Use of VEPs as electrodiagnostic biomarkers of mild cognitive impairment

Abstract

Alzheimer's disease (AD) and its precursor, mild cognitive impairment (MCI), are characterized by early onset of visuospatial impairment along with memory impairment and disorientation. Based on these clinical features, I hypothesized that visual impairment might be a candidate biomarker for early electrodiagnosis of MCI. Therefore, I have been focusing on the application of visual evoked potentials (VEPs) as a non‐invasive, simple, and objective method for evaluating visual impairment in MCI patients. In this review, I first outline the concept of the human visual system. Second, I briefly mention the basic technology of VEPs. Then, I describe the previous VEP studies on AD and MCI. These VEP studies have reported that the lower‐level visual pathways are less likely to be involved in AD and MCI, whereas the higher‐level visual streams frequently show VEP abnormalities. Finally, I introduce my new VEP techniques for examining visual impairment in MCI. VEPs with multimodal visual stimuli (especially, optic flow motion) are useful for distinguishing MCI patients from non‐impaired individuals. It may also be feasible to discriminate the type of dementia responsible for MCI. From this review, I stress that VEPs are plausible biomarkers for the early electrodiagnosis of MCI.

Evaluating the feasibility of cognitive impairment detection in Alzheimer’s disease screening using a computerized visual dynamic test

“…Alternatively, our preliminary results are also consistent with recent studies linking MCI and reduced visual processing [39,42,43]. These deficits in MCI and AD patients have been evidenced also in previous works analyzing brain electrical activity [44][45][46]. In terms of the ability of the tests to discriminate the participants of the two groups, Table 3 hints a disparity in classification performance across tests.…”

“…Alternatively, our preliminary results are also consistent with recent studies linking MCI and reduced visual processing [ 39 , 42 , 43 ]. These deficits in MCI and AD patients have been evidenced also in previous works analyzing brain electrical activity [ 44 – 46 ].…”

Disruption of early visual processing in amyloid-positive healthy individuals and mild cognitive impairment

“…To the extent that prior studies have been conducted, deficits have been observed primarily in later stages of visual processing, such as the higher-level processing within the dorsal visual stream, whereas earlier stages of processing were intact (rev. in [ 53 , 54 ]).…”

Nonwearable Sensor-Based In-Home Assessment of Subtle Daily Behavioral Changes as a Candidate Biomarker for Mild Cognitive Impairment

“…Point-of-care testing (defined as a test performed outside a central laboratory [39]) at home is advancing with regard to various diseases with the development of digital technologies in recent years, [40][41][42]. However, the diagnosis of dementia is mainly performed in hospitals or medical laboratories using various diagnostic biomarkers (e.g., neuropsychological, neurophysiological, biological, and genetic biomarkers) [43][44][45][46][47]. Using these biomarkers as point-of-care diagnostic tools is difficult because biomarkers are invasive, expensive, and can only be tested in medical institutions.…”