Electroencephalography and event-related potentials as biomarkers of mild cognitive impairment and mild Alzheimer's disease.

BACKGROUND Successful early detection of mild cognitive impairment (MCI) and Alzheimer's disease demands the identification of biomarkers capable of distinguishing individuals with prodromal or early cognitive impairment from healthy aging adults. Many laboratories are engaged in the discovery and validation of a wide array of potential genetic, proteomic, cognitive, and other types of biomarkers. METHODS This review focuses on the application of quantitative electroencephalography (qEEG) and event-related potential (ERP) technologies as markers of prodromal impairment and early disease progression. It is the aim of this review to critically assess where this field currently stands, as well as future directions for EEG biomarker development. RESULTS As a neuroimaging tool that is relatively inexpensive, potentially portable, and capable of providing high-density spatial mapping, qEEG offers a noninvasive, rapid, and replicable method for assessing age-related and disease-related neurophysiologic change. CONCLUSIONS As different signature changes associated with particular stages of disease burden are identified and validated, we anticipate expanded application of qEEG as a reliable and sensitive biomarker(s) of MCI and early Alzheimer's disease.