Auditory brainstem response anomalies despite normal hearing in a child with Down syndrome: case-based insight

Abstract Background Down syndrome (DS) is associated with a spectrum of cognitive and sensory impairments, including a high prevalence of hearing difficulties. While conductive hearing loss is well documented, reports describing auditory neural deviations in children with DS despite normal peripheral hearing remain limited. Understanding these neural anomalies is critical for optimizing audiological assessment and intervention strategies. Case report We present a 5-year-old child with DS, identified through the Rashtriya Bal Swasthya Karyakram (RBSK) neonatal program, who exhibited normal cochlear function bilaterally, as indicated by behavioural audiometry and transient-evoked otoacoustic emissions. Despite normal peripheral hearing, auditory brainstem response (ABR) testing revealed prolonged peak latencies and interpeak intervals, along with morphological asymmetries between ears. The right ear demonstrated poorer waveform morphology and relatively longer latencies, suggestive of neural conduction delays or unilateral desynchrony, while the left ear displayed clearly identifiable peaks. Behavioural attempts at sound localization were observed but inconclusive. These findings reveal subtle auditory pathway asymmetry and potential neural processing deficits that may not be detected through conventional audiometry alone. Conclusion This case highlights the importance of incorporating neurophysiological assessments, such as ABR, into routine audiological evaluations of children with DS, even when behavioural thresholds are normal. Detailed electrophysiological profiling can identify neural conduction anomalies, inform individualized intervention strategies, anticipate potential auditory processing difficulties, and support improved auditory and cognitive outcomes in this population.