Published papers

This study aimed to assess the clinical presentation, antibiotic therapy, surgery, and outcomes in patients with otitis media caused by Mycobacterium abscessus subsp. abscessus and discuss the efficacy of surgery. This is a retrospective case review of three patients diagnosed with otomastoiditis caused by M. abscessus subsp. abscessus. All patients had refractory otorrhea. One patient had granulation tissue in the tympanic membrane. They received medical treatment and underwent surgery. Otorrhea was resolved several months after the initiation of long-term multiantibiotic therapy in all cases. The timing of surgery varied among patients. Before initiating antibiotic therapy, mastoidectomy was performed to achieve definitive diagnosis in two patients, and wound dehiscence developed in these patients. Two patients underwent debridement after the initiation of multiantibiotic therapy. After antibiotic administration, tympanoplasty was performed to improve hearing in one patient. All patients achieved culture negativity after treatment, and no recurrences have been noted. From three cases, it is suggested that the mainstay of treatment for M. abscessus subsp. abscessus is long-term multiantibiotic therapy, and surgery itself may have little effect on achieving ear dryness. Thus, in most patients, drug therapy should be prioritized. Considering postoperative complications, surgery before achieving ear dryness should be avoided, except in emergency cases. In addition, if the diagnosis is not confirmed by repeated bacteriological tests, mastoidectomy should be performed to collect specimens. Tympanoplasty for hearing loss or eardrum perforation is recommended after discontinuation of medications.

OBJECTIVES: In the management of vestibular schwannoma (VS), patient-perceived outcomes should be given as much attention as physician-reported objective outcomes. Concomitant symptoms can be annoying for sufferers, lowering quality of life (QoL). However, it is difficult to determine the degree to which these symptoms lower QoL using only objective measures. The Penn Acoustic Neuroma Quality of Life Scale (PANQOL) is a validated disease-specific questionnaire commonly used to assess QoL in VS patients. It was developed and published in English. In this study, we translated the PANQOL questionnaire into Japanese and validated its reliability and utility. We also evaluated patient factors that could influence PANQOL scores. STUDY DESIGN: Cross-sectional study. METHODS: Seventy-two VS patients monitored conservatively were included in this study. They were assessed using the Japanese versions of PANQOL (PANQOL-J) and questionnaires about specific symptoms related to VS. The PANQOL questionnaire was translated into Japanese according to the accepted standards. The reliability and utility of the PANQOL-J questionnaire, as well as the relationship with VS-specific symptoms, were statistically analyzed. RESULTS: The mean total score was 78.7. Almost all of its domains had good internal consistency. Most PANQOL-J domains were related to those of the Short Form-36, with the exception of facial dysfunction domain. Scores of all PANQOL-J domains were comparable to scores of other questionnaires related to the VS-specific symptoms. Our analyses indicated tinnitus or facial palsy might affect the PANQOL-J total score. CONCLUSIONS: We confirmed the validity of the Japanese version of PANQOL questionnaire and its reliability and utility in the management of VS symptoms concerning facial function. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.

Objective: Quality of life (QoL) and subjective symptoms are predominantly used to evaluate treatment outcome of patients with vestibular schwannoma (VS). However, for patients undergoing conservative treatment-the most frequently used intervention-the association between QoL and subjective symptoms is unclear. Moreover, it is unknown whether VS-related tinnitus could be associated with the audiological and psychological status of the patient. Our overall aim is to provide objective evidence of this association to better guide treatment of VS. Methods: In a prospective study, we analyzed factors that influence VS-related tinnitus and QoL in 72 patients receiving conservative management of unilateral sporadic VS. This was done through questionnaires that assessed QoL, anxiety, depression, and audiological examinations. We used the SF-36 Short Form to assess QoL; the Tinnitus Handicap Inventory, Dizziness Handicap Inventory, Facial Clinimetric Evaluation Scale, Visual Analog Scale for hearing impairment to assess symptoms subjectively; and pure tone audiometry, the speech discrimination for hearing measurements. For psychological status, we used the Hospital Anxiety and Depression Scale. For analyses, we used Pearson correlation analysis and multiple regression between variables and QoL. Results: Correlation and regression analyses revealed that the severity of tinnitus distress had the largest negative impact on QoL in all domains of SF-36. The severity of tinnitus was significantly associated with subjective hearing impairment and the degree of depression and anxiety. Hearing thresholds had no statistical association with severity of tinnitus. Conclusions: To our knowledge, this is the first study to investigate VS-related tinnitus with respect to both patients' hearing status and psychological condition. Our results suggest that tinnitus distress strongly affects VS patients' QoL and that its characteristics are similar to primary tinnitus. An intervention for VS-related tinnitus, therefore, should assess to what extent tinnitus bothers patients, and it should reduce any unpleasant emotions that may exacerbate symptoms. This approach should improve their QoL.

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.

BACKGROUND: There are several types of silicone domes in receiver in the canal hearing aids (RICs), which have different occlusion levels. However, the frequency characteristics of each type of silicone dome are unclear. PURPOSE: This study aimed to determine the frequency characteristics of three types of silicone domes (open domes, double-type power domes, and tulip domes) in RICs. RESEARCH DESIGN: This is an interventional study. STUDY SAMPLE: In total, 11 participants with a normal sense of hearing were prospectively enrolled. INTERVENTION: Participants were fitted with hearing aids, which were adjusted to similar settings, and only the silicone domes were changed. The acoustic gain of hearing aids was adjusted to 20 dB in the range of 250 Hz to 4 kHz using the 2-cc coupler. DATA COLLECTION AND ANALYSIS: We measured the real-ear aided gain (REAG) for each type of silicone dome. In each frequency, we statistically compared the REAG of each type of dome. Acoustic gain using the Open Fit coupler of each type of dome was also measured. RESULTS: The REAG was obtained with no leakage with open domes only at 2 kHz, and with tulip domes and double-type power domes in the range of 1 to 2 kHz. Double-type power domes obtained significantly higher REAG than tulip domes at 250 and 500 Hz. Under the Open Fit coupler, all types obtained higher acoustic gain than the REAG. CONCLUSION: This study provides the analysis of the frequency characteristics of silicone domes in RICs. The highest degree of occlusion was observed in double-type power domes, followed by tulip domes, and the lowest was observed in open domes.

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.

BACKGROUND:  Cartilage conduction hearing aids (CCHAs) were newly devised and spread fast in Japan since their launch in 2017. However, little knowledge is available for this new device. PURPOSE:  The aim of this study was to establish the knowledge of CCHAs and suggest their indication. RESEARCH DESIGN:  Correlational study. STUDY SAMPLE:  A total 256 patients were registered. DATA COLLECTION AND ANALYSIS:  The fitting of CCHAs was surveyed in nine institutions. The outcomes were assessed by audiometric tests. The patients were classified into seven groups, depending on the ear conditions. The clinical characteristics, assessment results, and purchase rates were compared among the groups. The assessment results of CCHAs were also compared with those of previously used hearing aids. RESULTS:  Most patients who used CCHAs were classified into the bilateral closed (aural atresia or severe stenosis) ear (n = 65) or unilateral closed ear (n = 124) groups. The patients in these groups achieved good benefits that resulted in a high purchase rate. The bilateral continuous otorrhea group also supported a high purchase rate, although the benefits of CCHAs were not always excellent. In contrast, the purchase rate was poor in the patients who could use air conduction hearing aids (ACHAs) without absolute problems. As for using a CCHA as a contralateral routing of signals hearing aid, the benefits depended on the patients. CONCLUSIONS:  CCHAs are considered as a great option not only to the patients with closed ears but also to those who had difficulties in ACHAs usage.

Mammalian auditory hair cells are not spontaneously replaced. Their number and coordinated polarization are fairly well-maintained and both these factors might be essential for the cochlear amplifier. Cell cycle regulation has critical roles in regulating appropriate cell size and cell number. However, little is known about the physiological roles of the Hippo pathway, which is one of the most important signaling cascades that regulates cell growth, differentiation, and regenerative capacity in the cochlear sensory epithelium. Herein, we investigated the in vivo role of the large tumor suppressor 1 (LATS1), an essential kinase in the Hippo/yes-associated protein pathway, in the cochlea using the LATS1 knockout mice. LATS1 was expressed in hair cells and supporting cells. It was strongly expressed on the surface of the cuticular plate of the organ of Corti. We found that LATS1 knockout caused congenital hearing loss due to the irregular orientation and slightly reduced number of hair cells, whereas the number of supporting cells remained unchanged. On the surface of the hair cells, the kinocilium and stereocilia were dispersed during and after morphogenesis. However, the expression of the receptor-independent polarity regulators, such as Par3 or Gαi, was not affected. We concluded that LATS1 has an indispensable role in the maturation of mammalian auditory hair cells, but not in the development of the supporting cells, and thus, has a role in the hearing acquisition.

OBJECTIVES: Cartilage conduction hearing aids (CC-HAs) are novel hearing aids that use the third hearing pathway of cartilage conduction. We assessed the efficacy of CC-HAs and the hearing effects and safety of additional tape compression over the transducer in children with hearing loss. METHODS: The patients (n = 42) underwent a one-month free trial of CC-HAs. Forty of them were patients with auditory canal atresia or stenosis. CC-HA-aided and unaided hearing thresholds (48 fitted ears) were determined using standard audiograms, after which participants could choose to purchase the device or not. We calculated the purchase rates and compared the patient characteristics between the purchase and non-purchase groups along with the purchase reason (or not). We applied additional tape compression over the CC-HA transducer and assessed the hearing effects and side effects. RESULTS: CC-HA led to hearing improvements at all frequencies. Overall, 72.92% of participants purchased a CC-HA after the trial. By applying additional tape compression over the CC-HA transducer, the stability and hearing gains were improved mainly at low frequencies, and no side effects such as dermatitis were observed. CONCLUSIONS: CC-HAs are efficacious in producing hearing improvements in children, especially in patients with atresia or canal stenosis who cannot use air conduction hearing aids. Furthermore, we found that the additional tape compression over the transducer was an easy and a safe method for improving the hearing effects and stability of the CC-HA.

Schwannoma arising from the intermediate nerve is very rare, with only a few cases reported in the literature. Here, we report a rare case of a rapidly growing schwannoma that originated from the intermediate nerve in a 17-year-old woman. We performed tumor resection using the translabyrinthine approach with continuous intraoperative monitoring, in which the facial nerve root was used to evoke muscle action potential. The monitoring revealed the tumor origin and enabled complete surgical resection with the preservation of facial nerve motor function. The facial nerve root evoked muscle action potential-based continuous monitoring revealed the origin of the rare intermediate nerve schwannoma. Appropriate surgery using this monitoring system could spare facial nerve function even in this rare case and retain the patient's quality of life.