Frederick A. Boop
Kiyoshi Saito, Keizo Fukuta, Masakatsu Takahashi, Yukio Seki, and Jun Yoshida
✓ The authors report two patients with benign fibroosseous lesions involving the center of the skull base: a 15-year-old boy with repetitive meningitis and pneumocephalus and a 11-year-old boy with nasal obstruction and headache. The clinical diagnoses were ossifying fibroma and aneurysmal bone cyst, respectively. Lesions in both patients extended to the nasal cavity, the sphenoid and posterior ethmoid sinuses, and the skull base, where the planum sphenoidale, the sella turcica, the upper two-thirds of the clivus, and the medial portion of the middle cranial base were involved. The lesions were totally removed using an anterior craniofacial approach. Characteristics of these lesions and the surgical approach are discussed.
Tatsuya Nishioka, Akinori Kondo, Ikuhiro Aoyama, Kiyoshi Nin, and Jun Takahashi
✓ Aneurysms arising from the intracavernous portion of the internal carotid artery very rarely rupture. A patient is presented in whom rupture of an aneurysm wholly within the cavernous sinus caused a subarachnoid hemorrhage. The aneurysm was successfully clipped via a direct surgical approach. The possible mechanism by which subarachnoid hemorrhage occurred is briefly discussed.
Mauro Bergui and Gianni B. Bradac
Jun A. Takahashi, Manabu Fukumoto, Koichi Igarashi, Yoshifumi Oda, Haruhiko Kikuchi, and Masakazu Hatanaka
✓ Basic fibroblast growth factor (FGF) is a mitogen, a differentiation factor for neuroectoderm-derived cells, and a potent angiogenic factor. The authors have previously demonstrated that the messenger ribonucleic acid of basic FGF is expressed in more than 90% of human gliomas. In the present study, they examined the expression of basic FGF in human glioma tissues using immunohistochemical techniques with a mouse monoclonal antibody against human basic FGF. They also correlated the basic FGF level with the histological grades of malignancy assessed by the number of nucleolar organizer regions (NOR's). Basic FGF was detected in 18 of 19 gliomas, whereas it was undetectable in two normal brains. The expression level of basic FGF peptide increased proportionally with the degree of malignancy. There was also a tendency for the number of NOR's in glioma cells to increase in glioma samples with a high level of basic FGF expression. Furthermore, most of the cases with increased vascularity demonstrated on cerebral angiograms showed a relatively high level of basic FGF expression of tumor cells and a large number of NOR's in endothelial cells in tumor tissues. These results suggest that basic FGF is actually produced in most gliomas and is involved in tumorigenesis and malignant progression as an autocrine growth factor. Moreover, basic FGF may play an important role in tumor neovascularization as a paracrine angiogenic factor.
Susumu Miyamoto, Takeshi Funaki, Koji Iihara, and Jun C. Takahashi
The authors evaluated the efficacy of a new flow reduction strategy for giant partially thrombosed upper basilar artery (BA) aneurysms, for which proximal parent artery occlusion is not always effective.
Eight consecutive patients with severely symptomatic, partially thrombosed, giant upper BA aneurysms were treated with a tailored flow reduction strategy, or received conservative therapies. The flow reduction strategy comprised isolation of several branches from the upper BA at their origins with bypasses in addition to parent artery occlusion.
The median follow-up period of all 8 patients was 15.0 months (range 4–31 months). In 6 patients treated with flow reduction, the mean decrease in residual blood lumen was −10.7 mm (95% CI −19.7 to −1.7 mm; p = 0.029) and the mean decrease in diameter of the aneurysms was −11.5 mm (95% CI −25.1 to 2.1 mm; p = 0.082). Complete or virtually complete thrombosis was achieved in all but 1 aneurysm (83%) and shrinkage was observed in 4 (67%). In those in whom complete or virtually complete thrombosis was achieved, significant shrinkage of the aneurysm was observed (mean decrease in diameter −14.8 mm; 95% CI −28.8 to −0.8 mm; p = 0.043). Improvement or stabilization of symptoms occurred in 67% of the patients who received flow reduction treatment. Both patients who received conservative treatment had unfavorable outcomes.
The flow reduction strategy is effective at promoting complete thrombosis of the aneurysm. This strategy can also induce shrinkage of the aneurysm if successful thrombosis is achieved. Although the neurological outcome of the treatment appears favorable considering its intractable nature, further study of the treatment is necessary to confirm its clinical efficacy and safety.
Toru Iwama, Kohei Hayashida, Jun C. Takahashi, Izumi Nagata, and Nobuo Hashimoto
Object. The purpose of this study was to evaluate cerebral hemodynamic and metabolic features in patients with arteriovenous malformations (AVMs) by using positron emission tomography (PET) scanning.
Methods. Twenty-four patients with supratentorial cerebral AVMs participated in PET studies in which 15O inhalation steady-state methods were used. The authors recorded the values of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), the regional oxygen extraction fraction (rOEF), and the regional cerebral metabolic rate of O2 (rCMRO2) at three designated regions of interest (ROIs) in each patient. These ROIs included perilesional (ROI-p), ipsilateral remote (ROI-i), and contralateral symmetrical (ROI-c) brain regions. To identify the factors that exert a direct effect on the hemodynamics of brains affected by AVM, we also separated the lesions according to their size and flow type shown on angiograms, and grouped the patients according to the presence or absence of progressive neurological deficits. We then compared the PET parameters at different ROIs in individual patients and evaluated the mean values obtained for all 24 patients according to AVM flow type and size, and the presence or absence of progressive neurological deficits.
Conclusions. Overall, mean rCBV and rOEF values were significantly higher in ROI-p than in ROI-c (p = 0.00046 and p = 0.015, respectively). No significant differences were seen between the ROI-i and ROI-c with respect to rCBF, rCBV, and rOEF. Mean rCMRO2 values were similar in the three ROIs; however, the mean rCBF was significantly lower in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.019), large AVMs (p = 0.017), and progressive neurological deficits (p = 0.021). Furthermore, the mean rOEF values were significantly higher in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.005), large AVMs (p = 0.019), and progressive neurological deficits (p = 0.017). The PET studies revealed hemodynamic impairment characterized by decreased rCBF and increased rOEF and rCBV values in the ROI-p of patients with large, high-flow AVMs regardless of whether they exhibited progressive neurological deficits.
Tatsuo Takahashi, Naomi Mutsuga, Toshiki Aoki, Takashi Handa, Chiharu Tanoi, Jun Yoshida, and Tatsuya Kobayashi
✓ Demonstration of the exact site of dural fistulas in cases of cerebrospinal fluid rhinorrhea is difficult. Previous reports have described the use of metrizamide cisternography combined with either hypocycloidal tomography or computerized tomography; however, direct, dynamic, real-time visualization of the fistula is difficult with instillation of a minimal dose of metrizamide using those methods. A digital video subtraction fluoroscopy system can visualize the actual site of the fistula directly and dynamically using only a small amount of metrizamide.
Yasuhiro Kawabata, Jun A. Takahashi, Yoshiki Arakawa, and Nobuo Hashimoto
The prognostic significance of tumor grade and resection and the efficacy of prophylactic radiation remain controversial in the management of intracranial ependymoma. The outcomes in patients with intracranial ependymoma treated at the Kyoto University Hospital were reviewed retrospectively, and prognostic significance was analyzed.
Between 1972 and 2002, 29 patients were seen at the authors' institution. Eighteen cases involved a Grade II lesion according to the World Health Organization classification of ependymoma and 11 involved a Grade III lesion. Postoperative radiation was applied in 24 cases and chemotherapy was administered in nine. Overall survival and progression-free survival rates were significantly higher in patients with Grade II ependymoma (p = 0.006 and 0.004, respectively) and in patients who had undergone gross-total resection of the tumor (p = 0.002 and 0.04, respectively). Fourteen patients relapsed from 10 to 120 months (median 39 months) after diagnosis. In nine patients the ependymoma recurred only at the original tumor site. Three patients experienced both local and distant relapse, whereas two others had only a distant relapse. All relapses of the Grade II ependymoma initially occurred at the primary tumor site. Histological grade and extent of resection were significantly associated with tumor dissemination (p = 0.0034 and 0.0011, respectively). The field of postoperative radiation had no impact on patient survival or lesion recurrence.
Tumor grade and resection are the two important prognostic factors with respect to patient survival, tumor recurrence, and tumor dissemination. Considering that relapses were predominantly local and that there was no apparent benefit from prophylactic radiation, the authors concluded that postoperative radiation should be focused on local control, especially for Grade II ependymomas.