March 17, 2009 — People who have lost brain
cells in the hippocampus area of the brain are more likely to develop
dementia, according to a study published in the March 17, 2009, print
issue of Neurology®, the medical journal of the American Academy of Neurology.
The study involved 64 people with Alzheimer’s disease, 44 people
with mild cognitive impairment, which is the stage of memory problems
that precedes Alzheimer’s disease, and 34 people with no memory or
MRI scans were performed on all of the participants at the beginning
of the study and again an average of a year and a half later. During
that time, 23 of the people with mild cognitive impairment had
developed Alzheimer’s disease, along with three of the healthy
The researchers measured the volume of the whole brain and the
hippocampus area, which is affected by Alzheimer’s disease, at the
beginning and end of the study, and calculated the rate of shrinkage in
the brain over that time.
For the people who did not have dementia at the beginning of the
study, those with smaller hippocampal volumes and higher rates of
shrinkage were two to four times as likely to develop dementia as those
with larger volumes and a slower rate of atrophy.
"This finding seems to reflect that at the stage of mild cognitive
impairment, considerable atrophy has already occurred in the
hippocampus," said study author Wouter Henneman, MD, of VU University
Medical Center in Amsterdam, The Netherlands. "In people who already
have Alzheimer’s disease, the loss of nerve cells is more widespread
throughout the brain."
Source : American Academy of Neurology