Auditory evoked potentials in premature and full-term infants.
Accurate information about type, degree, and configuration of hearing loss are necessary for successful audiological early interventions. Auditory brainstem response with tone burst stimuli (TB ABR) and auditory steady-state response (ASSR) exams provide this information.


OBJECTIVE
To analyze the clinical applicability of TB ABR and ASSR at 2 kHz in infants, comparing responses in full-term and premature neonates.


METHODS
The study was cross-sectional, clinical and experimental. Subjects consisted of 17 premature infants and 19 full-term infants. TB ABR and ASSR exams at 2000 Hz were done during natural sleep.


RESULTS
The electrophysiological minimum response obtained with TB ABR was 32.4 dBnHL (52.4 dBSPL); the ASSR minimum was 13.8 dBHL (26.4 dBSPL). The exams required 21.1 min and 22 min, respectively. Premature and full-term infant responses showed no statistically significant differences, except for auditory steady-state response duration.


CONCLUSIONS
Both exams have clinical applicability at 2 kHz in infants, with 20 min of duration, on average. In general, there are no differences between premature and full-term individuals.
Medical Specialty Outpatient Unit, São José dos Campos.
Maria Angélica de Almeida
MA
Porto
Marisa Frasson de
MF
Azevedo
Daniela
D
Gil
D000161:Acoustic Stimulation; D001300:Audiometry, Evoked Response / Q000379:methods*; D001309:Auditory Threshold / Q000502:physiology*; D003430:Cross-Sectional Studies; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male