Biomedical subjects
Publications and source records attributed to M Tsuru.
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Twelve cases of cerebellar astrocytoma experienced in the Department of Neurosurgery, Hokkaido University School of Medicine were examined primarily for tumor stain and pathological tumor circulation by angiography. In addition, comparison on neuroradiological findings between cerebellar astrocytoma and hemispheric supratentorial astrocytoma (low-grade) was carried out, and neuroradiological differential diagnosis of cerebellar astrocytoma and cerebellar hemangioblastoma was discussed on the basis of the present results and those which were already reported by other investigations and the authors. The results are as follows: 1) Tumor stain was observed in only one case. A tumor was demonstrated as an avascular mass in the remaining 12 cases. 2) Demonstration of cerebellar astrocytoma as hypovascular or avascular masses was related to their low-grade malignancy in histology and cystic nature in gross appearance, as already pointed out. Furthermore, the present study suggested that mural nodules of cystic lesions should have certain weight and sizes so that they could be demonstrated as tumor stain. 3) Abnormal findings concerning tumor circulation were mostly limited to the cases with tumor stain. Early filling veins were not found in any case. Neither feeding artery nor draining vein was clearly identified in some cases. In addition, the abnormal vessels lacked hypertrophic and tortuous changes. 4) In the supratentorial region, five of the 12 low-grade astrocytoma exhibited abnormal tumor stain and tumor circulation by cerebral angiogram and we think that supratentorial and posterior fossa astrocytoma must usually exhibit different pathological tumor circulation by cerebral angiogram, since each group has distinctive clinical and biological characteristics. 5) CT was performed in 7 of 13 cases. It appeared to be more useful than cerebral angiography in the morphological diagnosis Especially in cystic tumors, CT produced minute information concerning peritumoral edema, enhancement of margin of cystic astrocytoma after intravenous contrast medium, and marginal enhancement with layering in the dependent part of the cyst. 6) Neuroradiological different diagnosis of cerebellar astrocytoma and cerebellar hemangioblastoma by CT was difficult in our cases of cystic tumors. However, both tumors were differentiated from each other with ease by tumor stain and tumor circulation in cerebral angiography, since cerebellar astrocytoma was lacking in abnormal vessels, whereas cerebellar hemangioblastoma was marked by many abnormal vessels. Thus, we concluded that cerebral angiography is superior to CT in differential diagnosis between cerebellar astrocytoma and cerebellar hemangioblastoma.
We reviewed 27 patients with developmental anomalies in craniovertebral junction, and special attention was paid to computed tomography (CT) findings in congenital atlantoaxial dislocation (AAD), basilar invagination and Chiari malformations. In ADD, CT clearly demonstrated the relationships of the atlas to the axis in axial plane. Four major types were distinguished; anteroposterior (6 cases), transverse (0 case), anteroposterior-transverse (4 cases) and rotatory (5 cases) dislocations. It was feasible by CT to analyse the pathomechanics in each individual with AAD. Soft tissue wad was shown on the posterior aspect of the odontoid in 7 out of 15 patients with AAD. Those two features, pathomechanics of AAD and intraspinal soft tissue wad, were felt to be important for patient's symptomatology. Basilar invagination presented in no patient as a single deformity and was always associated with other bony and neural abnormalities in 14 patients. Basilar invagination might be suggested of its existence in such a case as CT showing; (1) the odontoid at or above the level of the foramen magnum, (2) distinctive margin of the foramen magnum above the bottom of the posterior fossa, and (3) the posterior arch of the atlas at the same level as foramen magnum. Nevertheless, it is essential to confirm occipital hypoplasia by using either reformatting CT images in coronal and sagittal plane or conventional tomography; whereas high resolutional CT machine provides new dimension for demonstration of bony details. In Chiari malformations, plain CT scanned by high resolutional machine often makes it possible to delineate caudal migration of the cerebellar tonsils, so that it may be a choice of examination as a screening of the anomaly. In addition, metrizamide CT clearly demonstrated caudal migration both of cerebellar tonsils and medulla oblongata. Therefore, CT apparently exceeds other diagnostic modalities in evaluating this anomaly.
Atlantoaxial dislocation has received little attention in many studies of spinal deformity in neurofibromatosis. The only four cases of atlantoaxial dislocation associated with neurofibromatosis has been previously reported in the literature. We reported three rare cases of atlantoaxial dislocation associated with neurofibromatosis. These characteristics in roentgenogram were as follows; (1) marked narrowing of sagittal diameter at C1 level without instability (instability index 0%) (2) association with other mesodermal dysplasia, such as posterior vertebral body scalloping, vertebral body dysplasia, dural ectasia etc. Neurofibromatous tissue was found around the anterior region of the odontoid process in one of our three patients. We speculate that atlantoaxial dislocation in neurofibromatosis may be due to mesodermal dysplasia. On the other hand, a neurofibroma was found around the anterior region of the odontoid process in our third case. Therefore, there is a possibility that atlantoaxial dislocation in the instance was caused by the neurofibroma involving transverse atlantal ligament.
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Previous in vivo and in vitro studies have indicated that the Km for phenytoin hydroxylation is about 30 microM. Yet, the drug shows dose-dependent kinetics suggesting a Km of about 5 microM. The present studies indicate the discrepancy is not due to active transport of the drug in the hepatocyte or a decrease in the Km due to the low pO2 of the portal vein leading to uncompetitive inhibition. Studies in both hepatocytes and microsomes indicate the presence of a high affinity hydroxylase with a Km of 2 to 5 microM. These data suggest that this enzyme is the one primarily involved in the metabolism of phenytoin.
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We reported two cases of germinoma originating in the basal ganglia among the 50 cases of intracranial germinoma which were experienced at the Department of Neurosurgery, Hokkaido University Hospital. (Case 1) A 8-year-old boy was admitted to our hospital in October 1977, because of precocious puberty and left hemiparesis. Plain CT showed an irregularly-defined high density lesion in the right basal ganglia, which had several low density spots and was moderately enhanced on contrast CT. Endocrinological examination by radioimmunoassay revealed abnormally high level of serum luteinizing hormone and scanty level of serum follicle stimulating hormone. Beta-subunit of human chorionic gonadotropin (HCG) showed 46.4 ng/ml. Following radiation, the lesion on CT disappeared and beta-subunit turned to be in the normal range. It was concluded that the precocious puberty was due to hypersecretion of HCG by the tumor. About 2 years after the first admission, the tumors were disseminated to the spinal cord, followed several months later by the intracranial recurrence. The neurosurgical exploration was performed to both intracranial and spinal tumor lesions, which were proved to be germinoma by histological examination. Postoperative course was uneventful without recurrent signs. (Case 2) A 10-year-old boy was admitted to our hospital with 6-month history of right hemiparesis in February, 1979. CT at the first admission disclosed a slight high density lesion in the left basal ganglia, which had low density area suggesting cyst formation and was moderately enhanced on contrast CT. CT after one year showed multiple cysts in the tumor and displacement of neighboring structures. In February, 1980, a piece of the tumor was removed under bifrontal craniotomy and histologically diagnosed to be germinoma. Following radiation, the tumor disappeared on CT and his clinical features improved. In August, 1981, no recurrent signs were noted. From our 2 cases and review of the literature, it can be concluded that germinoma originating in the basal ganglia is rare and have high radiosensitivity as well as germinoma arising in the other sites, and common symptoms and signs are hemiparesis in all cases, not accompanied by intracranial hypertension in the early stage.
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Anterior decompression and fusion for treating ossification of the posterior longitudinal ligament of the cervical spine was performed in 12 patients. The central part of the vertebral body and the ossified area of the posterior longitudinal ligament were removed by means of a microrongeur and an air drill. The defect was filled with a long bone graft taken from the ilium. The operative results were excellent. Marked improvement of radicular and spinal cord signs was seen in all 12 cases. Three vertebral bodies were fused in one case, four in nine cases, and five in two cases. The highest level of fusion was C-2 and the lowest was T-1. It is considered that any ossification of the ligament below the C-2 level can be removed via an anterior approach as long as no more than five vertebral bodies are involved. Spinal computerized tomography was valuable in providing more detailed information about the stenotic spinal canal and the shape of the ossified ligament.
Tumor "stain" and pathological tumor circulation were investigated mainly by cerebral angiography in 8 patients of cerebellar hemangioblastoma who were hospitalized in the Hokkaido University Hospital and considered to be suitable for this study. The results are presented with some speculation in this paper. (1) Tumor stain was found in all of the 8 cases. (2) Histologically all 8 cases were composed of endothelial cells with numerous vascular channels. The characteristic tumor "stain" in cerebellar hemangioblastoma was supposed to be closely related to the histologic features. (3) Review of the reports published on tumor stain indicates that tumor staining patterns have been classified into 3 to 5 types. Similar items were established in all the classifications. (4) The 8 cases were divided into 4 types: cystic type, cystic and solid type, solid type, and multiple type based on macroscopic natures of the tumor. Tumor staining patterns in angiography were also tentatively classified into types 1 to 4 according to the natures of the tumor. (5) Concerning pathological tumor circulation, (a) the time of appearance of tumor "stain" was long; (b) early filling veins in the tumor were found in 4 of the 8 cases; (c) almost all feeding arteries had one or two branches; (d) arteries originating from meningeal vessels were enlarged in 2 cases and angiography of the external carotid artery was useful for their identification; and (3) draining veins were enlarged more markedly than feeding arteries and were mostly a single superficial vein. (6) CT was performed in 4 of the 8 cases. It was compared with vertebral angiography regarding diagnostic capability in consideration of the published reports. Vertebral angiography was superior to CT in (a) verification of the presence of multiple lesions in cerebellar hemangioblastoma and (b) differential diagnosis between cerebellar astrocytoma and hemangioblastoma.
Cerebrovascular moyamoya disease is a chronic occlusive disease of unknown etiology, 90% of which are found among Japanese. At the 3rd International Symposium on Microsurgical Anastomosis held in 1976, Kikuchi and Kawasawa reported an preventing effect of STA-MCA bypass surgery for ischemic episode of this disease. Thereafter, they proposed a new operation to place temporal muscle on the brain surface, namely Encephalo-Myo Synangiosis (EMS), for the patients lacking suitable recipient artery of middle cerebral artery territory. The authors report clinical experience of eight STA-MCA anastomosis, two STA-MCA anastomosis with EMS and one EMS performed on six cases with moyamoya disease. The follow up period after operation ranged from seven to 18 months. Four patients had excellent results, and one good. One died of subdural hematoma of non-operated side seven months after contralateral bypass procedure. STA-MCA bypass surgery is an effective treatment for moyamoya disease. Also, EMS is expected to be a replaceable surgical procedure for STA-MCA bypass under absence of suitable recipient artery.
METHODS: Either EMT Head Scanner, CT 1010 (slice thickness 10mm) or EMI Body Scanner, CT 5005 (slice thickness 13mm) was used. The concentration of metrizamide was 170-250 mgI/microliter and the amount was 7-10 microliters. Either lumbar puncture or lateral C puncture was made. MATERIALS: 26 cases were included in this study. 1) disc disease: 11 cases, 2) spinal cord tumor: 6 cases, 3) Arnold-Chiari malformation: 3 cases, 4) atlantoaxial dislocation: 3 cases, 5) ossification of the posterior longitudinal ligament (associated with ossification of the ligamentum flavum): 2 cases (1 case), 6) spinal foreign body (acupuncture needle): 1 case. RESULTS: 1) CT metrizamide myelography visualizes the subarachnoid space and makes it possible to know the lesion in the spinal canal in relation to the spinal cord in transverse plane. 2) It is difficult to determine the exact level of the lesion in axial plane. 3) The present technique does not allow to visualize the root sleeves. 4) It is difficult to delineate a compression of the subarachnoid space by small localized lesions (esp., disc diseases) due to overlapping the patent adjacent subarachnoid space within a slice 10 mm to 13 mm thick.