Dehiscence of the Superior Semicircular Canal Syndrome

Abstract

Superior semicircular canal dehiscence (SCD) syndrome was initially reported by Lloyd Minor in 1998 as vertigo, oscillopsia, or both, which were evoked by intense sounds (Tullio's phenomenon) or stimuli that caused changes in middle-ear and/or intracranial pressure. The evoked eye movements had vertical and torsional components. Most of these patients also had experienced chronic disequilibrium that was often the most debilitating symptom. Since then, other symptoms such as autophony, aural fullness mimicking eustachian tube dysfunction (including relief with Valsalva or supine position), and pseudoconductive hearing loss have been added to the symptomatology of this syndrome. In our experience, pulsatile tinnitus and persistent motion intolerance when hearing relatively loud sounds have been other symptoms of this syndrome. Some patients describe similar symptoms with straining, coughing, or exertion. Men and women are afflicted equally.