Auditory Late Response (ALR) and P300 in normal adults

Park, Joon Ho; Kang, Hyoun Wook; Lee, Ji Eun; Park, Jin Hyoung; Lee, Dong Ik; Lee, Sang Heun

Abstract

BACKGROUND: Auditory evoked potentials (AEPs) have assumed an essential role in the clinical practice of auditory and several other professions. AEP classification and nomenclature systems are generally based on such aspects as the time domain (short, middle, long), anatomic origin, stimulus-response relationship. The P300 component of the human event related potential is an endogenous positive wave with a latency of 300msec or greater.
OBJECTIVES
Our purpose of this study was to estimate normal values of auditory late response (ALR) and P300 in adults and use them in mapping of the brain. MATERIALS AND MEHTODS: An auditory evoked potential was performed on 40 normal adults, and a scalp surface electrode with 30 electrodes was attempted. Forty adults with normal hearing were divided into 2 groups, one consisting of thirty persons under 30 years of age and the other consisting of ten persons over 30 years of age.
RESULTS
The latencies of P1, N1, P2, N1-P2 were 53.17 +/- 19.57 msec, 98.25 +/- 32.68 msec, 166.12 +/- 44.0 msec, 65.12 +/- 23.68 msec, respectively, in the whole group and 54.23 +/- 20.86 msec, 98.7 +/- 34.35 msec, 160.93 +/- 44.02 msec 62.23 +/- 25.36 msec, respectively, in the group under 30 years old, and 50.0 +/- 15.57 msec, 96.9 +/- 28.69 msec, 181.7 +/- 42.28 msec 73.8 +/- 15.69 msec, respectively, in the group over 30 years old. The P300 latencies for the whole group and the two groups were 299.37 +/- 34.01 msec, 295.16 +/- 33.36 msec, 312.0 +/- 34.49 msec, respectively. There was no significant difference in the latency and amplitude of the ALR and P300 between the two groups (p>0.05).
CONCLUSION
ALR and P300 were measured in 40 normal adults. Description of the normal topography of P300 may facilitate the examination of the P300 topography in cognitive disorders. Such an examination might help ALR and P300 to serve as better diagnostic tools of cognitive disorder in adults.