Auditory neural myelination is associated with early childhood language development in premature infants.

BACKGROUND: Auditory neural myelination (ANM) as evaluated by auditory brainstem evoked response (ABR) during the neonatal period has been used as a surrogate outcome for long-term neurodevelopment. The validity of ANM as a surrogate outcome for long-term neurodevelopment has not been well studied.

AIM: Evaluate the association of ABR I-V interpeak latency (IPL), an index of ANM, at 35 week postmenstrual age (PMA) with language outcome at 3 years of age.

DESIGN: Prospective study.

SUBJECTS: 24-33 week gestational age (GA) infants were eligible if they did not meet exclusion criteria: craniofacial malformation, chromosomal disorders, deafness, auditory dys-synchrony, TORCH infection, or non-English speaking parents. Infants with malignancy, head injury, encephalopathy, meningitis, blindness, or who died or relocated were also excluded.

OUTCOME MEASURES: ABRs were performed at 35 week PMA using 80 dB nHL and I-V IPL (ms) measured. Auditory Comprehension (AC) and Expressive Communication (EC) were evaluated by a speech-language pathologist at 3 years of age using Preschool Language Scale.

RESULTS: Eighty infants were studied. The mean GA and birth weight of infants were 29.2 weeks and 1336 g, respectively. There was association of worse ear I-V IPL and better ear I-V IPL with AC (Coefficient-5.4, 95% CI: -9.8 to -0.9 and Coefficient-5.5, 95% CI: -10 to-0.9, respectively) and EC (Coefficient-5.6, 95% CI: -9.5 to-1.8 and Coefficient-6.7, 95% CI: -10.6 to-2.7, respectively) after controlling for confounders.

CONCLUSION: The neonatal I-V IPL is a predictor of language development at 3 years of age in preterms.