Evaluating the Impact of Cochlear Implantation on Cognitive Function in Older Adults.

OBJECTIVES/HYPOTHESIS: We hypothesize that treating hearing loss through cochlear implantation in older adults will improve cognitive function. STUDY DESIGN: Prospective, interventional study. METHODS: Thirty-seven participants aged 65 years and older who met criteria for cochlear implantation were enrolled. Subjects underwent preoperative cognitive testing with a novel arrangement of standard neuropsychological tests, including tests of general cognition and mood (Mini-Mental Status Exam [MMSE]), tests of verbally based stimuli and responses (Digit Span, Stroop, Hopkins Verbal Learning Test-Revised [HVLT-R], Hayling Sentence Completion), and comparable visually based tests (Spatial Span, d2 Test of Attention, Brief Visuospatial Memory Test [BVMT], Trails A and B). Testing was repeated 12 months postoperatively. RESULTS: One year postoperatively, subjects showed a statistically significant improvement in hearing and on the following tests of cognitive function: concentration performance of the d2 Test of Attention, Hayling Sentence Completion Test, HVLT-R (total and delayed recall), Spatial Span (backward), and Stroop Color Word Test. A subgroup analysis was performed comparing 13 participants with preoperative cognitive impairment (MMSE ≤ 24) to 24 participants with normal cognition (MMSE ≥ 25). In this subgroup analysis, a greater magnitude of improvement was seen in those with impaired cognition, with statistically significant improvement in Digit Span (scaled score), Stroop Word (T-score), Stroop Color-Word (residual and T-score), HVLT-R, and Hayling (overall). All verbally based test scores improved, and 75% of the visually based test scores improved. CONCLUSIONS: This study demonstrates the cognitive benefits of cochlear implantation in older adults 1 year after surgery. For older adults with cognitive impairment prior to cochlear implantation, the cognitive benefits were even greater than in subjects with normal cognition. LEVEL OF EVIDENCE: 3, nonrandomized controlled cohort Laryngoscope, 132:S1-S15, 2022.

Corrigendum: Characterizing Adult Cochlear Supporting Cell Transcriptional Diversity Using Single-Cell RNA-Seq: Validation in the Adult Mouse and Translational Implications for the Adult Human Cochlea.

[This corrects the article DOI: 10.3389/fnmol.2020.00013.].

Transmastoid Hydroxyapatite Resurfacing for Sigmoid Sinus Wall Anomalies Causing Pulsatile Tinnitus.

OBJECTIVE: Comprising 4% of tinnitus, pulsatile tinnitus (PT) can be particularly difficult for affected patients as well as surgeons looking to address their symptoms. Often the cause is not identified but can be secondary to turbulent flow in or near the sigmoid sinus, particularly if there is an identifiable sigmoid sinus dehiscence (SSDe) and/or diverticulum (SSDi). These sigmoid sinus wall anomalies (SSWA) may be treated with transmastoid sigmoid sinus resurfacing; however, this intervention remains relatively novel and its technique, materials used, resolution success, and complications need to be continuously reviewed. METHODS: A retrospective case series of patients with PT due to SSWA at a tertiary referral center was reviewed. A total of 6 patients (7 ears) treated by transmastoid resurfacing using hydroxyapatite (HA) were retrospectively assessed. Pre-operative demographics and symptoms, pre- and post-operative hearing results, and post-operative outcomes were reviewed. RESULTS: All patients were female with an average BMI of 32.9 (±5.4) and a mean age of 45.5 years (±15.3). Mean follow-up was 648 days. Objective tinnitus was noted in all ears with SSDi (100%); however, no objective tinnitus was noted with purely SSDe. In 100% of ears, PT was diminished with ipsilateral jugular compression and was amplified with contralateral head turn. Pre-operative symptoms of PT resolved in all patients, but delayed recurrence (>1 year) occurred in 1 ear (14%). No patient had pre- or post-operative hearing loss. No major complications were encountered. CONCLUSIONS: Transmastoid resurfacing for SSWA with HA bone cement is a safe, reliable intervention in properly identified PT patients.

Characterizing Adult Cochlear Supporting Cell Transcriptional Diversity Using Single-Cell RNA-Seq: Validation in the Adult Mouse and Translational Implications for the Adult Human Cochlea.

Hearing loss is a problem that impacts a significant proportion of the adult population. Cochlear hair cell (HC) loss due to loud noise, chemotherapy and aging is the major underlying cause. A significant proportion of these individuals are dissatisfied with available treatment options which include hearing aids and cochlear implants. An alternative approach to restore hearing would be to regenerate HCs. Such therapy would require a recapitulation of the complex architecture of the organ of Corti, necessitating regeneration of both mature HCs and supporting cells (SCs). Transcriptional profiles of the mature cell types in the cochlea are necessary to can provide a metric for eventual regeneration therapies. To assist in this effort, we sought to provide the first single-cell characterization of the adult cochlear SC transcriptome. We performed single-cell RNA-Seq on FACS-purified adult cochlear SCs from the LfngEGFP adult mouse, in which SCs express GFP. We demonstrate that adult cochlear SCs are transcriptionally distinct from their perinatal counterparts. We establish cell-type-specific adult cochlear SC transcriptome profiles, and we validate these expression profiles through a combination of both fluorescent immunohistochemistry and in situ hybridization co-localization and quantitative polymerase chain reaction (qPCR) of adult cochlear SCs. Furthermore, we demonstrate the relevance of these profiles to the adult human cochlea through immunofluorescent human temporal bone histopathology. Finally, we demonstrate cell cycle regulator expression in adult SCs and perform pathway analyses to identify potential mechanisms for facilitating mitotic regeneration (cell proliferation, differentiation, and eventually regeneration) in the adult mammalian cochlea. Our findings demonstrate the importance of characterizing mature as opposed to perinatal SCs.

Supporting cell survival after cochlear implant surgery.

Supporting cells (SCs) provide structure and maintain an environment that allows hair cells to receive and transmit signals in the auditory pathway. After insult to hair cells and ganglion cells, SCs respond by marking unsalvageable cells for death and maintain structural integrity. Although the histopathology after cochlear implantation has been described regarding hair cells and neural structures, surviving SCs in the implanted ear have not. We present a patient whose posthumous examination of an implanted cochlea demonstrated SC survival. This finding has implications for SC function in maintaining electrical hearing and candidacy for future hair cell regeneration therapies. Laryngoscope, 129:E36-E40, 2019.

Audiologic Natural History of Small Volume Cochleovestibular Schwannomas in Neurofibromatosis Type 2.

OBJECTIVE: To characterize the audiometric natural progression in patient-ears with small volume (<1,000 mm), treatment-naïve cochleovestibular schwannomas (CVSs) in Neurofibromatosis Type 2 (NF2). STUDY DESIGN: Prospective, longitudinal cohort study. SETTING: Quaternary medical research institute. PATIENTS: One hundred eleven ears in 71 NF2 patients with small, treatment-naïve CVSs observed from July 2006 to July 2016. INTERVENTION: Serial audiometric testing, including pure tone audiometry, speech audiometry, and magnetic resonance imaging (MRI). OUTCOME MEASURES: Four-frequency pure tone average (4f-PTA) of 0.5, 1, 2, and 4 kHz and word recognition score (WRS) were recorded. Their changes were compared with MRI changes in CVS volume over time. Times to significant hearing loss (10 dB loss in 4f-PTA) and WRS based on 95% critical difference were measured. RESULTS: Linear regression analysis showed a significant correlation with baseline hearing level (4f-PTA) and internal auditory canal (IAC) tumor volume to annual hearing decrease rate (AHDR) (p = 0.003, p = 0.0004). Hearing level at baseline and tumor volume correlate with AHDR while tumor volume growth rate does not. Two-way analysis of variance found significant differences in AHDR, risk of significant hearing loss, and risk of critical difference in WRS based on baseline hearing level (abnormal or normal) and IAC tumor volume (greater or less than 200 mm). CONCLUSION: Subjects with normal baseline hearing and small IAC tumor component had a low AHDR and low risk of significant hearing loss and may warrant conservative management while the presence of baseline hearing loss and large IAC volume resulted in higher ADHR and greater risk for further hearing loss and may benefit from early treatment interventions.