Slow cortical responses and the diagnosis of central hearing loss in infants and young children.
To evaluate the usefulness of slow cortical responses (ERA) for threshold estimation in infants and young children, 83 children were investigated with combinations of pure-tone audiometry, electrocochleography (ECochG) and ERA. The deviations between ECochG/ and ERA thresholds were correlated to brain function in order to diagnose central hearing losses. By comparing corresponding values of 2 kHz pure-tone and ERA thresholds, 32% (10/31) errors were found, mainly below 35 dB HL. In a group of patients with no sign of brain disorder, an overall error rate of 37% (20/53) was found. Below 35 dB HL, 72% (11/15) errors were found. In a group of patients with brain dysfunction, the overall rate was 70% (21/30), below 35 dB HL it was 84% (21/25). In the range below 35 dB HL, no significant difference (p greater than 0.05) in errors was found between the groups with and without brain disorders. It is concluded that ERA is unreliable for the estimation of moderate hearing losses and cannot per se detect a central hearing dysfunction. Elevated ERA thresholds may indicate a central hearing loss, but to establish this topical diagnosis, ECochG and neuropsychological examinations are necessary.
D001299:Audiometry; D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D001921:Brain / Q000502:physiology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003055:Cochlear Microphonic Potentials; D005072:Evoked Potentials, Auditory; D005260:Female; D006313:Hearing Loss, Central / Q000175:diagnosis*; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D008297:Male