Occlusion of the round window: A novel way to treat hyperacusis symptoms in superior semicircular canal dehiscence syndrome

摘要

Background: Conductive hyperacusis in superior semicircular canal dehiscence syndrome occurs due to the presence of a 'third window' created by the dehiscence. Reversible blocking of the round window can, in theory, cause a reduction in the compression-related volume displacement, and thereby minimise symptoms of conductive hyperacusis. This study describes a technique of permeatal blocking of the round window. Method: The tympanomeatal flap is elevated and the round window niche is identified. The round window membrane is subsequently identified and occluded with bone wax, muscle and fascia, in three separate layers. Finally, the tympanomeatal flap is reflected, and an ear wick is inserted. Results: Two patients who underwent the procedure reported a reduction in symptoms. Importantly, no Tullio phenomenon was reported post-operation. Conclusion: Blocking of the round window can be used to control symptoms of superior semicircular canal dehiscence syndrome in patients who present solely with symptoms of conductive hyperacusis. This technique provides an alternative to resurfacing techniques. The procedure is simple to perform, reversible and can be undertaken as day-case surgery.