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Dive into the research topics where Chikao Miyazaki is active.

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Featured researches published by Chikao Miyazaki.


Clinical Neurology and Neurosurgery | 2000

Unusual occipital condyle fracture with multiple nerve palsies and Wallenberg syndrome

Chikao Miyazaki; Mikiro Katsume; Takamasa Yamazaki; Kazuya Aoki; Takao Kuroki; Nobuyoshi Takasu

A 52-year-old male presented with an extremely rare fracture of the occipital condyle involving the jugular foramen with marked medial rostrad displacement of the fragments. He had ipsilateral VII through XII nerves palsies and Wallenberg syndrome. Conservative treatment did not improve the cranial nerve palsies. A high-resolution CT-scan is essential to visualize these fractures.


Neurologia Medico-chirurgica | 2015

Anatomical Reproducibility of a Head Model Molded by a Three-dimensional Printer

Kosuke Kondo; Masaaki Nemoto; Hiroyuki Masuda; Shinichi Okonogi; Jun Nomoto; Naoyuki Harada; Nobuo Sugo; Chikao Miyazaki

We prepared rapid prototyping models of heads with unruptured cerebral aneurysm based on image data of computed tomography angiography (CTA) using a three-dimensional (3D) printer. The objective of this study was to evaluate the anatomical reproducibility and accuracy of these models by comparison with the CTA images on a monitor. The subjects were 22 patients with unruptured cerebral aneurysm who underwent preoperative CTA. Reproducibility of the microsurgical anatomy of skull bone and arteries, the length and thickness of the main arteries, and the size of cerebral aneurysm were compared between the CTA image and rapid prototyping model. The microsurgical anatomy and arteries were favorably reproduced, apart from a few minute regions, in the rapid prototyping models. No significant difference was noted in the measured lengths of the main arteries between the CTA image and rapid prototyping model, but errors were noted in their thickness (p < 0.001). A significant difference was also noted in the longitudinal diameter of the cerebral aneurysm (p < 0.01). Regarding the CTA image as the gold standard, reproducibility of the microsurgical anatomy of skull bone and main arteries was favorable in the rapid prototyping models prepared using a 3D printer. It was concluded that these models are useful tools for neurosurgical simulation. The thickness of the main arteries and size of cerebral aneurysm should be comprehensively judged including other neuroimaging in consideration of errors.


Journal of Medical Case Reports | 2014

Basal encephalocele in an adult patient presenting with minor anomalies: a case report

Naoyuki Harada; Masaaki Nemoto; Chikao Miyazaki; Kosuke Kondo; Hiroyuki Masuda; Jun Nomoto; Nobuo Sugo; Takao Kuroki

IntroductionBasal encephalocele is rare in adults. Congenital and acquired cases have been reported with regard to the developmental mechanism, and the pathology has not been elucidated in detail.Case presentationWe encountered an adult with basal encephalocele strongly suggesting congenital development because of the presence of minor anomalies: strabismus and ocular hypertelorism. The disease manifested as persistent spontaneous cerebrospinal fluid rhinorrhea and repeated meningitis in a 66-year-old Japanese man. On computed tomography, brain tissue protruded through a part of the ethmoid bone of his right anterior skull base, and it was diagnosed as transethmoidal-type basal encephalocele. Regarding his facial form, the distance between his bilateral eyeballs was large compared to his facial width, and his canthal index (defined as inner to outer inter canthal ratio × 100) was calculated as 38.5, based on which it was judged as ocular hypertelorism. In addition, his right eyeball showed strabismus. A right frontotemporal craniotomy was performed for spontaneous cerebrospinal fluid rhinorrhea, and the defective dura mater region was patched with temporal fascia.ConclusionsMild minor anomalies that require no treatment are overlooked in adults, but the presence of several anomalies increases the possibility of congenital disease. Therefore, it may be necessary to examine minor anomalies in cases of adult basal encephalocele when considering the possibility that the disease may be congenital.


Journal of Stroke & Cerebrovascular Diseases | 2014

Hydroperoxide in Internal Jugular Venous Blood Reflects Occurrence of Subarachnoid Hemorrhage-Induced Delayed Cerebral Vasospasm

Hiroyuki Uekusa; Chikao Miyazaki; Kosuke Kondo; Naoyuki Harada; Jun Nomoto; Nobuo Sugo; Masaaki Nemoto

BACKGROUND To investigate the association between subarachnoid hemorrhage-induced delayed cerebral vasospasm (DCVS) and oxidative stress, an oxidation product, hydroperoxide, was measured in 3 specimens: peripheral arterial blood, cerebrospinal fluid (CSF), and internal jugular venous blood (IJVB). METHODS Hydroperoxide was measured using the diacron reactive oxygen metabolites (d-ROMs) test. The hydroperoxide levels were evaluated based on the rate of change in the d-ROMs test value on day 6 relative with that on day 3 (d-ROMs change rate). RESULTS The subjects were 20 patients. The d-ROMs change rate in IJVB was significantly higher in patients with DCVS on day 6 than in those without it (P < .01). When the patients were classified into the following 3 groups: Group A (no DCVS occurred throughout the clinical course); Group B (DCVS occurred, but no cerebral infarction [CI] was induced); and Group C (DCVS occurred and caused CI), the d-ROMs change rate in IJVB was the highest in Group C, followed by Group B then A (P < .01). The d-ROMs change rates in peripheral arterial blood and CSF were not related to the development of DCVS. CONCLUSIONS It was concluded that the more severe DCVS occurs and is more likely to progress to CI as the IJVB hydroperoxide level rises early after the development of subarachnoid hemorrhage.


Neurosurgery Quarterly | 2014

Ruptured Aneurysm of the Superior Cerebellar Artery Associated With Cerebellar Hemangioblastoma: A Case Report and Review of Literature

Takao Kuroki; Kosuke Kondo; Naoyuki Harada; Jun Nomoto; Hiroyuki Uekusa; Masaaki Nemoto; Nobuo Sugo; Chikao Miyazaki

Aneurysms associated with hemangioblastoma are very rare. We encountered a patient in whom an aneurysm of the distal superior cerebellar artery, the main feeding vessel of cerebellar hemangioblastoma, ruptured and caused hemorrhage. On the basis of the computed tomography findings, the superior cerebellar artery aneurysm was identified as the source of hemorrhage, and embolization using a Guglielmi detachable coil was performed in subsequent endovascular surgery. Endovascular embolization was applied to the artery feeding the tumor at 4 weeks after admission, and the tumor was removed using an occipital transtentorial approach. A favorable therapeutic outcome may be expected when using a combination of endovascular therapy and surgical craniotomy for aneurysms associated with hemangioblastoma.


Journal of Hypertension | 2016

OS 25-04 THE CHANGES OF ARTERIAL STIFFNESS MONITORED WITH CARDIO ANKLE VASCULAR INDEX (CAVI) DURING RAISED INTRACRANIAL PRESSURE IN THE RABBIT.

Chikao Miyazaki; Mao Takahashi; Kazuhiro Shimizu; Tatsuo Chiba; Takenori Morisita; Tomoyuki Yamamoto; Nobuo Sugo; Akira Takahara; Kohji Shirai

Objective: Cardio ankle vascular index (CAVI) is reflecting stiffness of the arterial tree from the origin of aorta to the ankles. We observed elevated CAVI in patients who suffered from apoplexy attack. To clarify the role and the mechanism by which arterial stiffness elevated just after apoplexy attack, the effect of enhanced intracranial pressure (ICP) by injecting saline into the cisterna magna of the rabbit on blood pressure, CAVI and cervical blood flow, were studied. Furthermore the role of sympathetic nerve was studied. Design and Method: The system of measuring CAVI of the New Zealand white rabbit was set up. General anesthesia was performed by ketamine and xylazine, and the respirator was set. Intracranial pressure (ICP) was monitored using a catheter inserted into subarachnoid space via right frontal bone craniotomy. Saline (15 ml) was inserted to raise ICP. Ganglion blocker, hexamethonium (10 &mgr;g/kg/10 min, and 100 &mgr;g/kg/10min) was administered just before saline injection. Results: When saline was injected into the cisterna magna and ICP was raised over 20 mmHg at least, blood pressure (62 ± 7.43 → 135 ± 27.41 mmHg), and CAVI (3.3 ± 0.39 → 4.8 ± 0.89) were increased. The heart rate and blood flow of common carotid artery increased. When hexamethonium (10 &mgr;g/kg/10 min and 100 &mgr;g/kg/10min) was administered before raising ICP, enhanced IPP -induced blood pressure increase (123 ± 9.58, 90 ± 5.42 mmHg, respectively) and CAVI increase (4.3 ± 0.35, 4.0 ± 0.16, respectively) were inhibited dose-dependently. Conclusions: Raised ICP induced an increase of blood pressure accompanying with an increase of CAVI, suggesting that enhanced stiffness of muscle artery might partly induce high blood pressure. Blocking sympathetic nerve by hexamethonium diminished raised blood pressure and CAVI, indicating that ICP increase-induced blood pressure and CAVI increases were mediated by sympathetic nerve activation.


Neurosurgery Quarterly | 2015

Cerebral Mass Lesion in Medulla Oblongata Causing Intractable Hiccups: A Report of 2 Cases and Review of the Literature

Masaaki Nemoto; Chikao Miyazaki; Naoyuki Harada; Kosuke Kondo; Jun Nomoto; Hiroyuki Masuda; Nobuo Sugo; Takao Kuroki

Intractable hiccups caused by an intracranial mass lesion are rare. We encountered surgical cases of cavernous angioma and hemangioblastoma in the medulla oblongata, which manifested with intractable hiccups. Herein, we report on 2 cases: case 1, a 30-year-old woman with a past medical history of surgery for cerebellar hemangioblastoma. The disease manifested with intractable hiccups, and a mass lesion was observed in the medulla oblongata on magnetic resonance imaging (MRI). During surgery, a vascular-rich tumor was localized near the obex of the mid-dorsal portion of the medulla oblongata. The hiccups were resolved immediately after total tumor excision, no event occurred thereafter, and the patient was discharged. The pathologic diagnosis was hemangioblastoma. Case 2, in a 22-year-old man, a lesion was observed in the dorsal portion of the medulla oblongata on computed tomography and MRI was performed to investigate the cause of intractable hiccups. During surgery, a mass lesion was present in the right dorsolateral aspect of the medulla oblongata. The hiccups resolved immediately after total excision of the lesion. No neurological deficit occurred, and the patient was discharged. The lesion was pathologically diagnosed as a cavernous angioma. In conclusion, a search for a dorsal medullary lesion using MRI is necessary when investigating intractable hiccups. To resolve intractable hiccups, the active application of surgical excision of the mass lesion is recommended.


Journal of Stroke & Cerebrovascular Diseases | 2014

Original ArticleHydroperoxide in Internal Jugular Venous Blood Reflects Occurrence of Subarachnoid Hemorrhage-Induced Delayed Cerebral Vasospasm

Hiroyuki Uekusa; Chikao Miyazaki; Kosuke Kondo; Naoyuki Harada; Jun Nomoto; Nobuo Sugo; Masaaki Nemoto

BACKGROUND To investigate the association between subarachnoid hemorrhage-induced delayed cerebral vasospasm (DCVS) and oxidative stress, an oxidation product, hydroperoxide, was measured in 3 specimens: peripheral arterial blood, cerebrospinal fluid (CSF), and internal jugular venous blood (IJVB). METHODS Hydroperoxide was measured using the diacron reactive oxygen metabolites (d-ROMs) test. The hydroperoxide levels were evaluated based on the rate of change in the d-ROMs test value on day 6 relative with that on day 3 (d-ROMs change rate). RESULTS The subjects were 20 patients. The d-ROMs change rate in IJVB was significantly higher in patients with DCVS on day 6 than in those without it (P < .01). When the patients were classified into the following 3 groups: Group A (no DCVS occurred throughout the clinical course); Group B (DCVS occurred, but no cerebral infarction [CI] was induced); and Group C (DCVS occurred and caused CI), the d-ROMs change rate in IJVB was the highest in Group C, followed by Group B then A (P < .01). The d-ROMs change rates in peripheral arterial blood and CSF were not related to the development of DCVS. CONCLUSIONS It was concluded that the more severe DCVS occurs and is more likely to progress to CI as the IJVB hydroperoxide level rises early after the development of subarachnoid hemorrhage.


Neurosurgery Quarterly | 2013

Double Plombage Using Abdominal Adipose Tissue for Posterior Transpetrosal Approach–induced Liquorrhea

Kosuke Kondo; Takao Kuroki; Chikao Miyazaki; Naoyuki Harada; Jun Nomoto; Hiroyuki Masuda; Hiroyuki Uekusa; Masaaki Nemoto; Nobuo Sugo

Objective:To prevent posterior transpetrosal approach–induced liquorrhea, we developed a method involving the double application of abdominal adipose tissue in the subdural and epidural spaces. Materials and Methods:The method was applied to 8 patients who underwent surgery under a posterior transpetrosal approach: 4 with petroclival meningioma and 1 each with tentorial meningioma, jugular foramen neurinoma, trigeminal neurinoma, and metastatic brain tumor. The combined transpetrosal approach was used for 6 patients and the combination with the lateral suboccipital approach was used for the other 2 patients. After tumor resection, the divided dura mater of the presigmoid space was closed as follows: first, a fat mass excised from the abdominal region was divided into 2 parts, and several excisions were made in each part to flatten them. The exposed brain surface was covered with the flattened fat, and the fat margin was circumferentially inserted under the dura mater. The division was then closed by suturing the dural stumps at several sites, loading tension to some extent. Finally, the other part of the adipose tissue was spread in the epidural space in the dural-defective region for double closure inside and outside the dura mater. Results:Liquorrhea was prevented in all patients. Conclusions:It was concluded that this method is useful to prevent postoperative liquorrhea induced by a posterior transpetrosal approach.


Neurologia Medico-chirurgica | 2002

Bilateral thalamic glioma--case report.

Masafumi Uchino; Satoru Kitajima; Chikao Miyazaki; Iekado Shibata; Myouta Miura

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