[The natural history of a dural arteriovenous fistula associated with sinus thrombosis: a case report].

The patient, a 52-year-old man, complained of vertigo. CT scan revealed right cerebellar infarction and he was admitted to our hospital. MRI revealed a fresh thrombus in the right transverse sinus and angiography revealed the occlusion of the right transverse-sigmoid sinus. He complained of vertigo again and he was re-admitted to our hospital 4 months after the first admission. Angiography revealed a dural arteriovenous fistula (DAVF) of the right transverse-sigmoid sinus fed by the right occipital artery and the right transverse-sigmoid sinus was found to be recanalized. The angiography which was carried out one year after the second admission, revealed also an enlarged DAVF fed by the left occipital artery and the right transverse sinus was occluded again. There are two theories about the pathogenesis of DAVF. One is that it is congenital and the other that it is acquired, but it is still controversial. Our case suggested that sinus thrombosis induced DAVF initially and the DAVF induced sinus thrombosis secondarily. The causal relations between DAVF and sinus thrombosis probably changed inversely over a long term and, when we discuss the pathogenesis of DAVF, we must understand the natural history of DAVF starting from the occurrence of sinus thrombosis.