Keishi Kobayashi

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.

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.

Metastatic ameloblastoma of the skull

A rare case of a metastatic ameloblastoma of the skull in a 29-year-old woman is reported. An ameloblastoma of the left mandible underwent histological malignant transformation following repeated operations and eventually metastasized to the left temporoparietal region of the skull. The skull tumor showed osteolytic change and marked vascularity in roentgenological examinations. It was removed totally. The histological findings were similar to those of the tumor of the left mandible. The route of the metastasis was considered to be via the left external carotid artery.