Cochlear Implant Outcomes in Adults and Children with Inner Ear Malformations

Abstract

Objectives:

Bony cochlear or vestibular malformations occur in approximately 20% of patients with congenital hearing loss, but their impact on audiologic outcomes is not entirely clear. Our objective was to assess the impact of inner ear malformations on surgical and audiologic outcomes in cochlear implantation (CI).

Methods:

A retrospective review of a single CI clinic identified a cohort of 57 children and 31 adults with inner ear malformations who had undergone CI between 1994 and 2010. Patients were classified into: common cavity, incomplete partition -I (IP-I); IP-II with or without enlarged vestibular aqueduct (EVA); IP-III, or EVA alone. We compared speech perception language development and surgical outcomes between the groups.

Results:

The type of malformation was not associated with CI performance in either adults or children. In children, the duration of profound hearing loss was correlated with scores for: open-set phoneme (r = -0.43, P = 0.004); open-set word (OSW) (r =-0.32, P = 0.03); Bench Kowal Bamford sentence (BKB) (r =-0.35, P = 0.02), and Peabody Picture Vocabulary Test delay (r = 0.49, P = 0.001). In adults, the duration of profound hearing loss was correlated with OSW (r=-0.36, P = 0.04) and BKB (r =-0.41, P = 0.02).

Conclusions:

The extent of inner ear malformation alone cannot predict CI performance. However, the presence of a gusher, incomplete insertion, and a longer duration of pre-implant hearing loss were associated with worse speech perception and language outcomes in children and adults.