An unusual case of post-cochlear implant performance degradation in a patient with suspected Cogan's syndrome.

Cogan's Syndrome is an autoimmune disorder that can affect the ear, eye and other organs. Although rare, Cogan's Syndrome is particularly relevant to the cochlear implant surgeon because the resulting hearing loss is often bilateral and the majority of cases progresses to profound levels where cochlear implantation may be indicated. There are many issues relating to this condition that concern the cochlear implant surgeon. Its rarity, lack of specific laboratory diagnostic tests and variability in the onset and types of manifestation relating to the ear, eye and other organs often pose diagnostic difficulties. Pre-operatively, the cochlear implant surgeon must anticipate and exclude the possibility of cochlear luminal obliteration and ossification. Although the post-implant hearing results are expected to be generally good in Cogan's Syndrome, the possibility of adverse hearing outcomes cannot be ruled out whether in the initial or subsequent post-operative period. The possible side effects of long-term immuno-suppressive therapy on the well-being of the cochlear implant are to be appreciated and managed. A case which posed much difficulty in management is presented and discussed to highlight some of these challenges.