Education 【 display / non-display 】

Education 【 display / non-display 】

• 2006

  -

  2010

  Sapporo Medical University   Graduate School of Medicine   博士課程 情報伝達医学専攻 中枢神経機能治療学  

• 1998

  -

  2004

  Sapporo Medical University   School of Medicine   医学科  

Degree 【 display / non-display 】

Degree 【 display / non-display 】

• 2010.03   札幌医科大学   博士

Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2018.12

  -

  Now

  札幌医科大学 脳神経外科学講座 助教  

• 2017.04

  -

  2018.03

  Kyoto University  

• 2018.04

  -

  2018.11

  市立札幌病院 脳神経外科 副医長  

• 2014.01

  -

  2017.03

  札幌医科大学 脳神経外科学講座 助教  

• 2013.12

  　

  　

  札幌医科大学 脳神経外科学講座 診療医  

Research Areas 【 display / non-display 】

Research Areas 【 display / non-display 】

• Life sciences   Neurosurgery  

Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• Sapporo Medical University   脳神経外科   助教  

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

• Intracranial aneurysm

• サイトカイン

• cytokine receptors

• Neurosurgery

• 脳動脈瘤

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Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Microbleeds Due to Reperfusion Enhance Early Seizures after Carotid Ligation in a Rat Ischemic Model.

  Takuro Saito, Takeshi Mikami, Tsukasa Hirano, Hiroshi Nagahama, Rei Enatsu, Katsuya Komatsu, Satoshi Okawa, Yukinori Akiyama, Nobuhiro Mikuni

  Neurologia medico-chirurgica   63 ( 6 ) 228 - 235  2023.06  [Domestic journal]

  　View Summary

  Impaired reperfusion in ischemic brain disease is a condition that we are increasingly confronted with owing to recent advances in reperfusion therapy. In the present study, rat models of reperfusion were investigated to determine the causes of acute seizures using magnetic resonance imaging (MRI) and histopathological specimens. Rat models of bilateral common carotid artery ligation followed by reperfusion and complete occlusion were created. We compared the incidence of seizures, mortality within 24 h, MRI, and magnetic resonance spectroscopy (MRS) to evaluate ischemic or hemorrhagic changes and metabolites in the brain parenchyma. In addition, the histopathological specimens were compared with those observed on MRI. In multivariate analysis, the predictive factors of mortality were seizure (odds ratios (OR), 106.572), reperfusion or occlusion (OR, 0.056), and the apparent diffusion coefficient value of the striatum (OR, 0.396). The predictive factors of a convulsive seizure were reperfusion or occlusion (OR, 0.007) and the number of round-shaped hyposignals (RHS) on susceptibility-weighted imaging (SWI) (OR, 2.072). The incidence of convulsive seizures was significantly correlated with the number of RHS in the reperfusion model. RHS on SWI was confirmed pathologically as microbleeds in the extravasation of the brain parenchyma and was distributed around the hippocampus and cingulum bundle. MRS analysis showed that the N-acetyl aspartate level was significantly lower in the reperfusion group than in the occlusion group. In the reperfusion model, RHS on SWI was a risk factor for convulsive seizures. The location of the RHS also influenced the incidence of convulsive seizures.

  DOI PubMed

• Transcranial electrical stimulation technique for induction of unilateral motor evoked potentials

  Shoto Yamada, Rei Enatsu, Shu Ishikawa, Yusuke Kimura, Katsuya Komatsu, Tomohiro Chaki, Yukinori Akiyama, Takeshi Mikami, Nobuhiro Mikuni

  Clinical Neurophysiology   150   194 - 196  2023.04  [International journal]

  　View Summary

  OBJECTIVE: Transcranial electrical stimulation motor evoked potentials (TES-MEP) are widely used to monitor motor function; however, broad current spread and induced body movement are limitations of this technique. We herein report a localized stimulation technique for TES-MEP that induces unilateral MEP responses. METHODS: The stimulation of C1(+)-C4(-) or C2(+)-C3(-) was performed to induce right- or left-sided muscle contraction, respectively, in 70 patients. Electromyography was recorded by placing electrodes on the bilateral abductor pollicis brevis (APB) and abductor hallucis (AH) muscles. Stimulation conditions were regulated in the range to induce unilateral muscle contractions contralateral to the anodal stimulation. The thresholds and amplitudes of TES-MEP were retrospectively analyzed. RESULTS: The thresholds of APB were lower than those of AH in 47 patients, AH thresholds were lower than those of APB in 6 patients, and both APB and AH started to respond at the same intensity in 15 patients. This technical stimulation induced contralateral limb contractions with a suprathreshold stimulation of 129.4 ± 35.6 mA (mean ± standard deviation) in 68 patients (97%). Amplitudes in the suprathreshold stimulation of APB and AH responses were 727.5 ± 695.7 and 403.3 ± 325.7 μV, respectively. CONCLUSIONS: The C1(+)-C4/C2(+)-C3(-) stimulation in TES-MEP enables a localized stimulation to induce unilateral MEP responses. SIGNIFICANCE: Our stimulation technique enables the stable and safe monitoring of unilateral limbs, and contributes to the reliable monitoring of motor function in neurosurgery.

  DOI PubMed

• A practical protocol for high-spatial-resolution magnetic resonance angiography for cerebral arteries in rats.

  Hiroshi Nagahama, Masanori Sasaki, Katsuya Komatsu, Kaori Sato, Yoshimi Katagiri, Masaki Kamagata, Yuko Kataoka-Sasaki, Shinichi Oka, Ryo Ukai, Takahiro Yokoyama, Kojiro Terada, Masato Kobayashi, Jeffery D Kocsis, Osamu Honmou

  Journal of neuroscience methods ( Elsevier {BV} )  386   109784 - 109784  2023.01  [International journal]

  　View Summary

  BACKGROUND: Magnetic resonance angiography (MRA) is an important tool in rat models of cerebrovascular disease. Although MRA has long been used in rodents, the image quality is typically not as high as that observed in clinical practice. Moreover, studies on MRA image quality in rats are limited. This study aimed to develop a practical high-spatial-resolution MRA protocol for imaging cerebral arteries in rats. NEW METHOD: We used the "half position method" regarding coil placement and modified the imaging parameters and image reconstruction method. We applied this new imaging method to measure maturation-related signal changes on rat MRAs. RESULTS: The new practical high-spatial-resolution MRA imaging protocol obtained a signal intensity up to 3.5 times that obtained using a basic coil system, simply by modifying the coil placement method. This method allowed the detection of a gradual decrease in the signal in cerebral vessels with maturation. COMPARISON WITH EXISTING METHODS: A high-spatial-resolution MRA for rats was obtained with an imaging time of approximately 100 min. Comparable resolution and image quality were obtained using the new protocol with an imaging time of 30 min CONCLUSIONS: The new practical high-spatial-resolution MRA protocol can be implemented simply and successfully to achieve high image quality with an imaging time of approximately 30 min. This protocol will benefit researchers performing MRA imaging in cerebral artery studies in rats.

  DOI PubMed

• Computational Fluid Dynamics Analysis Features in Aneurysm Development in Rats

  Shoichi KOMURA, Katsuya KOMATSU, Takeshi MIKAMI, Yukinori AKIYAMA, Sangnyon KIM, Rei ENATSU, Hiroshi NAGAHAMA, Nobuhiro MIKUNI

  Neurologia medico-chirurgica ( Japan Neurosurgical Society )  63 ( 6 ) 250 - 257  2023  [Domestic journal]

  　View Summary

  The investigation of how to control the development and growth of cerebral aneurysms is important for the prevention of subarachnoid hemorrhage. Although there have been several types of research studies on computational fluid dynamics (CFD) analysis of brain aneurysm development and growth, there has been no unified interpretation of the CFD analysis results. The purpose of this study is to clarify the characteristics of CFD analysis results related to the development of cerebral aneurysms using an animal model. Nineteen rat models of cerebral aneurysms were created, and the CFD analysis results between the cerebral aneurysm group [n = 10; the aneurysm was observed on magnetic resonance angiography (MRA) within 10 weeks after aneurysm induction surgery] and the nonaneurysm group (n = 9) were compared. All aneurysms were confirmed on the proximal segment of the left cerebral artery (P1), and the cross-sectional area and curvature of the left P1 were evaluated together. In the cerebral aneurysm group, there was a decrease in wall shear stress (WSS) that is consistent with the location of the aneurysm compared to the nonaneurysm group. The cross-sectional area of the left P1 gradually increased in the aneurysm group but not in the nonaneurysm group. The mean curvature in the entire left P1 was higher in the aneurysm group than in the nonaneurysm group. This study revealed that the development of cerebral aneurysms is due to changes in vascular morphology, namely, an increase in vessel diameter and a high curvature, and a decreased WSS consistent with the site of aneurysm development using this animal model.

  DOI PubMed

• Validity of Preoperative Screening Before Open-Heart Surgery in Reduction of Perioperative Ischemic Stroke.

  Katsuya Komatsu, Takeshi Mikami, Yusuke Kimura, Yukinori Akiyama, Nobuyoshi Kawaharada, Nobuhiro Mikuni

  Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association   31 ( 8 ) 106584 - 106584  2022.08  [International journal]

  　View Summary

  OBJECTIVES: Cerebrovascular event after open-heart surgery is a critical complication and contributes to poor prognosis, including increased mortality. The purpose of this study is to investigate the appropriate preoperative risk assessment and monitoring for reducing the risk of ischemic stroke after open-heart surgery. MATERIALS AND METHODS: 184 patients who underwent surgery for valvular heart disease were included in this study. Near-infrared oxygen saturation monitoring (INVOS system) was performed during open-heart surgery. For the purpose of perioperative stroke risk assessment, we evaluated the clinical and radiological factors of the group that underwent preoperative consultation and the group that did not, and of the patients with and without postoperative ischemic stroke. RESULTS: Preoperative consultation was performed in 60 cases. Large vessel steno-occlusive disease was found in nine cases, of which three had undergone revascularization surgery. Cerebral infarction developed in four cases, all of which had no large vessel steno-occlusive disease. There was no significant association between the development of postoperative ischemic stroke and presence of large vessel steno-occlusive disease. Preoperative baseline INVOS value was significantly low in the ischemic stroke group (49.5 ± 12.5) compared to the non-ischemic stroke group (66.8 ± 10.0), (P = 0.012). CONCLUSIONS: In open-heart surgery for valvular heart disease, low preoperative baseline INVOS values were associated with cerebral ischemic stroke after surgery. The combination of appropriate preoperative screening for large vessel steno-occlusive disease and measurement of INVOS could be used as a simple and useful method in screening for the risk of ischemic stroke after open-heart surgery.

  DOI PubMed

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Misc 【 display / non-display 】

Misc 【 display / non-display 】

• Intraoperative Mapping and Monitoring for Rootlets of the Lower Cranial Nerves Related to Vocal Cord Movement.

  Masahiko Wanibuchi, Yukinori Akiyama, Takeshi Mikami, Katsuya Komatsu, Toshiya Sugino, Kengo Suzuki, Aya Kanno, Shunya Ohtaki, Shouhei Noshiro, Nobuhiro Mikuni

  Neurosurgery   78 ( 6 ) 829 - 34  2016.06  [International journal]

  　View Summary

  BACKGROUND: Damage to the motor division of the lower cranial nerves that run into the jugular foramen leads to hoarseness, dysphagia, and the risk of aspiration pneumonia; therefore, its functional preservation during surgical procedures is important. Intraoperative mapping and monitoring of the motor rootlets at the cerebellomedullary cistern using endotracheal tube electrodes is a safe and effective procedure to prevent its injury. OBJECTIVE: To study the location of the somatic and autonomic motor fibers of the lower cranial nerves related to vocal cord movement. METHODS: Twenty-four patients with pathologies at the cerebellopontine lesion were studied. General anesthesia was maintained with fentanyl and propofol. A monopolar stimulator was used at amplitudes of 0.05 to 0.1 mA. Both acoustic and visual signals were displayed as vocalis muscle electromyographic activity using endotracheal tube surface electrodes. RESULTS: The average number of rootlets was 7.4 (range, 5-10); 75% of patients had 7 or 8 rootlets. As many as 6 rootlets (2-4 in most cases) were responsive in each patient. In 23 of the 24 patients, the responding rootlets congregated on the caudal side. The maximum electromyographic response was predominantly in the most caudal or second most caudal rootlet in 79%. CONCLUSION: The majority of motor fibers of the lower cranial nerves run through the caudal part of the rootlets at the cerebellomedullary cistern, and the maximal electromyographic response was elicited at the most caudal or second most caudal rootlet. ABBREVIATION: EMG, electromyographic.

  DOI PubMed

• arterial spin labeling法による髄膜腫内血流の評価

  鰐渕 昌彦, 小松 克也, 秋山 幸功, 長濱 宏史, 三國 信啓

  脳循環代謝 ( 日本脳循環代謝学会 )  27 ( 1 ) 183 - 183  2015.10

• Radical removal of recurrent malignant meningeal tumors of the cavernous sinus in combination with high-flow bypass.

  Masahiko Wanibuchi, Yukinori Akiyama, Takeshi Mikami, Satoshi Iihoshi, Kei Miyata, Yoshifumi Horita, Toshiya Sugino, Katsuya Komatsu, Kengo Suzuki, Ken Yamashita, Nobuhiro Mikuni

  World neurosurgery   83 ( 4 ) 424 - 30  2015.04  [International journal]

  　View Summary

  BACKGROUND: Meningiomas or solitary fibrous tumors arising from the cavernous sinus (CS) are usually treated with radiosurgery to control growth. Surgical removal of cavernous tumors is indicated only for tumors extending outside the CS. However, even after adequate treatment, the tumor may exhibit recurrence or malignant transformation. We report a treatment option for recurrent meningeal tumors of the CS. METHODS: In 4 patients with CS tumors that exhibited regrowth after multiple operations and radiosurgery, radical removal in combination with high-flow bypass was performed, and a vascularized muscle flap was used for reconstruction. One patient had a radiation-induced atypical meningioma, 2 patients had transformed atypical meningiomas, and 1 patient had a frequently recurring solitary fibrous tumor. RESULTS: No local recurrence was observed in any patients during a follow-up period of 13-41 months. In all patients, a Karnofsky performance scale score of >80 on admission was maintained at >70 at the final follow-up evaluation. CONCLUSIONS: Radical removal in combination with high-flow bypass provides favorable results and maintains quality of life in patients with recurrent CS meningeal tumors.

  DOI PubMed

• Radical removal of recurrent malignant meningeal tumors of the cavernous sinus in combination with high-flow bypass.

  Masahiko Wanibuchi, Yukinori Akiyama, Takeshi Mikami, Satoshi Iihoshi, Kei Miyata, Yoshifumi Horita, Toshiya Sugino, Katsuya Komatsu, Kengo Suzuki, Ken Yamashita, Nobuhiro Mikuni

  World neurosurgery ( ELSEVIER SCIENCE INC )  83 ( 4 ) 424 - 30  2015.04  [Refereed]  [International journal]

  　View Summary

  BACKGROUND: Meningiomas or solitary fibrous tumors arising from the cavernous sinus (CS) are usually treated with radiosurgery to control growth. Surgical removal of cavernous tumors is indicated only for tumors extending outside the CS. However, even after adequate treatment, the tumor may exhibit recurrence or malignant transformation. We report a treatment option for recurrent meningeal tumors of the CS. METHODS: In 4 patients with CS tumors that exhibited regrowth after multiple operations and radiosurgery, radical removal in combination with high-flow bypass was performed, and a vascularized muscle flap was used for reconstruction. One patient had a radiation-induced atypical meningioma, 2 patients had transformed atypical meningiomas, and 1 patient had a frequently recurring solitary fibrous tumor. RESULTS: No local recurrence was observed in any patients during a follow-up period of 13-41 months. In all patients, a Karnofsky performance scale score of >80 on admission was maintained at >70 at the final follow-up evaluation. CONCLUSIONS: Radical removal in combination with high-flow bypass provides favorable results and maintains quality of life in patients with recurrent CS meningeal tumors.

  DOI PubMed

Research Projects 【 display / non-display 】

Research Projects 【 display / non-display 】

• 線維芽細胞に着目したくも膜炎症の分子機構の解明と新たな脳保護薬の開発

  基盤研究(C)

  Project Year :

  2020.04

  -

  2023.03

   

  三上 毅, 鈴木 比女, 秋山 幸功, 三國 信啓, 小松 克也, 平野 司

  　View Summary

  臨床データから得られた知見として、慢性脳虚血性疾患に対する開頭血行再建術で得られたくも膜と脳脊髄液を使用した。対象群として開頭による非虚血性疾患で得られた前頭葉皮質血管(M4)直上のくも膜を使用した。これまでの研究成果としては、くも膜の厚さは年齢や疾患が影響しており、厚いくも膜では内層に線維芽細胞やマクロファージが増勢し、VEGFαやTGFβなどの炎症マーカーが増加していた。また、くも膜内の線維化や慢性炎症が確認されていることを基に、免疫組織学的に線維化に関わる炎症マーカーや間葉系幹細胞の存在、血管新生の有無を確認した。虚血性疾患において、強い炎症反応が認められており、疾患による影響もみられることがわかった。 また、実験動物として両側総頸動脈閉塞による認知症モデルによる評価を行った。8週のWister kyotoラットにおいて、両側総頚動脈閉塞モデルを作成し、頚動脈閉塞後4週間目に実験用7.0TMRIで脳小血管病性変化を計測した。また、電気生理学的な影響を測定するため、Pinnacle Technology社の大脳皮質脳波測定システムで、てんかん波や高次脳機能を反映するβ波やγ波などの高周波帯域のパワースペクトラム解析を行った。虚血によるてんかん原生が非常に強く影響を及ぼしていることを見出すとともに、MRI及び電気生理学的な虚血の影響を推し量れるシステムを確立した。また、両側頚動脈閉塞と再灌流の電気生理学的変化や組織変化、MRI画像変化の違いを検討し、組織学的変化が及ぼす電気生理学的異常について検討中である。

• analysis of molecular mechanism of invasion in malignant gliomas and development of a novel treatment by inhibition of glioma cell migrations

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2017.04

  -

  2020.03

   

  Wanibuchi Masahiko

  　View Summary

  Gliomas account for 24.1% of primary brain tumors. It is difficult to cure the disease with multimodality treatment combined with surgery, chemotherapy, and radiotherapy. The 5-year survival rate of glioblastoma which is the most malignant type of gliomas is only 10.1%. The reason for the poor prognosis is the invasive capacity, however, the factors and mechanisms of invasion or migration is still unknown.In this study, we found several factors which related to the prognosis of gliomas such as ACTC1 (actin alpha cardiac muscle 1), SERPINEA1, IL13 receptor alpha 2. Among these, ACTC1 was also closely related to the invasion of malignant gliomas. In addition, timelapse study of U87 malignant glioma cell line revealed gene knockdown of ACTC1 using by siRNA resulted in the inhibition of migration of glioma cells. The present study demonstrated that targeting of migration capacity of glioma cells may lead to the improvement of prognosis of malignant gliomas.

• Pathophysiology of oscillation in ischemic condition

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2016.04

  -

  2019.03

   

  Mikami Takeshi

  　View Summary

  To evaluate the neurofunction and effectiveness of revascularization, electrocorticography was evaluated in moyamoya disease. The average spectral power ratio of the beta band per total band in moyamoya disease before bypass was lower than that of control, and the significance disappeared after bypass surgery. The spectral power levels of the beta band and gamma band were increased in moyamoya disease after bypass surgery. Using rat model, similar result could be obtained in ischemic condition. Then, an effective neuromodulation is developing with neuro-stimulation.

• Prevention of neointimal hyperplasia induced by an endovascular stent via intravenous infusion of mesenchymal stem cells

  Grant-in-Aid for Scientific Research (C)

  Project Year :

  2016.04

  -

  2019.03

   

  Katsuya Komatsu

  　View Summary

  In-stent restenosis causes recurrent ischemic events. Neointimal hyperplasia induced by an inflammatory response to the stent strut may be a possible mechanism of in-stent restenosis. Intravenous infusion of mesenchymal stem cells (MSCs) has been reported to show therapeutic efficacy for cerebral stroke presumably by an anti-inflammatory effect. This study aimed to determine whether MSCs can reduce or prevent neointimal hyperplasia induced by an endovascular stent. We deployed two types of stents using an animal model. Stents were implanted in the common carotid artery (CCA), and superficial cervical artery (SCA). Infused MSC immediately after deployment of stents prevented in-stent stenosis of CCA and SCA. Intravenous infusion of MSCs inhibited the inflammatory reaction to an implanted stent strut, and prevented progressive neointimal hyperplasia in the stented CCA and SCA. Thus, MSC treatment could attenuate the recurrence of cerebral ischemic events after stenting.