Biomedical subjects
Publications and source records attributed to T Kayama.
Surgical experience with treatment of two lateral ventricle tumors using the anterior transcingulate approach demonstrate that this route provides an excellent approach to tumors attached to the lateral wall of the anterior ventricle, without causing gross neurologic deficits. This approach deserves attention as an alternative to the transcallosal approach in selected patients.
The following presents a case of an 85-year-old woman with intermittent claudication of a sacral nerve root cyst. The cyst wall was incised and oversewn while preserving the surrounding nerve fibers by microscopic procedures. All symptoms were eliminated following the operation. The syndrome of intermittent claudication may possibly arise while walking from the transient influx of cerebrospinal fluid into a cyst in a relatively narrow sacral canal. The present case may indicate that a sacral nerve root cyst is curable even in aged patients through thorough evaluation and management.
BACKGROUND: It is generally accepted that excellent development of collateral circulation can be achieved through indirect nonanastomotic bypass procedures for pediatric patients with moyamoya disease. However, there are no definitive conclusions about the effect of indirect revascularization for adult patients. To clarify the value of indirect bypass surgery for adult moyamoya disease, we have analyzed their follow-up angiographic results in comparison with those of the pediatric patients. METHODS: Between 1989 and 1993, 23 patients underwent combined direct and indirect bypass surgery. They consisted of 16 adults (mean age, 35; range, 20-59) and seven children (mean age, 10; range, 3-16). The main symptoms were those due to cerebral ischemia in all but 1 of 23 patients. Preoperative cerebral blood flow studies showed all patients to have decreased vascular reserve (misery perfusion). Postoperative follow-up angiography was done in all patients at a median of 6 months after the surgery. RESULTS: All pediatric patients showed good or moderate development of collaterals through the indirect bypass. Among the adult group, seven patients aged 20 to 29 had angiographic results similar to those of the pediatric group . On the other hand, nine patients older than 30 had results contrary to those of pediatric patients: (1) the degree of indirect revascularization declined to moderate or poor grades (especially in patients older than 40) and (2) the degree of direct bypass filling improved to high or medium grades. CONCLUSIONS: The results suggest that advancing age apparently affects the development of collateral formation through the indirect bypass. Consequently, direct bypass is thought to be the main treatment option for patients older than 40.
To evaluate prognostic value of complete disappearance of the tumor mass in contrast enhanced computerized tomography after initial treatment, 81 patients with supratentorial malignant astrocytomas (57 anaplastic astrocytomas and 24 glioblastomas) were divided into two groups. All complete response CR patients received the gross total resection (more than 95% resection). Average age of this group was significantly younger than that of noncomplete response patients (38.4 vs. 49.7 years old, p < 0.05; Student t-test). In the complete response group, median survival duration was 58 months, 2-year survival rate was 77%, and 5-year survival rate was 34% compared to 12 months, 29%, and 10%, respectively, in the noncomplete response group. The outcome of CR group was significantly better (p < 0.001; Wilcoxon test). Therefore, complete response at completion of the initial treatment is an important predictor of longer survival. Gross total resection is essential to obtain complete response and thus plays a crucial role in the initial treatment of malignant astrocytomas.
The antioxidant effect of Fructus Momordicae extract, FME (mogrosides 75 approximately 80%), was studied. FME reduced the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and scavenged superoxide radicals (O2-) generated by a hypoxanthine and xanthine oxidase system. It also scavenged hydroxyl radicals (.OH) generated by Fenton reaction. In addition, FME inhibited Fe(II) induced lipid peroxidation in rat cortex homogenates in a dose-dependent manner, as indicated by decreased thiobarbituric acid-reactive substances (TBARS) formation. Oral administration of FME inhibited TBARS and malonaldehyde (MDA) formation in the ipsilateral cortex 30 min after iron-salt injection into the left cortex of rat. FME showed inhibitory effect on 4-hydroxy-2(E)-nonenal (4-HNE) formation induced by Fe(III) injection into the rat cortex. These data suggest that Fructus Momordicae extract has an antioxidant activity against free radicals and lipid peroxidation.
We analyzed DNAs from 35 gliomas (27 malignant, grades III and IV; 8 less malignant, grades I and II) for loss of heterozygosity (LOH) using microsatellite sequences on chromosome 10 as polymorphic markers. An LOH was found in 8 of 11 (73%) glioblastomas (grade IV) and 4 of 16 (25%) grade III gliomas, but not in the less malignant types. We detected three commonly deleted regions. One was located in a telomeric region of 10p and the others were relatively large regions of 10q. Our results suggested that three putative tumor suppressor genes on chromosome 10 are involved in the malignant progression of gliomas.
A 2-month-old boy presented with a huge choroid plexus carcinoma in the left cerebral hemisphere. Almost total resection of the tumor was achieved, but a remnant abruptly enlarged 5 months later, requiring reoperation. After radical resection of the tumor, intraoperative radiation (10 Gy) was delivered. Postoperative chemotherapy was performed with methotrexate and vincristine, selected on the basis of in vitro chemosensitivity testing. No recurrence of the tumor was detected 18 months after the second operation. Radical surgery with these adjuvant therapies may be a good method to control this aggressive disease in infants.
PURPOSE: To test clinical proton MR spectroscopy as a noninvasive method for predicting tumor malignancy. METHODS: Water-suppressed single-voxel point resolved spectroscopy in the frontal white matter of 17 healthy volunteers and 25 patients with brain tumors yielded spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cre), and lactate. These peak intensities were semiquantitated as a ratio to that of the external reference. The validity of the semiquantitation was first evaluated through phantom and volunteer experiments. RESULTS: The variation in measurements of the designated region in the volunteers was less than 10%. Normal ranges of NAA/reference, Cho/reference, and Cre/reference were 3.59 +/- 0.68, 1.96 +/- 0.66, and 1.53 +/- 0.64 (mean +/- SD), respectively. In 17 gliomas, the Cho/reference value in high-grade gliomas was significantly higher than in low-grade gliomas. Levels of NAA/reference were also significantly different in low-grade and high-grade malignancy. In eight meningiomas (four newly diagnosed and four recurrent), the level of Cho/reference was significantly higher in recurrent meningiomas than in normal white matter or in newly diagnosed meningiomas. CONCLUSIONS: Higher grades of brain tumors in this study were associated with higher Cho/reference and lower NAA/reference values. These results suggest that clinical proton MR spectroscopy may help predict tumor malignancy.
A case is reported of mycotic aneurysm at the petrous portion of the internal carotid artery (ICA) treated with an endovascular procedure. A sixty-seven-year-old male who had suffered from chronic otitis media bilaterally for the last five years showed a sudden onset of massive left otorrhagia. Cerebral angiogram at the eighth day of otorrhagia disclosed a big aneurysm at the petrous portion of the left ICA. The aneurysm was round in shape but its wall was irregular. The angiogram also showed that a stenotic finding of the left ICA just at the proximal portion of the aneurysm and the neck of the aneurysm was not broad. Bone window computed tomography showed a destroyed petrous bone around the left ICA. The results of the Matas test and the Allcock test told us that left ICA occlusion should not be selected as a treatment. We decided that endovascular surgery could be applied as the treatment of this pathology. An endovascular procedure was performed for this pathology one month after the otorrhagia. The aneurysm was successfully embolized using platinum coils beside a part of the neck without occlusion of the parent artery. The patient's postoperative course was not eventful. We concluded that endovascular surgery might be the first choice for the treatment of an ICA petrous portion mycotic aneurysm.
A 59-year-old man presented with a rare cholesterol granuloma of the petrous apex manifesting as headache, left facial dysesthesia, diplopia, left hearing impairment, and left tinnitus. Neurological examination revealed dysesthesia of territory in all divisions of the left trigeminal nerve, left incomplete abducens nerve palsy, left mixed hearing impairment, and left tinnitus. Plain CT scan showed a smoothly marginated mass involving the left petrous apex. The mass was isodense with the brain parenchyma and not enhanced by contrast medium. The mass appeared heterogeneously slightly hyperintense on the T1-weighted MR image and homogeneously hyperintense on the T2-weighted MR image except for the peripheral portion. The mass was not enhanced after intravenous gadolinium DTPA administration. Surgery via a petrosal approach totally removed the mass in the intracranial, extradural space. Histological examination showed typical features of cholesterol granuloma, with cholesterin clefts, hemosiderin deposits, and erythrocytes in non-specific granulation tissue. Cholesterol granuloma most commonly occurs in the middle ear cavity, and rarely in the petrous apex. The characteristic hyperintense appearance of cholesterol granuloma on T1- and T2-weighted MR images is very useful for differentiation from other lesions of the petrous apex and the cerebellopontine angle such as cholesteatoma, mucocele, chordoma, and meningioma. Solid cholesterol granuloma of the petrous apex should be treated by total removal via craniotomy, not by drainage which is commonly performed by otorhinologists.
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Deletions of loci on chromosome 11p have been found frequently in several malignant tumors including gliomas, suggesting the presence of tumor suppressor genes. We analyzed 38 gliomas [26 malignant gliomas (grades III and IV) and 12 less malignant gliomas (grade I and II)] for loss of heterozygosity using microsatellite sequences on 11p as polymorphic markers. Loss of heterozygosity was found in 8 of 26 malignant gliomas (31%) but not in the less malignant gliomas. In the region with loss of heterozygosity, loci on 11p15.5-pter were commonly deleted. Our results suggest that a putative tumor suppressor gene involved in malignant progression of gliomas is located in an approximately 21-cM region on 11p15.5-pter.
We analyzed seven cases of anaplastic ependymoma, focusing on neuro-imaging, histopathology, and mutations of the tumour suppressor gene p53. Five of the seven tumours were supratentorial. All had both cystic and solid components, with fragment calcifications detectable on CT scan. The solid parts of the tumours were imaged as heterogenous hypo- or iso-intense areas with moderate enhancement on T1-weighted magnetic resonance images. Vascularity was not prominent on angiograms except for one case. Histologically, in addition to the WHO criteria, loss of typical cellular architecture, endothelial proliferation, and necrosis were commonly found. A mutation in Exon 5 of the tumour suppressor gene p53 was detected in one anaplastic ependymoma out of five tumours (two benign and three anaplastic ependymomas) examined by PCR-SSPC analysis of genomic DNA followed by direct sequencing. Anaplastic ependymoma typically presents as a calcified cystic tumour in the supratentorial parenchyma or transependyma. Mutations of p53 deserve further investigation to examine their possible role in the oncogenesis and malignant transformation of ependymoma.
BACKGROUND: Together with current advances in neuroimaging techniques, the chance of incidental discovery of unruptured cerebral aneurysms has increased and the selection of their appropriate management remains controversial. To provide current data about management results of patients with incidental cerebral aneurysms, we have made a retrospective review of 139 consecutive patients treated either by surgical or conservative means. METHODS: The surgical indication for each patient was decided, carefully considering several factors respectively, including the surgical difficulty, aneurysm size, patient's age, and medical condition. RESULTS: Forty-nine patients were managed conservatively. Eight (16%) of those conservatively managed patients had intracranial hemorrhage due to aneurysm rupture during the follow-up period (mean, 4.3 years). Seven of these eight patients died from a fatal subarachnoid hemorrhage (SAH). The follow-up data showed that the mean size of aneurysms with late hemorrhage was significantly larger than that of aneurysms without subsequent rupture. It was also confirmed that none of the 26 tiny aneurysms smaller than 4 mm in diameter had ruptured. Ninety patients harboring 119 incidental aneurysms less than 25 mm in diameter underwent surgery. There was no surgical mortality or morbidity in this series. CONCLUSIONS: These excellent surgical results were presumably achieved due to the strict patient selection. In respect to the size of aneurysms, it seems to be justified to recommend surgery for patients with aneurysms larger than 5 mm in diameter.
Magnetic resonance imaging (MRI) of titanium anterior cervical plating systems and their effect on postoperative images were evaluated ex vivo and in vivo. The Synthes and Caspar plating systems were examined by 0.5- or 1.5-T MRI scanners. A phantom study of these implants showed that in spin-echo modes, the plates and screws were seen as areas of signal loss accompanying a marginal hyperintense band, which was more obvious in higher tesla magnetic fields. Distortion of the magnetic field was more prominent in T2-weighted images. In gradient echo mode, the plate and screws were seen as areas of signal loss larger than the size of the metal because of the magnetic susceptibility effect. Postoperative MRI produced images of the implants similar to those observed ex vivo. The Synthes plating system did not interfere with the evaluation of the spinal cord, and the Caspar screw (which penetrated the posterior cortex of the vertebral body) caused a small artifact to be present at the anterior aspect of the spinal cord. In addition to being able to provide fixation of the cervical spine, titanium anterior cervical plates allow superior MRI of the postoperative spine.
A patient with a ganglioglioma in the basal ganglia is presented. An 18-year-old man presented with involuntary movement in his right hand and right homonymous hemianopsia. Computed tomography and magnetic resonance imaging revealed a cystic tumor with an enhancing nodule in the basal ganglia extending into the thalamus. The mass was totally resected by a trans-distal Sylvian approach and was histologically proven to be a ganglioglioma. This is a rare case of midline ganglioglioma in a patient who underwent gross total resection.
A 37-year-old male with mixed glioma was treated with combined radio- and chemotherapy. The amino acid metabolism of the tumor site and normal brain was followed by positron emission tomography using [11C]methionine ([11C]Met). The accumulation of [11C]Met in the tumor decreased during therapy and slightly increased 7 months after completion of the therapy, but then decreased markedly. However, computed tomography revealed no notable changes. The contralateral gray matter also showed a gradual decrease of [11C]Met accumulation. These findings indicate that reduction of amino acid metabolism in the tumor continues after radiochemotherapy although neuroimaging reveals no further morphological changes. Such therapy also has long-term effects on normal brain tissue.
An autopsy case of primary intracranial T-cell-rich B-cell lymphoma in a 69-year-old female is presented. The patient was admitted with a diagnosis of a brain tumor in July 1993 and a month long history of mental deterioration, motor weakness of the right arm and leg, and a tendency toward somnolence. Neurological examination revealed disturbance of consciousness, right hemiparesis, and papilloedema. However, her general physical examination was unremarkable. A CT scan and MR imaging revealed an irregular enhanced mass lesion at the paraventricular deep white matter in the bilateral parieto-occipital lobe. The patient was treated with surgical biopsy of the tumor followed by combined radiotherapy (a total of 50 Gy) and chemotherapy. Following repetitive episodes of remission and exacerbation, the patient expired about seven months after the onset of symptoms. Histopathological diagnosis of the tumor was malignant lymphoma (diffuse medium-sized cell type). In the immunohistochemical study, most of the lymphoma cells had T-cell markers, such as UCHL1. Some of the lymphoma cells were L26-positive. Neither glial fibrillary acidic protein nor neuron specific enolase were reactive with the lymphoma cells. At post-mortem examination, the specimens disclosed diffuse infiltration of medium-sized lymphoma cells. By contrast, most of the lymphoma cells were shown to be positive by the analysis of L26. None of the lymphoma cells exhibited the presence of UCHL1. These immunohistochemical evaluations conform to the criteria of T-cell-rich B-cell lymphoma.