Bilateral superior semicircular canal dehiscence: bilateral conductive hearing loss with subtle vestibular symptoms

Abstract

Superior semicircular canal dehiscence is caused by a bone defect on the roof of the superior semicircular canal. The estimated prevalence when unilateral varies between 0.4% and 0.7% and is still unknown when bilateral. Patients may present with audiologic and vestibular symptoms that may vary from asymptomatic to disabling. We report a case of a 72-year-old Caucasian woman presented to otolaryngology department reporting imbalance, bilateral pulsatile tinnitus, hypoacusis while being very sensitive to certain sounds. Physical examination was unremarkable, except for the Rinne test that was negative in both sides. The patient underwent an audiometry revealing a mild bilateral conductive hearing loss. A temporal bone CT scan was performed which evidenced bilateral superior semicircular canal dehiscence. Cervical vestibular evoked myogenic potentials and electrocochleography confirmed diagnosis. Although rare, superior semicircular canal dehiscence shall be considered in conductive hearing loss with vestibular symptoms.

Bilateral Semicircular Canal Dehiscence Analyzed Using the International Classification of Functioning, Disability, and Health (ICF) Framework: Case report.

“…While conservative treatment is reasonable in milder cases, surgery aimed at resurfacing or plugging the dehiscent canal can relieve symptoms 4 . The described bilateral B-SCD repair surgery improves conductive hearing loss, though vestibular disturbances may persist [3][4][5] . 2016) discussed a case of bilateral SSCD with the Tullio phenomenon, where sound-induced dizziness occurs 9 , as is the case in this report.…”

Predictors of non-primary auditory and vestibular symptom persistence following surgical repair of superior canal dehiscence syndrome

“…Theories to explain residual symptoms include “unmasking” of the contralateral ear in patients with bilateral dehiscence, iatrogenic alteration of the vestibular system or comorbid pathologies, and limitations of modern surgical repair techniques. Several studies have shown worse outcomes in patients with bilateral disease compared to those with unilateral disease, and it has come into question whether patients with bilateral defects receive bilateral repair or only unilateral repair ( 19 , 21 , 23 – 26 ). In addition, our group identified that in female patients, three factors were associated with prolonged recovery: (1) a history of migraines, bilateral SCD, and a larger dehiscence.…”