SENSITIVITY AND SPECIFICITY OF THE NEONATAL BRAIN-STEM AUDITORY-EVOKED POTENTIAL FOR HEARING AND LANGUAGE DEFICITS IN SURVIVORS OF EXTRACORPOREAL MEMBRANE-OXYGENATION

Objective: We determined the sensitivity and specificity of neonatal b rain-stem auditory evoked potentials (BAEP) as markers for subsequent hearing impairment and for developmental problems found later in infan cy and childhood. Methods: BAEP studies were performed before discharg e in infants treated with extracorporeal membrane oxygenation (ECMO), and two specific abnormalities were analyzed: elevated threshold and d elayed central auditory conduction. Behavioral audiometry was repeated during periodic follow-up until reliable responses were obtained for all frequencies, and standardized developmental testing was also condu cted. The sensitivity and specificity of an elevated threshold on the neonatal BAEP for detecting subsequent hearing loss, and the relations hip of any neonatal BAEP abnormality to language or developmental: dis orders in infancy, were calculated. Results: Test results for 46 ECMO- treated infants (57.5%) were normal, and those for 34 infants (42.5%) were abnormal, with either elevated wave V threshold, prolonged wave I -V interval, or both on neonatal BAEP recordings. Most significantly, 7 (58%) of the 12 children with subsequent sensorineural hearing loss had left the hospital after showing normal results on threshold tests. There was no significant difference in the frequency of hearing loss between subjects with abnormal (5/21, or 24%) and those with normal BA EP thresholds (7/59, or 12%; Fisher Exact Test, p = 0.28). Therefore t he sensitivity of neonatal BAEP testing for predicting subsequent hear ing loss was only 42%. Neonatal BAEP specificity for excluding subsequ ent hearing loss was 76%. In contrast, on language development testing , 19 children demonstrated receptive language delay. Of these children , 12 (63%) had abnormal neonatal BAEP recordings and 7 (37%) had a nor mal BAEP threshold, normal central auditory conduction test results, o r both (p = 0.04). Conclusions: Neonatal BAEP threshold recordings wer e of limited value for predicting subsequent hearing loss common in EC MO-treated survivors. However, an abnormal neonatal BAEP significantly increased the probability of finding a receptive language delay durin g early childhood, even in those with subsequently normal audiometry f indings. Because neonatal ECMO is associated with a high risk of heari ng and receptive language disorders, parents should be counseled that audiologic and developmental follow-up evaluations in surviving childr en are essential regardless of the results of neonatal BAEP testing.