Akiyama, Takenori



School of Medicine, Department of Neurosurgery (Shinanomachi)


Assistant Professor/Senior Assistant Professor

E-mail Address

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Academic Background 【 Display / hide

  • 1998.03

    Keio University, Faculty of Medicine

    University, Graduated

Academic Degrees 【 Display / hide

  • 博士(医学), Keio University, Dissertation, 2008.09


Research Areas 【 Display / hide

  • Neurosurgery (Cerebral Neurosurgery)

Research Keywords 【 Display / hide

  • interventional neuroradiology

  • cerebrovascular disease

  • spinal vascular diseases

Research Themes 【 Display / hide

  • 脳脊髄血管障害に対する診断・治療法の開発, 



Papers 【 Display / hide

  • Surgical resection of arteriovenous fistula at the cauda equina

    Shimizu T, Nagoshi N, Akiyama T, Suzuki S, Nori S, Tsuji O, Okada E, Yagi M, Watanabe K, Nakamura M, Matsumoto M

    Spinal Cord Series and Cases (Spinal Cord Series and Cases)  7 ( 1 ) 29 2021.12

    Joint Work, Except for reviews,  ISSN  2058-6124

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    Introduction: Although spinal arteriovenous fistula (AVF) has been reported widely, AVF at the cauda equina is quite rare. We described a case of AVF at the cauda equina that was fed by the distal radicular artery (DRA). Case presentation: A 50-year-old woman presented with sudden weakness of the lower extremities. Magnetic resonance imaging (MRI) revealed a lesion with a highly intense signal at the conus medullaris, which was surrounded by several low-intensity signals (flow voids). Digital subtraction angiography revealed AVF at the cauda equina and that it was fed by the DRA, which was directly fed by the L3 segmental artery. We performed surgical resection of the AVF while monitoring motor-evoked potentials. The patient’s postoperative course was uneventful, and her neurological symptoms gradually resolved. MRI 2 years after surgery showed the disappearance of both intramedullary edema and the flow voids. Discussion: For the AVF, located at the cauda equina and fed by the DRA in this case, surgical resection or endovascular embolization could have been selected. We performed open surgery to achieve complete obliteration of the AVF, which led to postoperative functional recovery without any adverse events. However, only a limited number of AVFs at the level of the cauda equina have been reported, and treatment standards have not been established. Further studies of AVFs at the cauda equina are necessary to clarify the epidemiological characteristics and clinical outcomes with an appropriate sample size.

  • [Mechanisms Underlying Novel Complications Associated with Neuroendovascular Therapy for Cerebrovascular Diseases].

    Akiyama T

    Brain and nerve = Shinkei kenkyu no shinpo 73 ( 9 ) 1007 - 1012 2021.09

    Single Work, Except for reviews,  ISSN  1881-6096

  • Molecular investigation of brain tumors progressing during pregnancy or postpartum period: the association between tumor type, their receptors, and the timing of presentation

    Ichimura S, Ohara K, Kono M, Mizutani K, Kitamura Y, Saga I, Kanai R, Akiyama T, Toda M, Kohno M, Yoshida K, Sasaki H

    Clinical Neurology and Neurosurgery (Clinical Neurology and Neurosurgery)  207   106720 2021.08

    Joint Work, Except for reviews,  ISSN  03038467

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    Objective: Brain tumors often become clinically evident during pregnancy; however, the mechanism has not been well elucidated. Purpose of this study is to investigate the influence of molecular genetic factors on the progression of brain tumors during pregnancy or the postpartum period. Methods: Twelve cases of brain tumors that presented during pregnancy or postpartum period were included: five gliomas, three meningiomas, two vestibular schwannomas, and two chordomas. Tumor samples were investigated by metaphase comparative genomic hybridization and immunohistochemistry, for chromosomal copy number aberration (CNA) and receptor expression of sex hormones and growth factors. Results: The results were correlated with the timing of tumor presentation in relation to the stage of pregnancy. EGFR, VEGFR-1/2, AR, and c-Myc were expressed in gliomas, PgR, ER, HER-2, VEGFR-1, EGF and VEGFR2 in meningiomas, VEGFR-1 in vestibular schwannomas, and EGFR, VEGFR-1/2, and c-Myc in chordomas. The CNAs of the tumors varied. Four of the five gliomas presented in the 2nd trimester, all three meningiomas in the 3rd trimester or postpartum period, and both of the two schwannomas in the late 2nd trimester. Expression of VEGFR-1/2 and EGFR was observed regardless of the timing of tumor presentation, whereas female hormone receptors and HER-2 were exclusively found in meningiomas. Interestingly, one anaplastic astrocytoma (IDH mut, non-codeleted) that progressed from precedent grade 2 tumor harbored amplification of the MYC locus. Conclusion: Progression of brain tumors during pregnancy is associated with various growth factors as well as sex hormones. The timing of presentation is likely dependent on molecular receptors specific to each tumor type.

  • Angio-anatomical study of the pterygovaginal artery based on cone-beam computed tomography

    Yoshida K, Akiyama T, Raz E, Kamamoto D, Ozawa H, Toda M

    Neuroradiology (Neuroradiology)  63 ( 8 ) 1325 - 1333 2021.08

    Joint Work, Except for reviews,  ISSN  00283940

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    Purpose: To investigate the anatomical characteristics and clinical implications of the pterygovaginal artery (PtVA), a recurrent branch from the distal internal maxillary artery (IMA), which courses through the pterygovaginal canal that connects the pterygopalatine fossa and nasopharynx. Methods: Eighty-two patients with 90 sides of cone-beam computed tomography (CBCT) reconstructed from rotational angiography of the external or common carotid artery with a field of view covering the pterygopalatine fossa were retrospectively reviewed. The origin from the IMA, branching type, distribution, and anastomoses was evaluated. The underlying lesions were 36 hypervascular lesions with possible supply from PtVA (17 cavernous sinus arteriovenous fistulas (AVFs), 6 anterior condylar AVFs, and 13 nasopharyngeal, parasellar, or paraclival tumors) and 46 other diseases. Results: PtVA was identified in 75 sides (83%). It originated from the pterygopalatine segment of the IMA in 45 sides (60%) and from the pterygoid segment in 30 sides (40%). It arose independently (77%), sharing the common trunk with the Vidian artery (15%) or with other branches. It ran posteromedially through the pterygovaginal canal to supply the mucosa over the nasopharyngeal roof, the choanae, and the pharyngeal ostium of the eustachian tube. It anastomosed with the ascending pharyngeal artery (n=37), the accessory meningeal artery (n=7), and the mandibular artery from the petrous internal carotid artery (n=2). It served as a feeder of osseous AVFs and skull base tumors. Conclusion: PtVA was often identified by CBCT even in normal anatomy. Its detailed angio-anatomy could be evaluated in the presence of parasellar or paraclival hypervascular lesions.

  • Cone-Beam Computed Tomography Fusion Technique for Vascular Assessment of Skull Base Meningiomas

    Yoshida K, Akiyama T, Takahashi S, Miwa T, Horiguchi T, Sasaki H, Toda M

    World Neurosurgery (World Neurosurgery)  151   61 - 69 2021.07

    Joint Work, Except for reviews,  ISSN  18788750

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    Objective: Cone-beam computed tomography (CBCT) images for skull base tumors provide detailed vascular information and localization in regard to surrounding bony structures. We report use of the CBCT fusion technique for skull base meningiomas. Methods: Six patients with petroclival or petrotentorial meningiomas supplied by multiple arterial systems were preoperatively evaluated using CBCT fusion imaging. Fusion images were reconstructed from three-dimensional rotational angiography with contrast agent injections from the internal carotid artery (ICA) and external carotid artery in 4 cases, vertebral artery and external carotid artery in 1 case, and ICA and vertebral artery in 1 case. Results: The feeding pedicles and tumor stains from 2 arterial systems were differentiated by separate colors. The courses and territories of the ICA dural feeders or ICA/vertebral artery pial feeders were easily distinguished from the external carotid artery dural feeders. Anastomoses between thin feeders from different arterial systems could be detected. Mixed stain (stain with both colors) was observed in some tumor compartments, suggesting dual supply from 2 arterial systems and the presence of peritumoral anastomoses. All patients underwent preoperative embolization without complications. Conclusions: CBCT fusion images clearly visualized the feeders from each arterial system, the vascular compartments within the tumor, and possible peritumoral anastomoses. This technique provides a substantial contribution to both preoperative embolization and surgical resection of skull base meningiomas.

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

Reviews, Commentaries, etc. 【 Display / hide

  • 【脳卒中治療に必要な基礎知識】カテーテル治療に関わる新たな合併症とその機序

    秋山 武紀

    BRAIN and NERVE: 神経研究の進歩 ((株)医学書院)  73 ( 9 ) 1007 - 1012 2021.09

    ISSN  1881-6096

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  • 【脳神経-もう一度眺めてみよう】特徴的症候群A to Z Cerebellopontine angle症候群

    秋山 武紀, 戸田 正博

    Clinical Neuroscience ((株)中外医学社)  39 ( 5 ) 592 - 593 2021.05

    Other article, Joint Work,  ISSN  0289-0585

  • 4D-CTAを用いた頭蓋内静脈の血流方向と血流速度の推定

    水谷 克洋, 荒井 信彦, 戸田 正博, 秋山 武紀, 藤原 広和, 陣崎 雅弘, 吉田 一成

    脳血管内治療 ((NPO)日本脳神経血管内治療学会)  5 ( Suppl. ) 64 - 64 2020.11

    Other article, Joint Work,  ISSN  2423-9119

  • 未破裂脳動脈瘤に対するコイル塞栓術後早期に生じた脳内多発病変

    高橋 里史, 秋山 武紀, 福村 麻里子, 中屋 雅人, 戸田 正博

    脳血管内治療 ((NPO)日本脳神経血管内治療学会)  5 ( Suppl. ) 68 - 68 2020.11

    Other article, Joint Work,  ISSN  2423-9119

  • 当院における初診時Borden type 1硬膜動静脈瘻の治療成績と治療後type 1で残存した症例の臨床経過

    吉田 啓佑, 秋山 武紀, 高橋 里史, 戸田 正博

    脳血管内治療 ((NPO)日本脳神経血管内治療学会)  5 ( Suppl. ) 16 - 16 2020.11

    Other article, Joint Work,  ISSN  2423-9119

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Presentations 【 Display / hide

  • 慢性閉塞性脳血管病変の治療前後における機能活動時の大脳皮質酸素代謝-多チャンネルfNIRSを用いた検討-

    'AKIYAMA TAKENORI, Ohira Takayuki, Kawase Takeshi, Kato Toshinori'

    第15回日本脳循環代謝学会総会 (大阪) , 2003.10, Poster (general)

  • 脳虚血疾患で運動負荷によって引き起こされた一次運動野の低酸素賦活反応—機能的NIRSを用いた検討—

    'AKIYAMA TAKENORI, Ohira Takayuki, Fukunaga Atsushi, Kawase Takeshi, Kato Toshinori'

    第33回日本臨床神経生理学会・学術大会 (旭川) , 2003.10, Poster (general)

  • 視床下核へのDBS電極留置術後に一過性にdyskinesiaが消失したParkinson病の一例

    'AKIYAMA TAKENORI, Ohira Takayuki, Hiraga Kenji, Ochiai Masato, Kawase Takeshi'

    第42回日本定位・機能神経外科学会 (仙台) , 2003.09, Oral Presentation(general)

  • Analysis of Hb concentration change detected by TMS mapping oriented NIRS in the activated cerebral cortex during motor task

    'AKIYAMA TAKENORI, Takayuki Ohira, Kenji Hiraga, Maki Niimi, Atsushi Fukunaga, Takeshi Kawase, Toshinori Kato '

    Human Brain Mapping 2003 ('New York, USA') , 2003.06, Poster (general)

  • 近赤外線トポグラフィーによる大脳皮質顔面一次運動野描出の試みと問題点


    第26回日本顔面神経研究会 (東京) , 2003.06, Oral Presentation(general)

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

  • 末梢血中マイクロRNAスクリーニングおよび発現解析による硬膜動静脈瘻の病期診断および新たな治療戦略の構築


    日本脳神経血管内治療学会, 日本脳神経血管内治療学会助成研究, 秋山 武紀, 高橋 里史, Research grant, Principal Investigator

  • microRNA expression profiling in serum of patients with subarachnoid hemorrhage


    高橋 里史, 秋山 武紀, Research grant, Co-investigator

  • 高分解能近赤外光イメージング法の開発と高次脳機能計測への応用


    平成16年度慶應医師会医学研究助成金, 秋山 武紀, Research grant, Principal Investigator

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Courses Taught 【 Display / hide











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Committee Experiences 【 Display / hide

  • 2021.10

    総務委員会 委員, 日本脳神経外科学会

  • 2021.10

    定款・規則等対応委員会 委員, 日本脳神経外科学会

  • 2019.09

    放射線防護委員会 委員, 日本脳神経血管内治療学会