Binaural hearing aid intervention for a patient with nonserviceable hearing loss after surgery for vestibular schwannoma: A case report.

A vestibular schwannoma is a benign tumor; however, the schwannoma itself and interventions can cause sensorineural hearing loss. Most vestibular schwannomas are unilateral tumors that affect hearing only on one side. Attention has focused on improving the quality of life for patients with unilateral hearing loss and therapeutic interventions to address this issue have been emphasized. Herein, we encountered a patient who was a candidate for hearing preservation surgery based on preoperative findings and had nonserviceable hearing after the surgery, according to the Gardner-Robertson classification. Postoperatively, the patient had decreased listening comprehension and ability to localize sound sources. He was fitted with bilateral hearing aids, and his ability to localize sound sources improved. Although the patient had postoperative nonserviceable hearing on the affected side and age-related hearing loss on the unaffected side, hearing aids in both ears were useful for his daily life. Therefore, the patient was able to maintain a binaural hearing effect and the ability to localize the sound source improved. This report emphasizes the importance of hearing preservation with vestibular schwannomas, and the demand for hearing loss rehabilitation as a postoperative complication can increase, even if hearing loss is nonserviceable.

Natural history of hearing and tumor growth in vestibular schwannoma in neurofibromatosis type 2-related schwannomatosis.

OBJECTIVES: To determine the natural history of hearing loss and tumor volume in patients with untreated neurofibromatosis type 2 (NF2)-related schwannomatosis. Moreover, we statistically examined the factors affecting hearing prognosis. METHODS: This retrospective cohort study was conducted on 37 ears of 24 patients with NF2-related vestibular schwannomatosis followed up without treatment for more than 1 year. We obtained detailed chronological changes in the PTA and tumor volume in each case over time, and the rate of change per year was obtained. Multivariate analysis was also conducted to investigate factors associated with changes in hearing. RESULTS: The average follow-up period was approximately 9 years, and hearing deteriorated at an average rate of approximately 4 dB/year. The rate of maintaining effective hearing decreased from 30 ears (81%) at the first visit to 19 ears (51%) at the final follow-up. The average rate of change in tumor growth for volume was approximately 686.0 mm3/year. This study revealed that most patients with NF2 experienced deterioration in hearing acuity and tumor growth during the natural course. A correlation was observed between an increase in tumor volume and hearing loss (r = 0.686; p < 0.001). CONCLUSIONS: Although the hearing preservation rate in NF2 cases is poor with the current treatment methods, many cases exist in which hearing acuity deteriorates, even during the natural course. Patients with an increased tumor volume during the follow-up period were more likely to experience hearing deterioration. Trial registration number 20140242 (date of registration: 27 October 2014).

Prediction of Cochlear Implant Effectiveness With Surface-Based Morphometry.

OBJECTIVE: This study aimed to determine whether surface-based morphometry of preoperative whole-brain three-dimensional T1-weighted magnetic resonance imaging (MRI) images can predict the clinical outcomes of cochlear implantation. STUDY DESIGN: This was an observational, multicenter study using preoperative MRI data. SETTING: The study was conducted at tertiary care referral centers. PATIENTS: Sixty-four patients with severe to profound hearing loss (≥70 dB bilaterally), who were scheduled for cochlear implant (CI) surgery, were enrolled. The patients included 19 with congenital hearing loss and 45 with acquired hearing loss. INTERVENTIONS: Participants underwent CI surgery. Before surgery, high-resolution three-dimensional T1-weighted brain MRI was performed, and the images were analyzed using FreeSurfer. MAIN OUTCOME MEASURES: The primary outcome was monosyllable audibility under quiet conditions 6 months after surgery. Cortical thickness residuals within 34 regions of interest (ROIs) as per the Desikan-Killiany cortical atlas were calculated based on age and healthy-hearing control regression lines. RESULTS: Rank logistic regression analysis detected significant associations between CI effectiveness and five right hemisphere ROIs and five left hemisphere ROIs. Predictive modeling using the cortical thickness of the right entorhinal cortex and left medial orbitofrontal cortex revealed a significant correlation with speech discrimination ability. This correlation was higher in patients with acquired hearing loss than in those with congenital hearing loss. CONCLUSIONS: Preoperative surface-based morphometry could potentially predict CI outcomes and assist in patient selection and clinical decision making. However, further research with larger, more diverse samples is necessary to confirm these findings and determine their generalizability.

Characteristics of pure tone audiogram in patients with untreated sporadic vestibular schwannoma: Analysis of audiometric shape and interaural differences stratified by age and mode of onset.

OBJECTIVE: Asymmetric sensorineural hearing loss (ASHL) is the most common symptom of sporadic vestibular schwannoma (VS). However, there is still no universally accepted MRI protocol for diagnosing VS. This study identified the characteristics of pure tone audiogram (PTA) in patients with VS. METHODS: We conducted a retrospective chart review of patients diagnosed with sporadic unilateral VS. In the analysis, we focused on the shape and interaural differences of PTA, stratified by the mode of onset and patient age. RESULTS: In total, 390 patients met the inclusion criteria. The U-shaped audiogram showed the highest proportion in patients with the onset of sudden sensorineural hearing loss (SSNHL). In patients with SSNHL, U-shaped audiograms were younger than other audiograms, and 86.7 % of patients under 40 had U-shaped audiograms. Patients with VS were more likely to have interaural differences at higher frequencies than at lower frequencies. Patients with SSNHL had a significantly higher percentage of interaural differences at 500-4000 Hz than those with onset other than SSNHL (non-SSNHL patients). In addition, non-SSNHL patients had a significant trend toward a higher percentage of interaural differences at all frequencies with increasing age. CONCLUSION: MRI screening can be considered in patients with SSNHL with U-shaped audiograms under 40 years of age. In ASHL, not SSNHL, MRI screening can be considered for older patients with interaural differences at wider continuous frequencies. Patients with interaural differences at high frequencies had a higher priority than those with interaural differences at low frequencies as indications for MRI screening for VS.

Effective cochlear implantation for idiopathic hypertrophic pachymeningitis with bilateral profound hearing loss: A case report.

RATIONALE: Hypertrophic pachymeningitis (HP) is a local or diffuse fibrous thickness of the dura mater of the brain or spinal cord, caused by infection or connective tissue disease. Headache is the most common clinical symptom, followed by various cranial nerve disorders such as visual impairment, diplopia, and hearing loss. HP can be classified into secondary and idiopathic. Here, we report a case of bilateral progressive profound sensorineural hearing loss diagnosed in a patient with idiopathic HP, where a cochlear implant was effectively used. PATIENT CONCERNS: The patient was a 77-year-old woman. Hearing loss gradually progressed bilaterally, and magnetic resonance imaging showed a space-occupying lesion with a continuous contrast enhancement in the bilateral internal auditory canals, and diffused dural thickening from the middle to the posterior cranial fossa. DIAGNOSES: A trans-labyrinthine biopsy was conducted, and a definite diagnosis of idiopathic HP was made. Thickening of the dura mater in the bilateral internal auditory canals was thought to cause profound hearing loss. INTERVENTIONS AND OUTCOMES: A cochlear implant was implemented 4 months after biopsy, and a favorable hearing response was obtained postoperatively. LESSONS: This is the first report of a cochlear implant in a patient with idiopathic HP. Cochlear implantation was considered a good treatment for profound hearing loss due to idiopathic HP, which provides a reference for patients to receive timely and correct treatment.

Bilateral Deafness Due to Relapsing Polychondritis with Semicircular Canal Calcification Treated With Cochlear Implantation: A Case Report.

Relapsing polychondritis (RP) is a rare chronic inflammatory disease characterized by recurrent inflammation of cartilages throughout the body, with treatment-resistant dizziness and hearing loss in 40%-50% of patients with RP. Although rare, severe binaural hearing loss in RP is an indication for cochlear implantation (CI). Therefore, there are only a few reports on CI insertion in cases of RP. This report describes a 68-year-old woman who developed binaural hearing loss due to RP. She was treated with steroids and immunosuppressive drugs; however, her hearing did not improve significantly, and she relied on written communication for conversation. Subsequently, the patient underwent CI in the right ear. The patient showed improvement in speech perception; at 14 months postoperatively, she was able to speak with lipreading, and at 2 years postoperatively, she was able to speak without lipreading. Previous case reports on CI in patients with RP have shown varying degrees of postoperative hearing improvement. Our case demonstrates the effectiveness of CI in improving hearing and speech recognition in patients with RP having semicircular canal calcification. However, previous reports have shown that speech recognition declines 13 years after CI for RP. Therefore, continuous long-term follow-up is necessary.

A novel intraoperative continuous monitoring method combining dorsal cochlear nucleus action potentials monitoring with auditory nerve test system.

Highly accurate real-time cochlear nerve monitoring to preserve cochlear nerve function is essential for simultaneous cochlear implantation and ipsilateral vestibular schwannoma resection. In the present study, we developed a novel real-time monitoring system that combines dorsal cochlear nucleus action potential monitoring with intracochlear stimulating electrodes (Auditory Nerve Test System, ANTS). We used this system for a case with vestibular schwannoma resection via the translabyrinthine approach. The monitoring system developed in this study detected highly reliable evoked potentials from the cochlear nerve every two seconds continuously during tumor resection. Near-total tumor resection was achieved, and cochlear implantation was performed successfully after confirming the preservation of cochlear nerve function in a case. The patient's hearing was well compensated by cochlear implantation after surgery. Our novel method continuously achieved real-time monitoring of the cochlear nerve every two seconds during vestibular schwannoma resection. The usefulness of this monitoring system for simultaneous tumor resection and cochlear implantation was demonstrated in the present case. The system developed in this study is compatible with continuous facial nerve monitoring. This highly accurate and novel monitoring method will broaden the number of candidates for this type of surgery in the future.

A Case of Vestibular Schwannoma with Deafness Showing Remarkable Hearing Recovery Following Hearing-Preserving Surgery.

Surgery for vestibular schwannoma can be divided into hearing-preserving and nonhearing-preserving surgeries. Hearing-preserving surgery is usually not considered in patients with deafness due to vestibular schwannoma, because hearing is unlikely to improve, and surgery aims to maximize the tumor resection at the expense of hearing. We report an extremely rare case of a 46-year-old man with unilateral profound hearing loss due to a vestibular schwannoma with marked cystic degeneration in the left cistern, which significantly recovered to near-normal hearing levels after hearing-preserving surgery. Hearing loss gradually worsened, and preoperative pure-tone evaluation showed complete hearing loss in the left ear. However, the response to the distortion product otoacoustic emission was preserved, and hearing loss was considered to be retrocochlear. Tumor resection was performed using the retrolabyrinthine approach with continuous monitoring using dorsal cochlear nucleus action potential, auditory brainstem response, and facial nerve function muscle action potential. The cistern portion of the tumor was almost completely resected along with the wall. Postoperatively, the pure-tone threshold on the left side markedly improved. The present case clearly demonstrates the possibility of hearing recovery in patients with retrocochlear hearing loss. We should consider expanding the indications for hearing-preserving surgery.

Distribution of macrophages in the developing cochlea of the common marmoset, a primate model animal.

Introduction: Macrophages are essential immune cells in the cochlea that contribute to inflammation, tissue repair, and homeostasis. They also play an important role in local cochlear immunity. The developmental immigration and maturation of macrophages in the cochlea have been investigated and are considered essential for normal hearing acquisition. Most of our current knowledge regarding cochlear development is based on rodent models because of the ethical challenges of using human fetal samples for research. However, inter-species differences between rodents and humans have been reported. In this study, we used a primate animal model to investigate the distributions of macrophages in the developing cochlea. The common marmoset (Callithrix jacchus), a small monkey species that inhabits the New World, was used as the model. Methods: We investigated the distribution of macrophages in the developing cochlea of the common marmoset by performing immunohistochemical analyses of cochlear tissue from common marmoset embryos at different development stages. Results: We revealed detailed distribution changes in the macrophages of a primate animal model cochlea. This observation indicates that most of the changes in the general distribution of macrophages were well preserved between rodents and this primate. The distribution changes observed in the common marmoset were also compatible with observations in the human fetus; although, observations in the human fetus are limited. Our observations in this study also revealed several differences between common marmosets and rodents. Conclusion: The time course of immunological development and maturations established in this study will aid in the study of the primate-specific developmental biology of the inner ear. These observations may eventually lead to new therapeutic strategies for hearing loss in humans. In addition, understanding the immunological steady-state of the cochlea may help in the study of age- and genetic-induced hearing loss and in the design of regenerative therapies.

Imaging of Temporal Bone Mass Lesions: A Pictorial Review.

Tumoral lesions of the temporal bone include benign or malignant tumors and congenital or inflammatory lesions. Temporal bone lesions are difficult to approach. Therefore, making a preoperative diagnosis and considering whether the lesions require treatment are necessary; if they require treatment, then the type of treatment requires consideration. These tumors cannot be observed directly and must be diagnosed based on symptoms and imaging findings. However, the differentiation of temporal bone lesions is difficult because they are rare and large in variety. In this pictorial review, we divided temporal bone lesions by location such as along the facial nerve, along the internal jugular vein, around the endolymphatic sac, in the internal auditory canal/cerebellopontine angle, petrous apex, middle ear, and mastoid, focusing on the imaging findings of temporal bone lesions. Then, we created a diagnostic flowchart that suggested that the systematic separation of imaging findings is useful for differentiation. Although it is necessary to make comprehensive judgments based on the clinical symptoms, patient background, and imaging findings to diagnose temporal bone mass lesions, capturing imaging features can be a useful differentiation method.

Development of cochlear spiral ligament fibrocytes of the common marmoset, a nonhuman model animal.

Spiral ligament fibrocytes generate potassium gradients, which hair cells require to convert mechanical sound waves into electrical palsy. Together with the stria vascularis, they regulate endolymph electrolyte homeostasis. Developing spiral ligament fibrocytes and generating endocochlear potential with an appropriate endolymph ion composition are essential for hearing. Understanding spiral ligament fibrocyte development is useful for studying age-related and genetic hearing loss, as well as for regenerative therapy and cochlear immunology. Despite interspecies differences, most studies of cochlear development have been conducted in rodent models due to the difficulty of using human fetal samples. This study investigated the cochlear development of spiral ligament fibrocytes in a small New World monkey species, the common marmoset (Callithrix jacchus). We examined the developmental expression of specific genes in spiral ligament fibrocytes, including those essential for the generation of endolymphatic potential. Our results showed that this animal model of spiral ligament fibrocyte development is similar to that of humans and is a suitable alternative for the analysis of human cochlear development. The time course established in this study will be useful for studying the primate-specific developmental biology of the inner ear, which may lead to novel treatment strategies for human hearing loss.

Apoptosis of type I spiral ganglion neuron cells in Otof-mutant mice.

Otof, which encodes otoferlin, knockout mice are considered model mice for auditory neuropathy spectrum disorder, which is characterized by an absent auditory brainstem response (ABR) despite preserved distortion product otoacoustic emission (DPOAE). Although otoferlin-deficient mice lack neurotransmitter release at the inner hair cell (IHC) synapse, it remains unclear how the Otof mutation affects spiral ganglions. Thus, we used Otof-mutant mice carrying the Otoftm1a(KOMP)Wtsi allele (Otoftm1a) and analyzed spiral ganglion neurons (SGNs) in Otoftm1a/tm1a mice by immunolabeling type Ⅰ SGNs (SGN-Ⅰ) and type II SGNs (SGN-II). We also examined apoptotic cells in SGNs. Four-week-old Otoftm1a/tm1a mice had an absent ABR but normal DPOAEs. The number of SGNs was significantly lower in Otoftm1a/tm1a mice on postnatal day 7 (P7), P14, and P28 compared with that of wild-type mice. Moreover, significantly more apoptotic SGNs were observed in Otoftm1a/tm1a mice than in wild-type mice on P7, P14, and P28. SGN-IIs were not significantly reduced in Otoftm1a/tm1a mice on P7, P14, and P28. No apoptotic SGN-IIs were observed under our experimental conditions. In summary, Otoftm1a/tm1a mice showed a reduction in SGNs accompanied by apoptosis of SGN-Ⅰs even before the onset of hearing. We speculate that the reduction in SGNs with apoptosis is a secondary defect caused by a lack of otoferlin in IHCs. Appropriate glutamatergic synaptic inputs may be important for the survival of SGNs.

Intracochlear signal in FIESTA-C and hearings of patients with cerebellopontine angle schwannoma.

BACKGROUND: Hearing loss in patients with cerebellopontine angle (CPA) schwannoma, is thought to be caused by the damage to the cochlea and the cochlear nerve. AIM: This study aimed to examine the relationships between the intracochlear signal in magnetic resonance imaging (MRI) and hearing in patients with CPA schwannoma. MATERIAL AND METHOD: In 79 patients with CPA schwannoma, we retrospectively examined the signal in the cochlea on the affected side was compared with that on the unaffected side to determine signal degradation in fast imaging reagents steady-state acquisition with cycle phases (FIESTA-C) MRI. For hearing evaluation, pure tone audiometry (PTA), speech audiometry, distortion product otoacoustic emissions (DPOAE), and auditory brainstem response (ABR) were used. For each parameter, we examined the differences between the groups with and without signal degradation. RESULTS: In the hearing test results, the I-wave latency of ABR was significantly longer in the group with signal degradation in FIESTA-C (1.84 ± 0.35 msec vs. 2.04 ± 0.37 msec, p = 0.048). There was no statistically significant difference in other tests. CONCLUSION: The MRI signal changes in the cochlear were related to the I-wave latency of ABR and reflected cochlear function. SIGNIFICANCE: We suggested the cochlear signal changes in CPA schwannoma patients related the hearing.

Vestibular Schwannoma Surgery with Endoscope-Assisted Retrolabyrinthine Approach under Modified Reinforced Continuous Intraoperative Monitoring for Hearing Preservation: Experience of 33 Cases in a Single Center.

Surgery for vestibular schwannoma includes various techniques such as the middle cranial fossa, suboccipital, translabyrinthine, and retrolabyrinthine approaches. The retrolabyrinthine approach does not impair the labyrinth and allows postoperative hearing preservation. Previously, we reported an endoscope-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring for preservation of hearing and facial nerve function. However, the hearing preservation rate was relatively low in patients with long-wave V latency in the auditory brainstem response or poor otoacoustic emission response under this approach. Thus, the hearing preservation rate in such patients remains to be improved. To overcome this limitation, we modified the previous approach. In 26 of the 33 consecutive cases (79%) over the last three years, preservation of hearing equivalent to that before surgery or improved hearing was achieved. Postoperative deafness was observed in only two of the 33 cases (6%). According to previous reports, the rate of hearing preservation using the retrolabyrinthine approach is approximately 30-50%. Therefore, we have achieved a higher hearing preservation rate than that previously reported using the endoscopy-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring. These improvements in our department are considered to be helpful for hearing preservation.

Association between atherosclerosis, hearing recovery, and hearing in the healthy ear in idiopathic sudden sensorineural hearing loss: a retrospective chart analysis.

Atherosclerosis is reported to be a risk factor for the severity of idiopathic sudden sensorineural hearing loss (ISSNHL). We evaluated the hypothesis that atherosclerosis affects the hearing thresholds of both the affected and healthy sides of ISSNHL patients. We conducted multivariate analyses on retrospectively collected data of patients with ISSNHL (N = 762) to evaluate the relationship between known factors linked to atherosclerosis and hearing thresholds on affected and healthy sides and whether these factors are prognostic for hearing recovery. Older ages, vertigo or dizziness, diabetes mellitus, and congestive heart failure were significantly related to higher hearing thresholds on the affected side. Older ages, male, and vascular disease were significantly related to higher hearing thresholds on the healthy side. Vertigo or dizziness, severe hearing loss and hearing loss at high frequencies on the affected side, higher hearing thresholds on the healthy side, regular anticoagulant medication, and delayed steroid treatment were significantly related to lack of recovery. Since several atherosclerosis-related factors are associated with higher hearing thresholds on both affected and healthy sides in ISSNHL and higher hearing thresholds on the healthy side predict poorer prognosis, diagnosis, and predicting prognosis of ISSNHL may benefit from rigorous evaluation of patients' cardiovascular comorbidities and hearing levels on both the healthy and affected sides.

Development of the stria vascularis in the common marmoset, a primate model.

Stria vascularis is a structure that generates potassium gradients in the cochlea, which is vital for hair cells to convert mechanical sound waves into electrical pulses. The precise development of the stria vascularis and subsequent generation of endocochlear potential are thus essential for hearing. Understanding the development of the stria vascularis is valuable for studying hearing loss caused by aging or genetics and designing regenerative therapy. Although inter-species differences have been reported between rodents and humans, most of our current knowledge regarding cochlear development has been obtained from rodent models because of the difficulty in using human fetal samples in this field of research. Therefore, we investigated the development of the cochlear stria vascularis in the common marmoset (Callithrix jacchus), a small monkey species native to the New World. Our study confirms that stria vascularis development in the common marmoset is similar to that in humans and is suitable for furthering our understanding of human cochlear development. The time course established in this report will aid in studying the primate-specific developmental biology of the inner ear, which could eventually lead to new treatment strategies for hearing loss in humans.

Intratemporal Facial Nerve Schwannomas: A Review of 45 Cases in A Single Center.

There are no established indications for facial nerve schwannoma treatment, including surgery, radiation and follow-up observation, and it is difficult to determine treatment policy uniformly. The treatment policy was examined from each treatment course. Data of patients with facial nerve schwannomas at our hospital from 1987 to 2018 were retrospectively examined. Their age, sex, clinical symptoms, tumor localization, treatment policies and outcomes were reviewed. In total, 22 patients underwent surgery and 1 patient underwent radiotherapy; 22 patients were followed up without treatment. After total resection, there were no tumor recurrences, and most patients had grade 3 or 4 postoperative facial paralysis. After subtotal resection, tumor regrowth was observed in four patients and reoperation was required in two patients. Facial nerve function was maintained in four patients and was decreased in two patients. During follow-up, six patients showed tumor growth. Only one patient had worsening facial nerve paralysis; four patients underwent facial nerve decompression owing to facial nerve paralysis during follow-up. If the tumor compresses the brain or it is prone to growth, surgery may be indicated, and when the preoperative facial nerve function is grade ≤3, consideration should be given to preserving facial nerve function and subtotal resection should be indicated. If the preoperative facial nerve function is grade ≥3, total resection with nerve grafting is an option to prevent regrowth. If there is no brain compression or tumor growth, the follow-up is a good indication, and decompression should be considered in facial nerve paralysis cases.

A rare case of external ear canal stenosis caused by COVID-19-related arterial thrombosis.

Thrombosis is a characteristic symptom of coronavirus disease 2019 (COVID-19). Here, we present a case of external ear stenosis caused by arterial thrombosis after COVID-19 infection. To the best of our knowledge, this is the first report of external ear stenosis related to COVID-19. A 62-year-old man presented with left hearing loss. The patient had a history of hospitalization for COVID-19 treatment 11 months prior to visiting our hospital. He had been experiencing ear fullness and tinnitus after COVID-19 treatment. Physical examination revealed severe left external ear canal stenosis with a subcutaneous mass. Surgical removal of the subcutaneous mass was performed. Histopathological analysis revealed that a subcutaneous thrombosis caused the external ear canal stenosis. This case describes an unusual case of external ear canal stenosis after COVID-19. Clinical and pathological findings indicate that COVID-19 affected the external ear canal. In addition, histopathological results confirmed the formation of arterial thrombosis in the temporal bone region after COVID-19 treatment. This case shows the broad range of body sites that can be involved with thrombotic events with COVID including the subcutaneous tissue around the outer ear. This observation would be helpful in investigating or explaining the various otological symptoms of COVID-19.

Understanding the Molecular Mechanism of Vestibular Schwannoma for Hearing Preservation Surgery: Otologists' Perspective from Bedside to Bench.

Vestibular schwannoma is a clinically benign schwannoma that arises from the vestibulocochlear nerve that causes sensorineural hearing loss. This tumor is clinically and oncologically regarded as a benign tumor as it does not metastasize or invade surrounding tissues. Despite being a benign tumor, its management is difficult and controversial due to the potential serious complications, such as irreversible sensorineural hearing loss, of current interventions. Therefore, preventing hearing loss due to the natural course of the disease and complications of surgery is a challenging issue for an otologist. Improvements have been reported recently in the treatment of vestibular schwannomas. These include advances in intraoperative monitoring systems for vestibular schwannoma surgery where the risk of hearing loss as a complication is decreased. Precise genomic analysis of the tumor would be helpful in determining the characteristics of the tumor for each patient, leading to a better hearing prognosis. These procedures are expected to help improve the treatment of vestibular schwannomas. This review summarizes recent advances in vestibular schwannoma management and treatment, especially in hearing preservation. In addition, recent advances in the understanding of the molecular mechanisms underlying vestibular schwannomas and how these advances can be applied in clinical practice are outlined and discussed, respectively. Moreover, the future directions from the bedside to the bench side are presented from the perspective of otologists.

Factors Influencing the Purchase Rate of Cartilage Conduction Hearing Aids.

BACKGROUND: Innovated hearing aids (HAs), termed cartilage conduction hearing aids (CC-HAs), show good performance in patients with closed ears and continuous otorrhea. However, factors other than the ear condition that influence the purchase rate of CC-HAs remain unclear. PURPOSE: To identify the factors that influence the purchase rate of CC-HAs. RESEARCH DESIGN: A correlational study. STUDY SAMPLE: A total of 249 patients were enrolled. DATA COLLECTION AND ANALYSIS: The patients' demographics, clinical characteristics, outcomes, and CC-HA transducer types were compared. The data were analyzed for six groups classified based on the ear condition. RESULTS: In the unilateral closed-ear group, the purchase cases were significantly younger than the nonpurchase cases (p < 0.05). Regarding the outcomes in the bilateral closed-ear group, the purchase cases showed significantly better-aided thresholds at 0.25 and 0.5 kHz than the nonpurchase cases. No significant differences in the functional gains and speech recognition scores were found between purchase and nonpurchase cases in all six groups. Regarding the transducer type, the continued-use rate of the simple transducer type was significantly lower in the bilateral chronic continuous otorrhea, bilateral open, and unilateral open groups. CONCLUSION: In the closed ears, no remarkable negative factors were found. Transducer type had a significant influence on the continued-use rate in the nonclosed ears including the ears with chronic continuous otorrhea, although the purchase rate of CC-HAs in the bilateral chronic continuous otorrhea group was comparable to the closed ears.