Concomitant otosclerosis (OTS) and superior semicircular canal dehiscence (SSCD) is a rare, but difficult-to-identify and treat diagnosis. A systematic review of the literature was performed to analyze the diagnostic and therapeutic approaches of concurrent OTS and SSCD cases and to identify possible factors that may help in predicting the surgical outcome.
PubMed, Scopus, Medscape, Ovid databases.
Studies showing diagnosis of OTS documented by audiometric test with or without associated radiological signs (computed tomography), and concomitant diagnosis of SSCD, documented at least by high-resolution computed tomography (and possibly supported by neurophysiological testing) were included. Both surgically treated and untreated patients were considered for data analysis.
The general characteristics of each study were recorded, when available. Clinical, audiological, vestibular testing, surgical, and radiological data were extracted from the published case reports and series, and recorded on a database. For each case, the diagnostic steps that confirmed OTS and concomitant SSCD in the same ear were extracted.
Twelve studies were included in the review and 18 cases affected simultaneously by the 2 conditions were extracted and analyzed. Seven of 12 ears (58.3%) undergoing stapes surgery experienced a hearing improvement. In four (33.3%) cases, vestibular symptoms (with or without associated acoustic symptoms) of SSCD were unmasked or worsened by stapes surgery.
A reliable preoperative diagnosis of the two concomitant conditions is possible with a proper interpretation of clinical signs, audiometric, and vestibular testing, in association with the radiologic assessment. Despite that the length and the location of the dehiscence may guide the surgical decision, definitive conclusions regarding the appropriate indications for surgical treatment cannot be drawn due to the limited number of cases with adequate data reported in the literature.