Surgical approach to Superior Semicircular Canal Dehiscence

Superior Semicircular Canal dehiscence is an infrequent condition. The absence of a bone segment in the semicircular canal is the main characteristic. Some cases presents with typical symptoms as vertigo and conductive hearing loss, making the diagnose easier. We present a 56 year old woman, with instability in noise and closed spaces, without hearing problems. There were no traumatic events, or any otological history. She lived in a remote area of Argentina, and was treated with agoraphobia by a psychiatrist, a local ENT was consulted first, but do to poor CT image quality, and a normal hearing, he was unable to make a good diagnosis . She was then refer to a mayor clinic in Buenos Aires, for new evaluation. She presented with normal otoscopy; a normal audiometry; Cervical vestibular evoked myogenic potentials (VEMP) with abnormal asymmetry in the right ear and hypersensitivity to sound; Videonystagmosgraphic (VNG) with Vertical nystagmus in response of sound; and High Resolution CT was performed. with evident dehiscence of the superior semicircular canal. A middle fossa approach was performed. The defect was covered with bone dust and fascia. After surgery the patient was asymptomatic. Vemp results were normaland she returned to a normal life style.