[A case of visual perseveration attack caused by transverse-sigmoid sinus dural arteriovenous fistula]

A case of visual perseveration attack in the right superior quadrantic visual field caused by left transverse-sigmoid sinus dural arteriovenous fistula (AVF) was reported. A 75-year old right-handed man noticed that when he saw an object, the image sometimes persisted even after he looked away or the object was removed. The palinoptic images always appeared in the right superior quadrant visual field, consisted of a row of multiple objects all identical to the real one in shape, and were accompanied by photopsia. The palinoptic images disappeared within a few minutes. He was neurologically normal and showed no hemianopia or quadrantanopia on admission. EEG showed no epileptic discharge. CT scanning of the brain revealed a small high density area in the left occipital lobe. MRI demonstrated hyperintensity in the left inferior occipital lobe corresponding to the lower part of Brodmann's areas 18 and 19 on T2 weighted image and flow-voids caused by the dilated left occipital artery. 99mTc-ECD SPECT disclosed a decrease of regional cerebral blood flow in the left occipital lobe. Cerebral angiography revealed dural AVF fed by three branches of the left occipital artery and another branch of the left ascending pharyngeal artery with retrograde drainage into the left transverse sinus, sigmoid sinus, and dilated cortical veins. The left transverse and sigmoid sinuses were occluded. Visual perseveration disappeared following the treatment of the dural AVF by transarterial embolization. Because the lesions on MRI and SPECT improved after the treatment, these lesions were considered to represent not infarction but vasogenic edema due to venous congestion. We emphasized the role of the left inferior occipital lesion including the secondary visual cortex (Brodmann's areas 18 and 19) as the cause of visual perseveration in the right superior quadrantic visual field.