Long-term outcomes of cochlear implantation in adolescents with early-onset hearing loss

Neonatal hearing screening (NHS) has long-term beneficial effects on the outcomes of cochlear implantation (CI); however, some adolescents still require CI evaluation because of progressive hearing loss. This study aimed to investigate long-term postoperative effects and to identify prognostic factors in adolescents with CI.

Thirty-four patients with pre- or perilingual severe-to-profound hearing loss who underwent CI after the age of 10 years (adolescent group) were included. The pre- and postoperative outcomes of this group were compared with those of 138 patients with pre- or perilingual severe-to-profound hearing loss who underwent CI before the age of 10 years (pediatric group). We collected data on the age at diagnosis of hearing loss, age at initiating hearing aid (HA) use, age at CI, postoperative observation time, pure-tone hearing thresholds on the affected and unaffected sides, preoperative (HA) and postoperative (CI) aided hearing levels, speech discrimination scores (SDSs), and communication mode. The prognostic factors for CI in the adolescent group were investigated based on postoperative SDS. In patients who provided consent for a questionnaire survey, postoperative listening comprehension, articulation, satisfaction, and expectations after CI were also evaluated.

In the adolescent group, significant improvements were noted in the aided hearing threshold and SDS after implantation (both p < 0.001) except for two cases, but both variables were significantly worse in the adolescent group than in the pediatric group (both p < 0.05). Postoperative SDS significantly correlated with preoperative SDS (ρ = 0.5056) and preoperative hearing level on the unaffected side (ρ = -0.3864; both p < 0.05). The age at CI, age at diagnosis, and age at initiating HA use were not significantly different between the two groups. In the adolescent group, users of the auditory-verbal communication mode scored the highest and showed significant differences in preoperative and postoperative factors. The questionnaire survey findings indicated that postoperative listening and articulation were significantly worse in the adolescent group (both p < 0.05), but satisfaction and expectations after CI did not significantly differ between the two groups.

CI appears to provide satisfactory long-term outcomes even among adolescents with hearing loss. Better preoperative SDS and hearing might be important for the outcomes of CI in this age group.