BACKGROUND: By analyzing brain synaptic function, cognitive event-related potentials (ERPs) could provide powerful and innovative tools for early Alzheimer's disease (AD) diagnosis.

OBJECTIVE: We investigated the relevance of the ERP-P300 component as a potential diagnosis marker in elderly subjects at risk of developing AD.

METHODS: ERP-P300 was analyzed on 85 subjects recruited from the Multidomain Alzheimer Preventive Trial (MAPT). PET-AV45 brain imaging was available from 36 subjects.

RESULTS: Two ERP-P300 subgroups were identified according to their PET-AV45 status: PET-Aβ positive (n = 15) and PET-Aβ negative (n = 21). In the amyloid positive group, we observed a highly significant increase in P3b latency in parietal brain regions (p = 0.0052). P3b in parietal regions correctly categorized 69.4% elderly subjects from the P300-PET Aβ positive group. Combined analysis of parietal P3b latencies and category fluency correctly classified 75% subjects from the P300-PET Aβ positive group.

CONCLUSIONS: The P300 ERP presents good predictive measure of brain amyloid load and has the potential to be used as a screening instrument for preclinical AD. The incorporation of P3b latency may be used as an adjunctive tool with neuropsychological assessment (i.e., verbal category fluency) as a specific and sensitive method for preclinical assessment of AD.