Dural arteriovenous fistula causing complex visual hallucinations without an anopsia

Abstract

We report the case of a 76-year-old woman who presented with recurrent episodes of complex visual hallucinations in her right visual field without an anopsia. The electroencephalogram showed sharp transients in the left parietotemporal region with phase reversals at T5 and P3. FLAIR MRI revealed hyperintense lesions in the left temporo-occipital lobe, located mainly in the left inferior temporal lobe. Cerebral angiography revealed an arteriovenous shunt from the left occipital artery to the left transverse sinus with cortical venous reflux. The complex visual hallucinations were resolved after transarterial embolization. We therefore hypothesize that this patient’s complex visual hallucinations were caused by epileptic seizures or changes in cortical blood flow caused by the cortical venous reflux from the arteriovenous fistula. In general, epileptic hallucinations expand into the bilateral visual field. We reveal that in rare cases, complex visual hallucinations can also be limited to the unilateral visual field without an anopsia. Additionally, we reveal that a dural arteriovenous fistula can cause visual hallucinations without hemianopia.