Hearing loss in inner ear and systemic autoimmune disease: A systematic review of post‐cochlear implantation outcomes

Abstract

Objectives To assess outcomes following cochlear implantation (CI) in patients with hearing loss secondary to primary or secondary autoimmune inner ear disease (AIED). Methods A systematic review and narrative synthesis was completed according to PRISMA guidelines. Databases searched included MEDLINE, PubMed, EMBASE, Web of Science, Cochrane Collection, and http://clinicaltrials.gov. No limits were placed on year of publication or language. Results A total of 551 studies were identified, of which 29 were included after removal of duplicates, and screening the title, abstract, and full text. All except one study were OCEBM grade IV. 114 of 115 patients displayed improvement in hearing following cochlear implantation. With implant use, roughly a third of these patients had hearing that improved over time, a third improved and plateaued, and a third remained stable. There was no additional risk of perioperative complications found in AIED patients compared what is generally accepted in general cochlear implantation, although two episodes of device failure after 6 months were noted, and four patients with secondary AIED displayed poor initial audiological outcomes. Conclusion CI in both primary and secondary AIED provides marked improvement in hearing. Early CI may be a valid management option, provide long‐lasting hearing in patients and reduce the side effects of long‐term systemic immunosuppressants. However, patients should be counseled residual hearing may be lost if there is cochlear ossification or fibrosis which may make implant insertion more traumatic. Level of Evidence NA.

Cochlear implantation in systemic autoimmune disease

“…Lee et al reported from data pooled in a systematic review and meta-analysis that 53.5% of patients with AIED had cochlear fibrosis or ossification. This is less than the reported incidence in bacterial meningitis of 74% [2,25,26 ▪ ,27]. However, it's important to note that preoperative imaging may not be sensitive enough to pick up some cases of fibrosis [25].…”

“…Postoperatively, there should be close monitoring for wound-related complications, especially if skin atrophy was evident intraoperatively. However, the overall risk of wound infection of 3.5% in this group of patients has not been found to be higher than that of the general population undergoing cochlear implantation [26 ▪ ,29]. The patient should continue follow-up and medical management of their underlying systemic autoimmune disorder with their attending rheumatologist to avoid uncontrolled disease flares which have been found to affect implant performance [30 ▪▪ ,31].…”

“…This is despite having 23% of the patients having severe fibrosis requiring a ‘drill out’ operation. The time interval between deafness and implantation did not seem to affect postcochlear implantation hearing outcomes in AIED [26 ▪ ]. But again, these conclusions are limited by poor reporting across studies.…”

“…Our recent systematic review and meta-analysis found that the audiological outcomes after cochlear implantation in AIED patients were generally good, with improvement compared to preimplantation test scores [26 ▪ ]. Aftab et al [2] compared AIED Cochlear implant patients and controls, and found no statistical difference in patients in postoperative audiological results between AIED and non-AIED patients.…”

“…There should be meticulous soft tissue handling as patients might have atrophic skin, and to ameliorate skin necrosis, a well planned periosteal flap for which the incision is ‘stepped’ either posteriorly or anterior to the skin incision. Even so, appraisal of the literature only found that skin-related complications occurred in only approximately 3% of AIED patients who underwent CI, and all were successfully managed with dressings and antimicrobial therapy [26 ▪ ]. Placement of the implant receiver-stimulator package should be in a position high enough to avoid pressure points like ear hooks of spectacles and implant processors.…”