Obliterated cochlea in Cogan's syndrome - Implications for cochlear implant surgery

Background: Acute, often bilateral deafness in Cogan's syndrome or other autoimmune diseases is caused by autoimmune mediated inflammatory attack on the membranous labyrinth. Auditory rehabilitation in case of bilateral deafness can be achieved by cochlear implant surgery. Methods: A retrospective analysis of all patients suffering from Cogan's syndrome that had received a cochlear implant, was carried out. Results: 6 of 295 adult patients (2.6%) that had received a cochlear implant, had become deaf due to Cogan's syndrome. Partial obliteration or ossifikation was encountered in all cases and influenced surgical procedure. In one case a fibrous obliteration of the scala tympani was found 8 weeks after acute onset of complete deafness. Conclusions: The course of obliteration is unknown. With regard to our results a fibrous obliteration may occur as early as 8 weeks after complete deafness. This has to be considered in counseling of patients. Only early cochlear implant surgery facilitates best possible rehabilitation results.