Publications by authors named "Naoki Yajima"

Background: Some aneurysms cause edema formation in the surrounding brain parenchyma and are thought to reflect various phenomena occurring in the aneurysm. Some authors highlighted perianeurysmal edema (PAE) as a finding that indicates higher risk of rupture of the aneurysm. On the other hand, there are no reports of image changes in the surrounding brain parenchyma of aneurysm other than edema formation.

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Background: Acute neurological deterioration develops paradoxically in some patients after obliteration of a spinal dural arteriovenous fistula (SDAVF), with thrombosis of the spinal cord veins as its primary cause. The authors aimed to clarify the clinical and radiological characteristics of acute deterioration to identify high-risk patients. They also discussed the optimal treatment for this complication.

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Objective: In this study, we provide long-term outcome data of patients with primary central nervous system lymphoma.

Methods: The long-term outcomes of PCNSL patients diagnosed between 1982 and 2006 were reviewed. Neurological late neurotoxicity symptoms, neuroradiological brain atrophy and leukoencephalopathy were evaluated.

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Background: Although the superficial middle cerebral vein (SMCV) usually connects with the cavernous sinus, there are several anatomical variations. We determined whether differences in SMCV drainages patterns affected the perioperative management of petroclival meningioma.

Methods: The subjects included 17 patients (4 men; 13 women) who underwent resection of a petroclival meningioma.

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Purpose: The long-term results of decompressive surgery for degenerative spondylolisthesis (DS) were evaluated with reference to instability.

Materials And Methods: Patients (n=48) undergoing decompressive surgery without fusion were studied. The diagnosis of spondylolisthesis was made based on the presence of sagittal vertebral slippage greater than 3mm.

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Objective: Monitoring pharyngeal motor evoked potential (PhMEP) with a modified endotracheal tube is useful for predicting postoperative swallowing dysfunction. However, the relationship between intraoperative PhMEP findings and recovery from postoperative swallowing dysfunction has not been clarified. The aim of this study was to determine whether PhMEP monitoring predicts swallowing dysfunction not only immediately after surgery but also in the postoperative recovery period.

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Purpose: The long-term results of decompressive surgery for degenerative spondylolisthesis with symptomatic lumbar spinal stenosis were evaluated retrospectively with regard to the postoperative progression of slippage and clinical symptoms.

Materials And Methods: The study included 53 patients who underwent surgery, and for whom follow-up of at least 5 years was conducted. Spondylolisthesis was diagnosed based on the presence of sagittal vertebral translation greater than 3mm on lateral radiographs.

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Objective: To determine whether various clinical factors are related to long-term outcomes of patients with sporadic cerebellar hemangioblastomas.

Methods: Subjects included 36 patients (19 men and 17 women) who underwent resection of sporadic hemangioblastoma in the cerebellum. Age at surgery ranged from 17-79 years (mean, 49.

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Background: Swallowing disturbance is among the most burdensome complications suffered by patients with glossopharyngeal and vagus nerve involvement in lesions adjacent the jugular foramen. For monitoring these nerves, we have developed new devices that comprised four contacts adhering to the surface of the cuff of an endotracheal tube, with attachment the posterior pharyngeal wall. To determine whether these devices are useful for monitoring the glossopharyngeal and vagus nerves and predicting postoperative swallowing dysfunction in patients undergoing removal of skull base tumors involving these nerves.

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The present study aimed to identify genes associated with patient survival to improve our understanding of the underlying biology of gliomas. We investigated whether the expression of genes selected using random survival forests models could be used to define glioma subgroups more objectively than standard pathology. The RNA from 32 non-treated grade 4 gliomas were analyzed using the GeneChip Human Genome U133 Plus 2.

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Object: In this paper, the authors' goal was to report their novel presurgical simulation method applying interactive virtual simulation (IVS) using 3D computer graphics (CG) data and microscopic observation of color-printed plaster models based on these CG data in surgery for skull base and deep tumors.

Methods: For 25 operations in 23 patients with skull base or deep intracranial tumors (meningiomas, schwannomas, epidermoid tumors, chordomas, and others), the authors carried out presurgical simulation based on 3D CG data created by image analysis for radiological data. Interactive virtual simulation was performed by modifying the 3D CG data to imitate various surgical procedures, such as bone drilling, brain retraction, and tumor removal, with manipulation of a haptic device.

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Purpose: Better understanding of the underlying biology of primary central nervous system lymphomas (PCNSL) is critical for the development of early detection strategies, molecular markers, and new therapeutics. This study aimed to define genes associated with survival of patients with PCNSL.

Experimental Design: Expression profiling was conducted on 32 PCNSLs.

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Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of vascular malformations of the spine and are defined as abnormal arteriovenous shunts within the dura. SDAVFs are considered to be acquired and should be distinguished from congenital intradural perimedullary arteriovenous fistulas (PMAVFs). A 32-year-old female presented with both SDAVF and PMAVF, manifesting as a slowly progressive paraparesis over a 6-month period.

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Object: The purpose of this paper is to report on the authors' advanced presurgical interactive virtual simulation technique using a 3D computer graphics model for microvascular decompression (MVD) surgery.

Methods: The authors performed interactive virtual simulation prior to surgery in 26 patients with trigeminal neuralgia or hemifacial spasm. The 3D computer graphics models for interactive virtual simulation were composed of the brainstem, cerebellum, cranial nerves, vessels, and skull individually created by the image analysis, including segmentation, surface rendering, and data fusion for data collected by 3-T MRI and 64-row multidetector CT systems.

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Better understanding of the underlying biology of malignant gliomas is critical for the development of early detection strategies and new therapeutics. This study aimed to define genes associated with survival. We investigated whether genes selected using random survival forests model could be used to define subgroups of gliomas objectively.

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Autophagy is a dynamic process of protein degradation. Induction of autophagy by temozolomide (TMZ) has been noted in glioma cell lines. Twenty-eight specimens, obtained from 14 patients before and after TMZ treatment, were analyzed to investigate whether induction of autophagy could be detected in surgical specimens by immunohistochemical analysis.

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Three patients developed hemorrhage in the splenium of the corpus callosum 2 weeks after the onset of subarachnoid hemorrhage (SAH) associated with acute hydrocephalus. Computed tomography performed a few days after the onset showed a low density area in the splenium of corpus callosum in all three patients, and preventive measures against symptomatic vasospasm were begun, including vasodilator administration. Computed tomography showed hemorrhage in the splenium of the corpus callosum 17 to 22 days after onset of SAH, manifesting as mental deterioration or headache.

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Background: Chemotherapy with or without radiotherapy is the mainstay of treatment for primary central nervous system lymphoma (PCNSL). High-dose methotrexate (MTX) is the most effective drug available to treat these lesions, either as a single agent or in combination with other drugs. Due to the lack of well-conducted randomized trials, the optimal treatment remains controversial.

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We report the efficacy of salvage therapy with a modified ProMACE-MOPP combined with radiation in patients with primary central nervous system lymphoma (PCNSL). Thirty-two immunocompetent patients were treated with a regimen of pirarubicin, cyclophosphamide, etoposide, vincristin, and methotrexate (MTX: 500 mg/m(2)) administered in 21-day cycles. Patients received 20 Gy of whole-brain radiotherapy after three cycles of chemotherapy.

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The ECT2 (epithelial cell transforming sequence 2) proto-oncogene encodes a guanine nucleotide exchange factor for Rho GTPases, and regulates cytokinesis. ECT2 plays a critical role in Rho activation during cytokinesis, and thus may play a role in the pathogenesis of glioma. In this study, we investigated relationships between ECT2 expression, tumor histology, and prognosis in glioma patients.

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C/EBP beta (CCAAT/enhancer binding protein beta) is a transcriptional factor that belongs to the basic region-leucine zipper class DNA-binding proteins and plays a role in cell differentiation and inflammatory reactions. Although high tissue levels of inflammatory cytokines, such as interleukin (IL)-6, IL-8 and transforming growth factor-beta, have been observed in glioma patients, the mechanisms underlying this phenomenon remain to be elucidated. C/EBP beta induces a variety of cytokines and thus may play a role in the pathogenesis of glioma.

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We have isolated and characterized N-linked oligo-saccharides that are significantly increased in glioblastoma tissue and cell lines. The structures of N-linked oligosaccharides present in 3 human normal brain tissues, 15 patients with glio-blastoma and 3 glioma cell lines were analyzed by partially automated technique for the isolation and fluorescent labeling of N-linked sugar chains from glycoproteins. Characterization of the sugar chains was achieved with the use of a combination of HPLC columns and a highly sensitive fluorescence detector at femtomole levels.

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