Cerebral Hemodynamic Changes in People with Subjective Cognitive Decline: A Systematic Review Based on Near Infrared Functional Spectroscopy

Subjective cognitive decline (SCD) has been proposed as a preclinical phase of dementia/Alzheimer's disease (AD), but its brain abnormalities are not yet fully characterized. In recent years, Functional Near-Infrared Spectroscopy (fNIRS) has emerged as a cost-effective technique able to detect hemodynamic changes associated with cognitive decline, and may be a valuable tool to investigate SCD neural underpinnings. Although there is a growing interest in the use of fNIRS in people with SCD, no stud-ies have synthesized the available evidence in this population. This systematic review synthesizes current fNIRS evidence regarding the neural correlates of SCD both at resting state and cognitive tasks conditions. Following PRISMA statements, Scopus, PubMed, and Web of Science databases will be used to search studies combining key words (‘subjective cognitive decline’, ‘cognitive complaints’, ‘memory complaints’, ‘fNIRS’, and ‘near-infrared spectroscopy’) with Boolean connectors.