Normal Value of Cognitive Evoked Potentials in Koreans

Kim, Hyung Doo; Kim, Gook Ki; Lim, Young Jin; Kim, Tae Sung; Rhee, Bong Arm; Leem, Won

Abstract

Cognitive evoked potential(CEP) is the result of endogenous brain response following cognitive stimulus. There are several kinds of waves, including N1, P2, P3 and slow, but only P3 has wide clinical application. In order to obtain normal data, we studied CEP in 174 normal Koreans using the odd-ball paradigm, and our results concerning the latencies and amplitudes of P3 waves, and their relation to age., were were as follows: 1) The average latency of P3 waves of Fz, Cz and Pz was 332.95, 333.34 and 333.66 msec, respectively, in those aged over 60, P3 latency was more delayed than in other age groups. 2) Among teenager, the average latency of P3 waves of Fz, Cz and Pz decreased by 8.35, 9.58 and 9.58msec/year, respectively, but among those aged over 20, increased by 0.87, 0.90 and 0.91msec/year, respectively. 3) The average amplitude of P3 waves of Fz, Cz and Pz was 14.41, 15.37 and 15.12uV, respectively, and in those aged over 60, P3 amplitude showed a greater decrease. 4) The average amplitude of P3 waves of Fz, Cz and Pz decreased by 0.31, 0.32 and 0.23 uV/year in those aged under 29, decreased by 0.65, 0.63 and 0.67uV/year in those over 50, but was stationary in those aged 30 to 49. 5) Due to wide variation and poor constancy, the amplitude of P3 waves does not appear to be especially useful for initial evaluation of cognitive function; it may, however, be useful for follow-up evaluation of a single subject. For each age group, relatively constant P3 latency data can be obtained, and for the evaluation of cognitive function, P3 waves could therefore be useful.