Superior Semicircular Canal Dehiscence Syndrome: Review of Clinical Manifestations in Adults and Children

Objective: This report aims to determine the clinical manifestations and management of patients with superior semicircular canal dehiscence syndrome (SSCDS). Methods: Study Design: Case series. Setting: Tertiary hospitals and private clinics Participants: Out of 30 patients with vestibular vertigo or otologic symptom, 14 patients were diagnosed with SSCDS based on high resolution computed tomographic scan (HRCT).  The demographic features, incidence of specific signs and symptoms and management of these patients were described, including the audiograms, vestibular evoked myogenic potential (VEMP) responses and ancillary tests. Results: Vertigo was the most common vestibular symptom of SSCDS. Tullio phenomenon was elicited in 50% of patients with confirmed dehiscence on HRCT scan. Low frequency (250 Hz and 500 Hz) air-bone gap was noted in 21.4% of patients. Lowered VEMP responses were also noted in 66.7% of patients with confirmed SSCDS. Severity of symptoms may determine its management. Conclusion: The diagnosis of SSCDS does not conform to a specific clinical presentation or audiologic result thus good clinical correlation is needed in order to raise suspicion of the disease and prompt the clinician to order confirmatory imaging by computed tomographic scan or magnetic resonance imaging. The presence of this syndrome in a proportion of children that is greater than previously reported needs further study as these children may be genetically predisposed to have thinned out superior semicircular canals that eventually become dehisced albeit at an earlier age. Key words: Superior semicircular canal dehiscence, pure tone audiometry, vestibular evoked myogenic potential