Details of a Researcher - Nishiyama, Takanori

Papers - Nishiyama, Takanori

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

Makoto Hosoya, Kaho Iwabu, Tsubasa Kitama, Takanori Nishiyama, Naoki Oishi, Hideyuki Okano, Hiroyuki Ozawa

Scientific reports (Scientific Reports) 13 ( 1 ) 11789 - 11789 2023.12

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.

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

Katsuyoshi Idei, Mitsuru Kitamura, Marie N Shimanuki, Makoto Hosoya, Nobuyoshi Tsuzuki, Natsuki Hasebe, Takanori Nishiyama, Hiroyuki Ozawa, Naoki Oishi

Medicine (Medicine (United States)) 102 ( 47 ) e36124 2023.11

ISSN 00257974

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.

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小児滲出性中耳炎に対する短期留置型鼓膜換気チューブの効果

利國桂太郎, 西山崇経, 羽生昇, 富永健裕, 石川直明, 若林毅, 中村伸太郎, 北村充, 大石直樹, 小澤宏之

日本耳鼻咽喉科頭頸部外科学会会報 ((一社)日本耳鼻咽喉科頭頸部外科学会) 126 ( 11 ) 1229 - 1234 2023.11

ISSN 2436-5793

難治化リスクを伴わない小児滲出性中耳炎の初回鼓膜チューブ挿入術において,ガイドラインでは短期留置型チューブを第一選択として推奨している.今回,短期留置型鼓膜チューブ(D型)を用いて鼓膜チューブ挿入術を行った15歳未満の小児69例122耳を対象とし,再発率,穿孔残存率,感染率について,留置期間や中耳貯留液の性状,血清学的指標との関連について検討した.平均留置期間は15.7ヵ月で,再発率は13.1%,穿孔率は6.0%,感染率は7.4%であった.再発の有無での2群間比較を行うと,再発なし群で有意に留置期間が長かった.また,血清学的指標と中耳貯留液の性状,再発率の間に明らかな傾向は認めなかった.(著者抄録)

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

Yusuke Sakaki, Makoto Hosoya, Takanori Nishiyama, Takeshi Wakabayashi, Marie N Shimanuki, Hiroyuki Ozawa, Naoki Oishi

The journal of international advanced otology (Journal of International Advanced Otology) 19 ( 5 ) 426 - 430 2023.09

ISSN 13087649

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.

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Imaging of Temporal Bone Mass Lesions: A Pictorial Review.

Marie N Shimanuki, Takanori Nishiyama, Makoto Hosoya, Takeshi Wakabayashi, Hiroyuki Ozawa, Naoki Oishi

Diagnostics (Basel, Switzerland) (Diagnostics) 13 ( 16 ) 2023.08

ISSN 2075-4418

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.

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Transferability Based on Drug Structure Similarity in the Automatic Classification of Noncompliant Drug Use on Social Media: Natural Language Processing Approach.

Nishiyama T, Yada S, Wakamiya S, Hori S, Aramaki E

Journal of medical Internet research 25 e44870 2023.05

ISSN 1439-4456

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

Nobuyoshi Tsuzuki, Kazunori Namba, Chika Saegusa, Hideki Mutai, Takanori Nishiyama, Naoki Oishi, Tatsuo Matsunaga, Masato Fujioka, Hiroyuki Ozawa

Neuroscience letters (Neuroscience Letters) 803 137178 - 137178 2023.04

ISSN 03043940

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.

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Bell麻痺・Hunt症候群に対する経乳突顔面神経減荷術　手術による治療効果と聴力への影響

須田悟史, 都築伸佳, 大石直樹, 西山崇経, 細谷誠, 若林毅, 神崎晶, 小澤宏之

Otology Japan ((一社)日本耳科学会) 33 ( 1 ) 42 - 49 2023.02

ISSN 0917-2025

末梢性顔面神経麻痺に対する顔面神経減荷術は,その有効性について統一した見解は得られておらず,術後難聴の可能性も指摘されている.今回,当科で診療したBell麻痺・Hunt症候群のうち,ENoG値≦10%等の所見から重症例と診断され,治癒もしくは発症後6ヵ月以上経過観察可能であった48例(Bell麻痺:33例,Hunt症候群:15例)を対象として,経乳突顔面神経減荷術の治療成績および術後聴力閾値変化について検討した.治癒率について両疾患の手術群と保存加療群を比較し,Bell麻痺では有意差は見られなかったが[手術群(n=18):44.4%vs保存加療群(n=15):33.3%,p=0.52],Hunt症候群においては顔面神経減荷術の有効性が示唆された[手術群(n=9):66.7%vs保存加療群(n=6):0%,p=0.02].また術後は気導聴力で0.25,0.5,2,4,8kHz,骨導聴力では2,4kHzにおいて5～15dB程度の閾値上昇を来たす可能性が示された.本研究の限界として少数例の検討であることが挙げられ,今後の課題と考えている.(著者抄録)

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.

Makoto Hosoya, Takanori Nishiyama, Takeshi Wakabayashi, Marie N Shimanuki, Hidemi Miyazaki, Hiroyuki Ozawa, Naoki Oishi

Diagnostics (Basel, Switzerland) (Diagnostics) 13 ( 2 ) 2023.01

ISSN 2075-4418

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.

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

Kenichiro Arashi, Takanori Nishiyama, Makoto Hosoya, Nobuyoshi Tsuzuki, Takeshi Wakabayashi, Hiroyuki Ozawa, Naoki Oishi

Ear, nose, & throat journal (Ear, Nose and Throat Journal) 1455613231215173 - 1455613231215173 2023

ISSN 01455613

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.

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

Mitsuru Kitamura, Naoki Oishi, Takanori Nishiyama, Makoto Hosoya, Natsuki Hasebe, Nobuyoshi Tsuzuki, Kaoru Ogawa

Acta oto-laryngologica (Acta Oto-Laryngologica) 143 ( 1 ) 19 - 23 2023

ISSN 00016489

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.

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

Makoto Hosoya, Tsubasa Kitama, Marie N Shimanuki, Takanori Nishiyama, Naoki Oishi, Hideyuki Okano, Hiroyuki Ozawa

Frontiers in immunology (Frontiers in Immunology) 14 1229414 - 1229414 2023

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.

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

Nobuyoshi Tsuzuki, Koichiro Wasano, Naoki Oishi, Ko Hentona, Marie Shimanuki, Takanori Nishiyama, Yoshihiko Hiraga, Masafumi Ueno, Narihisa Suzuki, Seiichi Shinden, Kaoru Ogawa, Hiroyuki Ozawa

Scientific reports (Scientific Reports) 12 ( 1 ) 21571 - 21571 2022.12

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.

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

Makoto Hosoya, Tsubasa Kitama, Kaho Iwabu, Takanori Nishiyama, Naoki Oishi, Hideyuki Okano, Hiroyuki Ozawa

Scientific reports (Scientific Reports) 12 ( 1 ) 19811 - 19811 2022.12

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.

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Comparison of Cartilage Conduction Hearing Aid, Bone Anchored Hearing Aid, and ADHEAR: Case Series of 6 Patients with Conductive and Mixed Hearing Loss

Tsubasa Kitama, Takanori Nishiyama, Kaho Iwabu, Takeshi Wakabayashi, Marie N. Shimanuki, Makoto Hosoya, Naoki Oishi, Hiroyuki Ozawa

Applied Sciences (Switzerland) (Applied Sciences (Switzerland)) 12 ( 23 ) 2022.12

Cartilage conduction hearing aids (CC-HA), bone anchored hearing aids (Baha), and ADHEAR are good choices to improve hearing in patients who cannot use air conduction hearing aids because of aural atresia or continuous otorrhea. As there are many overlaps in the characteristics of these devices, we conducted a comparative trial of CC-HA, Baha, and ADHEAR. We provided patients with the opportunity to select their devices. The data of 6 patients who underwent comparative trials in our department between October 2021 and August 2022 were retrospectively examined. The gains of Baha and CC-HA outweighed those of ADHEAR. Regarding the sound localization test, there was no significant tendency for any of the hearing devices. Regarding the Glasgow Benefit Inventory, there was no clear tendency among the three devices in the quality of life evaluation. The most satisfactory model was the one subjectively chosen by the patient, regardless of the gain and score of the sound source localization test. Therefore, we believe that it is necessary to provide an opportunity for comparative trials and a consultation with each patient in the process of selecting a device.

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症例をどうみるか　内頸動静脈の露出を伴う先天性真珠腫症例に対する耳後部切開併用内視鏡下摘出術

西山崇経, 大石直樹, 若林毅, 北間翼, 細谷誠, 小澤宏之

JOHNS ((株)東京医学社) 38 ( 10 ) 1403 - 1406 2022.10

ISSN 0910-6820

症例は8歳男児で、5ヵ月ほど前より右耳漏が出現し、近医で耳処置を行った際に真珠腫上皮を認め、側頭骨CTで内頸動脈と頸静脈球の露出を伴う先天性真珠腫が疑われたため当科紹介受診となった。経過と画像所見より、内頸動脈と高位頸静脈球の露出を伴う前鼓室の先天性真珠腫の診断となった。内視鏡下経外耳道アプローチにて手術を行うこととし、術中所見では真珠腫の上方は耳管鼓室口下端、下方は前鼓室下端まで進展していた。真珠腫上皮を母膜の連続性を保ちながら剥離して適宜減量した。前下方の真珠腫上皮を摘出するために、骨性鼓膜輪前下方と外耳道入口部を必要に応じて削開し視野と操作野を作成した。最終的に内頸動脈壁が2ヶ所露出しており、母膜の連続性を保ちながら慎重に吸引管を用いて剥離・摘出した。術後はめまい、味覚障害、顔面神経麻痺を認めず、経過良好で術後2日目に退院となった。

外傷性アブミ骨陥入に対してアブミ骨摘出術後にアパセラムCを用いた伝音再建を行った1例

笠原健, 西山崇経, 中山梨絵, 小澤宏之

Otology Japan ((一社)日本耳科学会) 32 ( 3 ) 320 - 327 2022.09

ISSN 0917-2025

中耳外傷により耳小骨まで損傷が及ぶ例は多くなく、特にアブミ骨底板が卵円窓に陥入したという報告は外傷性耳小骨損傷の7.7%～19.0%と比較的少ない。今回、左耳かきによりアブミ骨が卵円窓へ陥入し外リンパ瘻を伴った症例を経験した。術前に55dBの混合性難聴を認め、激しいめまい症状を認めた。来院当日に手術加療を行い、術中はアブミ骨が卵円窓へ深く陥入し整復困難であったため摘出し、アパセラム耳小骨Cにて伝音再建を行った。術後めまいは速やかに改善し、聴力も徐々に改善した。アブミ骨の卵円窓への陥入が軽度な症例は、アブミ骨の整復のみで治療が可能という報告があるが、本症例のようにアブミ骨が深く卵円窓へ陥入している症例に関しては、アブミ骨摘出を伴う伝音再建術が必要となる。アブミ骨摘出を要する症例では術後聴力改善が得られない症例も少なくなく、術前から聴力予後が悪い可能性についての説明が重要であると考えられた。(著者抄録)

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

Tsubasa Kitama, Makoto Hosoya, Masaru Noguchi, Takanori Nishiyama, Takeshi Wakabayashi, Marie N Shimanuki, Masaki Yazawa, Yasuhiro Inoue, Jin Kanzaki, Kaoru Ogawa, Naoki Oishi

Diagnostics (Basel, Switzerland) (Diagnostics) 12 ( 8 ) 2022.08

ISSN 2075-4418

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.

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A novel auricular prosthesis which incorporates a cartilage conduction hearing aid based on 3D data processing technique: a preclinical evaluation.

Takanori Nishiyama, Shintaro Hayashi, Naoki Oishi

European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery (European Archives of Oto-Rhino-Laryngology) 279 ( 7 ) 3741 - 3744 2022.07

ISSN 09374477

PURPOSE: To achieve the challenging goal of simultaneously improving aesthetics and auditory function in the treatment of microtia, we developed an auricular prosthesis incorporating a cartilage conduction hearing aid (APiCHA), which covers a cartilage conduction hearing aid (CC-HA). We evaluated the acoustic characteristics generated by the method of combining these two components using an artificial mastoid and investigated the possibility of clinical translation. METHODS: The first step in creating an APiCHA is to take molds of both the affected and normal auricles and invert the 3D data of the normal auricle to create data for the auricular prostheses. Grooves were then made inside the prosthetic data to fit the affected ear and a CC-HA, and the APiCHA was made of silicone. The acoustic characteristics were measured using an artificial mastoid, and the results were compared between CC-HA alone and with APiCHA. RESULTS: Compared with CC-HA alone, the gain was approximately 2 dB lower at high frequencies from 1 k Hz and higher, and approximately 2 dB higher at approximately 900 Hz when CC-HA was used with APiCHA. For the other frequencies, the acoustic characteristics were almost the same. CONCLUSION: The changes in acoustic characteristics caused by the combined use of APiCHA and CC-HA were minimal and did not pose a clinical problem. The combined use of APiCHA and CC-HA can be considered as a non-invasive and clinically applicable treatment option to achieve both aesthetic and auditory improvements for microtia.

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

Makoto Hosoya, Takeshi Wakabayashi, Koichiro Wasano, Takanori Nishiyama, Nobuyoshi Tsuzuki, Naoki Oishi

Diagnostics (Diagnostics) 12 ( 5 ) 2022.05

ISSN 2075-4418

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.

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