Tadashi Tsuchida

Dural arteriovenous malformations of the base of the anterior cranial fossa

SummaryTwo cases of dural arteriovenous malformation at the base of the anterior fossa are reported. The angiographic appearance in both cases is quite uniform and resembles the findings in 12 cases previously reported. Feeders are anterior and/or posterior ethmoidal arteries and the external carotid system also contributes. A drainage vein always shows aneurysmal dilatation of its proximal portion. CT findings are also mentioned and radiological literature reviewed.

Treatment of Moyamoya Disease by Temporal Muscle Graft Encephalo-Myo-Synangiosis’

10 young patients from 7 to 16 years of age with moyamoya disease were treated by temporal muscle graft (encephalo-myo-synangiosis: EMS) for the purpose of increasing extracranial and intracranial collateral circulation. Ischemic cerebrovascular symptoms and signs were encountered in all of them without intracranial hemorrhage. The patients were observed for 6-26 months after the first operation. Transient ischemic attacks disappeared in 4 out of 7 patients, and improved in frequency and duration in the remaining 3. Paresis of the limbs disappeared in 1 patient and improved in 2. In 2 patients, facial palsy disappeared and dysarthria improved as well. Ataxia disappeared in 2 patients, and involuntary movement of the extremities disappeared in 2. There were no ineffective cases clinically. In postoperative carotid angiography, the middle cerebral arteries were visualized clearly to the peripheral portion mainly via the thickened deep temporal arteries, and the abnormal vascular networks in the region of the basal ganglia reduced in size in most of patients. Improvements in intelligence quotient, electroencephalogram and cerebral blood flow were also obtained in several patients, respectively. EMS seemed to be an effective surgical treatment in young patients with moyamoya disease who suffered from cerebral ischemic symptoms.

Rupture of anterior communicating artery aneurysm during transsphenoidal surgery for pituitary adenoma

The case of a 55-year-old man with a nonfunctioning pituitary adenoma associated with an anterior communicating artery aneurysm that ruptured during transsphenoidal surgery is presented. This small aneurysm was not detected on bilateral angiography of the carotid artery before surgery. Computed tomography (CT) scans showed the pituitary adenoma extending to the suprasellar region and the sphenoid sinus. After intracapsular removal of the tumor, cerebrospinal fluid from an intraspinal catheter became bloody and CT scans disclosed massive subarachnoid hemorrhage. Repeated angiography revealed a tiny anterior communicating artery aneurysm, which was clipped on the 37th day after the operation. Risk factors in the procedure of transsphenoidal surgery, especially of a pituitary adenoma with suprasellar extension, are discussed.

Ultrastructural alterations of neuronal cells in a brain stem ganglioglioma.

SummaryA brain stem ganglioglioma in a 9-year-old female was examined ultrastructurally. The constituent neuronal (ganglion) cells displayed various ultrastructural features of neuronal degeneration including Hirano, Lafora and zebra bodies, inclusion-like aggregates of neurofilaments and large dilatations of rough endoplasmic reticulum. Although similar observations have been reported in peripheral neuronal tumors, this is the first reported occurrence in ganglioglioma, an uncommon tumor in the central nervous system. The coincidence of these alterations in the present tumor appeared to be of great interest, however, their exact etiology remained uncertain.

Computed tomography in moyamoya disease.

Eighteen patients with moyamoya disease were examined by computed tomography (CT). At the first examination, CT findings were normal in one patient and abnormal in 17 patients. Significant abnormalities on precontrast CT were characterized by low density lesions in 14, ventricular dilatation in 9, and cerebral atrophy in 11 patients. Postcontrast CT showed the presence of contrast enhanced lesions in three patients. Follow-up examinations were performed in 13 patients, and the following changes on CT were found in 10 of them: increase or development of low density lesions in 10, ventricular dilatation in 4, cerebral atrophy in 5, appearance of a contrast enhanced lesion in 1, and disappearance of the enhanced lesion in 3. The patient with normal findings at the first examination showed a low density lesion on the second examination. The abnormal vascular networks in the region of the basal ganglia were visualized successfully in six examinations of five patients by higher concentration of contrast medium in blood than usual. Abnormal CT findings consisted of those seen in multiple cerebral infarctions and the visualization of the abnormal vascular networks. Computed tomographic findings on these patients showed evolution as seen in clinical and angiographic findings.

Brain Tumors in Tuberous Sclerosis

We report on 4 cases of brain tumors associated with tuberous sclerosis. In each case the tumor was in the region of Monro’s feramen and was associated with ventricular dilatation. Computer tomography

Computed tomographic and histopathological studies of pontine glioma

Correlative study of computed tomography (CT) and pathologic findings was performed in eight cases of pontine glioma. All patients except one had chemotherapy and radiotherapy, with no surgical intervention. On initial CT scans, all patients had hypodense lesions in part or the whole of the pons, and there was evidence of mass effect. Four of eight cases showed contrast enhancement. After chemotherapy and radiotherapy, swelling of the pons and the width of the hypodense areas decreased. The hypodense areas sometimes became isodense in correlation with clinical amelioration. After several months of remission in responding cases, ring-enhanced lesions reappeared at the primary site, together with recurrent neurological signs. Pathological study postmortem was focused on the histological counterparts of the CT findings of central and perifocal hypodense areas and contrast enhancement. In six of seven treated cases, the central hypodense area surrounded by ring enhancement was shown to be coagulation necrosis. Higher cellularity and hypervascularity with glomeruluslike structures of small vessels were generally observed in enhanced areas. The areas diffusely infiltrated by tumor cells, but not enhanced in CT scans, had few abnormal vessels. Tumor cells were seen not only in hypodense areas around the enhanced portion but also in areas far beyond the enhanced portion. Exophytic expansion of tumor was observed in two cases on postmortem examination. One of these was detected by CT scans before death.

CT Findings of Medulloblastoma

Computed tomography (CT) of 11 patients with medulloblastoma was evaluated. 6 of them showed solid, nearly homogenous lesions and definite enhancement after infusion of contrast medium. However, 5 cases showed heterogenous mass lesions composed of the areas of low density and iso- or slightly high density which was attenuated by contrast enhancement. Histological examinations revealed that 2 cases had differentiated medulloblastomas, but the other 3 typical medulloblastomas. It should be reminded in the differential diagnosis of cerebellar tumors of pediatric patients that medulloblastoma can reveal heterogenous mass in CT scan.