Long-term Hearing Research Articles

Reorganization of auditory-visual network interactions in long-term unilateral postlingual hearing loss

Long-term unilateral hearing loss could reorganize the functional network association between the bilateral auditory cortices, while alterations of other functional networks need to be further explored. We attempted to investigate the pattern of the reorganization of functional network associations between the auditory and visual cortex caused by long-term postlingual unilateral hearing loss (UHI) and its relationship with clinical characteristics. Therefore, 48 patients with hearing loss caused by unilateral acoustic tumors and 52 matched healthy controls were enrolled, and their high-resolution structural MRI and resting-state functional MRI data were also collected to depict the brain network. Degree centrality (DC) was employed to evaluate the functional network association of the auditory-visual network interaction. Group comparisons were performed to investigate the network reorganization, and its correlations with clinical data were calculated. Compared with the healthy control group, patients with UHI showed significantly increased DC between the auditory network (superior temporal gyrus and the medial geniculate body) and the visual network. Meanwhile, this difference was positively correlated with the extent of hearing impairment, and the correlation was more significant with the ipsilateral superior temporal gyrus in cases of acoustic neuroma. These results suggest that long-term unilateral hearing impairment may lead to enhancement of the visual-auditory network interactions and that the degree of reorganization is positively correlated with the pure tone average (PTA) and is more significant for the ipsilateral superior temporal gyrus, which provides clinical evidence regarding cross-modal plasticity in the UHI and its lateralization.

Treatment of Long-term Sudden Sensorineural Hearing Loss as an Otologic Migraine Phenomenon.

To describe a cohort of patients presenting with long-term sudden sensorineural hearing loss (SSNHL) treated with prophylactic migraine and intratympanic steroid therapy. Patients presenting to a neurotology clinic at least 6 weeks from SSNHL onset were included. All patients received migraine prophylactic medication (nortriptyline, topiramate, and/or verapamil) and lifestyle changes for at least 6 weeks, as well as intratympanic steroid injections, if appropriate. Twenty-one patients (43% female) with a mean age of 64 ± 11 years who presented 9 ± 8 months (median = 5) from symptom onset were included. Posttreatment hearing thresholds were significantly improved compared with pretreatment thresholds at 500 Hz (49 ± 19 dB versus 55 ± 20 dB, p = 0.01), 1000 Hz (52 ± 19 dB versus 57 ± 21 dB, p = 0.03), low-frequency pure-tone average (53 ± 15 dB versus 57 ± 17 dB, p = 0.01), and speech-frequency pure-tone average (57 ± 13 dB versus 60 ± 15 dB, p = 0.02). Posttreatment word-recognition-score (WRS) and speech-recognition-threshold (SRT) were also significantly improved (45 ± 28% versus 70 ± 28% and 57 ± 18 dB versus 50 ± 16 dB, respectively, both p < 0.01). Notably, ≥15% improvement in WRS and ≥10 dB improvement in SRT was observed in 13 (68%) and 8 (40%) patients, respectively. Of the 11 patients who presented with initial < 50% WRS, 8 (73%) had improved posttreatment >50% WRS with an average improvement of 39 ± 9%. Migraine medications in addition to intratympanic steroid injections significantly improved SRT and hearing frequencies in 40% and 29% of SSNHL patients, respectively, while significant WRS recovery was observed in most (68%) patients. This suggests SSNHL may be an otologic migraine phenomenon, which may be at least partially reversible even after the traditional 30-day postonset window.

Study of the Role of Hearing Aid on the Area of the Acoustic Field of Vowels.

The method of transformation of acoustic vowel triangles (AVT) /a/, /i/, /u/ was used for an objective assessment of the acoustic features of vowels in the speech production of 20 persons with long-term hearing impairment (LHI). The logarithm of the values ​​of the first two formants of each vowel (logF1, logF2) was determined for each subject. AVTs were transformed into the right-angled triangles, the vertices of the sound /u/ of which were moved to the origin of coordinates and the legs were aligned with the coordinate axes. In patients with LHI, the size of the triangles usually decreased, and they were stretched along one of the axes, which probably depends not only on the hearing loss severity but also on the duration of hearing aid use. The presented approach to the normalization of AVTs makes it possible to distinguish at least three groups of persons with LHI: in the first group, vowel triangles are stretched along the logF1 axis; in the second group, vowel triangles are stretched along the logF2 axis; and in the third group, AVT are symmetric.

Compliance of diagnosis and early management of congenital hypothyroidism

Objective: This study aimed to estimate the prevalence and the compliance of early diagnosis and early management of congenital hypothyroidism (CH). Materials and Methods: This retrospective cohort study gathered data from all infants born over 10 years from January 2007 to December 2016. All children diagnosed with CH as per standard definition of cord and follow-up thyroid-stimulating hormone (TSH) levels were analyzed to calculate the prevalence and the compliance rates to early treatment goal and time normalization of TSH. These children were evaluated for neurodevelopment outcomes. Results: 31,311 newborns screened for CH with a prevalence over 10 years of 1:3085 per live births. Among the 11 cases, five were found to have thyroid dysgenesis (1:6200), 5 thyroid dyshormonogenesis (1:6200), and only one case of generalized resistance to thyroid hormone (1:31000). The compliance with an early diagnosis within the first 2 weeks was 100%, and compliance with the initial treatment goal was 40%. Normalization was achieved in all cases within 16 weeks; however, all had normal hearing, vision, and development at their current age. Conclusion: The prevalence of CH in this single tertiary care center is similar to national and international data. Dyshormonogenesis has a higher prevalence than global data. Moreover, compliance with early diagnosis is excellent due to the strict adherent cord TSH protocol. The compliance with the initial treatment goal in our center is comparable with international data. However, large population-based studies are needed to establish a benchmark on such compliance rates. The long-term hearing, vision, and development milestone assessments of diagnosed cases were age appropriate.

Dynamics of vowel acoustic space indicators in patients with long-term hearing loss

To characterize VAS of adult Russian speakers with long-term HL using newly developed acoustic indicators. Recordings of sustained Russian cardinal vowels /a/, /i/, /u/ of 10 women and 10 men with long-term HL were acoustically analyzed. For each participant, two first formants of each vowel were measured and log-transformed (logF1, logF2). VAS was transformed into right triangles, their /u/ corners were moved to the origin, and their legs were aligned with axes. VAS was almost symmetrical, equal and have a maximum size in the control group consisted of subjects without hearing impairment while these of long-term HL group VAS size tended to have reduced and VAS stretched along one axis. Our study showed that a new VAS normalization approach can distinguish at least three groups of people with long-term HL. There are those with vowel triangles stretched along logF1-axis, with vowel triangles stretched along logF2-axis, and with symmetrical vowel triangles. Causes of the VAS differences require further investigation.

Ototoxicity among multidrug-resistant TB patients: a systematic review and meta-analysis.

BACKGROUND: The use of injectable antibiotics to treat multidrug-resistant TB (MDR-TB) is associated with substantial morbidity due to long-term hearing loss. This systematic review evaluates the incidence of ototoxicity among patients treated for MDR-TB, and the evidence for routine audiometric monitoring to mitigate its severity.METHODS: Studies of ototoxicity among patients with MDR-TB were identified from six databases: PubMed, MEDLINE, Web of Science, Embase, SCOPUS and the Cochrane Library. Meta-analyses were performed to determine the overall incidence of hearing loss, tinnitus and vertigo. The incidence of hearing loss was further stratified by country income status and the injectable agent used during treatment.RESULTS: Among 64 studies from 25 countries including 12 793 patients, 28.3% (95%CI 23.4-33.1) of patients treated with injectables reported hearing loss. Tinnitus and vertigo were experienced by respectively 14.5% (95%CI 10.3-18.7) and 8.1% (95%CI 4.7-11.6) of patients. The incidence of hearing loss was highest among patients treated with amikacin (33.4%, 95%CI 18.2-48.6), and lowest among those treated with capreomycin (2.0%, 95%CI 0-5.5). We found that audiometry was widely used as a method of evaluating hearing loss, and was feasible in a wide range of settings.CONCLUSION: Injectable antibiotics contribute to significant morbidity in patients with MDR-TB. In settings where they are used, routine audiometric monitoring is recommended to prevent irreversible damage.

The Effect of Long-Term Unilateral Deafness on Auditory Performance

Background and Objectives We investigated whether there are differences in auditory performance between the healthy ears of subjects with unilateral deafness (UD) and the control ears of subjects with normal hearing (NH) in both ears.Subjects and Method Sixteen subjects with acquired UD and 16 subjects with NH thresholds for both ears were enrolled. We compared the auditory performance of UD group and control group with NH in both ears.Results We found no meaningful differences in the three measures of psychoacoustic performance between the total healthy ears of subjects with UD and the ears of the control group. However, in the subgroup comparison, the left ears of subjects with right UD showed significantly poorer spectral-ripple discrimination (SRD) than the right ears of the subjects with left UD (&lt;i&gt;p&lt;/i&gt;=0.006) and the ears of control subjects with NH (&lt;i&gt;p&lt;/i&gt;=0.004).Conclusion Our findings indicate that after unilateral auditory deprivation, auditory processing is differentially affected by the side involved. In the subjects with acquired UD, the longterm hearing deprivation on the right side induced the down-regulation of central auditory process for SRD, but hearing deprivation on the left side did not affect SRD.

Vestibular Schwannoma Practice Patterns: An International Cross-specialty Survey.

To assess vestibular schwannoma (VS) practice patterns among providers. Cross-sectional survey. 8th Quadrennial International Conference on Vestibular Schwannoma and Other CPA Tumors. Clinicians who specialize in the management of VS. Responses to questions on the management and anticipated outcomes of VS for a series of common clinical scenarios were compared by specialty (otolaryngology versus neurosurgery), level of experience, scope of practice (surgery versus radiation and surgery), and geographic location of practice (United States versus international). Responses from 110 participants were analyzed. Overall, 53% of respondents were otolaryngologists, 60% had greater than 10 years of experience, and 57% practiced within the United States. In total, 86% of respondents would pursue initial observation for themselves if diagnosed with a 4 mm distal intracanalicular VS; however, practicing radiosurgeons were more likely to select stereotactic radiosurgery for this scenario compared with providers who solely practice surgery (14 versus 0%; p = 0.032). Otolaryngologists and neurosurgeons alike report that radiosurgery should not be considered a long-term hearing preservation strategy.Otolaryngologists were more optimistic regarding microsurgical hearing preservation outcomes for small distal intracanalicular tumors compared with neurosurgeons (11 versus 3% selected a high likelihood of maintaining class A/B hearing; p = 0.007). Ninety-five percent of respondents prioritized facial nerve outcome over complete disease removal in the context of microsurgical resection of large tumors. Management decision-making and expected outcomes for various clinical scenarios were largely similar among providers; however, variances in several key clinical areas exist. This study points to the feasibility of developing a widely accepted consensus statement among VS experts across specialties.

Identical twins affected by congenital cytomegalovirus infections showed different audio-vestibular profiles.

This study explored whether there were long‐term hearing and vestibular outcome differences between five pairs of identical twins who had been infected with the congenital cytomegalovirus (CMV) infection before birth. Data were collected from the medical records at the Audiological Clinic, Karolinska University Hospital, Stockholm. The congenital CMV infection resulted in high variations in vestibular and hearing function within, and between, the genetically identical twin pairs. Clinicians need to be aware that treatment and interventions may need to differ substantially when identical twins have hearing issues related to the congenital CMV infection.

Erratum. Predicting hearing outcomes before primary radiosurgery for vestibular schwannomas.

OBJECTIVE Optimizing outcomes in the management of patients with vestibular schwannomas (VSs) requires consideration of the patient's goals. Earlier recognition of VS by imaging has led to an evolution in management. Stereotactic radiosurgery (SRS) has emerged as a frequently used strategy designed to reduce management risks, obtain long-term tumor control, and preserve current neurological function. The authors analyzed features that impact hearing preservation rates in patients with serviceable hearing prior to SRS. METHODS The study included 307 patients who had serviceable hearing (Gardner-Robertson hearing scale [GR] grade 1 or 2, speech discrimination score ≥ 50%, pure tone average ≤ 50 dB) at the time of SRS. The authors evaluated parameters that included age, tumor volume, hearing status, disequilibrium, tinnitus, Koos class, sex, and tumor margin dose. The Pittsburgh Hearing Prediction Score (PHPS) was evaluated as a method to predict long-term hearing outcomes in these cases. RESULTS At a median of 7.6 years after SRS (range 1-23 years), tumor control was achieved in 95% of patients. The overall serviceable hearing preservation rate was 77.8% at 3 years, 68.8% at 5 years, and 51.8% at 10 years. The PHPS assigns a total of 5 points based on patient age (1 point if < 45 years, 2 points if 45-59 years, and 3 points if ≥ 60 years), tumor volume (0 points if < 1.2 cm3, 1 point if ≥ 1.2 cm3), and GR grade (0 points if grade 1 hearing, 1 point if grade 2 hearing) The serviceable hearing preservation rate was 92.3% at 10 years in patients whose score total was 1. In contrast, none of the patients whose PHPS was 5 maintained serviceable hearing at 10 years (p < 0.001). CONCLUSIONS SRS resulted in a high rate of long-term tumor control and cranial nerve preservation. The PHPS helped to predict long-term hearing preservation rates in patients who underwent SRS when they still had serviceable hearing. The best long-term hearing preservation rates were found in younger patients with smaller tumor volumes.

Corrigendum to: "Long-Term Hearing Outcomes Following Stereotactic Radiosurgery in Vestibular Schwannoma Patients-A Retrospective Cohort Study" by Santa Maria et al. Neurosurgery, nyy407, https://doi.org/10.1093/neuros/nyy407.

Corrigendum to: "Long-Term Hearing Outcomes Following Stereotactic Radiosurgery in Vestibular Schwannoma Patients-A Retrospective Cohort Study" by Santa Maria et al. Neurosurgery, nyy407, https://doi.org/10.1093/neuros/nyy407.

An observation of long term effect of one-stage hearing reconstruction on tympanosclerosis

Objective:To observe the long-term hearing stability of patients with tympanosclerosis after one-stage hearing reconstruction. Method:Forty-one patients with tympanosclerosis were included in the study. Their puretone thresholds before operation and those at 3 months, 6 months, 1 year, 2 to 5 years after operation were retrospectively analyzed. Differences between pre-and postoperative air-bone gaps（ABG） for speech frequencies（0.5, 1, 2, 4 kHz） as well as those of averaged ABG were calculated. Result:Preoperative averaged ABG of 44 ears was （36.0±10.4） dB. Averaged ABG at 3 months, 6 months, 1 year, 2 to 5 years after operation were （24.1±8.8） dB, （24.5±9.8） dB, （22.4±11.3） dB and （22.5±4.1） dB respectively. Averaged ABG at different time after operation were all significantly less than preoperative results but didn't differ between each other. Postoperative ABG for different frequencies varied between 9.3 and 33.7 dB. They were significantly less than preoperative results, but didn't differ between the four frequencies. At different time after operation, averaged ABG of type Ⅰ were always significantly less than those of type Ⅱ, while the latter were always significantly less than those of type Ⅳ. Differences between preoperative ABG and ABG at different postoperative time were not significantly different. Neither were differences between pre-and postoperative ABG for different frequencies. Conclusion:Hearing reconstruction has the same effect on hearing improvement of patients with tympanosclerosis at different frequencies. Type Ⅰ patients has the best hearing results while type Ⅳ patients has the worst. There is no significant difference between the long-term（1 year and more than 2 years after operation） and the short-term（3 months and 6 months after operation） hearing level. Hearing level of patients with tympanosclerosis remain stable in a long time after operation.

Preimplant Hearing Threshold: An Important Predictor of Hearing Preservation in Cochlear Implantation With Lateral Wall Electrodes.

To evaluate the outcomes and association factors of long-term hearing preservation (HP) in cochlear implantation with lateral wall (LW) electrode arrays. Retrospective case review. Tertiary academic center. Thirty-four consecutive ears from 32 patients with a ≤ 80 dB HL preoperative low-frequency pure-tone average of 250 to 500 Hz were included. Cochlear implantation with LW electrode arrays and the intention of achieving HP. HP classifications according to the HEARRING group and functional HP methods (≤ 85 dB HL of pure-tone threshold at 250 Hz) at 1 year postoperatively. Based on the HEARRING classification, complete, partial, and minimal HP was achieved in 7 ears (21%), 12 ears (35%), and 4 ears (12%), respectively. Under functional classification, 14 ears (41%) exhibited functional hearing after surgery. The average threshold shift was 17.1 dB HL (SD = 16.9 dB HL). Among various clinical features, a ≤ 60 dB HL preimplant pure-tone threshold of 250 Hz was associated with HP outcome in both classifications (OR = 12.95, 95% CI = 1.29-130.01, p = 0.029 in HEARRING classification; OR = 14.36, 95% CI = 1.07-191.40, p = 0.044 in functional classification). The following parameters were not associated with HP (p > 0.05): patient demographics, surgical aspects (insertion route and depth), electrode array size, scalar electrode position, and presence of comorbidity. With LW electrode arrays, HP was achieved in 68% of HEARRRING group patients and 41% of functional classification patients. A ≤ 60 dB HL preimplant pure-tone threshold of 250 Hz was significantly associated with an increased rate of long-term HP.

Fifteen-Year Follow-Up of Stapedotomy Patients: Audiological Outcomes and Associated Factors in a Middle Income Country

Objective: To evaluate the short-term (postoperative), medium-term (5 years), and long-term (10 and 15 years) audiometric results of patients who underwent stapedotomy and to determine specific factors associated with better postoperative outcomes. Methods: This study is a retrospective case review of 486 ears with surgically confirmed stapes fixation who underwent microscopic small fenestra stapedotomy. Preoperative, postoperative, and medium- and long-term air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were assessed. Postoperative factors associated with better postoperative outcomes were evaluated. Results: At 10- and 15-year follow-ups, ABG, AC, and BC were significantly deteriorated but clinically preserved in comparison with postoperative results. According to a multiple quantile regression, younger age was associated with better postoperative results at 0.25 kHz (p = 0.003) and 4 kHz (p = 0.028) and a smaller preoperative ABG was associated with better audiometric results at 0.25 kHz (p = 0.048), 0.5 kHz (p = 0.001), and 4 kHz (p = 0.001). In addition, younger age (p = 0.001 for AC and p < 0.001 for BC) and preoperative AC PTA (p < 0.001 for AC) were significantly associated with better postoperative AC and BC PTA. Conclusions: Stapedotomy surgery provides short-, medium-, and long-term hearing benefits in our studied cohort. ABG, AC, and BC thresholds obtained after the surgery are clinically preserved in 5-, 10-, and 15-year follow-ups, with an age-expected BC deterioration. Smaller preoperative ABG and younger age were positive predictors for better postoperative ABG. Future research should address long-term subjective and quality of life outcomes.

Is ossicular chain fixation predictable for tympanosclerosis on preoperative temporal bone computed tomography?

To report the predictability of ossicular chain (OC) fixation on preoperative temporal bone computed tomography (TBCT) in chronic otitis media (COM) with tympanosclerosis (TS). Fifty-six patients who had surgery for COM in our ear, nose and throat clinic between 2015 and 2017 were included in this retrospective case-control study. The patients were equally divided into two groups as those with TS and without TS. The complaint of preoperative otorrhea, values of incudostapedial joint (ISJ) angulation on preoperative TBCT scans, postoperative long-term hearing results, and postoperative complications were compared between the two groups. There was a statistically significant difference between the ISJ angulations of the operated and healthy sides in the COM group with TS (102.27 ± 7.92 and 91.90 ± 5.59 degrees, respectively, p < 0.001). However, no statistically significant difference was observed between the ISJ angulation of the operated and healthy sides in the COM group without TS (95.04 ± 4.86 and 94.35 ± 4.57 degrees, respectively, p > 0.05). In addition, when the ISJ angulations of the operated sides of the two groups were compared, it was statistically significantly higher for the TS group compared to the non-TS group (102.27 ± 7.92 and 95.04 ± 4.86 degrees, respectively, p < 0.001). Increased ISJ angulation may indicate OC fixation. COM cases with TS can be predicted by the measurement of ISJ angulation on preoperative TBCT.

How Long Is Otosclerosis Surgery Effective? Hearing Results after a 22-Year Follow-Up

Introduction: Stapes surgery is a safe procedure, with favourable hearing outcome. The objective of the study is to assess the long-term hearing results, addressing the bone conduction (BC) decay and the need for hearing aids in otosclerosis patients. Methods: We enrolled patients who underwent stapes surgery by means of stapedectomy or stapedotomy between 1991 and 2001. All enrolled patients underwent pure-tone audiometry (PTA) between September 2017 and June 2018. A set of questions was administered to record the prevalence of subjective symptoms and the need for hearing aids. Results: Seventy patients were enrolled for a long-term evaluation; 37 patients underwent bilateral surgery; therefore, 107 ears were included in the analysis. The average follow-up period was 22 years. No statistically significant difference was found between early and late post-operative air conduction (AC) PTA (41 vs. 49 dB; p > 0.05) nor between early and late post-operative BC-PTA (29 vs. 37 dB; p > 0.05). A significant difference was observed for AC at 8 kHz (65 vs. 78 dB; p < 0.05) and BC at 2 and 4 kHz (28 vs. 40 dB and 45 vs. 58 dB, respectively; p < 0.05). Conclusions: This is, to our knowledge, the longest mean follow-up time in the literature. A mild decrease in both AC and BC threshold can be expected and the sensorineural decay is more pronounced on the high frequencies. The subjective hearing symptoms and overall sound perception are satisfactory.

Influence of Semicircular Canal Dehiscence on Cochlear Implant Outcome

Introduction: Semicircular canal dehiscence (SCD) is defined as a defect of the bone overlying the semicircular canal. It has a relatively high prevalence of 3% in the general population, which makes it likely that a certain number of patients receiving a cochlear implant (CI) would have it. However, little is known about the influence of SCD on the CI outcome. Therefore, the aim of this study was to determine the influence of SCD on CI outcome with regard to short- and long-term word perception and hearing preservation. Methods: This study was a retrospective analysis of postoperative word perception ability in the electric-only condition after 6, 12, and ≥18 months and of hearing preservation 4 weeks after surgery in CI recipients with and without SCD. All patients received a preoperative 1.5- or 3-tesla magnetic resonance imaging. Results: Fifty-five patients were included. Forty-eight patients (87%) had no SCD, and 7 patients (13%) had SCD. Mean postoperative word perception scores were 66% in the non-SCD group versus 50% in the SCD group (p = 0.17) after 6 months, 74 versus 64% (p = 0.28) after 12 months, and 77 versus 73% (p = 0.62) after 18 or more months. The mean postoperative hearing loss in patients with functional residual hearing before surgery (n = 34) was 22 dB in the non-SCD group versus 31 dB in the SCD group (p = 0.15). Conclusions: CI outcome is comparable between recipients without and with SCD. Specifically, hearing preservation rate and word perception ability in the electric-only condition seem not affected by SCD. The rate of progress of word perception ability in the first 12 months after cochlear implantation is not influenced by SCD.

Effectiveness and Safety of Advanced Audiology-Led Triage in Pediatric Otolaryngology Services.

Expansion of the scopes of practice of allied health practitioners has the potential to improve the efficiency and cost-effectiveness of healthcare, given the identified shortages in medical personnel. Despite numerous examples in other allied health disciplines, this has yet to be applied to pediatric Audiology. This study aimed to investigate the effectiveness and safety of using audiologists with advanced training to independently triage children referred to otolaryngology (ORL) services, and compare the subsequent use of specialist resources, and postoperative grommet care to a standard medical ORL service. One hundred twenty children consecutively referred to a large ORL outpatient service in Queensland, Australia, for middle ear and hearing concerns were prospectively allocated to either the ORL service or Advanced Audiology-led service. Demographic and clinical data were extracted from electronic medical records and compared between the two services. Clinical incidents and adverse events were recorded for the Advanced Audiology-led service. Approximately half of all children referred to ORL for middle ear or hearing concerns were discharged without requiring any treatment, with the remaining half offered surgical treatment. The Advanced Audiology-led model increased the proportion of children assessed by ORL that proceeded to surgery from 57% to 82% compared with the standard medical ORL model. Children followed up by the audiologists after grommet insertion were more likely to be discharged independently and at the first postoperative review appointment compared with the standard medical ORL service. There were no reports of adverse events or long-term bilateral hearing loss after discharge by the Advanced Audiology-led service. These findings indicate that an Advanced Audiology-led service provides a safe and effective triaging model for the independent management of children not requiring treatment, and children requiring routine postoperative grommet review, and improves the effective use of specialist resource compared with the standard medical ORL service.

Low-Normal Platelets and Decreasing Platelets Are Risk Factors for Hearing Impairment Development.

Identification of undefined risk factors will be crucial for the development of therapeutic strategies in hearing impairment. Platelets are likely to affect the development of sudden sensorineural hearing loss, which is a primary risk factor for permanent hearing impairment. This implies that abnormal platelets might contribute to long-term hearing loss. This study investigated the role of platelets in the development of hearing impairment over a 5-year period. This study was a retrospective cohort study and consisted of a population-based survey, which was performed for 1,897 participants in 2014 to 2019. To evaluate the effect of platelet level on hearing ability, the subjects were divided into two groups: a high-normal platelet group (25 ∼ 40 × 104 cells/μL) and a low-normal platelet group (15 ∼ 25 × 104 cells/μL). Subjects were defined as having hearing impairment when pure tone audiometry was over 25 dB HL in either ear (tested in 2017 and 2019). Incidence of hearing impairment was analyzed. Incidence of hearing impairment at low frequencies was significantly higher in the low-normal platelet group than in the high-normal group year over year. Low-normal platelet count associated with low-frequency hearing impairment (LFHI) incidence (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.15-4.76). In the low-normal platelet group, subjects whose counts declined from baseline developed more LFHI than those whose counts increased over time. Further, decreasing platelets appeared to be an independent risk factor contributing to the incidence of LFHI (OR, 2.10; 95%CI, 1.09-4.06) in the low-normal platelet group. Both a low-normal platelet and a declining platelet count were independently associated with the incidence of LFHI. 3 Laryngoscope, 131:E1287-E1295, 2021.

Progression of Contralateral Hearing Loss in Patients With Sporadic Vestibular Schwannoma.

Background and Introduction: Vestibular schwannomas (VSs) are the most common tumors of the cerebellopontine angle, typically presenting unilaterally with ipsilateral sensorineural hearing loss (SNHL). The mechanism of tumor-induced hearing loss has recently been shown to be related to secreted tumor factors, in addition to mechanical compression of the adjacent auditory nerve, and these factors may percolate through CSF or blood to affect contralateral hearing as well.Methods: This is a retrospective study of medical records for patients treated for VS at Mass Eye and Ear from January 1994 through October 2018. Included patients had unilateral VS and sequential audiometry allowing for longitudinal assessment of hearing over time. Mass Eye and Ear's audiology database was used to select age- and sex-matched case controls, also with sequential audiometry, from the non-VS population. Subgroup analysis was performed by age, sex, baseline hearing, and tumor size at initial diagnosis. Hearing loss progression was performed using Kaplan-Meier analysis to account for variable follow-up times.Results: A total of 661 patients were identified with VS and sequential audiometry. The population was predominantly female vs. male (368 vs. 293, p = 0.0035), driven primarily by younger patients with Koos 4 tumors (76 female vs. 49 male, p = 0.016). Patients with normal baseline hearing bilaterally (N = 241) demonstrated no significant difference in hearing loss progression in VS-contralateral vs. control ears. Patients with abnormal baseline VS-ipsilateral hearing (N = 190), however, demonstrated significantly higher likelihood of reaching moderate SNHL in VS-contralateral ears. Subgroup analysis by age, sex, and baseline tumor size did not yield any subgroup-specific trends for hearing loss progression.Discussion and Conclusion: This is the largest study to date tracking long-term bilateral hearing outcomes in patients with VS, and demonstrates that, in patients with abnormal hearing in the VS-ipsilateral ear, there exists a long-term risk of progression to moderate hearing loss in the contralateral ear as well. Combined with the absence of significant changes in word understanding in the affected ears, these findings may provide clues to the nature of tumor-secreted factors involved in VS-associated hearing loss. Female predominance within the VS patient population is confirmed, driven mostly by younger female patients with Koos 4 tumors.