Abstract
A 75-year-old man was admitted to our hospital because of repeated transient visual obscurations of greying vision. The transient visual obscurations were caused by rotating his neck or the Valsalva manoeuver, and they recovered in about 30 seconds. A few weeks later, pulsatile tinnitus of the right ear and a dull headache developed. Both ocular fundi showed papilledema, and there was significant intracranial hypertension on cerebrospinal fluid examination. He was diagnosed as having right sigmoid sinus thrombosis and a dural arteriovenous fistula with a rapid arteriovenous shunt from the right ascending pharyngeal artery and the right occipital artery to the right transverse sinus. Anticoagulant therapy was started, and coil embolization was performed. The transient visual obscurations, headache, and tinnitus improved dramatically after the procedure. We hypothesized that the transient visual obscurations were triggered by rotating the neck or performing the Valsalva manoeuver as they both increase the pressure of cerebrospinal fluid, inducing transient optic nerve ischemia and visual obscurations under mild intracranial hypertension. Transient visual obscurations are an important initial symptom of intracranial hypertension.
