode. Study Design: Clinical capsule report. Setting: Tertiary academic referral center. Results: ECOG measurements were performed during cochlear implant surgery in an adult patient with significant residual acoustic hearing. The 500, 1000, and 2000 Hz CM tracings from the most apical electrode showed an amplitude peak at three different instances during the early phase of cochlear implant electrode insertion. These results are consistent with the tonotopic organization of the cochlea. During final electrode placement a slight advancement of the electrode array resulted in a correlated decrease in 250, 500, and/or 1000 Hz CM amplitude. The electrode array was retracted and repositioned which resulted in a recovery of CM amplitude. Intraoperative CM thresholds revealed a correlation of r = 0.87 with preoperative audiometric thresholds. Conclusion: We present a report on simultaneous multi-frequency ECOG monitoring during cochlear implant surgery. Multi-frequency ECOG can be used to differentiate between electrode trauma and the advancement of the apical electrode beyond the CM source in the cochlea.

Objective: To date, prediction models for estimating risk of acquiring non-serviceable hearing in subjects with observed vestibular schwannoma (VS) have evaluated outcomes primarily based on features at initial diagnosis. Herein, we evaluate the association of rate of hearing decline during the initial period of observation with time to non-serviceable hearing. If significant, rate of hearing decline may inform decision making after an introductory period of observation. Setting: Two tertiary care centers. Patients: VS patients with serviceable hearing who underwent at least three audiograms and two magnetic resonance imaging (MRI) studies before intervention or being lost to follow-up. The rate of change in pure-tone average (PTA) and word recognition score (WRS) was calculated as the score from the second audiogram minus the score from the first audiogram, divided by the duration in months between the two. Main Outcome Measure(s): Serviceable hearing, defined as PTA ≤50 dB HL and WRS ≥50%. Results: Among 266 patients meeting inclusion criteria, 52 developed non-serviceable hearing at last follow-up. Kaplan–Meier estimated rates of maintaining serviceable hearing (95% CI; number still at risk) at 1, 3, 5, 7, and 10 years were 97% (95–100; 206), 78% (72–85; 98), 68% (60–77; 39), 60% (50–73; 17), and 44% (29–67; 2), respectively. In a univariable setting, each 1 dB increase per month in the rate of initial PTA change was associated with a 96% increased likelihood of acquiring non-serviceable hearing (hazard ratio [HR] 1.96; 95% CI 1.44–2.68; p < 0.001). Each 1% increase per month in the rate of initial WRS change was associated with a decreased likelihood of acquiring non-serviceable hearing (hazard ratio [HR] 0.79; 95% confidence interval [CI] 0.66–0.94; p = 0.009). After multivariable adjustment, both rate of PTA change (HR 2.42; 95% CI 1.72–3.41; p < 0.001) and rate of WRS change (HR 0.81; 95% CI 0.67–0.99; p = 0.043) remained statistically significantly associated with time to non-serviceable hearing. Conclusion: Rate of early PTA and WRS decline during the initial period of observation are significantly associated with time to development of non-serviceable hearing. This information may facilitate accurate patient counseling and inform decision-making regarding prospective disease management.