Risk factors and consequences of atrophy of the hippocampal formation in patients with manifest arterial disease: the SMART-Medea study

At older age, depression and cognitive decline are very common, and often
co-occur. However, the nature of the relation between late-life depression and
cognitive decline is not well understood. Vascular brain changes and atrophy of
the hippocampal formation are associated with both depression and cognitive
decline, but they are also commonly observed in normal aging, and are thus
relatively aspecific neurobiological markers for depression and cognitive
decline. At conventional (1.5T- 3T) MRI it is possible to differentiate the
entorhinal cortex from the rest of the hippocampus, and studies indicate that
the entorhinal cortex is affected in an earlier stage of cognitive decline /
Alzheimer*s disease than the rest of the hippocampus. We hypothesize that the
entorhinal cortex and the rest of the hippocampus differentially increase risk
for cognitive decline and late-life depression, and that they are
differentially related to risk factors.
Recently, we made it possible for the first time to visualize and measure the
other subfields within the hippocampus using ultra high field strength (7T)
MRI. We hypothesize that these subfields also are differentially related to
risk factors, cognitive decline and late-life depression.

The first (primary) objective (study 1) is to examine 1a) risk factors for
volume loss in the entorhinal cortex and compare these with risk factors for
volume loss in the rest of the hippocampus at 1.5T MRI over 7 years of
follow-up; and to examine 1b) whether the entorhinal cortex and the rest of the
hippocampus differentially increase risk for cognitive decline and late-life
depression over 7 years of follow-up in patients with manifest arterial disease.

The second objective (study 2) is 2a) to examine whether subfields of the
hippocampal formation at 7T MRI are differentially related to cognitive
impairment and late-life depression; and 2b) to explore risk factors of
subfield volume reductions in patients with manifest arterial disease.

The study design of the primary objective is a prospective cohort study; for
the second objective the design is a cross-sectional study.

The burden will consist of a visit to the UMC Utrecht on a normal weekday,
which will take about the whole day and completing an extra questionnaire at
home. Upon suspicion of pregnancy, a pregnancy test will be performed before
the 7T MRI can take place.
The risks will be the possibility of nausea or dizziness during the MRI. These
risks will not result in permanent damage, but only in short-term discomfort.