Clinical role of electrocochleography in children with auditory neuropathy spectrum disorder

Objectives: To assess electrocochleography (ECochG) to tones as an instrument to account for CI speech
perception outcomes in children with auditory neuropathy spectrum disorder (ANSD).
Materials & methods: Children (<18 years) receiving CIs for ANSD (n ¼ 30) and non-ANSD (n ¼ 74)
etiologies of hearing loss were evaluated with ECochG using tone bursts (0.25e4 kHz). The total response
(TR) is the sum of spectral peaks of responses across frequencies. The compound action potential (CAP)
and the auditory nerve neurophonic (ANN) in ECochG waveforms were used to estimate nerve activity
and calculate nerve score. Performance on open-set monosyllabic word tests was the outcome measure.
Standard statistical methods were applied.
Results: On average, TR was larger in ANSD than in non-ANSD subjects. Most ANSD (73.3%) and non-
ANSD (87.8%) subjects achieved open-set speech perception; TR accounted for 33% and 20% of variability
in the outcomes, respectively. In the ANSD group, the PTA accounted for 69.3% of the variability,
but there was no relationship with outcomes in the non-ANSD group.
In both populations, nerve score was sensitive in identifying subjects at risk for not acquiring open-set
speech perception, while the CAP and the ANN were more specific.
Conclusion: In both subject groups, the TRs correlated with outcomes but these measures were notably
larger in the ANSD group. There was also strong correlation between PTA and speech perception
outcome in ANSD group. In both subject populations, weaker evidence of neural activity was related to
failure to achieve open-set speech perception.