Objective: To investigate the change of peak latency, interpeak latency and amplitude of auditory brainstem evoked potentials (AEPs) in normal preterm infants in accordance with the age, and to find out the correlation between reproducibility of AEPs and high risk of premature infants.

Method: AEP studies were performed on 266 premature infants (male 143, female 123) within a month of the birth. Acquired potentials were grouped by the reproducibility of waveforms, and latency, interpeak latency and amplitude were measured in each group of potentials to interpret age appropriate changes of AEPs.

Results: 1) Peak latency of peak I, III and V were shortened in accordance with the age, especially latency of peak V was significantly decreased from 7.42 msec to 6.84 msec. 2) There was no significant change in interpeak latency or amplitude of AEPs according to the postmenstrual age. 3) Reproducibility of AEPs was worse in premature infants with history of asphyxia.

Conclusion: Considering the results, the latency of peak V can be used as one of the useful parameter to investigate and follow up the premature infants. Significant negative correlation between low grade reproducibility and history of neonatal asphyxia was found.

Objective: The purpose of the study is to draw the three-dimensional reconstructions of nuclei and tracts of the auditory pathway structures of drainstem.

Method: The drawings of 1 mm sections of the brainstem were scanned with a computer scanner into AUTOCAD program. All lines of structures except for the auditory pathway structures and outlines were removed. Each layer was plotted to a x, y, and z coordinated plotting reference to the corresponding points on the mid-sagittal plane and reconstructed to a three-dimensional drawing. Center point of the auditory pathway structures of all cross section layers were connected with a line in succession and that was thought to be a imaginary pathway of auditory pathway through the brainstem.

Results: This auditory pathway has several turning points, at the cochlear nucleus, superior olivary nucleus, and inferior colliculus which correspond with known generation sources of the peak of brainstem evoked potentials.

Conclusion: This study presents a method for the conversion of the two-dimensional transverse sections into a three-dimensional format, to allow the visualization of the auditory pathway structures from multiple directions.