Semicircular canal dehiscence (SCD) is thought to occur in 3% of the population, it is mostly asymptomatic, but patients may present with sound-induced vestibular symptoms, low-frequency conductive hearing loss, autophony, hyperacusis and aural fulness. With the increasing utilisation of cochlear implants (CI) in the adult population, there is some interest in the outcomes for patients with SCD requiring a CI. The study aim was to carry out a retrospective analysis of SCD among CI recipients, word perception outcome over time, and rate of preservation of residual hearing in a single centre (University Hospital, Zurich). The postoperative word perception ability was assessed using the Swiss version of the German Freiburger monosyllabic test in quiet. SCD diagnosis was made using preoperative MRI evaluation by two independent investigators blinded to patient and outcome information. A total of 55 patients were identified over a 10-year period from 2003-2013, with 491 exclusions due to incomplete audiological or imaging data. Seven patients had SCD. Mean postoperative word perception scores were 77% in non-SCD group versus 74% in SCD group (p=0.62) after 18 months. The mean postoperative hearing loss in patients with functional residual hearing before surgery (34 cases) was 22 dB in the non-SCD versus 31 dB in the SCD group (p=0.15). I found this an interesting article; the drawbacks include the retrospective nature, small sample size and lack of power. It is interesting that SCD may have a higher incidence (13% in this article) in CI candidates. In addition, it is useful to know there are similar outcomes reported between the two arms.
Semicircular canal dehiscence and cochlear implantation
Reviewed by Aaron Ferguson
Influence of Semicircular Canal Dehiscence on Cochlear Implant Outcome.
