Published papers

MRIの普及に伴い、より小・中型の聴神経腫瘍が診断される機会が増えてきている。「早期発見」によって、聴神経腫瘍における疾患予後である「腫瘍の大きさが制御され、より良好な機能が温存される」症例の増加が期待される。疾患の自然経過を踏まえたうえで、「早期治療」をすべき症例を選別することが重要である。当科では、聴力温存・経側頭骨手術である後迷路法に近年取り組み、精度の高い術中持続神経モニタリングを併用し約4年間で施行した聴神経腫瘍手術は68例であり、その6割で後迷路法を施行した。後向きの検討から、術前ABR/DPOAEの結果により、より高い確率で聴力温存を果たし得る症例を選別できることが判明した。現在当科では、将来に聴力を喪失するあるいは腫瘍が増大する可能性が高いと判断される症例に対し、小腫瘍あるいは聴力が比較的良好な段階で聴力温存手術を施行する治療プロトコールを採用し、聴力温存率の向上に取り組んでいる。(著者抄録)

軟骨伝導補聴器は成人と小児で適応や購入理由・価格が異なるため別々に検討することが望ましいが,小児単一の報告は極めて少ない.今回我々は,軟骨伝導補聴器を試聴した20歳以下の小児症例68例を振り返り,対象における補聴器の継続率,継続群・返却群における臨床的特徴,装用効果などを検討した.全体の継続率は72%で,疾患別では両側外耳道閉鎖/狭窄群63%,片側外耳道閉鎖/狭窄群79%,外耳道開放群25%であった.年齢が上がるにつれて継続率が低下する傾向が見られた.継続群と返却群のファンクショナルゲインに有意差はなかった.購入・継続の判断には装用効果だけでなく,費用や装用感も影響していた.片側例では両耳聴効果や方向感の改善が高い継続率につながった.一方,外耳道開放例では気導補聴器との比較で継続率が低かった.本研究により,小児症例に対する軟骨伝導補聴器の有用性が示され,積極的に試聴してもらうことの重要性が示唆された.(著者抄録)

BACKGROUND: Salivary gland choristoma (SGCh) is a rare benign tumor reported in several unusual sites, such as the gastrointestinal tract, the optic nerve, and the internal auditory canal, but never reported in the inner ear. CASE PRESENTATION: An 8-year-old girl with a history of left profound congenital hearing loss presented to us with ipsilateral progressive severe facial nerve palsy (House-Brackmann Grade VI). The left tympanic membrane was swollen with a pulsatile tumor. Radiological investigations revealed a multilocular tumor in the inner ear extending into the middle ear and internal auditory canal (IAC). We performed a partial resection of the tumor by transmastoid approach to preserve the anatomical structure of the facial nerve. The tumor was pathologically diagnosed as SGCh. Two years after surgery, her facial function recovered to House-Brackmann Grade II and the residual tumor did not show regrowth on MRI. CONCLUSIONS: Although the natural course of this rare tumor is unknown, a partial resection is an acceptable treatment procedure when functional recovery of the facial nerve is anticipated.

PURPOSE: To evaluate tinnitus and its management in patients with vestibular schwannoma (VS) who underwent surgery, we investigate the effect of surgical approach or residual hearing on tinnitus severity and the effects of intervention for tinnitus including educational counseling, sound therapy using hearing aids (HAs), and medication (selective serotonin reuptake inhibitors, and SSRIs). METHODS: Seventy-one subjects of VS patients who underwent surgery were included. Their tinnitus severity was evaluated using the Japanese version of the Tinnitus Handicap Inventory (THI). The relationships between postoperative THI scores and surgery types or residual hearing levels were examined. We also examined longitudinal changes in THI scores and the efficacy of the intervention. RESULTS: Surgery approach, hearing preservation or hearing loss surgery, and residual hearing levels were not significantly related to the postoperative tinnitus severity. In 71 cases, 45 cases did not require any management for tinnitus. On the contrary, 26 patients had at least one episode of tinnitus distress (THI score was greater than or equal to 18). Educational counseling alone was found to be effective in 17 cases out of the 26 cases, and the remaining 9 cases required more intervention than educational counseling alone. We selected sound therapy with HA for 7 cases and administration of SSRI for 2 cases, which was found to be highly effective in 8 cases. CONCLUSION: Based on the present study, we consider that appropriate management may be possible for tinnitus in the majority of VS patients who underwent surgery.

PURPOSE: Cartilage conduction hearing aids (CC-HAs) are novel hearing aids using the third hearing pathway of cartilage conduction. We assessed the efficacy of CC-HAs in adult hearing-loss patients who had various anatomical conditions of their ear canal(s) and determined who are good candidates for CC-HAs. METHODS: Patients (n = 37) were categorised into three groups of participants based on ear canal anatomy: (1) canal stenosis; (2) abnormal canal; (3) normal canal. After a 1-month free trial of normal usage, CC-HA-aided and unaided hearing thresholds (43 fitted ears) were determined using standard audiograms, after which participants could choose to purchase the device or not. Group and subgroup purchase rates were calculated along with the purchase reason (or not). Subgroup binary analysis of purchase rates was done according to hearing loss severity (< 70 dB and ≥ 70 dB) of unaided average air conduction (AC) hearing thresholds. RESULTS: CC-HA provided hearing improvements in all frequencies within each group. Overall, 60.47% of participants purchased a CC-HA after the trial. Over 70% participants with canal stenosis purchased CC-HAs, regardless of their AC hearing thresholds (severe vs. mild), and significantly more mild-loss participants in the abnormal canal group purchased their trial CC-HA compared to severe-loss participants (85.71% vs. 20%). CONCLUSION: Adult patients with ear canal stenosis or closure are the best candidates for CC-HAs, regardless of their hearing thresholds. Patients with more severe hearing loss accompanied by ear canal anomalies and patients with normal canal anatomy may not be good candidates.

Cricotracheostomy is a useful surgical procedure for opening the airway in cases where conventional tracheotomy is difficult. This is a safe and easy technique involving removal of the anterior portion of the cricoid cartilage. Herein, we report the case of a patient with difficulty in neck extension due to severe kyphosis, who underwent cricotracheostomy. A 65-year-old woman developed dyspnea and was transported to our hospital. SpO2 was 60% (room air) and endotracheal intubation was performed. She was managed on ventilator. However, weaning off the ventilator was difficult, and endotracheal intubation was prolonged. Subsequently, the patient was referred to us for a tracheostomy. The patient was unable to maintain the supine position due to severe kyphosis, and computed tomography revealed that the brachiocephalic artery was running just below the thyroid gland. Therefore, conventional tracheostomy was difficult to perform, and we performed cricotracheostomy instead. After the cricotracheostomy, there were no tracheal problems, such as tracheal stenosis and stomal hemorrhage. Cricotracheostomy can be performed in cases where multiple anatomical difficulties may be faced in the tracheostomy site, as in this case. Furthermore, cricotracheostomy is beneficial for long-term airway management because it causes fewer complications compared to conventional tracheotomy.

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.

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.

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).

The cause of idiopathic sudden sensorineural hearing loss (idiopathic SSNHL)-diagnosed after excluding other causes of hearing loss, such as SSNHL associated with vestibular schwannoma (VS)-is unknown. The presumed pathogenesis of idiopathic SSNHL includes circulatory disorders (e.g., cochlear infarction). We tested the hypothesis that patients with SSNHL who are at high stroke risk will have a lower rate of VS compared to those with low stroke risk. The rationale is that the primary cause of SSNHL in patients with high stroke risk might be a circulatory disturbance. We conducted a retrospective study in six hospitals. Our sampling of SSNHL patients included those diagnosed with idiopathic SSNHL and VS-associated SSNHL. SSNHL patients who had a head MRI were stratified by severity of hearing loss and evaluated for differences in the detection rate of VS between the high-scoring CHADS2 (CHADS2-H-), an index of stroke risk, and low-scoring CHADS2 (CHADS2-L-) groups. We identified 916 patients who met the inclusion criteria. For severe hearing loss, the CHADS2-H group had a significantly lower rate of VS than the CHADS2-L group (OR 0 [95% CI 0.00-0.612]; P = 0.007). These results indirectly support the hypothesis that a primary cause of severe idiopathic SSNHL in those at high risk of stroke might be a circulatory disorder.

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.

光学機器の進歩と各種器具の上市を背景に、昨今急速に普及している経外耳道的内視鏡下耳科手術(TEES)は、その近接した広い視野角による死角の減少と微細で鮮明な映像情報とを利点とする反面、片手操作ゆえの不便さが常に伴う。一方、鼻科領域で標準術式となっている内視鏡下鼻副鼻腔手術は経鼻内視鏡頭蓋底手術(EESBS)へと発展を見せており、EESBSでは二人の術者による"4 hands surgery"が一般的である。当科ではEESBSの手法をTEESに導入し、助手が内視鏡を持ち視野を作る、"3 hands surgery"によるTEESを積極的に行っている。術者が両手操作で作業を行うことができ、かつ内視鏡が術野の変化に合わせて迅速に移動できるため、出血をコントロールしながら、近接した死角の少ない視野を確保することが可能である。一方で、TEESでは鼻副鼻腔以上に狭いスペースで手術が展開されるため、スコーパーの臨機応変、迅速かつ的確な内視鏡操作により、視野とワーキングスペースを同時に確保することがEESBS以上に厳しく要求される。内視鏡操作と術操作を異なる術者が行うと、術者の遠近感の把握感覚が異なるため、EESBS同様、特殊な手技として修練を経験することが望ましい。術者とスコーパーが相補的な手技を同時に行うチームワークが手術の円滑な進行には不可欠であり、EESBSの手術教育を基盤とした手技習得と、cadaver dissectionによる十分なトレーニングが肝要と私達は考えている。(著者抄録)