Cochlea development in infants with central nervous system impairment occurring as an effect of perinatal asphyxia

UNLABELLED: Asphyxia in neonates with inadequate blood-inner ear barrier function causes damage to the inner ear included the degeneration of outer hair cells of the organ of Corti and oedematous changes in stria vascularis. The major consequences in the central nervous system (CNS) are found to be hypoxic-ischemic encephalopathy (HIE) in term newborns, peri- (PVH) or intraventricular hemorrhages (IVH) and periventricular leucomalacia (PVL) in preterm neonates. THE AIM OF THE STUDY: was to carry out the objective assessment of the cochlea development using CEOAEs in infants with CNS impairment occurring as an effect of perinatal asphyxia, imaged during trans-fontanel ultrasonography. MATERIAL AND METHODS: To the investigation 36 infants with HIE, IVH or PVL were included, the control group encompassed 32 born at term, health children. In all children three times otoscopic examination and CEOAEs recordings were performed: after birth, in 3rd and in 6th month of life using Otodynamics Otoacoustic Analyser ILO-88 in Quick Screen version. Perinatal anamnesis, general pediatric status, results of trans-fontanel ultrasonography and biochemical test results were taken into account in statistical analyses. RESULTS: The mean amplitudes of CEOAEs in the first days of life were significantly reduced in InvG comparing to control babies. In half-octave frequency bandwidth analysis significant reduction of S/N Ratio at 1,5–4 kHz in InvG was observed. 3 and 6 months later the recorded responses significantly increased, they didn't reach values of CG but no statistical differences between groups were observed. CONCLUSION: In conclusion, the outer hair cells activity in first days of life is reduced in newborns with CNS impairment and perinatal asphyxia in anamnesis comparing to health children. The maturation of the cochlea is intensive during first 3 months of life, later only subtle changes in CEOAEs are observed.