Exploration of speech-evoked brainstem responses to assess indicators of neurotoxicity in at-risk newborns
Bilirubin-induced neurologic dysfunction (BIND) is a spectrum of central nervous system (CNS) disorders that frequently impacts auditory system development in premature infants. Abnormal development of the auditory system can have a profound effect on hearing and language outcomes. However, the incidence, severity, and time course of central auditory system abnormalities (inclusive of bilirubin binding status, co-morbidities, etc.) in premature infants is not known. In addition, there are currently no reliable methods of assessing CNS dysfunction in preterm infants. If signs of dysfunction could be reliably and validly assessed, brain damage prevention or treatment could be undertaken. The automatic auditory brainstem response (AABR), used for universal hearing screening, is routinely used in neonatal intensive care units (NICUs) and used to assess peripheral auditory function. The AABR, however, is not designed to detect central auditory processing abnormalities. A potentially more useful measure is the complex ABR (cABR) which is similar to the AABR, but uses a speech stimulus that can capture more subtle aspects of central auditory system neuromaturation and injury. Previous cABR data confirm observable differences in normal developing infants as they age and children with language impairments, dyslexia, autism, or poor reading skills. To test whether bilirubin levels were related to cABR measures in preterm infants, we compared the magnitude of speech-evoked brainstem responses to total bilirubin (TB) levels in 23 NICU infants. Our results show a negative correlation between TB levels and measures of the cABR, such that lower TB levels are associated with more robust speech encoding. These data advance our understanding of neurologic deficits associated with preterm birth and exposure to high TB levels.
Association for Research in Otolaryngology
02/10/2018 - 02/14/2018
Musacchia, Gabriella; Hu, Jiong; Bhutani, Vinod K.; Wong, Ronald J.; Tong, Meiling; and Ftizgerald, Matthew B., "Exploration of speech-evoked brainstem responses to assess indicators of neurotoxicity in at-risk newborns" (2018). All Faculty Scholarship. 195.