Subjective cognitive impairment and mild cognitive impairment: a sign of incipient Alzheimer*s disease?
* A longitudinal study of functional and structural brain changes in healthy older adults with and without cognitive complaints.

Previous imaging research has significantly increased our knowledge on how the
brain changes in patients with Alzheimer*s disease (AD), the most common form
of dementia. AD is characterized by a slow decline in cognitive function, and
its neuropathology may be present long before clinical symptoms become
apparent. Amnestic mild cognitive impairment (MCI) refers to the symptomatic
pre-dementia phase of AD. Subjective cognitive impairment (SCI) is a common
condition in which a person has memory complaints but no deficits on formal
cognitive testing. It is still unclear whether SCI represents the latent phase
of AD, but the idea of SCI as a precursor of AD is supported by several
longitudinal studies that identified SCI as a predictor of AD. To date only a
few imaging studies have focused on the detection of incipient AD, and no
longitudinal resting state fMRI studies have been conducted in healthy at-risk
populations. If resting state fMRI is able to show functional connectivity
differences in SCI patients, and is also able to predict the cognitive status
of a patient at a later point in time, it will substantiate its promise as a
biomarker for the early detection of AD.

1. To investigate the differences between healthy older adults with and without
cognitive complaints (SCI) and MCI patients in: a) resting state functional
connectivity; b) brain structure; and c) cognitive function. 2. To investigate
longitudinal changes in functional connectivity, brain structure, and cognitive
function in people with SCI and older adults without cognitive complaints; and
whether these longitudinal changes differ between groups.

Combined cross-sectional and longitudinal study.

This is a non-therapeutic group relatedness study. This research may help to
elucidate early functional and structural biomarkers in the brain for the onset
of dementia and Alzheimer's. The study consists of two visits, one at baseline,
and one after 18 months and during a visit the following procedures will be
done: MRI scan, neuropsychological assessment (SCI and controls only) and
collection of 2 ml saliva. These procedures have no consequences for the health
of the participants. Contra-indications will be carefully investigated per
subject to minimize the risks. Burden will be kept at a minimum by using short
protocols.