Auditory function evaluation in high risk neonates

ABSTRACT

Hearing impairment can be considered as the most common benign defect. Early detection of hearing loss at, or shortly after, birth and appropriate intervention are critical to speech, language and cognitive development. Seventy-four neonates were included in this study [40 males and 34 females]. Twenty-two patients had neonatal hyper-bilirubinemia [total bilirubin >/= 18 mg/dL] [group A], 24 patients had hypoxic ischemic encephalopathy [group and 28 were premature low birth weigh [>37 weeks, >/= 2500 gm respectively] [group C]. Twenty apparently healthy full term infants of matching age and sex were also enrolled in the study as controls. Beside complete history and clinical examination, all patients and controls evaluated by automated auditory brainstem responses [A-ABR] and transient evoked otoacoustic emissions [TEOAEs]. Neonates who had auditory dysfunction [from either the studied cases or controls] were followed up 3 months later by the same tests. Hearing dysfunctions were detected in 45%, 29% and 53.5% in group A, B and C of patients respectively. There were statistically significant higher serum bilirubin level in cases with abnormal hearing [28.5 +/- 3.73] than in those without [20.42 +/- 3.95] P < 0.001, in group A of patients. In group B of patients there was statistically significant lower Apgar score at 5 minutes in cases with abnormal hearing [4.5 +/- 2.39] than in those without [8.3 +/- 3.4] P < 0.025. In group C of patients there were statistically significant lower gestational age and birth weight in cases with abnormal hearing [30.86 +/- 1.76 and 1653.33 +/- 393.91 respectively] than in those without [34.85 +/- 1.5, and 2380.76 +/- 165.25 respectively] P < 0.001 for both