Using event-related potential P300 as an electrophysiological marker for differential diagnosis and to predict the progression of mild cognitive impairment: a meta-analysis.

P300 event-related potential component may sensitively predict mild cognitive impairment (MCI) progression. Here, pooled effect size estimates of P300 amplitude and latency were computed at midline electrodes among controls, MCI patients, and Alzheimer's disease (AD) patients. Baseline data were compared to one-year follow-up data. MCI patients showed decreased P300 amplitude and prolonged latency compared to controls. Pooled standardized mean differences (SMDs) were -0.67 (95 % CI -1.12 to -0.23, P = 0.003) and 0.90 (95 % CI 0.66-1.14, P < 0.00001), respectively. P300 latency decreased in MCI compared to AD patients where the pooled SMD was -0.52 (95 % CI -0.85 to -0.18, P = 0.003). Amplitude and latency differed between MCI baseline and follow-up. Pooled SMDs were 0.47 (95 % CI 0.29 to -0.65, P < 0.00001) and -0.52 (95 % CI -0.71 to -0.34, P < 0.00001), respectively. Group differences in MCI P300 latency existed compared to control and AD patients. P300 latency may therefore be a sensitive indicator for early cognitive decline or disease progression in MCI patients and identifying elderly patient progression to MCI and/or AD.