Audiovestibular Findings in a Patient with Superior Semicircular Canal Dehiscence

Superior Semicircular Canal Dehiscence (SSCD) is a rare medical condition of the inner ear leading to auditory and vestibular symptoms. The audiovestibular symptoms exhibited by patients with SSCD can be quite similar to other otologic disorders such as Meniere’s disease, patulous eustachian tube or early otosclerosis. Therefore, diagnosis and treatment of SSCD requires careful correlation of clinical presentations with radiological imaging. In this case report, pre and postoperative findings in a 59-year-old woman with a right sided SSCD are presented. Pre-operative tests showed a mild low frequency pseudo conductive hearing loss in the right ear, lower thresholds on cervical vestibular evoked myogenic potentials (cVEMP), and reduced mean vestibulo-ocular reflex (VOR) gain (0.62) on the right anterior (or superior) canal. Middle cranial fossa approach was used to close the canal dehiscence and the patient’s vestibular symptoms improved immediately after the procedure. Post operatively, pure tone audiometry confirmed closure of the air bone gap, an increased threshold of cVEMP responses and the mean VOR gain decreased from 0.62 to 0.58 in the plugged right superior canal.