Another etiology for vertigo due to idiopathic lateral semicircular canal bony defect.

Superior semicircular canal dehiscence syndrome (SSCDS) is a set of symptoms, related to vestibular and/or auditory, which dues to a dehiscence of bone at the superior semicircular canal. We reported an extremely rare case with idiopathic bony dehiscence at the lateral semicircular canal, which presents the similar symptoms with SSCDS, and performed a pertinent literature review. A 76-year-old male patient complained experiencing vertigo and autophony caused by loud noises, with a sign of horizontal eye movements for the stimuli of loud noise to his right ear. HRCT scanning presented a solitary 2.0mm bony defect at the right lateral semicircular canal. For a chief complaint of sound-/pressure-induced vertigo and/or oscillopsia and/or auditory symptoms, semicircular canal dehiscence syndrome should be considered. Then the doctor could presume the location of the dehiscence via the way of the oscillopsia. If the dehiscence lying the lateral semicircular canal, in clinical radiology, both axial and coronal images to be produced though the lateral semicircular canal plane in a parallel and perpendicular way should be carefully assessed for making diagnosis.