Auditory Brainstem abnormalities in infants exposed to congenital TORCH infections: implications for longitudinal audiological monitoring

Abstract To evaluate the integrity and maturation of the auditory pathway in infants exposed to congenital infections by comparing them with infants without risk indicators for hearing loss. This prospective longitudinal study included 55 infants exposed to congenital TORCH infections (study group—SG) and 38 infants without risk indicators for hearing loss (control group—CG) enrolled in a Neonatal Hearing Screening program at a public hospital in São Paulo, Brazil. Infants exposed to congenital TORCH infections and a control group without risk indicators for hearing loss were evaluated. Participants underwent three assessments: before 3 months of age (T1), 3 months after the first assessment (T2), and 6 months after the first assessment (T3). Auditory Brainstem Response (ABR) and Long-Latency Auditory Evoked Potentials (LLAEP) were recorded. Absolute latencies and interpeak intervals of the ABR, as well as the P1 component latency of the LLAEP, were analyzed. Infants exposed to congenital infections showed a higher frequency of ABR abnormalities involving waves III and V, interpeak intervals I–III and I–V, and the overall ABR outcome, particularly at the initial assessments. Progressive reductions in ABR wave and interpeak latencies, as well as in LLAEP P1 latency, were observed over time in both groups. No significant between-group differences were found in P1 latency. Conclusion: Infants exposed to congenital infections exhibit alterations in brainstem auditory pathway maturation, suggesting a slower or distinct maturational trajectory than infants without risk indicators for hearing loss. Longitudinal audiological follow-up is essential for the early identification of auditory pathway abnormalities in this population. What is known: • Congenital infections may impair auditory development by affecting the peripheral and central auditory pathways. What is new: • Infants exposed to congenital TORCH infections showed a higher frequency of Auditory Brainstem Responses abnormalities, suggesting a slower or distinct brainstem auditory maturation trajectory.