Auditory neuropathy in hyperbilirubinemia: is there a correlation between serum bilirubin, neuron-specific enolase levels and auditory neuropathy?

Abstract

This study evaluated whether a correlation exists between increased serum bilirubin and neuron-specific enolase (NSE) assays (a biochemical index of neuronal damage) and auditory neuropathy. Nineteen term neonates without hemolysis whose serum bilirubin levels were above 20 mg/dl and 27 healthy term newborns with bilirubin levels <13 mg/dl were included in the study. Auditory brainstem responses (ABRs) and transient evoked otoacoustic emissions (TEOAEs) of patients with hyperbilirubinemia were obtained before discharge. This preliminary study did not show any correlation between the serum NSE and bilirubin values. However, infants who had auditory neuropathy had significantly higher NSE levels, and thus these patients, being in the high-risk group, need close follow-up.

Auditory neuropathy in late preterm infants treated with phototherapy for hyperbilirubinemia

“…Moreover, based on the results derived from our study, we may assert that total serum bilirubin levels Ͼ 20 mg/dl (mean 22.3 Ϯ 1.76 mg/dl) may cause AN/ AD in 2% of late preterms treated with phototherapy, Table 1. The low prevalence of AN/AD in the present study was a consequence of our stricter inclusion criteria, and was not in accordance with the high rates of AN/AD seen in the studies of Saluja et al (46.15%), Xu (Saluja et al, 2010;Akman et al, 2004;Baradaranfar et al, 2011;Xu et al, 2011). Our fi nding of a very signifi cant difference (p Ͻ 0.001) between total serum bilirubin levels of late preterms with and without AN is not in line with the fi ndings of other authors who observed no signifi cant difference between mean peak total serum bilirubin concentrations of neonates with and without acute AN (Saluja et al, 2010).…”

“…However, because of the high sensitivity of the central auditory system to bilirubin toxicity, neonatal history of hyperbilirubinemia was observed to be a signifi cant factor among terms and preterms in recent studies (Starr et al, 2000;Akman et al, 2004;Berlin et al, 2010;Shapiro & Popelka, 2011;Kirkim et al, 2008;Rhee et al, 1999).…”

Auditory neuropathy spectrum disorder in late preterm and term infants with severe jaundice

“…[7] Although sensorineural hearing loss has been widely described as a characteristic feature of chronic post-kernicteric encephalopathy, more recently auditory dys-synchrony (auditory neuropathy spectrum disorder), an auditory disorder characterized by normal otoacoustic emission test (OAE) but abnormal or absent auditory brainstem evoked response (ABR), has been described in early childhood in association with prior history of neonatal jaundice. [7–20] The neurological findings of choreo-athetoid cerebral palsy are not usually seen until beyond infancy and the diagnosis of sensori-neural hearing loss is usually not confirmed until several months after severe jaundice. However, compared to these later manifestations of bilirubin-induced neurotoxicity, auditory neuropathy spectrum disorder can be evaluated and diagnosed at the time of neonatal jaundice.…”

Auditory neuropathy: Endocochlear lesion or temporal processing impairment? Implications for diagnosis and management

“…Even though a firm correlation is yet to be established, there is a trend among children with AN/AD towards higher enolase values, which might in turn help as a marker in the closer follow-up of these children [94].…”