Transverse-sigmoid sinus dural arteriovenous fistula diagnosed after convulsions

A 61-year-old healthy man drank 60 g of Japanese sake. One hour later, tonic convulsions occurred for 3min, after which he lost consciousness. He was transported by ambulance, but he fully regained consciousness immediately after being examined. No obvious abnormalities were observed on non-contrast head computed tomography images, and the cause of the convulsions and impaired consciousness was considered to be heavy alcohol consumption. Fluid replacement was administered, and he was admitted to the hospital. On the next day, tonic convulsions in both arms and legs lasting several minutes and 20min of impaired consciousness were observed. Magnetic resonance imaging (MRI) was performed, revealing a high intensity region in the left cerebellar dentate nucleus, the left cerebellar hemisphere, and the left parietal cortex (Fig. 1a). Additionally, magnetic resonance angiography (MRA) of the head revealed an abnormal blood vessel intersecting from the left middle meningeal artery and the left occipital artery to the left transverse-sigmoid sinus (Fig. 1b). Angiography led definitive diagnosis of a left transverse-sigmoid sinus dural arteriovenous fistula. The proximal and distal ends of the transverse-sigmoid sinus were occluded, and so transvenous