BACKGROUND: Early diagnosis and effective management are pivotal steps in preventing the transition from mild cognitive impairment (MCI) to Alzheimer's disease. Previous investigations indicated that some event-related potential (ERP) components in MCI are sensitive to cognitive decline. However, several comparative analyses of these components in MCI and healthy controls (HC) yielded inconsistent results.

OBJECTIVE: The aim was to perform a systematic review and meta-analysis of ERP studies on MCI patients.

METHODS: We systematically searched on PubMed and Web of Science for MCI-related ERP studies published from April 1986 to August 2016. Standard mean difference estimates of all components were compared between MCI and HC.

RESULTS: Our study showed increased P50 amplitude at the Cz site; reduced N2pc amplitude and delayed P200 latency at the Cz site; N200 latency at the Cz and Pz sites, and P300 latency at the Cz and Pz sites in MCI patients compared to HC.

CONCLUSIONS: In summary, our study indicated that some ERP components, such as P50 and N2pc amplitude, P200, N200, and P300 latency might be potential electrophysiological biomarkers for MCI diagnosis.