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 】

• 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.

  Nobuyoshi Tsuzuki, Tsubasa Kitama, Koichiro Wasano, Takeshi Wakabayashi, Makoto Hosoya, Takanori Nishiyama, Hiroyuki Ozawa, Naoki Oishi

  Auris, nasus, larynx （Auris Nasus Larynx)  51 （ 2 ） 347 - 355 2024.04

  ISSN  03858146

  　View Summary

  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.

  • Access to Document (DOI)

• Prediction of Cochlear Implant Effectiveness With Surface-Based Morphometry.

  Shujiro Minami, Masahiro Takahashi, Seiichi Shinden, Kyoko Shirai, Naoki Oishi, Hiroshi Nishimura, Masatsugu Masuda, Sawako Masuda, Takanori Nishiyama, Makoto Hosoya, Masafumi Ueno, Akinori Kashio, Hiroyuki Yamada, Tatsuo Matsunaga, Kimitaka Kaga, Ayumi Shintani, Kiyotaka Nemoto

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology （Otology and Neurotology)  45 （ 2 ） 114 - 120 2024.02

  ISSN  15317129

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  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.

  • Access to Document (DOI)

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

  Takeshi Wakabayashi, Ryota Tamura, Kosuke Karatsu, Makoto Hosoya, Takanori Nishiyama, Yasuhiro Inoue, Kaoru Ogawa, Jin Kanzaki, Masahiro Toda, Hiroyuki Ozawa, 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)   2024

  ISSN  09374477

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  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).

  • Access to Document (DOI)

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

  Makoto Hosoya, Yuriko Nagaoka, Takeshi Wakabayashi, Marie N Shimanuki, Takanori Nishiyama, Masafumi Ueno, Hiroyuki Ozawa, Naoki Oishi

  Journal of otolaryngology - head & neck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale （Journal of Otolaryngology - Head and Neck Surgery)  52 （ 1 ） 67 - 67 2023.12

  ISSN  1916-0208

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  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.

  • Access to Document (DOI)

• 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

  　View Summary

  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.

  • 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 】

• 【軟骨伝導聴覚-耳鼻咽喉科医に必要な知識-】軟骨伝導補聴器と骨導補聴デバイス　骨導補聴器,骨導インプラントとの違い

  西山 崇経

  ENTONI ((株)全日本病院出版会)   ( 294 ) 34 - 39 2024.03

  ISSN  1346-2067

  　View Summary

  骨導補聴デバイスは技術の進歩に伴い,小型・高性能化とともに選択肢が増えてきている.また,本邦では軟骨伝導補聴器が臨床応用されており,骨導補聴器と異なり圧迫感がなく,小型で目立たないという特徴をもつ.両者の主な適応症例は,外耳道閉鎖症や持続性耳漏を伴う症例と重複しており,機器の使い分けに苦慮する症例を経験する.執筆時点において,軟骨伝導補聴器は骨固定型骨導補聴器と比して同等からやや弱い程度の補聴効果が得られ,貼付型骨導補聴器と比して補聴効果が強い可能性が示唆されている.また,軟骨伝導補聴器は骨固定型骨導補聴器と比して,雑音下聴取能力の改善効果はやや弱い可能性が示唆されるが,音源定位能力については特定の傾向を示しておらず,軟骨伝導補聴器と骨導補聴デバイスの両耳聴に与える影響の差については,未解明である.軟骨伝導補聴器は義耳など新たな技術との融合などの可能性を秘めており,今後の発展が期待される.(著者抄録)

• 【伝音難聴を克服する 一歩進んだ診断と手術・人工聴覚器の適応の見極め】一歩進んだ診断のために　一側性伝音難聴のハンディキャップ

  西山 崇経

  耳鼻咽喉科・頭頸部外科 ((株)医学書院)  96 ( 1 ) 17 - 20 2024.01

  ISSN  0914-3491

  　View Summary

  ＜文献概要＞POINT　▼一側性伝音難聴は,両耳聴ができなくなることで生活の質の低下,音源定位能力の低下,雑音下聴取能力の低下を生じる。▼感音難聴とは異なり,聴力改善手術や軟骨伝導補聴器などの治療選択肢が存在する。▼一側性伝音難聴に伴って音源定位能力は低下し,聴力改善によって音源定位能力は改善すると考えられるが,検査音圧の設定や治療開始すべき年齢,長期治療成績などは明らかになっていない。▼一側性伝音難聴に伴って雑音下聴取能力は低下し,聴力改善によって雑音下聴取能力は改善すると考えられるが,評価方法の標準化などの課題が存在する。

• 先天性外耳道閉鎖症・小耳症に対する治療戦略について　小耳症への非侵襲的かつ審美・機能同時改善の試み

  西山 崇経

  日本耳科学会総会・学術講演会抄録集 ((一社)日本耳科学会)  33回   25 - 25 2023.11

• 顔面神経麻痺と感音難聴を生じた若年発症の頭蓋底骨髄炎の治療経験

  若林 毅, 北間 翼, 細谷 誠, 西山 崇経, 島貫 茉莉江, 上野 真史, 小澤 宏之, 大石 直樹

  日本耳科学会総会・学術講演会抄録集 ((一社)日本耳科学会)  33回   158 - 158 2023.11

• 聴神経腫瘍摘出と同時同側人工内耳植え込み術のための蝸牛内電気刺激による新規術中持続聴覚モニタリング法

  細谷 誠, 若林 毅, 島貫 茉莉江, 上野 真史, 西山 崇経, 小澤 宏之, 大石 直樹

  日本耳科学会総会・学術講演会抄録集 ((一社)日本耳科学会)  33回   143 - 143 2023.11

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

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

• 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

  -

  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

  　View Summary

  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。

• LATS1キナーゼ欠損で起きる先天性難聴の原因および聴毛機能解析

  2019.04

  -

  2022.03

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

  　View Summary

  Hippo経路は細胞周期を調節し、組織の大きさや形態、硬さや脆弱性などを規定する細胞内シグナル伝達経路である。細胞の骨格を維持する分子としてLATS1/2キナーゼがあり、そのうちLATS1のみが内耳コルチ器に存在すること、LATS1の欠損によって先天性内耳有毛細胞障害を引き起こすことを見出している。本研究では、胎生期から出生までにおけるLATS1のコルチ器形成における生理的意義を明らかにするべく、LATS1ノックアウト (KO) マウスを用いて、LATS1 KOがPCP蛋白に与える影響やHippo経路における働きを解明する。
  本年度までの研究結果からLATS1 KOマウスは、体格の小型化および内外有毛細胞の配列不整や聴毛の異常を伴う先天性内耳性難聴を呈していた。内耳性難聴の原因としては、発生段階でのKinociliumの分布異常を呈しており、Planar Cell Polarity (PCP) の異常を疑う所見が得られた。本年度は、出生後の体重とABR閾値の時系列の追跡およびPCPと関連が疑われたGαiやPar3などへのLATS1 KOによる影響を研究した。
  出生後の体重は出生早期から体格は小さく、その後6ヶ月齢までの成長でも体格の小ささは維持される結果であった。出生後のABR閾値は、正確な計測が可能となる4週齢から6ヶ月齢までにおいて、KOマウスは一貫して70dB程度の高度聴力障害を示し、野生型やヘテロマウスは正常な聴力から徐々に加齢性変化に伴う聴力障害を生じていた。このことから、LATS1 KOに伴う体格や聴力への影響は先天性非進行性の変化であることが確認された。
  胎生マウスや新生マウスを用い、GαiとPar3をKOおよび同腹のマウスコルチ器の免疫染色を行い検討した。GαiとPar3共にKOマウスは野生型やヘテロマウスと同様の分布を示していた。このことからLATS1 KOはGαiやPar3とは異なった経路を介した内耳発生障害を起こしていると考えられ、前立腺における先行論文とは異なるメカニズムが、内耳には存在することが示唆された。
  前立腺の先行論文では、細胞配列を決定づける段階でLATS1とGαi、Par3が共役しており、Par3が障害されることでLATS1とGαiの分布に異常を来たし細胞配列が乱れるというものであった。当初の予想では内耳においても同様の変化が起きており、それに伴い有毛細胞の配列異常が説明可能と考えていたが、内耳においては異なるメカニズムが示唆される結果となっており、内耳表現系を説明することが出来なかった。そのため、表現系を説明するためのLATS1 KOが影響を与えているメカニズムを再度探索する必要が生じている。
  PCPやKinociliumに何らかの影響を与えている可能性は高いため、それらに関連する蛋白の解析を続けると共に、その他の蛋白への影響についてもPCRなどを用いて解析する予定である。

• 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

  　View Summary

  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

  2024

• DISEASES AND PHARMACOTHERAPY 3 (PSYCHIATRIC DISEASES AND OTHERS)

  2024

• PATHOPHYSIOLOGICAL ISSUES IN CHRONIC CARE

  2023

• DISEASES AND PHARMACOTHERAPY 3 (PSYCHIATRIC DISEASES AND OTHERS)

  2023