Bilateral Superior Semicircular Canal Dehiscence Associated with Ehlers-Danlos Syndrome: A Report of 2 Cases.

Background: Superior semicircular canal dehiscence (SSCD) is a rare bony defect in the petrosal temporal bone, creating a new opening between the inner ear and middle cranial fossa. Ehlers-Danlos syndrome (EDS) is an inherited connective tissue disorder characterized by a defect in collagen synthesis. Patients with EDS are more likely to have bony abnormalities, which may predispose them to developing SSCD.

Case Description: We report the cases of 2 women with history of EDS hypermobility type (HT). Both patients presented with bilateral auditory and vestibular symptoms, and computed tomography scan confirmed the presence of bilateral dehiscence in their superior semicircular canals. They underwent elective surgical repair via middle fossa craniotomy and report improvement in their symptoms.

Conclusions: Because of the rarity of both diseases and their pathophysiology, a history of EDS may predispose an individual to developing SSCD. Although further research is necessary, this report aims to improve clinical screening of patients with EDS HT by suggesting an auditory and vestibular evaluation and assessment of pertinent bony abnormalities.