Hearing Evaluation for Pediatric Cochlear Implant with ASSR

Abstract

Objective: The aim of this study was to evaluate Auditory Steady-State Responses (ASSR) at high intensities in pediatric cochlear implant candidates and to compare the results to behavioral test responses. Method: This prospective study evaluated 54 children with severe-to-profound hearing loss, aged from 3 to 72 months, between January and December 2011. All had absent ABR and OAE responses. ASSR were evoked using binaural single frequency stimuli at 110 dBHL with a 10 dB-down seeking procedure. ASSR and behavioral test results were compared. Results: Forty-two subjects completed both ASSR and behavioral evaluation. In 13 children behavioral tests were not available, 1 had inconclusive ASSR. Among 42 children with absent ABR and OAE, 11 (26.1%) had bilateral ASSR, 10 correlated well to behavioral results. Four (9.5%) showed unilateral responses in at least 2 frequencies, all confirmed by behavioral results. Among 27 subjects with absent ASSR, 8 had no behavioral responses; 12 had responses only in low frequencies >110 dBHL, 7 showed behavioral responses at all frequencies in medium to high intensities. No spurious ASSR responses were observed at 100 or 110 dBHL in any frequency. Conclusion: ASSR is a valuable tool to detect residual hearing in young children with absent ABR and OAE. No false-positive ASSR results were observed, but in 7 cases with absent ASSR, the test underestimated residual hearing as compared to the behavioral responses.