Brainstem Auditory Evoked Potential in Preterm Infants and its Relation with Gestational Age

Abstract

Introduction: Preterm births are associated with different neuro developmental abnormalities. During the last trimester of pregnancy, a part of foetal brain development occurs. Some area of the brain does not show normal growth even after the birth of preterm babies. Due to advanced obstetric and neonatal care of the present time, neonatal complications and mortality has reduced substantially. However, the preterm newborns experience many perinatal developmental abnormalities including prematurity of auditory pathway. Among the paediatric population, subjective tests for auditory evaluation are non reliable. Brainstem Evoked Response Audiometry (BERA), which assesses Brainstem Auditory Evoked Potential (BAEP), is a simple, non-invasive and an objective way of evaluating functional integrity of auditory pathway. Aim: To assess the neurological maturation and integrity of the auditory pathway by BAEP in preterm infants with respect to the gestational age. Materials and Methods: The present cross-sectional study was done in the Eastern region of India. A total of 74 preterm infants and 30 fullterm infants were included from the Department of Paeadiatrics, R.G. Kar Medical College, Kolkata, India. In the Department of Physiology, BAEPs were compared among preterm and full-term infants. The preterm babies were divided into three subgroups according to gestational age, Group 1 (≤28 weeks); Group 2 (29-32 weeks); Group 3 (33-36 weeks). Intergroup comparison was done by Student’s t-test, ANOVA and Post-Hoc test. Results: Preterm babies had prolonged wave I, wave V latency and I-V Interwave latency in the right ear (p<0.05) In Group 1, wave V and I-V latency were prolonged in both the sides. Right sided prolongation of wave I and wave V latency were present in Group 2. Left I-V interwave latency was prolonged in Group 1 than Group 3. A total of 24 preterm infants had absent waves. Conclusion: Preterm infants had premature peripheral and central auditory pathway. Group 1 showed central pathway immaturity compared to term infants and Group 3. Group 2 showed immature peripheral pathway. Absent waves were present in all the groups but maximum in Group 3, suggestive of dysfunction of auditory pathway but exact location of pathology was uncertain.

Keywords

• intrauterine age
• neuronal maturation
• premature birth