Citations

ABSTRACTObjectiveThe primary objective of this study is to review the evidence for aspirin use to prevent the growth of vestibular schwannomas (VS) and to propose a prospective trial to determine the progression‐free survival of VS patients after up to 42 months of treatment with aspirin. Secondary study objectives are to determine the effect of aspirin on VS growth, hearing function, serum biomarker levels, and the quality of life, as well as to determine the tolerability of aspirin treatment and whether serum biomarker and salicylate levels predict the response to aspirin.Study DesignLiterature review.SettingSix academic and private medical centers.MethodsReview of recent English literature regarding prophylactic aspirin use for VS.ResultsThe retrospective reviews on the utility of aspirin to prevent VS growth are inconclusive. Eighty‐four patients have been enrolled in a prospective double‐blinded, placebo‐controlled trial thus far to determine the effect of aspirin on VS.ConclusionsCompletion of a robust study design is necessary. The current aspirin dose has been well tolerated, with minimal adverse events to date.Level of EvidenceReview of retrospective studies: Level 4; Proposed randomized, placebo‐controlled, double‐blinded clinical trial: Level 2.

Objective To analyze the use of electrical field imaging (EFI) in the detection of extracochlear electrodes in cochlear implants (CI) Study Design Retrospective cohort study Setting Tertiary academic medical center Methods EFI patterns from 6 recipients with extracochlear electrodes were compared with 10 recipients with all intracochlear electrodes to identify differences in EFI patterns between these two groups. For the extracochlear group, EFI patterns were analyzed using two methods: visual inspection and calculation of the average impedance difference (AID) between specific EFI curves. These results were then compared with information from CT and plain film imaging, surgical notes, and audiology tests to confirm the placement of the electrodes in each recipient. Results An average AID of 0.06 kΩ was calculated from the EFI patterns for recipients with complete electrode insertion, whereas an average AID of 0.15 kΩ was calculated from the EFI curves measured for the extracochlear electrodes. Visual analysis of the EFI impedance curves for extracochlear electrodes showed a distinct separation from those measured for intracochlear electrodes. Based on AID analysis and visual inspection the EFI, patterns were in close agreement with the number of extracochlear electrodes detected based on either imaging, intraoperative surgical note, or audiological findings. Conclusion EFI is a noninvasive, inexpensive, and time-efficient measurement that can be used to detect extracochlear electrodes and monitor electrode migration from the cochlea.

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.

OBJECTIVE Imaging surveillance with serial MRI, or a "wait-and-scan" approach, is a management option for patients with small or medium-sized vestibular schwannomas (VSs). Prior publications have indicated no distinct quality of life advantage to upfront treatment compared with initial wait-and-scan management. However, imaging surveillance is dependent on patient adherence to follow-up. In this study, the authors aimed to identify rates and predictors of patient loss to follow-up during wait-and-scan management of sporadic VS. METHODS A single-center study was conducted including all patients from 2013 to 2018 who had undergone upfront imaging surveillance of sporadic VS. Patient data were retrospectively obtained from the electronic medical record. Outcomes of interest included loss to follow-up unrelated to death and inconsistent adherence to imaging surveillance recommendations. Logistic regression analyses were conducted to evaluate factors associated with loss to follow-up. RESULTS Over a 6-year study period, 270 patients underwent initial imaging surveillance of a sporadic VS. The median tumor diameter was 8.6 mm (range 1–28.9 mm). At the time of censoring, 106 patients (39.3%) had received treatment, 157 (58.1%) had been advised to continue follow-up, and 7 (2.6%) had died of non–VS-related causes. In total, 73 patients (27.0%) were completely lost to follow-up prior to the first treatment or death. Additionally, 60 patients (22.2%) missed at least 1 MRI follow-up or imaging follow-up was delayed by more than 1 year. Multivariable logistic regression identified an out-of-state residence (OR 3.05, 95% CI 1.58–5.89, p = 0.0009) and a smaller tumor size (unit OR per 1-mm increase in size, OR 0.88, 95% CI 0.83–0.95, p = 0.0006) to be associated with loss to follow-up. Patients living ≥ 350 miles from the hospital or with tumors ≤ 3 mm at the time of initial clinic evaluation were most likely to be lost to follow-up. Only a smaller tumor size was associated with an increased risk of inconsistent imaging follow-up (unit OR per 1-mm increase in size, OR 0.92, 95% CI 0.87–0.98, p = 0.007). CONCLUSIONS Patients undergoing imaging surveillance of VS are at risk for loss to follow-up and inconsistent imaging surveillance. Patients with smaller tumors or those living farther away from the treating institution are at highest risk for being lost to follow-up.

Objectives Describe a single institution's cochlear implant outcomes for patients with inner ear schwannomas (IES) in the setting of various tumor management strategies (observation, surgical resection, or stereotactic radiosurgery [SRS]). Study Design Single-institution retrospective review. Patients Patients diagnosed with isolated, sporadic IES who underwent cochlear implantation (CI). Interventions CI with or without IES treatment. Main Outcome Measures Speech perception outcomes, tumor status. Results Twelve patients with IES underwent CI with a median audiologic and radiologic follow-up of 12 months. Six patients underwent complete resection of the tumor at the time of CI, four underwent tumor observation, and two underwent SRS before CI. At 1 year after CI for all patients, the median consonant–nucleus–consonant (CNC) word score was 55% (interquartile range, 44–73%), and the median AzBio sentence in quiet score was 77% (interquartile range, 68–93%). Overall, those with surgical resection performed similarly to those with tumor observation (CNC 58 versus 61%; AzBio in quiet 74 versus 91%, respectively). Patients who underwent tumor resection before implantation had a wider range of speech performance outcomes compared with patients who underwent tumor observation. Two patients had SRS treatment before CI (10 months previous and same-day as CI) with CNC word scores of 6 and 40%, respectively. Conclusions Patients with IES who underwent CI demonstrated similar speech performance outcomes (CNC 56% and AzBio 82%), when compared with the general cochlear implant population. Patients who underwent either tumor observation or surgical resection performed well after CI.

Abstract Objective To describe the experience and results from coordinated and closely scheduled radiosurgery and cochlear implantation (CI) in a vestibular schwannoma (VS) cohort. Patients Patients with VS who underwent radiosurgery followed by CI on the same or next day. Interventions Interventions included sequential radiosurgery and CI. Main Outcome Measures Tumor control defined by tumor growth on posttreatment surveillance and audiometric outcomes including consonant-nucleus-consonant words and AzBio sentences in quiet. Results In total, six patients were identified that met the inclusion criteria, with an age range of 38 to 69 years and tumor sizes ranging from 2.0 to 16.3 mm. All patients successfully underwent radiosurgery and CI on the same or immediately successive day. Postoperatively, all patients obtained open-set speech recognition. Consonant-nucleus-consonant word scores ranged from 40 to 88% correct, and AzBio scores ranged from 44 to 94% correct. During posttreatment magnetic resonance imaging surveillance, which ranged from 12 to 68 months, all tumors were noted to be adequately visualized, and no tumor progression was noted. Conclusion Coordinated radiosurgery and CI can be safely performed in patients with VS on the same or next day, serving to decrease burden on patients and increase access to this vital rehabilitative strategy.

Objectives A small number of cochlear implant (CI) users experience facial nerve stimulation (FNS), which can manifest as facial twitching. In some patients, this can be resolved by adjusting the electrical stimulation parameters. However, for others, facial stimulation can significantly impair CI outcomes or even prevent its use. The exact mechanisms underlying FNS are unclear and may vary among patients. Design Transimpedance measurements were used to assess lateral and longitudinal spread of current within 15 cochlea of nucleus CI recipients with FNS (13 unilateral recipients and 1 bilateral recipient). We compared the transimpedance measurements with programming parameters from clinical visits and pre- and postoperative temporal bone computed tomography (CT) scans to identify factors that may contribute to FNS in each CI ear. Results In nine ears, transimpedance curves showed inflection, which suggests a localized current sink within the cochlea. This indicates a low-impedance pathway through which current exits the cochlea and stimulates the labyrinthine segment of the facial nerve canal. Electrodes near this current sink were disabled or underfit to minimize facial stimulation. In the other seven ears, current flow peaked toward the basal end of the cochlea, suggesting that current exits through the round window or other structures near the basal end of the cochlea, stimulating the tympanic segment of the facial nerve. Conclusions Objective transimpedance measurements can be used to elucidate the mechanisms of FNS and to develop strategies for optimizing electrical stimulation parameters and speech coding to minimize or eliminate FNS in a small subset of CI users.

Objective The treatment paradigm of vestibular schwannoma (VS) focuses on preservation of neurologic function, with small tumors increasingly managed with active surveillance. Often, tumor size and hearing outcomes are poorly correlated. The aim of the current work was to describe the natural history of hearing among patients with nongrowing VS during observational management. Study Design Historical cohort study. Patients Adults with sporadic VS. Intervention Wait-and-scan management. Main Outcome Measure Maintenance of serviceable hearing (SH) after diagnosis. Results Among 228 patients with nongrowing VS, 157 patients had SH at diagnosis. Rates of maintaining SH (95% CI; number still at risk) at 1, 3, and 5 years after diagnosis were 94% (89–98; 118), 81% (74–89; 65), and 78% (71–87; 42), respectively. Poorer hearing at diagnosis (hazard ratio [HR] per 10 dB hearing level increase in pure-tone average of 2.51, p < 0.001; HR per 10% decrease in word recognition score of 1.70, p = 0.001) was associated with increased likelihood of developing non-SH during observation. When controlling for baseline hearing status, tumors measuring 5 mm or greater in the internal auditory canal or with cerebellopontine angle extension were associated with significantly increased risk of developing non-SH (HR, 4.87; p = 0.03). At 5 years after diagnosis, 95% of patients with nongrowing intracanalicular VS measuring less than 5 mm maintained SH. Conclusions Hearing worsens during periods of nongrowth in sporadic VS. Patients with small (<5 mm) intracanalicular tumors demonstrate robust maintenance of SH over time, reinforcing the consideration of initial observation in this patient subset.