title: Evaluation of auditory brain stems evoked response in newborns with pathologic hyperbilirubinemia in mashhad, iran.
abstract: BACKGROUND
  Neonatal jaundice is a common cause of sensorneural hearing loss in children.
  
  
  OBJECTIVE
  We aimed to detect the neurotoxic effects of pathologic hyperbilirubinemia on brain stem and auditory tract by auditory brain stem evoked response (ABR) which could predict early effects of hyperbilirubinemia.
  
  
  METHODS
  This case-control study was performed on newborns with pathologic hyperbilirubinemia. The inclusion criteria were healthy term and near term (35 - 37 weeks) newborns with pathologic hyperbilirubinemia with serum bilirubin values of ≥ 7 mg/dL, ≥ 10 mg/dL and ≥14 mg/dL at the first, second and third-day of life, respectively, and with bilirubin concentration ≥ 18 mg/dL at over 72 hours of life. The exclusion criteria included family history and diseases causing sensorineural hearing loss, use of auto-toxic medications within the preceding five days, convulsion, congenital craniofacial anomalies, birth trauma, preterm newborns < 35 weeks old, birth weight < 1500 g, asphyxia, and mechanical ventilations for five days or more. A total of 48 newborns with hyperbilirubinemia met the enrolment criteria as the case group and 49 healthy newborns as the control group, who were hospitalized in a university educational hospital (22 Bahaman), in a north-eastern city of Iran, Mashhad. ABR was performed on both groups. The evaluated variable factors were latency time, inter peak intervals time, and loss of waves.
  
  
  RESULTS
  The mean latencies of waves I, III and V of ABR were significantly higher in the pathologic hyperbilirubinemia group compared with the controls (P < 0.001). In addition, the mean interpeak intervals (IPI) of waves I-III, I-V and III-V of ABR were significantly higher in the pathologic hyperbilirubinemia group compared with the controls (P < 0.001). For example, the mean latencies time of wave I was significantly higher in right ear of the case group than in controls (2.16 ± 0.26 vs. 1.77 ± 0.15 milliseconds, respectively) (P < 0.001).
  
  
  CONCLUSIONS
  Pathologic hyperbilirubinemia causes acute disorder on brain stem function; therefore, early diagnosis of neonatal jaundice for prevention of bilirubin neurotoxic effects is essential. As national neonatal hearing screening in not yet established in Iran, we recommend performing ABR for screening of bilirubin neurotoxicity in all cases with hyperbilirubinemia.
authors: Student Research Committee, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, IR Iran ; ABR Center, Mashhad Branch, Islamic Azad University, Mashhad, IR Iran.
authors: Tooba
authors: T
authors: Okhravi
authors: Department of Pediatrics, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, IR Iran.
authors: Saeedeh
authors: S
authors: Tarvij Eslami
authors: Mashhad Branch, Islamic Azad University, Mashad, IR Iran.
authors: Ali
authors: A
authors: Hushyar Ahmadi
authors: Department of Pediatrics, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, IR Iran.
authors: Hossain
authors: H
authors: Nassirian
authors: Student Research Committee, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, IR Iran.
authors: Reza
authors: R
authors: Najibpour
keywords: Auditory Brain Stem Evoked Response; Bilirubin; Hyperbilirubinemia; Newborn