Superior Semicircular Canal Dehiscence Syndrome with a Patulous Eustachian Tube

Abstract

Superior semicircular canal dehiscence syndrome SSCDS is important to differentiate from patulous eustachian tube PET. We report a 50 year old woman with SSCDS accompanied by PET who presented with dizziness. She visited our hospital with a month's history of gradually progressive dizziness associated with left autophony. She also gave a history of having suffered from bilateral autophony for the previous one year that was relieved by lying down in the head down position. The diagnosis of PET was aided by positional change eustachian tube function testing, which revealed no show sound or pressure induced eye movements. Ocular VEMP testing to ACS 2 kHz tone bursts revealed a large amplitude of 46 μV on the left side and a low threshold of 80 dBSPL. CT revealed superior anterior semicircular canal dehiscence on the left. We administered conservative treatment for the PET. As the PET improved, the dizziness also resolved.