Does Location of Intralabyrinthine Vestibular Schwannoma Determine Objective and Subjective Vestibular Function?

BACKGROUND AND OBJECTIVE: The incidence of intralabyrinthine schwannomas is increasing, and a growing attention is given to the detrimental effects on hearing function. On the contrary, the vestibular profile of intralabyrinthine vestibular schwannomas (VSs) is still not well understood. We aimed to investigate and report the observed relationships between the intralabyrinthine location of the schwannomas and objective and subjective vestibular profile of the patients. METHODS: Retrospective cohort study of 20 consecutive individuals with sporadic intralabyrinthine schwannomas and grouped according to the intralabyrinthine location of the schwannomas. Vestibular testing consisted of the video head impulse test of all three semicircular canals, the caloric test, cervical and ocular vestibular evoked myogenic potentials, and the dizziness handicap inventory. A nonparametric unpaired t test was performed to compare groups, and Fisher's exact test was used for categorical data. RESULTS: The median video head impulse test gains (lateral, anterior, posterior) were 0.40, 0.50, and 0.75 for intravestibular schwannomas and 0.93, 1.52, and 0.91 for intracochlear schwannomas ( p = 0.0001, p = 0.009, p = 0.33), respectively. Caloric unilateral weakness had a median of 100% for intravestibular schwannomas and 14% for intracochlear schwannomas ( p = 0.0001). The mean dizziness handicap inventory was 21 for intravestibular schwannomas and 1 for cochlear schwannomas ( p = 0.02). There were no significant differences in vestibular evoked myogenic potentials according to intralabyrinthine location. CONCLUSION: By both objective and subjective measures, intralabyrinthine schwannomas with an intravestibular component has significantly worse vestibular function than schwannomas with purely cochlear involvement.

Cochlear Implantation in Sporadic Intralabyrinthine Schwannomas with Single-Sided Deafness: Implications for Binaural Hearing.

BACKGROUND AND OBJECTIVE: Intralabyrinthine schwannomas (ILSs) may have detrimental effects on ipsilateral hearing, commonly leading to single-sided deafness (SSD). Cochlear implantation in patients with ILSs is an option to partly restore ipsilateral hearing; however, the available literature fails to account for the binaural hearing benefits of a cochlear implant (CI) for ILSs. METHODS: We prospectively evaluated SSD patients with sporadic ILS undergoing cochlear implantation with simultaneous tumor resection (n = 10) or with tumor observation (n = 1). Patients completed the Speech, Spatial and Qualities Questionnaire (SSQ12) and the Nijmegen Cochlear Implant Questionnaire (NCIQ) pre- and postoperatively, as well as the Bern Benefit in Single-Sided Deafness (BBSSD) questionnaire postoperatively. Patients were also tested postoperatively with and without their CI to measure the effect on localization ability and binaural summation, squelch, and head shadow. RESULTS: Evaluation was completed for nine and six patients (subjective and objective data, respectively). The CI significantly improved the speech reception threshold (SRT) in the head shadow condition where the target signal was presented to the CI side and the noise to the front (SCIN0). On the other hand, the SRTs in the colocated condition (S0N0) and the condition where the target signal was presented to the front and the noise to the CI side (S0NCI) were unaffected by the CI. The mean localization error decreased significantly from 102° to 61° (p = 0.0031) with the addition of a CI. The scores from SSQ12 demonstrated nonsignificant changes. For NCIQ, the self-esteem and the social interaction domains increased significantly but insignificantly for the remaining domains. The BBSSD responses ranged from +0.5 to +3.5 points. CONCLUSION: After implantation, patients achieved significantly better scores across some of the patient-reported and objective parameters. In addition to reporting on a number of ILS cases where implantation was performed, the study is the first of its kind to document patient-reported and objective binaural hearing improvement after cochlear implantation in patients with ILS and, thereby, lends support to the active management of ILS.

Transmastoid Surgery for Superior Canal Dehiscence: Prospective Longitudinal Objective and Patient-Reported Audiovestibular Outcomes.

OBJECTIVE: We assess symptom control, reversal and stability of objective third-window indicators, and hearing and balance function after transmastoid superior canal dehiscence plugging. To do this, we combine patient self-assessment questionnaires with auditory and vestibular test data collected at a preoperative and multiple postoperative visits. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary referral center. PATIENTS: Patients who underwent transmastoid plugging for superior canal dehiscence from 2012 to 2020. INTERVENTIONS: Plugging of the superior semicircular canal using the transmastoid approach. MAIN OUTCOME MEASURES: Patients were evaluated preoperatively, 3-month postoperative, and at yearly follow-ups (up to 8 yr postoperative). Self-assessment questionnaires included Autophony Index, Dizziness Handicap Inventory, Tinnitus Handicap Inventory, and Hearing Handicap Inventory. Objective tests included audiometry, cervical vestibular evoked myogenic potential, ocular vestibular evoked myogenic potential, and video head impulse test. RESULTS: There was a statistically significant improvement in Autophony Index and Hearing Handicap Inventory total scores from the preoperative evaluation to 1 year postoperative. Dizziness Handicap Inventory and Tinnitus Handicap Inventory total scores also improved but statistically insignificant. Cervical and ocular vestibular evoked myogenic potential amplitudes and low-frequency air-bone gap showed statically significant reversal of the third-window effect preoperative versus 1 year postoperative. Video head impulse test of the superior semicircular canal revealed cases of pathological function preoperative with postoperative recovery. Results were stable over time. CONCLUSIONS: Superior canal dehiscence repair resolves symptoms of autophony and improves hearing disability. Objective third-window indicators reverse and show long-term stability. Auditory and vestibular function is preserved postoperative, even superior semicircular canal function may be normal. Data suggest that surgical outcomes should not be evaluated until 1 year postoperative.

Enlarged Vestibular Aqueduct and Associated Inner Ear Malformations: Hearing Loss Prognostic Factors and Data Modeling from an International Cohort.

ACKGROUND: There is a need to operationalize existing clinical data to support precision medicine in progressive hearing loss (HL). By utilizing enlarged vestibular aqueduct (EVA) and its associated inner ear abnormalities as an exemplar, we model data from a large international cohort, confirm prognostic factors for HL, and explore the potential to generate a prediction model to optimize current management paradigms. METHODS: An international retrospective cohort study. Regression analyses were utilized to model frequency-specific HL and identify prognostic factors for baseline average HL severity and progression. Elastic-net regression and machine learning (ML) techniques were utilized to predict future average HL progression based upon routinely measurable clinical, genetic, and radiological data. RESULTS: Higher frequencies of hearing were lost more severely. Prognostic factors for HL were the presence of incomplete partition type 2 (coefficient 12.95 dB, P=.011, 95% CI 3.0-22 dB) and presence of sac signal heterogeneity (P=.009, 95% CI 0.062-0.429) on magnetic resonance imaging. Elastic-net regression outperformed the ML algorithms (R2 0.32, mean absolute error 11.05 dB) with coefficients for baseline average hearing level and the presence of sac heterogeneity contributing the most to prediction outcomes. CONCLUSION: Incomplete partition type 2 and endolymphatic sac signal heterogeneity phenotypes should be monitored closely for hearing deterioration and need for early audiological rehabilitation/cochlear implant. Preliminary prediction models have been generated using routinely collected health data in EVA. This study showcases how international collaborative research can use exemplar techniques to improve precision medicine in relatively rare disease entities.

Tinnitus suppression in a prospective cohort of 45 cochlear implant recipients: occurrence, degree and correlates.

OBJECTIVE: To determine tinnitus prevalence and severity in a cohort of unselected first-time cochlear implant (CI) recipients whose primary motive for CI was sensorineural hearing loss (SNHL), and to evaluate the effect of CI on tinnitus after cochlear implantation. METHODS: Prospective longitudinal study of 45 adult CI recipients with moderate to profound SNHL. Patients completed the Danish version of the Tinnitus Handicap Inventory (THI) and a visual analogue scale (VAS) for tinnitus burden before implantation, 4 months after implantation and 14 months after implantation. RESULTS: The study included 45 patients, of which 29 (64%) had pre-implant tinnitus. Median THI score (IQR) significantly decreased from 20 (34) to 12 (24) at first follow-up (p < 0.05) and to 6 points (17) at second follow-up (p < 0.001). Median VAS (IQR) for tinnitus burden decreased from 33 (62) to 17 (40; p = 0.228) and 12 (27, p < 0.05) at the first and second follow-ups, respectively. Tinnitus was totally suppressed in 19% of patients, improved in 48%, remained unchanged in 19% and worsened in 6%. 2 patients reported new tinnitus. At the second follow-up, 74% of patients had slight or no tinnitus handicap, 16% had mild handicaps, 6% had moderate handicaps, and 3% had severe handicaps. High pre-implant THI and VAS scores correlated with greater decrease in THI scores over time. CONCLUSION: 64% of the patients with SNHL had pre-implant tinnitus, which was decreased 4 and 14 months after implantation. Overall, 68% of patients with tinnitus improved their tinnitus handicap after CI. Patients with higher THI and VAS scores had a larger decline and the highest benefits in terms of tinnitus handicap improvement. The study findings demonstrate that the majority of patients with moderate to profound SNHL eligible for cochlear implantation benefit from complete or partial tinnitus suppression and improved quality of life after implantation.

Cochlear Implantation for Patients with a Vestibular Schwannoma: Effect on Tinnitus Handicap.

BACKGROUND: Tinnitus is a common symptom among individuals with a vestibular schwannoma. In recent years, cochlear implantation, often combined with tumor resection, is an increasingly used option in the management of these patients. The existing literature does not account well for the effect of treatment on tinnitus burden. Thus, this paper reports the effect of cochlear implantation on tinnitus in a cohort of vestibular schwannoma patients. METHODS: Individuals with vestibular schwannoma undergoing cochlear implantation were retrospectively reviewed for tinnitus burden, as evaluated by the Tinnitus Handicap Inventory, administered before and after implantation. The outcome measures were total Tinnitus Handicap Inventory score and scores from each of the Tinnitus Handicap Inventory subdomains (functional, emotional, and catastrophic). In addition, the existing literature on tinnitus in cochlear implanted vestibular schwannoma patients was reviewed. RESULTS: Tumor management consisted of simultaneous resection (77%), previous resection (9%), observation (9%) and radiation (5%). Complete Tinnitus Handicap Inventory evaluation was available for 17 patients. After implantation, the median THItotal changed from 18 to 10 (P = .0006), the subdomain THIfunctional from 10 to 3 (P = .006), the THIemotional from 3 to 0 (P = .023) and the THIcatastrophic from 6 to 1 (P = .004). In the scarcely reported tinnitus outcomes in the literature, most but not all cases experienced a decrease in tinnitus. CONCLUSIONS: The tinnitus burden is significantly reduced by cochlear implantation in individuals with a vestibular schwannoma. This agrees with findings for other etiologies indicating cochlear implantation and supports the eligibility for hearing rehabilitation with a cochlear implant for this specific group of patients.

Cochlear implantation and simultaneous posterior semicircular canal plugging.

BACKGROUND: Intractable benign paroxysmal positional vertigo (BPPV) may be treated by plugging the affected semicircular canal (SCC). A cochlear implant (CI) can diminish subjective symptoms of tinnitus. We present a case with intractable BPPV and incapacitating tinnitus who underwent surgery, simultaneously plugging his posterior SCC (PSCC) and implanting an ipsilateral CI. CASE: A 50-year-old male experienced single-sided deafness (SSD) with severe ipsilateral tinnitus, and intractable BPPV related to the ipsilateral PSCC. Two years earlier, he had been treated with a bone anchored hearing system (BAHS) for his single-sided hearing loss, but his tinnitus and BPPV persisted. The patient was elected for surgical plugging of the affected SCC and was offered a simultaneous ipsilateral CI to treat his hearing loss and reduce his disabling tinnitus. The procedure was initially clinically and subjectively successful, but the tinnitus worsened, following an MRI despite regular precautions. CONCLUSION: This is the first case presentation of cochlear implantation performed concurrent to plugging of the ipsilateral PSCC. The outcome of the procedure was overall successful.

Impact of an Endolymphatic Sac Tumor on Subjective and Objective Audiovestibular Function.

OBJECTIVE: This study reports subjective and objective audiovestibular function in patients diagnosed with an endolymphatic sac tumor (ELST), to evaluate the clinical implication of vestibular testing in ELST patients. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center/university hospital. PATIENTS: Five patients diagnosed with unilateral ELST. INTERVENTION: Subjective and objective audiovestibular tests; pure-tone average; speech discrimination score; the Video Head Impulse Test; the cervical vestibular evoked myogenic potential test; the caloric irrigation test; the Speech, Spatial and Qualities of Hearing Scale; the Tinnitus Handicap Inventory; and the Dizziness Handicap Inventory. MAIN OUTCOME MEASURE: Findings and characteristics of both subjective and objective audiovestibular functions. RESULTS: The mean pure-tone average and the mean speech discrimination score were 49 dB HL and 68% on the tumor ear and 13 dB HL and 99% contralaterally. The mean Speech, Spatial and Qualities of Hearing Scale score was 84, and the mean Tinnitus Handicap Inventory score was 64. Caloric testing showed a mean unilateral weakness of 80%. The Video Head Impulse Test of the lateral semicircular canal revealed refixation saccades on all tumor ears and an average gain value of 0.75 on the tumor ear versus 0.94 contralaterally. No cervical vestibular evoked myogenic potentials were elicited on the tumor side, whereas all but one was elicited contralaterally. The average Dizziness Handicap Inventory score was 47. CONCLUSION: A characteristic pattern of abnormal caloric findings, refixation saccades, and normal vestibulo-ocular reflex gain alongside sensorineural hearing loss on the tumor ear was identified. Asymmetric sensorineural hearing loss in any patient should lead to objective vestibular evaluation to strengthen not only a targeted tumor surveillance strategy and the indication for imaging, but also the design of vestibular rehabilitation. In addition, vestibular findings may guide the choice of surgical approach.

Cochlear Implantation Improves Both Speech Perception and Patient-Reported Outcomes: A Prospective Follow-Up Study of Treatment Benefits among Adult Cochlear Implant Recipients.

Cochlear implantation is considered the best treatment option for patients with severe-to-profound sensorineural hearing loss for whom conventional hearing aids are insufficient. We used a repeated measures longitudinal approach to evaluate speech recognition and patient-reported outcomes after cochlear implantation in an unbiased cohort of Danish adult patients in a prospective cohort study. We assessed 39 recipients before and two times after implantation using a battery of tests that included Dantale I, the Danish Hearing in Noise Test, the Nijmegen Cochlear Implant Questionnaire, and the Speech, Spatial, and Qualities of Hearing Scale. The study group improved significantly on all outcome measures following implantation. On average, Dantale I scores improved by 29 percentage points and Hearing in Noise Test scores improved by 22 percentage points. Most notably, the average Dantale score improved from 26 to 70% in the CI in quiet condition and from 12 to 42% in the cochlear implantation in noise condition when tested monaurally. Dantale demonstrated a significant positive correlation with Nijmegen Cochlear Implant Questionnaire and Speech, Spatial, and Qualities of Hearing Scale scores, while Hearing in Noise Test had no significant correlation with the patient-reported outcome measures. Patients improved significantly at 4 months and marginally improved further at 14 months, indicating that they were approaching a plateau. Our study's use of audiometric and patient-reported outcome measures provides evidence of the treatment benefits of cochlear implantation in adults, which may help physicians advise patients on treatment decisions and align treatment benefit expectations, as well as serve as a foundation for the development of new cochlear implantation selection criteria.

Cochlear implantation in Branchiootorenal syndrome - case report and review of the literature.

INTRODUCTION: Branchiootorenal syndrome (BOR) manifests with branchial fistulae, otological anomalies and renal dysplasia. Management remains largely symptomatic. The most common consequence of BOR is mild-to-profound sensorineural, conductive or mixed hearing loss, where conventional hearing aids (HA) provide limited benefit. Cochlear implantation for BOR-associated hearing loss is an emerging treatment. Existing literature remains limited, centring around paediatric cases. OBJECTIVES: This paper is the first to present a case of an adult/non-paediatric BOR patient receiving bilateral cochlear implants (CI), including pre- and postoperative objective and subjective hearing outcomes. Additionally, an overview of reported cases of cochlear implantation in BOR/BO patients is given. METHODS: A review of the case patient's medical charts from initial visit at our tertiary center to latest follow-up was conducted. A search of the Medline database resulted in four papers on cochlear implantation in BOR/BO patients, forming the basis of a literature review on this topic. RESULTS: Excellent hearing outcomes were achieved after bilateral CI despite the patient's inner ear malformation. DISCUSSION: The case patient's outcomes were comparable to results reported for unselected adult, non-syndromic CI-recipients with normal inner ear anatomy. CONCLUSION: BOR patients experiencing insufficient benefit from conventional HA should be considered for cochlear implantation.

Cochlear Implantation After Radiotherapy of Vestibular Schwannomas.

BACKGROUND AND OBJECTIVES: Vestibular schwannomas (VS) frequently lead to ipsilateral sensorineural hearing loss (HL) as part of its natural history or as a result of treatment. Cochlear implantation represents a well-documented treatment of profound HL that cannot be treated adequately with a conventional hearing aid, thus being offered to selected VS patients. A functional cochlea and cochlear nerve are prerequisites for sound perception with a cochlear implant (CI). The potential impact of radiotherapy on these structures is thus an important issue for subsequent CI hearing outcomes. The objective of this article is to present a case and to review the existing literature on the outcomes of cochlear implantation in irradiated VS patients systematically. METHODS: A systematic literature review using preferred reporting items for systematic reviews and meta-analyses was conducted. Medline was searched systematically. Papers reporting ipsilateral CI outcomes after radiotherapy of VS were included. Additionally, results of CI after stereotactic radiotherapy in a 54-year-old male with neurofibromatosis type 2 are presented. RESULTS: A total of 14 papers (33 patients) fulfilled inclusion criteria. Moderate preoperative HL was found in 11 patients. Six had moderate to severe HL, whereas 16 had severe HL or total deafness. Postoperative hearing outcomes varied from poor in 27% of patients to excellent in 19%, with remaining cases lying in between (mean follow-up of 19 months). Most patients achieved improvement in hearing and quality of life. CONCLUSION: Despite variation in the degree of hearing outcome, CI after radiotherapy of VS appears to be effective in the majority of cases, as more than 70% of patients have good or excellent outcomes within 1-2 years post-implantation. Subjective benefits are considerable, even in cases with relatively poor objective outcome.

Long-Term Vestibular Outcomes in Cochlear Implant Recipients.

Background: Vestibular dysfunction is likely the most common complication to cochlear implantation (CI) and may, in rare cases, result in persistent severe vertigo. Literature on long-term vestibular outcomes is scarce. Objective: This paper aims to evaluate vestibular dysfunction before and after cochlear implantation, the long-term vestibular outcomes, and follows up on previous findings of 35 consecutive adult cochlear implantations evaluated by a battery of vestibular tests. Methods: A prospective observational longitudinal cohort study was conducted on 35 CI recipients implanted between 2018 and 2019; last follow-up was conducted in 2021. At the CI work-up (T0) and two postoperative follow-ups (T1 and T2), 4 and 14 months following implantation, respectively, all patients had their vestibular function evaluated. Evaluation with a vestibular test battery, involving video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMP), caloric irrigation test, and dizziness handicap inventory (DHI), were performed at all evaluations. Results: vHIT testing showed that 3 of 35 ears had abnormal vHIT gain preoperatively, which increased insignificantly to 4 of 35 at the last follow-up (p = 0.651). The mean gain in implanted ears decreased insignificantly from 0.93 to 0.89 (p = 0.164) from T0 to T2. Preoperatively, 3 CI ears had correction saccades, which increased to 11 at T2 (p = 0.017). Mean unilateral weakness increased from 19 to 40% from T0 to T2 (p < 0.005), and the total number of patients with either hypofunctioning or areflexic semicircular canals increased significantly from 7 to 17 (p < 0.005). Twenty-nine percent of CI ears showed cVEMP responses at T0, which decreased to 14% (p = 0.148) at T2. DHI total mean scores increased slightly from 10.9 to 12.8 from T0 to T1 and remained at 13.0 at T2 (p = 0.368). DHI scores worsened in 6 of 27 patients and improved in 4 of 27 subjects from T0 to T2. Conclusion: This study reports significant deterioration in vestibular function 14 months after cochlear implantation, in a wide range of vestibular tests. vHIT, caloric irrigation, and cVEMP all measured an overall worsening of vestibular function at short-term postoperative follow-up. No significant deterioration or improvement was measured at the last postoperative follow-up; thus, vestibular outcomes reached a plateau. Despite vestibular dysfunction, most of the patients report less or unchanged vestibular symptoms.

Vestibular Function in Pendred Syndrome: Intact High Frequency VOR and Saccular Hypersensitivity.

OBJECTIVE: Although Pendred syndrome involves anatomical abnormalities in the vestibular system and patient-perceived dizziness, the literature on vestibular function is scarce. The objective was to evaluate objective vestibular function in patients with PS using the video head impulse test (VHIT) and the cervical vestibular evoked myogenic potential (cVEMP) test, assessing the high frequency vestibulo-ocular reflex (VOR) and the saccular function, respectively. METHODS: Twenty-six subjects (52 ears) with Pendred Syndrome and severe-to-profound hearing loss (cochlear implant candidacy) were studied retrospectively. Main outcome measures were VHIT VOR gain, refixation saccades, cVEMP stimulus thresholds and amplitudes. RESULTS: In total, 4 of 52 ears (8%) had pathological VHIT outcomes (2 ears with low VHIT gain and 2 ears with saccades). The mean VHIT gain value was 0.96 (range 0.63-2.02). No patients had complete VOR loss. CVEMP responses were present in 76% of tested ears and absent in 24%. The mean cVEMP amplitude value was 192 µV. Absence of cVEMP response was associated with the presence of VHIT saccades (p = 0.038) and advanced age (rs = -0.34; p < 0.05). cVEMP amplitude was correlated with VHIT gain (rs = 0.46; p < 0.001). CONCLUSION: Despite dysmorphic vestibular anatomy and severe loss of hearing, the VHIT VOR function is normal in patients with Pendred Syndrome. However, saccular function appears to be abnormally sensitive, as documented by low cVEMP thresholds and high amplitudes, which agrees with a "third window" effect secondary to the large vestibular aqueduct.

Intracochlear Vestibular Schwannoma Presenting with Mixed Hearing Loss.

As for other vestibular schwannomas, intralabyrinthine schwannomas commonly cause a sensorineural hearing loss, contrary to more lateral ear pathology that can cause conductive or mixed hearing loss. This case report features a patient that presented with a mixed and thus partly pseudo-conductive hearing loss due to an intracochlear schwannoma, a finding that is very rare. As a result, the patient was initially misdiagnosed as having otosclerosis and a stapedotomy was performed, without hearing improvement. We discuss the clinical implications of this atypical presentation, which illustrates the importance of performing supplementary audiological testing (e.g., the Gellé test), and the importance of considering vestibular system testing when otosclerosis is suspected. In addition, the importance of imaging and considering differential diagnoses in cases of conductive hearing loss is stressed.

Objective Vestibular Test Battery and Patient Reported Outcomes in Cochlear Implant Recipients.

OBJECTIVE: Cochlear implantation (CI) may have undesired effects on the vestibular apparatus. However, the literature holds no consensus on vestibular affection and the testing tools applied to test for vestibular dysfunction after cochlear implantation are inconsistent. We aimed to investigate the impact of CI on vestibular function by an extensive test battery including patient-reported outcomes. STUDY DESIGN: Prospective observational study. SETTING: University hospital. PATIENTS: Forty adult unilateral first-time CI recipients. INTERVENTION: Vestibular function was evaluated pre- and post-implantation with the video head impulse test (VHIT), the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs), and the patient-reported dizziness handicap inventory (DHI). RESULTS: Mean VHIT gain decreased from preoperative 0.92 to 0.84 postoperative (p = 0.018); mean caloric unilateral weakness increased from 20.5% preoperative to 42.9% postoperative (p < 0.0001); cVEMP responses were present on 10 operated ears preoperative and five ears postoperative, and compared with non-implanted ears, cVEMP responses on implanted ears were impaired (p = 0.023). 50% of patients reported early postoperative dizziness, but the mean DHI score remained unchanged (p = 0.94). The DHI scores correlated poorly with the objective outcomes (rs = 0.19 and rs = -0.22). CONCLUSION: Vestibular function is significantly affected after cochlear implantation, but vestibular hypofunction varies with the test used. Although early dizziness after implantation is common, later DHI scores are not significantly higher than before the implantation, indicating that central compensation plays a major role for these patients.

[Auditory brainstem implantation].

In this review, we discuss the auditory brainstem implant (ABI), which is a neuroprosthetic device being an advanced hearing aid in cases of bilateral, profound or complete hearing impairment due to a non-functional or absent cochlear nerve, or an inner ear malformation precluding cochlear implantation. Originally indicated in patients with bilateral vestibular schwannomas caused by neurofibromatosis type 2, the ABI has in recent years seen an increase in the aural rehabilitation of congenitally deaf children. Outcomes for patients are mixed, but generally the device leads to a reasonable improvement in speech perception.

Video head impulse test saccades and loss of cervical vestibular evoked myogenic potentials are late vestibular footprints of cochlear implantation.

BACKGROUND: Cochlear implantation may be complicated by concurrent injury to the vestibular apparatus, potentially resulting in disabling vertigo and balance problems. Information on vestibular function before implantation as measured by the video head impulse test (VHIT) and cervical vestibular evoked myogenic potentials (cVEMPs) is scarce and literature on long-term effects is non-existing. OBJECTIVE: We aimed to evaluate how vestibular function was affected by cochlear implantation (CI), as measured by VHIT and cVEMPs in the late phase after implantation. METHODS: Retrospective repeated measurement study. PATIENTS: Among the 436 patients elected for CI surgery during 2013 to 2018, 45 patients met the inclusion criteria (CI recipients with a vestibular assessment prior to the first CI and a repeated vestibular assessment after the CI operation). INTERVENTION: VHIT and cVEMPs before and after cochlear implantation. Main outcome measures were vestibular function as evaluated by VHIT gain, saccades and cVEMPs. RESULTS: The mean time between first and second vestibular screening was 19 months. The mean VHIT gain on implanted ears was 0.79 before the operation and showed no change at follow-up (p = 0.65). Likewise, the number of abnormal VHIT gain values was equal before and after the operation (p = 0.31). Preoperatively, saccades were present on 12 ears (14%) compared with 25 ears (29%) postoperatively (p = 0.013) and were associated with significantly lower VHIT gain values. Preoperatively, positive cVEMPs were found in 20 CI ears (49%) and 24 contralateral ears (62%). 10 CI ears lost cVEMP postoperatively compared with 2 ears on the contralateral side (p = 0.0047). CONCLUSIONS: Even though VHIT gain has been reported to be affected in the immediate post-implantation period, the findings in this study show that VHIT gain is normalized in the long-term. However, cochlear implantation is associated with the occurrence of VHIT saccades in the long-term and these are associated with lower VHIT gain values. In addition, cVEMP responses are significantly reduced long-term on implanted ears, which agrees with other studies with shorter follow-up.

The natural history of vestibular schwannoma growth-prospective 40-year data from an unselected national cohort.

BACKGROUND: Optimal management of vestibular schwannoma (VS) is still debated and thus international consensus has not been achieved. Treatment options are observation, radiotherapy, and surgery. Knowledge on the natural history of tumor growth is essential for choice of treatment modality. The aim is to present intra-/extrameatal tumor growth and management data from a prospective, unselected national cohort of patients diagnosed with VS during the period 1976-2015. METHODS: Since 1976, all data from patients diagnosed with sporadic VS in Denmark have been referred to our national treatment center, where they have been entered prospectively into the national database. Data on tumor localization, growth, and treatment were retrieved. Growth definition: >2 mm by linear measurement, in accordance with the Tokyo 2001 consensus-meeting recommendations. RESULTS: 3637 cases of VS were diagnosed, in which 1304 patients had surgery and 21 received radiotherapy post diagnosis. 2312 patients were observed with mean follow-up of 7.33 years. Of these, 434(19%; 102 intra-and 332 extrameatal tumors) changed to active treatment during the observation period due to tumor growth. 5 years after diagnosis, 21% of the intrameatal tumors exhibited growth during observation, whereas 37% of extrameatal tumors had grown, increasing to 25% intrameatal and 42% extrameatal after 10 years. Following growth, the intrameatal tumors were mostly observed further and the extrameatal mostly underwent surgery. Tumor growth occurred mainly within the first 5 years post diagnosis. CONCLUSION: This natural history study documents the growth occurrence of both intra-and extrameatal VS during the first 12 years after diagnosis and should be used in patient counseling, management, and treatment decision making.

Vestibular Screening Before Cochlear Implantation: Clinical Implications and Challenges in 409 Cochlear Implant Recipients.

OBJECTIVE: Cochlear implantation (CI) carries a risk of loss of vestibular function following surgery. Thus, vestibular assessment presurgery is used to identify vestibulopathy that may contraindicate implantation and guide in selecting the candidate ear. The aim of this study was to evaluate the clinical implications of preoperative vestibular assessment, and to identify challenges in performing vestibular testing in patients with profound hearing loss, i.e., CI candidates. STUDY DESIGN: Retrospective study of all CI recipients implanted since the introduction of a vestibular screening program. SETTING: Tertiary referral center in 2013. PATIENTS AND INTERVENTION: CI candidates routinely underwent testing with the video head impulse test (VHIT) and the cervical vestibular evoked myogenic potential (cVEMP) test as a part of the CI work up. RESULTS: Three hundred thirty-five individuals were screened before the first CI and 74 individuals before the second CI. In 301 cases (73.6%), the vestibular function was considered normal and consequently carried no contraindications for surgery or implications for choice of ear to be implanted. Bilateral vestibular loss was found in 43 cases (10.5%) and unilateral vestibular loss was found in 62 cases (15.2%). In the latter cases, evaluation of multiple variables was indicated to select candidate ear. In nine implanted patients (2.2%), a relative contraindication to operate based on an "only balancing" ear was overruled by other factors. Vestibular testing was challenged by various factors (e.g., neck immobility, eye tracking issues, communication, and other patient issues), limiting the vestibular data output. This resulted in omittance, testing failure, or interpretation uncertainty 24 times (5.9%) for VHIT and 65 times (15.9%) for cVEMP. CONCLUSION: Vestibular screening is an important part of the clinical workup with respect to selection of candidate ear for cochlear implantation, as 15.2% of CI candidates present with unilateral vestibulopathy. Challenges in performing the vestibular tests are not uncommon, as test failure occurred in 15.9% of cases for the cVEMP and 5.9% for the VHIT. The most common reasons for test failure were neck immobility, communication issues, and problems of pupil tracking.

[Cochlear implantation for adults].

A cochlear implant is an electrode, which is implanted in the inner ear to establish or re-establish hearing. Based on estimates on the prevalence of undertreated bilateral profound hearing loss, the number of adult people receiving a cochlear implant is low. In addition, many people with residual acoustic hearing or people with single-sided deafness could benefit from a cochlear implant. Due to the recent expansions in the indications for cochlear implantation and the unmet need for hearing improvement among the adult population, more focus on referring these patients to audiological cochlear implantation workup is recommended, as argued in this review.