Dural arteriovenous fistula involving the posterior condylar canal.

Although dural arteriovenous fistulas (DAVFs) occur in any structure that is covered by the dura mater, DAVFs at the posterior condylar canal have not been reported. We present a DAVF that involves the posterior condylar canal and drains into the posterior condylar vein and the occipital sinus, which was treated by selective transvenous embolization. Knowledge of venous anatomy of the craniocervical junction and careful assessment of the location of the arteriovenous fistula can contribute to successful treatment.

Differential distribution and expressions of collagens in the cerebral aneurysmal wall.

To investigate the role of collagens in the formation and rupture of cerebral aneurysms, we examined the distribution and synthesis of vascular collagens in the wall of normal human cerebral main trunks and of cerebral aneurysms using immunohistochemistry and in situ hybridization techniques. Fifteen cerebral aneurysmal walls were resected at operation; control cerebral main trunks were obtained from seven autopsy cases. Semiserial sections from the specimens were subjected to immunofluorescence and immunohistochemical staining with antibodies to collagen types I, III, IV, V, VI, desmin and alpha-smooth muscle actin. In addition, type III collagen mRNA was examined by in situ hybridization. Immunohistochemical study showed that all collagen types were grossly preserved in the aneurysmal wall, although the distribution patterns were different for each collagen. The distribution of major fibrillar collagen types I and III was more diffuse and homogeneous in the luminal layer of the aneurysmal wall than the media of the control artery, although the intensity of immunohistochemical staining was weaker in the abluminal layer of the aneurysmal wall than the adventitia of the control artery. Collagen types IV and V were distributed more sparsely in the luminal layer of the aneurysmal wall than the media of the control artery. Collagen type VI was noted in the luminal as well as the abluminal layer of the aneurysmal wall, whereas it was located exclusively in the adventitia of the control artery. In situ hybridization showed that the signal for collagen type III mRNA on fibroblastic and smooth muscle cells was higher in the aneurysmal walls than the control arteries, suggesting up-regulation of type III collagen transcription in the cerebral aneurysmal wall. The study of the distribution and synthetic regulation of various types of collagen in the aneurysmal wall may be essential for understanding the formation of the aneurysmal wall and its protection against enlargement or rupture.

Differential expressions of collagen types IV, III, and I during the development of invasive trophoblasts in rats.

We examined the differential expressions of collagen types IV, III and I in the developing feto-maternal placental tissue of pregnant rats by a combination of in situ hybridization and immunohistochemistry. At day 9.5 of gestation, polygonal invasive cytotrophoblasts from the ectoplacental cone, which was modifying the maternal central artery, revealed intensely expressed alpha 1 (IV) and alpha 1 (III) collagen mRNAs. The localization patterns of these translated products, collagen type IV and procollagen type III, were slightly different in the invasive cytotrophoblasts. Collagen type IV densely deposited intracellularly and intercellularly in the maternal central artery and in the thickened basement membranes of the cytotrophoblasts. However, expression of alpha 1 (I) collagen mRnA and procollagen type I was hardly detectable in the cytotrophoblasts. At day 13 of gestation, a high level of alpha 1 (IV) collagen mRNA was expressed in the cytotrophoblastic cell layer (trophospongium) and in the invasive large cytotrophoblasts. A moderate level of alpha 1 (III) collagen mRNA was also expressed mainly in the cytotrophoblasts, while alpha 1 (I) collagen mRNA was expressed at very low levels. Interestingly, procollagen type III failed to show linear immunoreactivity in the subepithelial extracellular matrix beneath the maternal artery with the invasive cytotrophoblasts. Additional quantitative analyses of these type IV, III, and I collagen mRNA levels in in situ hybridization experiments between several cell types also revealed significant differences individually. Electron-microscopic study detected no cross-striated collagen fibers in the thickened basement membrane-like structures adjacent to the invasive cytotrophoblasts. Fibrillar and basement membrane collagen gene expressions, their protein syntheses, and the processing of these procollagens seems to be developmentally regulated in the invasive cytotrophoblasts during the organization of feto-maternal placental tissue. The remodeling of the maternal central artery by the invasive cytotrophoblasts is important for ensuring the adequate blood supply to the developing placenta and fetus.

Reconstruction of the posterior inferior cerebellar artery in the treatment of giant aneurysms. Report of two cases.

Two techniques of revascularizing the posterior inferior cerebellar artery (PICA) during aneurysm surgery are presented. One involves transposition of the PICA to the vertebral artery proximal to the aneurysm using a superior temporal artery (STA) as a graft. This is used in cases in which the PICA has branched off from the wall of the giant vertebral artery aneurysm. The other technique involves end-to-end anastomosis of the PICA after excision of a giant distal PICA aneurysm located at the cranial loop near the roof of the fourth ventricle. The reconstructions of the PICA described here are surgical procedures designed to preserve normal blood flow in the PICA in patients treated for giant aneurysms involving that artery.

Malignant trigeminal schwannoma associated with xeroderma pigmentosum--case report.

A 46-year-old male with xeroderma pigmentosum developed an intracranial malignant schwannoma originating from the second branch of the left trigeminal nerve. The tumor was subtotally removed and postoperative radiation therapy given, but the tumor recurred twice over 3 years, and extended to the third branch of the left trigeminal nerve and the ipsilateral facial nerve. Radical surgery and radiation therapy finally achieved a cure. This is the first case of malignant trigeminal schwannoma with xeroderma pigmentosum, although various other internal neoplasms including central nervous system tumors have been reported in xeroderma pigmentosum patients. Radical surgery and radiation therapy are effective for treating intracranial malignant schwannoma. Radiation therapy is considered safe for xeroderma pigmentosum patients.

Anaplastic astrocytoma with extracranial extension--case report.

A 44-year-old female presented with anaplastic astrocytoma of the right temporal lobe which had destroyed the skull base and extended extracranially. Histologically, the extracranial portion of the tumor was astrocytoma with desmoplastic reaction. She was treated by subtotal tumor removal, radiation therapy, and chemotherapy, but died of meningeal dissemination. Spontaneous extradural extension of malignant glioma is rare and always fatal.

[Spinal extradural angiolipoma: a case report].

This 60-year-old man had been well until four years prior to admission, when he developed slowly progressive weakness of the lower extremities. On admission he was found to have a spastic paraparesis, sensory disturbance below the level of T10 and mild sphincter dysfunction. Conventional myelography and CT myelography demonstrated an epidural mass located from T5 to T8 vertebral level. MRI revealed that the epidural mass was fusiform and markedly enhanced by the contrast medium. Laminectomy was performed and a fibrous tumor red in color was subtotally removed. Histological findings were consistent with those of angiolipoma. Angiolipoma is a rare tumor in the central nervous system and is regarded as a clinical entity different from a spinal lipoma. Occurrence of angiolipoma in the central nervous system has been reported in 40 cases in the world literature. Thirty nine cases of them occurred in the spinal canal, especially in the dorsal epidural space of the thoracic region. The fusiform shape demonstrated in this case might also be characteristic of angiolipoma in this region.

[Primary malignant lymphoma in the dura and subdural space along the superior sagittal sinus. Case report].

A 56-year-old male with a 11-month history of late-onset epilepsy was hospitalized because of status epilepticus. The physical examination and laboratory data were normal. Neurological examination revealed weakness of the right leg. Coronal computed tomography showed a mass of slightly high density in the bilateral parietal convexity, with homogeneous enhancement by contrast medium. Magnetic resonance imaging disclosed an en-plaque epidural tumor in the parietal region along the superior sagittal sinus, which was normointense on T1- and T2-weighted images. Conventional and digital subtraction angiography showed an avascular mass between the superior sagittal sinus and the inner table of the skull at the parietal region. The mass was thought to be situated in the parietal epidural space. On surgery, however, the tumor was found to be located mainly in the dura and subdural space. The histological diagnosis was malignant lymphoma of the B cell type. Ga-scintigraphy, physical examination, and bone marrow and peripheral blood examinations disclosed no systemic abnormalities. Therefore, the tumor was interpreted as a primary intracranial malignant lymphoma. Reports of primary intracranial malignant lymphoma have been increasing, but most have been located in the cerebrum. The dural-subdural location in this case is evidently rare.

[Lipid metabolism of the patients with subarachnoid hemorrhage due to ruptured intracranial aneurysm--with special reference to the occurrence of cerebral angiospasm].

Lipid metabolism, which can be an important factor for arteriosclerosis, was studied in the patients with subarachnoid hemorrhage due to ruptured intracranial aneurysm. Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride and Atherogenic Index were determined in 131 patients, who were admitted to our hospital since May, 1984 to March, 1986. Those results were analyzed in relation to the grading on admission, outcome and especially cerebral angiospasm. Serum levels of LDL-cholesterol and Atherogenic Index tended to correlate with the grading on admission. Total cholesterol, Atherogenic Index well correlated with the recovery of the patients and the activity of daily life. In this study, we especially examined the relationship with cerebral angiospasm. The results suggested that the role of cerebral arteriosclerosis caused by disturbance of lipid metabolism was rather negative to the development of cerebral angiospasm after subarachnoid hemorrhage.