How can we define a brain health chart? A narrative review and a proposal.

In recent years, there has been a significant change in the type of patients referred to memory clinics, characterized by an increase in mildly symptomatic individuals and potentially even healthy people at risk of cognitive decline due to Alzheimer's disease and other neurodegenerative diseases in this context. Additionally, there is growing interest in developing health services focused on brain health throughout the lifespan, particularly within a primary prevention framework. This effort has led to proposing dedicated "brain health services" for dementia risk reduction. However, in the context of cognitive disorders, distinguishing between primary and secondary prevention poses significant challenges, particularly in identifying individuals within the general population who may exhibit subtle cognitive decline or early-stage neurodegeneration. We propose seven key dimensions for assessing "brain health": cognitive reserve along with social and functional status, cognitive decline, mood and sleep disorders, general dementia risk factors, geriatric syndromes in older adults, structural brain damage, and neurodegenerative proteinopathies. Together, these dimensions form a comprehensive "brain health chart". We review the known evidence for each dimension's role in assessing brain health, emphasizing approaches that can be applied in a community setting. We believe that by identifying broadly applicable assessment methods for these dimensions, the development of personalized strategies for maintaining brain health could be facilitated.