Distortion product otoacoustic emissions (DPOAEs) were recorded in 46 term infants who suffered perinatal hypoxia-ischaemia to identify which frequencies in the cochlear audiogram are susceptible to perinatal hypoxia-...Distortion product otoacoustic emissions (DPOAEs) were recorded in 46 term infants who suffered perinatal hypoxia-ischaemia to identify which frequencies in the cochlear audiogram are susceptible to perinatal hypoxia-ischaemia.On days 3-5 after birth, the pass rates across the frequencies of the f2 primary tone between 1 and 10 kHz, particularly 1-5 kHz, were all lower than those in normal term controls (X2 = 7.27-32.30, all P < 0.01).Of the 92 ears, 15 (16.3%) failed the DPOAE test, which was significantly higher than in the controls (4.3%, X2 = 5.81, P < 0.05).At 1 month, 80 ears with a type A tympanogram were retested.The pass rates at most frequencies, mainly 1 and 2 kHz, were slightly further decreased.Thirteen ears (16.2%) failed the DPOAE test.These results suggest that the neonatal cochlea, mainly at the frequencies 1-5 kHz, is impaired shortly after perinatal hypoxia-ischaemia and the impairment remains at 1 month.Conclusion: Perinatal hypoxia-ischaemia impairs the neonatal cochlea mainly at the frequencies 1-5 kHz and the impairment detected on days 3-5 after birth is unlikely to improve in the later neonatal period.These findings may have implications for the management of hearing impairment in infants after perinatal hypoxia-ischaemia.展开更多
文摘Distortion product otoacoustic emissions (DPOAEs) were recorded in 46 term infants who suffered perinatal hypoxia-ischaemia to identify which frequencies in the cochlear audiogram are susceptible to perinatal hypoxia-ischaemia.On days 3-5 after birth, the pass rates across the frequencies of the f2 primary tone between 1 and 10 kHz, particularly 1-5 kHz, were all lower than those in normal term controls (X2 = 7.27-32.30, all P < 0.01).Of the 92 ears, 15 (16.3%) failed the DPOAE test, which was significantly higher than in the controls (4.3%, X2 = 5.81, P < 0.05).At 1 month, 80 ears with a type A tympanogram were retested.The pass rates at most frequencies, mainly 1 and 2 kHz, were slightly further decreased.Thirteen ears (16.2%) failed the DPOAE test.These results suggest that the neonatal cochlea, mainly at the frequencies 1-5 kHz, is impaired shortly after perinatal hypoxia-ischaemia and the impairment remains at 1 month.Conclusion: Perinatal hypoxia-ischaemia impairs the neonatal cochlea mainly at the frequencies 1-5 kHz and the impairment detected on days 3-5 after birth is unlikely to improve in the later neonatal period.These findings may have implications for the management of hearing impairment in infants after perinatal hypoxia-ischaemia.
