Citations

Objectives: To evaluate blood–labyrinth barrier permeability using delayed gadolinium enhanced three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) in patients with untreated sporadic vestibular schwannoma (VS) to interrogate the etiopathogenesis of progressive sensorineural hearing loss. Design: Prospective case series. Setting: Single institution tertiary care center. Participants: Patients with previously untreated small to medium-sized unilateral VS undergoing 3D-FLAIR imaging 10 minutes (immediate) and 5 to 8 hours (delayed) after administration of intravenous gadolinium. Main Outcome Measures: Comparison of cochlear and vestibular signal intensity ratios (SIRs) across immediate and delayed images and across the tumor and nontumor ear. Results: Six of eight (75%) patients demonstrated asymmetric enhancement of inner ear structures on delayed contrast-enhanced imaging. Delayed mean cochlea and vestibule SIRs were significantly greater than immediate SIRs (cochlea: 1.91 versus 1.21 [p = 0.02]; vestibule 1.74 versus 1.15 [p = 0.02]). A higher vestibule SIR was statistically significantly associated with poorer pure-tone average and word recognition scores (p = 0.001). Conclusion: Ears with VS exhibited increased enhancement on delayed 3D FLAIR imaging. These findings suggest that alterations in blood–labyrinth barrier permeability may explain progressive sensorineural hearing loss in a subset of patients with untreated VS.

Objective: Definitive treatment of sporadic vestibular schwannoma (VS) following documented growth is common practice at most centers in the United States. However, as a natural extension of this paradigm, very little evidence exists surrounding the natural history of growing tumors. The primary objective of the current work was to describe the natural history of sporadic VS following documentation of initial tumor growth. Study Design: Retrospective cohort study. Setting: Tertiary referral center. Patients: Patients diagnosed with sporadic VS between January 1, 2001 and December 31, 2015 who elected continued observation despite having volumetric growth ≥20% of original tumor volume on interval magnetic resonance imaging (MRI). Main Outcome Measure: Survival free of subsequent volumetric growth. Results: Of 361 patients undergoing observation with serial imaging during the study period, 85 patients met inclusion criteria at a median age of 66 years (interquartile ranges [IQR] 55–71). Within this cohort, 40 patients demonstrated subsequent volumetric growth at a median of 1.7 years (IQR 1.0–2.6) from the date of initial MRI that documented growth. The median volumetric growth was 43% (IQR 28–57), and the median growth rate was 0.026 cm3 per year (IQR 0.009–0.107). Survival free of subsequent volumetric growth rates (95% CI; number still at risk) at 1, 2, 3, 4, and 5 years were 93% (87–99; 75), 67% (58–79; 45), 54% (43–67; 29), 44% (33–59; 19), and 41% (30–56; 12), respectively. Conclusions: In a cohort exclusively comprised of sporadic VS with documented growth, over 40% of tumors demonstrated no subsequent volumetric growth after 5 years of continued MRI surveillance. These data challenge the supposition that once growth occurs, all tumors will exhibit sustained growth. Continued observation after documented growth of sporadic VS is a reasonable consideration in appropriately selected cases.

Objective: Describe the outcomes of treatment for patients with cholesteatomas that are medially invasive to the otic capsule, petrous apex, and/or skull base. Study Design: Retrospective case series Setting: Two tertiary care academic centers. Patients: Patients surgically managed for medially-invasive cholesteatoma at two tertiary care institutions from 2001 to 2017. Interventions: Surgical management of medially-invasive cholesteatomas. Main Outcome Measures: The presenting symptoms, imaging, pre- and post-operative clinical course, and complications were reviewed. Results: Seven patients were identified. All patients had pre-operative radiographic evidence of invasive cholesteatoma with erosion into the otic capsule beyond just a lateral semicircular canal fistula. Five patients had a complex otologic history with multiple surgeries for recurrent cholesteatoma including three with prior canal wall down mastoidectomy surgeries. Average age at the time of surgery was 41.3 years (range 20-83). Two patients underwent a hearing preservation approach to the skull base while all others underwent a surgical approach based on the extent of the lesion. Facial nerve function was maintained at the pre-operative level in all but one patient. No patient developed cholesteatoma recurrence. Conclusions: The medially-invasive cholesteatoma demonstrates an aggressive, endophytic growth pattern, invading into the otic capsule or through the perilabyrinthine air cells to the petrous apex. Surgical resection remains the best treatment option for medially-invasive cholesteatoma. When CSF leak is a concern, a subtotal petrosectomy with closure of the ear is often necessary.

Podcasts are online digital audio programs that are disseminated via online subscription that are easily accessible through computers or smartphones. Increasingly, residents and medical students are prioritizing podcasts for asynchronous medical education due to ease of use, convenience (eg, use while exercising or commuting), and repeatability. Some trainees have found podcasts more useful than traditional didactic lectures. Given the increasing requirements of social distancing and the need for distance medical education platforms, podcast production can serve as a useful tool to complement resident and medical student education and is a resource that will remain accessible in perpetuity. An otolaryngology specialty podcast, “Headmirror’s ENT in a Nutshell,” was created to augment asynchronous learning and address the acute need for distance learning opportunities. Over the first 7 weeks of production, 50 episodes were created. Episodes were posted on www.headmirror.com, with subscription services available through Apple Podcast, Spotify, and other platforms.

Electrocochleography (ECochG) is an electrophysiological technique that records electrical potentials generated by different components of the inner ear and peripheral cochlear nerve in response to acoustic stimulation. ECochG responses can be analyzed into (1) cochlear microphonics (CM), (2) auditory nerve neurophonics, (3) summating potential, and (4) compound action potential. Over the past few decades, there have been ongoing refinements in technique and updates in the understanding of recorded potentials. Historically, ECochG found its main application in the diagnostic evaluation of Meniere's disease (MD). However, in the last decade, the focus has shifted towards cochlear implantation (CI). In patients with residual hearing after CI, combined electric and acoustic stimulation has resulted in improved hearing and speech outcomes. Despite efforts to mitigate trauma during electrode insertion, hearing preservation rates vary after surgery. During implantation, real‐time ECochG offers an opportunity to measure frequency specific CMs elicited from a localized region in the cochlea as the surgeon inserts the electrode array. In extracochlear ECochG recordings, the recording electrode can be placed on the promontory, the stapes, or the tympanic membrane. Intracochlear ECochG can be performed by inserting a recording electrode into the cochlea or by using one of the CI electrodes as the recording electrode. The loss of intraoperative ECochG signal may indicate cochlear trauma from electrode insertion, but the association between intraoperative ECochG changes and cochlear trauma remains controversial. The ability to monitor cochlear trauma during CI electrode placement holds promise to improve hearing preservation outcomes, modify surgical techniques, and change electrode design. The goal of this review is to provide a comprehensive overview of the electrophysiology and history of ECochG, discuss its recent applications in CI, and explore the ongoing research in this expanding field.

Fourteen single-sided deaf listeners fit with an MED-EL cochlear implant (CI) judged the similarity of clean signals presented to their CI and modified signals presented to their normal-hearing ear. The signals to the normal-hearing ear were created by (a) filtering, (b) spectral smearing, (c) changing overall fundamental frequency (F0), (d) F0 contour flattening, (e) changing formant frequencies, (f) altering resonances and ring times to create a metallic sound quality, (g) using a noise vocoder, or (h) using a sine vocoder. The operations could be used singly or in any combination. On a scale of 1 to 10 where 10 was a complete match to the sound of the CI, the mean match score was 8.8. Over half of the matches were 9.0 or higher. The most common alterations to a clean signal were band-pass or low-pass filtering, spectral peak smearing, and F0 contour flattening. On average, 3.4 operations were used to create a match. Upshifts in formant frequencies were implemented most often for electrode insertion angles less than approximately 500°. A relatively small set of operations can produce signals that approximate the sound of the MED-EL CI. There are large individual differences in the combination of operations needed. The sound files in Supplemental Material approximate the sound of the MED-EL CI for patients fit with 28-mm electrode arrays.

Objective: To report and discuss the effectiveness of stereotactic radiosurgery (SRS) or fractionated radiotherapy (FRT) for tumor control following surgical resection of endolymphatic sac tumors (ELST). Study Design: Retrospective case series. Setting: Multi-institutional academic referral centers. Patients: Patients undergoing surgical resection for ELST followed by SRS or FRT. Intervention(s): Surgical resection followed by radiotherapy. Main Outcome Measures: Local tumor control. Results: Two of the five patients experienced tumor recurrence after gross total microsurgical at 78 and 11 months, respectively. The former patient received salvage 3D conformal radiotherapy (3D-CRT) and while the latter patient underwent three courses of salvage SRS for recurrence, two of which were in-field and was disease-free at last follow up. Two additional patients underwent subtotal tumor resection (STR) followed by intensity-modulated radiation therapy (IMRT) and are currently without disease. One patient underwent STR followed by proton-beam therapy (PBT) and was free of disease at most recent follow-up. Conclusion: SRS/FRT remains a useful adjuvant for treatment of residual or recurrent ELSTs, where the risk of revision microsurgical resection is high.

ObjectiveAlthough granulomatosis with polyangiitis (GPA; Wegener’s granulomatosis) is classically characterized by systemic disease involving the kidneys and airway, approximately 10% of patients who have it present with isolated central nervous system disease. When involving the skull base, GPA frequently mimics more common pathology, resulting in diagnostic challenges and delay. The primary objective of this study is to characterize the cranial base manifestations of GPA, highlighting aspects most relevant to the skull base surgeon.Study DesignRetrospective review.SettingTertiary academic referral center.Subjects and MethodsRetrospective analysis of all patients with skull base GPA treated at a tertiary referral center from January 1, 1996, to May 1, 2018.ResultsTwenty‐nine patients met inclusion criteria. Twenty‐one (72%) initially presented with skull base symptomatology as their cardinal manifestation of GPA. Twenty‐four (82%) presented with cranial neuropathy at some point in their disease course. The trigeminal nerve was most commonly involved (12 of 24, 50%), followed by the facial (11 of 24, 46%) and optic (8 of 24, 33%) nerves. Eighteen patients reported hearing loss attributed to the GPA disease process, presenting as conductive, sensorineural, or mixed. The most common locations for GPA‐derived inflammatory skull base disease on imaging included the cavernous sinus (12 of 29, 41%) and the orbit (7 of 29, 24%).ConclusionEstablishing the diagnosis of skull base GPA remains challenging. Cranial neuropathy is diverse in presentation and often mimics more common conditions. Imaging findings are also unpredictable and frequently nonspecific. Careful review of patient history, clinical presentation, serology and biopsy results, and imaging can reveal important clues toward the diagnosis.

526 Background: Antidepressants do not adequately alleviate all HFs. Based on placebo-controlled data demonstrating that GABA is an alternative therapy for HFs, this trial was initiated to test whether the combination of an antidepressant and GABA was better than GABA alone in PTS with inadequate HF control on an antidepressant alone. Methods: Eligible PTS on antidepressants with bothersome HFs were randomized to two groups. PTS kept a daily HF diary during a baseline wk (while continuing their antidepressant). Following the baseline wk, all PTS were given GABA 300 mg at hs for 3 days, then BID for 3 days, and then TID for 22 days. One group continued their antidepressant while the other group was weaned off it over several days. PTS continued a daily HF diary during this 4-wk period. Efficacy was measured using the mean daily HF number and score; the latter measured by assigning points (1–4, for mild to very severe) to each HF and then adding the points for a given time. The study design provided 80% power to detect a difference in the changes from baseline at 4 wks between the two groups of 1.2 HFs/day, or 3 points/day in HF scores. Results: 115 PTS were randomized and given GABA. PTS continuing their antidepressant reported a 48% mean reduction in HF score after 4 wks, vs 49% for PTS stopping it (p=0.97). Mean HF numbers were reduced 50% and 47%, respectively (p=0.54). 16 other symptoms and quality of life items were measured by PT-completed weekly questionnaires, with the only suggestive changes from baseline between the two arms being more mood troubles after 2 wks of treatment (p=0.06) and more nervousness after 4 wks of treatment (p=0.01) in PTS stopping their antidepressant. Also, a mild temporary increase in dizziness after 1 wk of treatment was observed in the same group (p=0.08) suggestive of an antidepressant withdrawal reaction. Conclusion: This trial failed to provide any evidence that the combination of GABA and an antidepressant decreased HFs any more than did GABA alone in PTS who had inadequate HF control with an antidepressant alone. The 50% reduction in HFs in both arms is commensurate with the efficacy of GABA delineated in other published reports. No significant financial relationships to disclose.