KEIO RESEARCHERS INFORMATION SYSTEM

Career 【 Display / hide 】

Career 【 Display / hide 】

• 2011.04

  -

  2013.03

  Saiseikai utsunomiya hospital

• 2013.04

  -

  2014.06

  Nasu red cross hospital

• 2014.09

  -

  2017.03

  Yokohama municipal citizens hospital

• 2017.04

  -

  2019.03

  Department of Otorhinolaryngology-Head and Neck Surgery

• 2019.04

  -

  2021.03

  Kawasaki Municipal Kawasaki Hospital

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Academic Background 【 Display / hide 】

Academic Background 【 Display / hide 】

• 　

  Kyorin University

  University

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• Ph.D., Keio University, Dissertation, 2021.03

Licenses and Qualifications 【 Display / hide 】

Licenses and Qualifications 【 Display / hide 】

• 補聴器適合判定医

• 日本耳鼻咽喉科学会専門医

• Medical Doctor

• 耳科手術指導医, 2024.04

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Life Science / Otorhinolaryngology

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Cell-specific α and β subunit expression patterns of Na+/K+-ATPases in the common marmoset cochlea

  Hosoya M., Ueno M., Shimanuki M.N., Nishiyama T., Oishi N., Ozawa H.

  Scientific Reports 15 ( 1 ) 26814 2025.12

  　View Summary

  High potassium concentration in the cochlear endolymph electrically drives hair cell activity. Sodium potassium ATPase (Na⁺/K⁺-ATPase) is an essential pump for ion homeostasis in the cochlea. Most of our knowledge regarding Na⁺/K⁺-ATPase has been obtained from rodent models, and knowledge of its distribution in primates, including humans, is limited. This study investigated the distribution of Na⁺/K⁺-ATPase in a common marmoset primate model. We investigated expression patterns of Na⁺/K⁺-ATPase α1 (ATP1A1), Na⁺/K⁺-ATPase α2 (ATP1A2), Na⁺/K⁺-ATPase α3 (ATP1A3), Na⁺/K⁺-ATPase β1 (ATP1B1), Na⁺/K⁺-ATPase β2 (ATP1B2), and Na⁺/K⁺-ATPase β3 (ATP1B3) in the cochlea of the neonates and the embryos of the common marmoset. We have described the distributions of specific pairs of Na⁺/K⁺-ATPase α and β subunits in each cochlear part, including spiral ganglion neurons, stria vascularis, and the organ of Corti. We also described developmental changes in Na⁺/K⁺-ATPases in common marmosets. The distribution of Na⁺/K⁺-ATPases in the common marmoset is similar to that in humans and is suitable for furthering our understanding of human cochlear development. The distribution established in this report will aid the study of primate-specific ion homeostasis in the inner ear.

  • Access to Document (DOI)

• Relationship between hearing thresholds and cognitive function in hearing aid non-users and long-term users post-midlife.

  Takanori Nishiyama, Tomomi Kimizuka, Chinatsu Kataoka, Mami Tazoe, Yasunori Sato, Makoto Hosoya, Marie N Shimanuki, Takeshi Wakabayashi, Masafumi Ueno, Hiroyuki Ozawa, Naoki Oishi

  npj aging 11 ( 1 ) 14 - 14 2025.12

  　View Summary

  The extent of hearing loss requiring hearing aid (HA) to prevent cognitive decline is unclear; we assessed this post-midlife along with the relationship between hearing thresholds and cognitive function in those who had never used HA (non-users) or used HAs for >3 years (long-term users). This study comprised 117 individuals ≥55 years with an average hearing threshold of ≥25 dB HL in their better ear and 55 of the non-users and 62 of the long-term users. The Mini-Mental State Examination, the Symbol Digit Modalities Test (SDMT), and pure-tone and sound-field audiometry were assessed. Mean ± SD hearing levels of the non-user and long-term user group were 40.83 ± 8.16 and 51.13 ± 14.80 dB HL. Non-users showed a significant association (P = 0.01) between the hearing thresholds and SDMT scores, with a cutoff value of above 38.75 dB HL identified as affecting cognitive function. There were no significant associations for long-term users.

  • Access to Document (DOI)

• Course of a sudden sensorineural hearing loss case diagnosed as intra-labyrinthine hemorrhage with MRI in the early phase

  Ide K., Hosoya M., Nishiyama T., Shimanuki M.N., Ueno M., Ozawa H., Oishi N.

  Auris Nasus Larynx 52 ( 4 ) 479 - 483 2025.08

  ISSN  03858146

  　View Summary

  Intralabyrinthine hemorrhage (ILH) is a rare differential diagnosis of sudden sensorineural hearing loss. Investigations using magnetic resonance imaging (MRI) in the early phase from the onset are inevitable to diagnose ILH. However, MRI is not usually performed during the early phases of sudden sensorineural hearing loss. Hence, ILH is rarely diagnosed, and the hearing prognosis and vestibular function in patients have been poorly understood. In the present study, we report the detailed course of ILH with relatively good hearing recovery. Additionally, vestibular function recovery was quantitatively examined using a video head impulse test. A 75-year-old man presented at our clinic with a chief complaint of dizziness, sudden hearing loss, left sensorineural hearing loss, and nystagmus. MRI 18 days after onset showed a left ILH. Following treatment with prednisone, the patient's hearing level partially recovered and nystagmus disappeared. Our experience emphasizes that MRI in the early phase is crucial for diagnosing ILH. Furthermore, MRI in the early phase should be considered in cases of sudden sensorineural hearing loss or dizziness and is beneficial for investigating ILH as a subpopulation of sudden sensorineural hearing loss.

  • Access to Document (DOI)

• A small vestibular schwannoma with preoperative facial palsy treated via retrolabyrinthine approach

  Hatomi S., Hosoya M., Ueno M., Shimanuki M.N., Nishiyama T., Ozawa H., Oishi N.

  Auris Nasus Larynx 52 ( 3 ) 216 - 221 2025.06

  ISSN  03858146

  　View Summary

  Facial nerve paralysis caused by a vestibular schwannoma is a rare but critical symptom; however, few reports have focused on preoperative facial nerve palsy from the viewpoint of treatment. In addition, its mechanism is not fully understood. We report a rare case of preoperative facial nerve palsy that improved after the surgical resection of a small vestibular schwannoma with hearing preservation. A small vestibular schwannoma within the internal auditory canal caused acute deafness and facial paralysis in a 51-year-old woman. Conservative treatment was initially administered, but severe hearing loss and facial paralysis persisted for 3 months after onset. Subsequently, we performed tumor resection using the retrolabyrinthine approach. The tumor, which compressed the cochlear and facial nerves, was almost completely removed under continuous intraoperative monitoring to preserve the facial nerve function. “Wait and scan” is generally recommended for vestibular schwannomas within the internal auditory canal. However, this case suggests that early successful surgery, at least in selected cases, can improve paralysis without hearing deterioration and maintain the patient's quality of life.

  • Access to Document (DOI)

• Noise-Induced Hearing Loss: Overview and Future Prospects for Research on Oxidative Stress

  Kitama T., Nishiyama T., Hosoya M., Shimanuki M.N., Ueno M., You F., Ozawa H., Oishi N.

  International Journal of Molecular Sciences 26 ( 10 )  2025.05

  ISSN  16616596

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  Noise-induced hearing loss (NIHL) is a common type of sensorineural hearing loss caused by exposure to high-intensity noise that leads to irreversible cochlear damage. Despite extensive research on cochlear pathophysiology, the precise mechanisms remain unclear, and no established treatment exists. This is due to the challenges in imaging and the inability to perform biopsies in human patients. Consequently, animal models, particularly mice, have been widely used to study NIHL. Clinically, NIHL presents as either a temporary threshold shift, in which hearing recovers, or a permanent threshold shift, which results in an irreversible loss. Histopathological studies have identified the key features of NIHL, including outer hair cell loss, auditory nerve degeneration, and synaptic impairment. Recent findings suggest that oxidative stress and inflammation are major contributors to NIHL, highlighting the potential for therapeutic interventions, such as antioxidants and anti-inflammatory agents. Given the increasing prevalence of NIHL owing to occupational noise exposure and personal audio device use, addressing this issue is a pressing public health challenge. This review summarizes the clinical features, underlying mechanisms, and emerging treatment strategies for NIHL while identifying current knowledge gaps and future research directions.

  • Access to Document (DOI)

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Papers, etc., Registered in KOARA 【 Display / hide 】

Papers, etc., Registered in KOARA 【 Display / hide 】

• Large tumor suppressor kinase 1欠損マウスは蝸牛奇形を伴う先天性難聴を呈す

  Nishiyama, Takanori

  (慶應義塾大学大学院医学研究科)  2020

• Large tumor suppressor kinase 1欠損マウスは蝸牛奇形を伴う先天性難聴を呈す

  Nishiyama, Takanori

  (慶應義塾大学大学院医学研究科)  2020

• Large tumor suppressor kinase 1欠損マウスは蝸牛奇形を伴う先天性難聴を呈す

  Nishiyama, Takanori

  (慶應義塾大学大学院医学研究科)  2020

• Regulation of hair cell microstructure and auditory function by Hippo pathway

  Nishiyama, Takanori

  科学研究費補助金研究成果報告書 2018

Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• 【耳鼻咽喉科と薬の副作用-薬物副作用マニュアル-】耳鼻咽喉科・頭頸部外科領域に現れる薬物副作用　薬物性難聴

  島貫 茉莉江, 西山 崇経

  JOHNS ((株)東京医学社)  41 ( 4 ) 421 - 424 2025.04

  ISSN  0910-6820

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  ＜文献概要＞はじめに　薬物性難聴とは原疾患治療に投与された薬物の有害事象として惹起される難聴であり,内耳障害が生じることが多い。わが国でも厚生労働省が作成している重篤副作用疾患別対応マニュアルに薬物性難聴が挙げられており,患者・医療者双方への普及・啓発の取り組みが行われている。症状から耳鼻咽喉科を受診する機会は多いと考えられ,どのような薬物で難聴が生じるかの知識を持ち,また難聴を生じた時に投薬歴を確認し鑑別することが重要であると考える。

• 【臨床ですぐ役立つ! 診療ガイドライン・手引き・指針のポイント解説】耳鼻咽喉科・頭頸部外科領域　人工聴覚器　埋込型骨導補聴器

  西山 崇経

  耳鼻咽喉科・頭頸部外科 ((株)医学書院)  97 ( 5 ) 44 - 46 2025.04

  ISSN  0914-3491

  　View Summary

  ＜文献概要＞POINT◆2025年3月時点で適応可能な埋込型骨導補聴器はBahaとBONEBRIDGEである。◆Bahaは両側難聴者で一側の骨導聴力レベル55dB以内が適応となる。◆BONEBRIDGEは一側の骨導聴力レベル45dB以内が適応となる。◆装用方法,MRIへの影響が大きく異なるため,患者へ十分に情報提供を行う必要がある。

• 【小児耳鼻咽喉科疾患のすべて　ファーストタッチから専門診療へ】主要疾患に対する専門診療　新生児期　小耳症,外耳道閉鎖症

  西山 崇経

  小児科診療 ((株)診断と治療社)  88 ( 3 ) 307 - 311 2025.03

  ISSN  0386-9806

  　View Summary

  ＜文献概要＞▽小耳症に外耳道閉鎖症を合併している場合,聴覚と審美面の両面が治療対象となる.▽両側外耳道閉鎖症を合併している場合,速やかに骨導もしくは軟骨伝導補聴器を導入したほうがよい.▽一側外耳道閉鎖症を合併している場合,軟骨伝導補聴器や人工中耳による治療が行える.▽審美面の治療としては,耳介形成術や義耳という選択肢がある.▽義耳と軟骨伝導補聴器を組み合わせて,聴覚と審美面の両面を改善させる治療が始まっている.

• 【耳鼻咽喉科・頭頸部外科領域の手術手技トレーニング】慶応義塾大学手術手技セミナー

  西山 崇経, 大石 直樹

  JOHNS ((株)東京医学社)  41 ( 3 ) 329 - 332 2025.03

  ISSN  0910-6820

  　View Summary

  ＜文献概要＞はじめに　人工聴覚器の進歩によって,本体そのものや電極はより生体親和性が高くかつ高効率・高性能になってきている。しかし,機器の進歩とともに機器を取り扱う新たな手術手技を身に付ける必要があり,実際の症例で行う前にトレーニングを行う必要がある。また耳科手術における側頭骨削開を伴う手術は,解剖学的指標を同定することの難しさや危険部位を想定しながら十分な視野を展開する必要があり,手術手技を向上させるためには,実際に側頭骨削開を行いながら術中・術後のフィードバックを行うことが重要と考えている。

• 【年代別　補聴器・人工内耳装用の実際】年齢を考慮した補聴器両耳聴効果

  西山 崇経

  ENTONI ((株)全日本病院出版会)   ( 306 ) 27 - 32 2025.02

  ISSN  1346-2067

  　View Summary

  二つの耳を用いて音を聞くことを両耳聴と呼び,一つの耳だけで聞く時と比較して,聴取能力が向上する両耳加重効果(binaural summation),雑音下聴取能力が改善する両耳スケルチ効果(binaural squelch),音源定位能力の改善などの効果がある.両側難聴者に対して,両耳補聴器装用を行うことは,片耳装用時と比較して両耳聴の効果を得られることがわかっている.小児における補聴器両耳装用は,いわゆる両耳聴効果で得られるような聴覚的な利点だけではなく,その結果として教育や学習効果としても利点があるため,積極的に推奨すべき治療である.成人においても同様である.近年では,骨導補聴デバイスによる両耳聴効果の報告も存在する.本稿では,小児・成人の両側難聴者における補聴器両耳聴効果について,その評価法も含めて解説する.(著者抄録)

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• 3D画像技術による小耳症例への非侵襲的な審美・聴覚同時治療の広域展開

  2024.04

  -

  2025.03

  国立研究開発法人新エネルギー・産業技術総合開発機構, NEDO Entrepreneurs Program (NEP), No Setting

• 一側伝音・混合難聴に対し軟骨伝導と骨伝導が与える聴覚利得の差とその起源の研究

  2023.04

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  2026.03

  日本学術振興会, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  　View Summary

  軟骨伝導補聴器と骨導補聴器の利得を同等に設定する。健聴者に対して耳栓を用いることで擬似的な難聴を作成し、軟骨伝導補聴器と骨導補聴器をそれぞれ装用し、実耳挿入利得や雑音下語音聴取レベル、方向感検査結果を比較検討することで、軟骨伝導と骨伝導の患側気導聴力に与える影響を評価する。HATSに対して同様の条件で比較検討することで、軟骨伝導と骨伝導の患側骨導聴力に与える影響を評価する。未固定遺体に対して異なる出力の軟骨伝導補聴器を装用し、実耳測定を行うことで、軟骨伝導の線形増幅性の有無を評価する。これらの結果を元に学会発表を行い、情報交換・収集を行う。

• マウスと小型霊長類コモンマーモセットにおける内耳幹細胞能についての比較検討

  2023.04

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  2026.03

  日本学術振興会, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), No Setting

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  有毛細胞障害により生じる感音難聴は、哺乳類の蝸牛においては、自発的に有毛細胞が再生しないため不可逆的であるとされており、現在は有効な治療法に乏しい。近年、他分野での幹細胞医学の発展は著しく、有毛細胞障害による感音難聴に対しても、コルチ器内の支持細胞の分化転化による有毛細胞の再生が期待されている。しかし有毛細胞障害後の支持細胞の幹細胞能に対して加齢が与える影響に関して、十分な検討がなされていない。
  本研究では、有毛細胞障害後の支持細胞の幹細胞能の変化を加齢の観点から齧歯類モデルと霊長類モデルを用いて検討を行い、「加齢の影響」と「種差」を明らかにすることを目的とする。

• Cause and stereo cilia function analysis of congenital hearing loss induced by LATS1 kinase deficiency.

  2019.04

  -

  2022.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Nishiyama Takanori, Grant-in-Aid for Early-Career Scientists , Principal investigator

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  The Hippo pathway is an intracellular signalling pathway that regulates the cell cycle and defines tissue size and morphology. LATS1/2 kinases are molecules that maintain the cell skeleton, of which only LATS1 is found in the organ of Corti, and deficiency of LATS1 causes congenital inner ear hair cell damage. The pathology of congenital cochlear deafness is caused by the irregular allignment of inner and outer hair cells due to LATS1 deficiency, indicating that LATS1 is an essential protein during the development of inner ear anatomies. On the other hand, hetero mice were found to be devoid of such a condition.

• Regulation of hair cell microstructure and auditory function by Hippo pathway

  2016.04

  -

  2019.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Takanori Nishiyama, FUJIOKA Masato, OISHI Naoki, SAYA Hideyuki, Grant-in-Aid for Young Scientists (B), Principal investigator

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  Hippo pathway regulates organ size, self-renewal of stem cells, and cell differentiation. LATS1 and LATS2 participate in Hippo signaling pathway. We examined expression pattern of LATS1 and LATS2 in the mouse cochlea, particularly in the organ of Corti. Because we only found LATS1 expression in the organ of Corti, we next investigated Lats1 deficiency mice. We found LATS1 deficiency caused congenital hearing loss with abnormal polarity and stereocilia bundles in both inner and outer hair cells. Those phenotypes indicate the possibility of LATS1 relating to the inner ear development.

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• PATHOPHYSIOLOGICAL ISSUES IN CHRONIC CARE

  2025

• LECTURE SERIES, OTORHINOLARYNGOLOGY

  2025

• DISEASES AND PHARMACOTHERAPY 3 (PSYCHIATRIC DISEASES AND OTHERS)

  2025

• CLINICAL CLERKSHIP IN OTORHINOLARYNGOLOGY

  2025

• PATHOPHYSIOLOGICAL ISSUES IN CHRONIC CARE

  2024

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