2021 Volume 156 Pages 180-185
Subjects with superior semicircular canal dehiscence syndrome (SCDS) show various characteristic symptoms, including hyperacusis, autophony, and pressure-induced vertigo. SCDS should be differentiated from patulous Eustachian tube (PET), since the auditory symptoms of the two conditions could be similar. Herein, we report a case of SCDS who had been misdiagnosed as having PET at a previous ENT clinic. A 46-year-old male patient was referred to our hospital from an ENT clinic, as he had not responded satisfactorily to treatment for PET. While he showed symptoms that could be consistent with the diagnosis of PET, sonotubometry and tubo-tympano-aerodynamic-graphy failed to reveal any characteristic objective features of PET. High-resolution computed tomography of the temporal bone revealed dehiscence of the superior semicircular canal in both ears. The thresholds of the cervical vestibular evoked myogenic potential response were lower than the normative level in both ears. On the basis of these findings, we diagnosed the patient as having SCDS, although we could not elicit Valsalva maneuver-induced eye movements or nystagmus. We performed round window reinforcement, since the patient did not improve with conservative treatments. The symptoms improved after the operation, and there has been no evidence of recurrence.
