BRAIN-STEM AUDITORY EVOKED-RESPONSES FROM BIRTH TO ADULTHOOD - NORMATIVE DATA OF LATENCY AND INTERVAL

Development of wave latency and interpeak interval (IPI) in brainstem auditory evoked responses (BAER) from birth to adulthood was examined. Adult equivalence was reached for most wave latencies and IPIs between the ages of 9 months and 3 years. The observation of the III-V/I-III interval ratio suggests that after term date the I-III IPI decreases more than the III-V IPI. I-III, III-V and I-V IPIs shortened from the 1-month old group to the 4-6 year old group by 22%, 15% and 19% respectively. The III-V/I-III interval ratio may be a useful BAER measure. Normative data of various BAER measures at different ages are presented. The slope of the L-I function for wave V was slightly steeper in younger groups than in older groups (40-mu-s/dB in the 1-month old group; 32-mu-s/dB in the adult group). This change which was accompanied by an age-related difference in the absolute wave latency. It is suggested that age-dependent norms should be used in evaluation of the L-I function.