Diagnosis and management of bilateral and multiple semicircular canal dehiscence: a case report

Semicircular canal dehiscence (SCCD) is a rare inner ear disease caused by an anatomical defect in the bony covering of the semicircular canal (SCC). This condition most commonly affects the superior semicircular canal, and less frequently involves multiple canals in one or both ears. Although the clinical and physiological features of a single SCCD are well known, there are only a few reported cases of multiple semicircular canal dehiscences. Thus, their clinical and physiological characteristics require further investigation. We present the case of a 59-year-old male patient of Moroccan ethnicity who presented with chronic imbalance and mild dizziness, induced by loud noises. As a dentist, he experienced extreme difficulty while drilling his patients' teeth, exhibiting nausea, tachycardia, and sweating. Clinical oto-vestibular and neurological examinations, tonal audiometry, and videonystagmography (VNG) revealed peripheral vestibular syndrome. Bilateral multiple SCCD was subsequently confirmed using high-resolution computed tomography imaging of the temporal bone. The clinical manifestations in this case were primarily neurovegetative symptoms of vestibular dysfunction. Functional assessments revealed vibratory-induced down-beating nystagmus and left preponderance on caloric testing. Computed tomography (CT) imaging confirmed dehiscence in the posterior and superior semicircular canals on the right side, and posterior semicircular canal dehiscence on the left side.