The flash visual evoked potential-P2 and the detection of amnestic mild cognitive impairment: A review of empirical literature

Amnestic Mild Cognitive Impairment (aMCI) is now recognized as an early risk state for the development of Alzheimer's dementia (AD). Biomarkers, including those that are cerebrospinal fluid or brain imaging based, have yet to provide the ultimate marker variable. A need currently exists for a non-invasive, easy to administer biomarker that contains aMCI/AD specific pathognomic information. The objective of the present investigation was to provide an updated review of the Flash Visual Evoked Potential-P2 (FVEP-P2) as a biomarker for aMCI and AD. The FVEP-P2 has been shown to possess AD specific pathognomic information. A review was conducted of all articles published between the years 1976 and 2019 that examined the clinical utility of the FVEP-P2 in the diagnosis of aMCI or AD. Only 17 published investigations met the criteria of the review. The weighted average effect size, as measured by Cohen's d, was 1.07, with patients diagnosed with either aMCI or AD exhibiting a significant delay in the FVEP-P2 latency. The weighted mean latency for the controls was 143.92 ms (SD = 17.13). The weighted mean latency for the aMCI/AD was 164.02 ms (SD = 21.33). Estimates of sensitivity, specificity, and accuracy were based on the weighted means and standard deviations and were equal to 0.73. The area under the curve was equal to 0.78. The results of the current review suggest that the FVEP-P2 latency possesses AD specific pathognomic information and that it should be included as part of a much larger assessment process that includes neuropsychological, cerebrospinal fluid, and brain imaging findings. •The FVEP-P2 is the second positive waveform (component) produced by the visual cortex in response to a strobe flash.•Patients diagnosed with MCI and AD have exhibited a selective delay in the latency of the FVEP-P2.•The present investigation represents a comprehensive review of FVEP-P2 research as a potential biomarker for both MCI and AD.•Results of the review suggest that the selective delay in the latency of the FVEP-P2 may provide diagnostic information that other studies may not provide.•Issues related to the use of the FVEP-P2 as a biomarker for MCI and AD are discussed.