Insights from therapeutic strategies in superior canal dehiscence syndrome: is there anything beyond surgical treatment?

Introduction: Superior semicircular canal dehiscence syndrome (SCDS) is a clinical syndrome that can cause instability, vertigo, fullness, tinnitus, autophony, hearing loss (HL), Tullio phenomenon, or Hennebert's sign. Historically, surgery has been the primary treatment reported in the literature, although some medical treatments may also be proposed. This study aims to comprehensively characterize SCDS in a large series of patients from clinical, auditory, and vestibular perspectives, and explore medical alternatives to conventional surgical treatments by comparing their results and evolution.

Methods: A retrospective observational study was designed in a tertiary care center. Audiovestibular tests evaluated included pure-tone audiometry (PTA), VEMPs, video head impulse test (vHIT), and CT imaging. Improvement was assessed over a follow-up period of up to 6 months for seven cardinal symptoms to verify the efficacy of the proposed treatments.

Results: 71 subjects with SCDS and a mean age of 51.20 ± 12.22 years were included in the study. The most common symptom found in our sample was instability in 31 patients (43.66%), followed by aural fullness or tinnitus in 29 subjects (40.85%). 36 patients (43.66%) received medical treatment, with 28 of them (77.78%) showing symptom reduction. Surgical repair was indicated in five patients, with all showing symptom improvement. Statistically significant improvement (p < 0.05) was observed, particularly with surgical treatment and acetazolamide, in both symptoms and objective tests such as pure-tone audiometry and VEMPs.

Conclusion: SCDS shows significant similarities with other otic capsule dehiscences. It is essential to perform VEMPs and CT scans to complete the diagnosis, which is usually accompanied by clearly recognizable clinical criteria. Surgery for SCDS is effective, safe, and without complications. However, in cases where symptoms are mild to moderate, addressing this condition with medical treatment using diuretics such as acetazolamide has shown promising results.