Khandalavala, Karl R.

Objective: To evaluate the impact of cochlear implantation (CI) and simultaneous endolymphatic sac decompression (ELSD) on vestibular and audiometric outcomes in patients with advanced Ménière disease (MD). Study design: Historical cohort. Setting: Tertiary academic medical center. Patients: Patients with medically refractory MD who underwent CI with or without simultaneous ELSD from 2000 through 2024. Interventions: CI with or without ELSD. Main outcome measures: Post-CI patient-reported changes in vertigo severity and frequency, Consonant-Nucleus-Consonant word (CNCw) scores, and AzBio sentences in quiet scores. Results: Ninety-nine patients with preoperative vertigo secondary to MD were eligible for study, including 17 (17%) who underwent simultaneous ELSD. In total, 15 (88%) and 2 (12%) of the 17 patients with simultaneous ELSD reported improvement and stability in vertigo severity, respectively; in comparison, 26 (32%), 40 (49%), and 16 (20%) of the 82 patients with CI alone reported improvement, stability, and worsening in vertigo severity, respectively ( P <0.001). Likewise, 15 (88%) and 2 (12%) of the patients with simultaneous ELSD reported improvement and stability in vertigo frequency, respectively, whereas 21 (26%), 43 (52%), and 18 (22%) of patients with CI alone reported improvement, stability, and worsening in vertigo frequency, respectively ( P <0.001). Post-CI speech recognition scores were not significantly different between the simultaneous ELSD and CI alone groups [median (IQR) CNCw 70 (38 to 82) vs. 72 (58 to 82) and median (IQR) AzBio quiet 87 (67 to 96) vs. 87 (73 to 94), respectively]. Conclusions: In patients with MD, CI with simultaneous ELSD provides improvement in vertigo symptoms and similar audiometric outcomes when compared with CI alone. In appropriately selected patients with both refractory vestibular symptoms and sensorineural hearing loss meeting criteria for implantation, CI with simultaneous ELSD offers improvement in severity and frequency of vertigo as well as successful auditory rehabilitation.

Objective: Vestibular schwannomas (VSs) treated with stereotactic radiosurgery (SRS) often show transient loss of central tumor enhancement. We hypothesized that this loss of enhancement may correlate with better tumor control on follow-up imaging. Methods: We evaluated 198 consecutive patients from a single center who met eligibility criteria. Tumor volumes on the pre-SRS and post-SRS scans were quantified along with regions of loss of enhancement on the first post-SRS study. The latter was correlated with tumor volumes at follow-up, radiation isocenter density, and loss of serviceable hearing. Results: For the entire cohort, the median loss of enhancement on the first post-SRS scan was 14% (IQR: 6 to 25) and median rate of change in tumor volume was −4.5% per year (IQR: −10.5 to 1.5). Percent loss of central enhancement showed significant negative correlation with tumor growth not only for the entire cohort (correlation coefficient: −0.18, P =0.01), but also for the subset of patients who had available imaging until at least 2 years (n=185) and 4 years (n=179) post-SRS. Loss of enhancement also strongly correlated positively with tumor volumes and number of radiation isocenters and negatively with isocenter density. Finally, patients with greater percent loss of enhancement had an increased likelihood of progression to non-serviceable hearing, although this association was not statistically significant. Conclusions: These findings suggest that loss of central tumor enhancement in VSs post-SRS may be associated with improved tumor control.

Objective: To systematically review the existent literature on radiosurgery for treatment of sporadic facial nerve schwannomas (FNS). Databases reviewed: PubMed, SCOPUS, EMBASE, and Web of Science databases. Methods: Systematic review was performed per PRISMA criteria of studies published from 1990 through 2024 on patients diagnosed with sporadic FNS who were treated with radiosurgery. Outcomes included change in facial nerve function, change in hearing class, and radiosurgical treatment failure defined by need for reintervention. Study quality was assessed using the LEGENDS rubric for mixed modality studies. Results: In total, 35 studies encompassing 364 patients were included for data abstraction. Gamma Knife was the most common modality reported. Longitudinal patient-level data on facial nerve function were available for 101 patients, with 8% of patients experiencing worsening facial nerve function and 92% of patients having either stable nerve function or improvement in facial nerve function following treatment over a median follow-up of 36 months. Longitudinal patient-level hearing data were available for 53 patients, including 35 patients with serviceable hearing (AAO-HNS class A or B) at baseline; only 2 patients developed nonserviceable hearing (AAO-HNS class C or D) following treatment over a median follow-up of 36 months. Clinical tumor control data were available for 295 patients, of whom 11 required salvage treatment over a mean follow-up of 49 months. Conclusions: This systematic review demonstrates a relatively low risk of worsening facial nerve function and a high rate of clinical tumor control following radiosurgery for sporadic FNS.

Objective To describe the potential applications of awake cochlear implantation (CI). Patients Adult patients with sensorineural hearing loss who qualify for CI. Interventions CI under local anesthesia, without any form of systemic analgesia or anesthesia. Main Outcome Measures Acoustic hearing preservation, subjective patient report of cochlear implant pitch matching, and subjective patient report of cochlear implant sound quality. Results Four illustrative cases are presented, highlighting the potential uses of CI performed under local anesthesia for optimizing outcomes in hearing preservation, implant pitch matching, and implant sound quality. Conclusions CI under local anesthesia allows surgeons to use real-time patient feedback during electrode array insertion to minimize intracochlear trauma, particularly in cases where hearing preservation is a goal of CI, and to potentially improve implant performance by optimizing pitch matching and sound quality.

AbstractObjectiveTo examine associations with changes in quality‐of‐life (QOL) outcomes following treatment of vestibular schwannoma (VS) using stereotactic radiosurgery (SRS).Study DesignProspective longitudinal study.SettingTertiary academic center.MethodsPatients who were treated for sporadic VS using SRS from 2015 to 2022 were included. QOL outcomes were measured using the disease‐specific Penn Acoustic Neuroma QOL (PANQOL) scale.ResultsSeventy‐nine patients with pre‐SRS and at least one post‐SRS PANQOL assessments were available for analysis. The mean change in total PANQOL scores was −2 (SD 13) on a 100‐point scale. The mean duration between assessments was 4.6 years (SD 2.0). Age at SRS, sex, and SRS treatment doses were not significantly associated with changes in total PANQOL scores. Total PANQOL scores improved a mean of 4 points for patients with tumors confined to the internal auditory canal but declined a mean of 5 points for patients with tumors extending into the cerebellopontine angle (P = .01); however, these changes did not exceed the minimum clinically significant threshold of 11 points. The correlation coefficient between treated tumor volume at SRS and change in total PANQOL scores was −0.30 (P = .007). Changes in PANQOL total (P = .5) and hearing domain (P = .3) scores for patients who maintained serviceable hearing or progressed to nonserviceable hearing did not significantly differ.ConclusionTumor extent and treated volume at SRS had a statistically significant but likely not clinically important impact on total PANQOL scores. Progression to nonserviceable hearing did not have a significant impact on PANQOL total or hearing domain scores.

Objective To compare differences in sporadic vestibular schwannoma (VS)–associated patient-reported symptom scores among patients receiving observation, microsurgery, or radiosurgery. Study Design Prospective longitudinal survey. Setting Tertiary referral center and the national Acoustic Neuroma Association. Patients Adults with sporadic VS. Intervention Observation, microsurgery, or radiosurgery. Main Outcome Measure Baseline and follow-up surveys on patient-reported severity of tinnitus, dizziness/imbalance, and headaches scored on a 10-point numeric scale, with higher scores indicating more severe symptoms; changes of 2 or more points from baseline were considered clinically important. Results A total of 455 patients were eligible for study with a mean (SD) follow-up of 4.5 (2.4) years, including 122 (27%) managed with observation, 226 (50%) undergoing microsurgery, and 107 (23%) undergoing radiosurgery. Changes in tinnitus severity scores differed significantly among management groups (p = 0.006), with severity scores increasing significantly in the radiosurgery (+0.8, p = 0.005) group but not in the observation (+0.2, p = 0.5) or microsurgery (−0.2, p = 0.18) groups. The changes in dizziness/imbalance and headache severity scores did not differ significantly among management groups. When comparing clinically important improvements (decrease of 2 or more points), the microsurgery and observation cohorts had a greater proportion of patients experiencing a clinically important improvement in tinnitus compared with the radiosurgery cohort; no other clinically important changes were significantly different among management groups. Conclusions In this prospective study of 455 patients comparing patient-reported symptoms after VS management, radiosurgery was associated with worsening tinnitus severity scores overall and resulted in fewer patients reporting clinically important improvements in tinnitus compared with observation and microsurgery. As there was substantial variability in the effect of management modality on changes in symptom severity scores, possible treatment effects on subjective symptoms, including tinnitus, dizziness/imbalance, and headache, should not be used in isolation to inform clinical decision-making for management of sporadic VS.

Objective To examine comfort (C) and threshold (T) levels in adult cochlear implant (CI) recipients over the first 18 months postactivation. Study Design Retrospective review of longitudinal CI programming data. Setting Tertiary academic center. Patients A total of 480 CIs among 428 adult CI recipients. Interventions Cochlear implantation with Cochlear Ltd. devices with subsequent programming to behavioral standards using Custom Sound® fitting software. Main Outcome Measures Charge levels needed to achieve C and T levels were measured longitudinally using Custom Sound®, from time of activation to a minimum of 6 and a maximum of 18 months postactivation. Charge (nC) levels were calculated as the product of pulse width (μs) and current amplitude (μA) to standardize among implant models. Changes in C and T charge levels over time were evaluated using repeated-measures analysis of variance. Results When considering the entire electrode, the largest increases were seen at 1 month postactivation, and C and T charge levels did not increase significantly after 6 and 12 months, respectively. These findings were consistent across patient age at implantation and sex. When considering proximal electrodes only, C and T levels did not increase significantly after 6 months. In distal electrodes only, C levels did not increase significantly after 6 months, but T levels continued to demonstrate small, but statistically significant increases up to 18 months postactivation. Conclusions Across the entire electrode, we observed the largest changes in C and T charge levels at 1 month postactivation. Small increases in C and T levels continued out to 6 and 12 months, respectively, but may be of limited clinical significance. The stability of programming levels over time may support selective de-escalation of CI follow-up after the initial postactivation period, but, given small yet persistent increases with time, most notably in the distal electrodes, alternatives for follow-up or remote programming may still be encouraged.

AbstractObjectiveLimited evidence guides the optimal timing of treatment after the detection of tumor growth during the observation of sporadic vestibular schwannoma (VS). The current work aimed to inform the timing of radiosurgical intervention based on an analysis of patient outcomes among those who ultimately failed stereotactic radiosurgery (SRS) and underwent salvage microsurgery.Study DesignA historical cohort study.SettingSeven centers across the United States and Norway.MethodsAdults with sporadic VS who underwent salvage microsurgery following failed primary SRS were included. The primary outcome of interest was the association between tumor size at the time of primary SRS and the ability to achieve gross total resection (GTR) and maintain postoperative House–Brackmann (HB) facial nerve grade I at the last follow‐up after salvage microsurgery.ResultsAmong 96 patients, the median (interquartile range [IQR]) cerebellopontine angle (CPA) tumor size at primary SRS was 14.5 mm (10.0‐19.0). Each 1‐mm increase in CPA tumor size at the time of primary SRS was associated with a 13% increased likelihood of near‐total/subtotal resection or most recent postoperative HB grade >I (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.05‐1.21, P = .001), with an optimal tumor size threshold to distinguish this outcome of 12 mm of CPA extension (c‐index 0.73). Similarly, for each 1‐mm increase in CPA tumor size at the time of primary SRS, a 9% increase in any postoperative complication with salvage microsurgery was observed (OR 1.09, 95% CI 1.02‐1.15, P = .009).ConclusionCorroborated by size threshold surveillance data informing the timing of primary microsurgical resection, the current study suggests that VS outcomes are optimized when primary radiosurgical intervention is undertaken on growing tumors when they harbor 10–15 mm of cerebellopontine angle extension or less.

Objective To compare the utility of intraoperative electrically evoked auditory brainstem response (eABR) and electrically evoked stapedial reflex testing (eSRT) for cochlear nerve integrity monitoring during simultaneous translabyrinthine resection of vestibular schwannoma (VS) and cochlear implantation. Study design Historical cohort study. Setting Tertiary academic referral center. Patients Eleven patients (12 cases) who underwent translabyrinthine tumor resection with simultaneous placement of a standard, unmodified cochlear implant (CI). Intervention A CI placed at the beginning of the operation before tumor resection to facilitate intraoperative cochlear nerve monitoring through a CI-delivered electrical stimulus. Main outcome measure Correlation of intraoperative monitoring outcomes with postoperative CI performance. Results Among the 12 cases (median age, 47 years), eABR waveforms were present at the conclusion of tumor resection in 10, including 6 that achieved open set speech perception. Of the 2 cases with negative eABR, 1 achieved open set speech perception. By contrast, of the 8 cases with a positive eSRT response, 7 achieved open set speech perception. Of the 4 cases with a negative eSRT response, none achieved open set speech perception. The 3 cases that did not receive auditory stimulation included 2 with positive and 1 with negative eABR; all 3 had a negative eSRT response. Conclusions Intraoperative eSRT using an unmodified CI is a promising new method for monitoring the integrity of the cochlear nerve during simultaneous VS resection. eSRT response at the conclusion of tumor resection strongly correlated with CI open set speech capacity. Although still useful, eABR was less reliable at predicting postoperative hearing outcomes in this series.