Impact of length of auditory pathway on baep latencies

Introduction: BAEP latencies and amplitudes tend to vary with many factors like age, gender, corebody temperature,hormones and headsize. controversy exists regarding the effect of head size on BAEP latencies. It was hypothesized that headsize would indirectly reflects brainsize and hence the length of the auditory pathway. Therefore in this study, BAEP latencies were compared with headsize for males and females to analyze the impact of length of the auditory pathway on BAEP latencies. Methods: 36 subjects, 18 males and 18 females of age group between 17-25 were selected. Head measurements like head circumference (HC), nasion to inion (AP-anteroposterior-measured across the top of the head),and right external auditory meatus to left (RL-also measured across the top of the head), were measured. BAEPs were performed by brief acoustic monaural click stimuli. Results: Statistical analysis showed a significant difference in head size(HC,AP, RL and total head size) between males and females with a significant P value of < 0.001.Wave V absolute latency and I-V inter peak latency were slightly prolonged in males than females but statistically insignificant. However, when wave V latency and IPL I-V were corelated with head measures ;head size has a significant weak positive influence on BAEP latency. Conclusion: Results revealed that males had significantly bigger head size than females. Slight prolongation of wave V and IPL I-V latencies in males could be because of larger head size .Pearson’s correlation study revealed, regardless of subject gender, head size has a weak positive influence on BAEP waveV and IPL I-V latencies. Thus head size should be considered for normal BAEP recording.