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Hokari M.,Sapporo Asabu Neurosurgical Hospital | Kuroda S.,Hokkaido University | Yasuda H.,Sapporo Asabu Neurosurgical Hospital | Iwasaki M.,Sapporo Asabu Neurosurgical Hospital | And 2 more authors.
Acta Neurochirurgica | Year: 2010

Aneurysms of the choroidal branches of the posterior inferior cerebellar artery (PICA) are quite rare; only seven such cases have been reported thus far. In this study, we present a very rare case of a ruptured aneurysm of a choroidal branch of the PICA; the aneurysm was exposed by splitting the vermis and resected after proximal arterial ligation. We have also undertaken a thorough review of the literature on aneurysms in choroidal branches of the PICA, focusing on the clinical presentation, etiology, radiological findings, and surgical strategies. We found that the aneurysms in our patient and the aneurysms in seven published case reports were small, and frequently associated with vascular anomalies. Intraventricular hemorrhage (IVH) in the fourth ventricle was detected in all eight cases. The outcomes of surgical treatment were generally favorable, notwithstanding the high incidence of rebleeding after rupture of distal PICA aneurysms. The recognition of predominant fourth ventricular hemorrhage should raise the suspicion of the presence of an underlying aneurysm, and digital subtraction angiograms (DSAs) should be immediately obtained in order to detect small aneurysms of the choroidal branches of the PICA. © 2009 Springer-Verlag. Source

Terasaka S.,Hokkaido University | Kawabori M.,Hokkaido University | Kobayashi H.,Hokkaido University | Murata J.,Sapporo Asabu Neurosurgical Hospital | And 3 more authors.
Brain Tumor Pathology | Year: 2012

We report an unusual case of neurohypophyseal germinoma with abundant fibrous tissue and clival invasion that was initially misdiagnosed as lymphocytic hypophysitis. A 40-year-old woman presented with diabetes insipidus and panhypopituitarism after delivering her second son and which lasted for 4 years. Magnetic resonance imaging showed the intrasellar mass extending to the suprasellar region with enlarged pituitary stalk. The mass was heterogeneously enhanced and invaded the clivus. Biopsy of the intrasellar mass was performed via the trans-sphenoidal route, and histological examination revealed marked fibrous tissue and infiltration of lymphocytes, with no evidence of tumor cells. Lymphocytic hypophysitis was the initial diagnosis, and corticosteroid therapy was begun. Despite intensive treatment, the lesion enlarged and clinical symptoms worsened 2 weeks after surgery. Subtotal removal of the mass was performed, and a second histological examination revealed typical findings of the germinoma. Subsequently, the patient underwent chemoradiotherapy, and complete remission was achieved. Histological diagnosis is sometimes incorrect in fibrous tumors at the sellar region, and biopsy from several points is strongly recommended for this entity. © 2011 The Japan Society of Brain Tumor Pathology. Source

Narita T.,Hokkaido University | Aoyama H.,Niigata University | Hirata K.,Hokkaido University | Onodera S.,Hokkaido University | And 6 more authors.
Japanese Journal of Clinical Oncology | Year: 2012

Two glioblastoma multiforme patients underwent. 18F-FMISO (fluoromisonidazole) positron emission tomography study to access the tumor oxygenation status before and immediately after fractionated radiotherapy concomitant with temozolomide chemotherapy. In both cases, a prominent. 18F-FMISO tumor accumulation observed in the first study was notably decreased in the second study, which was supposed to be a reoxygenation of the tumor. As far as we investigated, this is the first report of the changes of oxygenation status in glioblastoma multiforme treated through radiation therapy with temozolomide. © The Author 2011. Published by Oxford University Press. All rights reserved. Source

Yamaguchi S.,Hokkaido University | Kobayashi H.,Hokkaido University | Hirata K.,Hokkaido University | Shiga T.,Hokkaido University | And 3 more authors.
Journal of Neuro-Oncology | Year: 2011

Gliomas are regionally heterogeneous tumors. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and 11C-methionine (MET) evaluates the heterogeneity of histological malignancy within the tumor. We present two patients with oligodendrocytic tumors that showed discrepancies in the highest uptake areas with these two tracers. PET studies with MET and FDG were performed on the same day, 2 weeks before surgery. In both cases, biopsy specimens were separately obtained from the highest MET and FDG uptake areas guided by intraoperative neuronavigation. Histological examinations demonstrated that the specimens from the highest MET uptake area revealed low-grade oligoastrocytoma or oligodendroglioma, whereas histological anaplasias were contained in the specimens from the highest FDG uptake area. With gliomas with oligodendroglial components, the MET uptake ratio does not always correspond to histological anaplasia, which can be detected only by FDG PET. Sole application of MET PET for preoperative evaluation may lead to misunderstanding of histological heterogeneity in gliomas, especially those with oligodendroglial components. FDG and MET tracers play complementary roles in preoperative evaluation of gliomas. © 2010 Springer Science+Business Media, LLC. Source

Uchino H.,Sapporo Asabu Neurosurgical Hospital | Uchino H.,Hokkaido University | Nakamura T.,Sapporo Asabu Neurosurgical Hospital | Houkin K.,Hokkaido University | And 3 more authors.
Acta Neurochirurgica | Year: 2013

Background: Postoperative hyperperfusion may lead to severe neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. However, there are no reliable modalities to predict the occurrence of postoperative hyperperfusion during surgery. The purpose of this study is to evaluate whether a semiquantitative analysis of indocyanine green (ICG) videoangiography could be useful in predicting postoperative hyperperfusion after STA-MCA anastomosis. Methods: This study included seven patients who underwent STA-MCA anastomosis due to occlusive carotid artery diseases. During surgery, ICG videoangiography was performed before and after bypass procedures, and ICG intensity-time curves were semiquantitatively analyzed to evaluate hemodynamic changes by calculating maximum intensity, time to peak (TTP), and blood flow index (BFI). Results: Maximum intensity significantly increased from 252.6 ± 132.5 to 351.7 ± 151.9 after bypass (p < 0.001). TTP was significantly shortened from 12.9 ± 4.4 s to 9.8 ± 3.7 s (p < 0.001). Furthermore, BFI significantly increased from 33.9 ± 28.1 to 74.6 ± 88.4 (p < 0.05). Postoperative hyperperfusion was observed in five of seven patients 1 day after surgery. The ratio of BFI before and after bypass procedures was significantly higher in patients with postoperative hyperperfusion than those without, 2.5 ± 1.1 and 1.5 ± 0.4, respectively (p = 0.013). Conclusions: These findings suggest that semiquantitative analysis of ICG videoangiography is helpful in predicting occurrence of hyperperfusion after STA-MCA anastomosis in patients with occlusive carotid artery diseases. © 2013 Springer-Verlag Wien. Source

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