[Aging through P300 in a Mexican population]

Research on aging processes have involved the study of evoked potentials. The last decades have witnessed increases in the study of the relationship between event related potentials and the brain's information processes. P300 has been widely studied to assess the neurophysiologic bases that underlie changes which take place during normal and physiologic aging settings. This study was aimed to establish normative data on the P300 component (latency and amplitude) in a Mexican population. One hundred and six (106) neurologically intact subjects, with ages ranging from 20 to 100 years were divided into seven groups. An electrophysiologic assessment using the classical paradigm to generate P300 was used. Monopolar registries referring to the auricular lobules and short circuiting in the Fz, Cz y Pz derivations while monitoring eye movements were used. ANOVA was used for analyzing the effects of age in the latency and the amplitude of both the N100 and P300 components for each one of the derivations. This analysis revealed statistically significant differences (p < 0.05) among the seven groups. The linear regression analysis showed an increase for each aging year in the 0.38 ms latency (r = 0.3804, p < 0.001) and a decrease in the 0.20 mV amplitude (r = 0.2036, p < 0.03). The normative data of the P300 component in the Mexican population studied yielded an objective reference for differential diagnosis and early detection of dementia disorders in patients belonging to a normal aging population.