Study
identifies Chemical Changes in brains of
people at risk for Alzheimer's Disease
August 29, 2011-- A brain imaging scan
identifies biochemical changes in the brains
of normal people who might be at risk for
Alzheimer’s disease, according to research
published in the August 24, 2011, online
issue of Neurology®, the medical journal of
the American Academy of Neurology.
The study of 311 people in their 70s and 80s
with no cognitive problems, from the
population-based Mayo Clinic Study of Aging,
used an advanced brain imaging technique
called proton MR spectroscopy to see if they
had abnormalities in several brain
metabolites that may be biomarkers for
Alzheimer’s disease.
They also had PET scans to assess the level
of amyloid-beta deposits, or plaques, in the
brain that are one of the first signs of
changes in the brain due to Alzheimer’s
disease. The participants were also given
tests of memory, language and other skills.
“There is increasing evidence that Alzheimer
disease is associated with changes in the
brain that start many years before symptoms
develop,” said Jonathan M. Schott, MD, of
the Dementia Research Centre, University
College London in England and a member of
the American Academy of Neurology, who wrote
an editorial accompanying the study.
“If we could identify people in whom the
disease process has started but symptoms
have not yet developed, we would have a
potential window of opportunity for new
treatments—as and when they become
available—to prevent or delay the start of
memory loss and cognitive decline.”
The study found that 33 percent of the
participants had significantly high levels
of amyloid-beta deposits in their brains.
Those with high levels of amyloid-beta
deposits also tended to have high levels of
the brain metabolites myoinositol/creatine
and choline/creatine.
People with high levels of choline/creatine
were more likely to have lower scores on
several of the cognitive tests, regardless
of the amount of amyloid-beta deposits in
their brains.
“This relationship between amyloid-beta
deposits and these metabolic changes in the
brain are evidence that some of these people
may be in the earliest stages of the
disease,” said study author Kejal Kantarci,
MD, MSc, of the Mayo Clinic in Rochester,
Minn., and a member of the American Academy
of Neurology. “More research is needed that
follows people over a period of years to
determine which of these individuals will
actually develop the disease and what the
relationship is between the amyloid deposits
and the metabolites.” At the present time,
MR spectroscopy cannot be used for
diagnosis.
The study was supported by the Paul Beeson
Award in Aging, National Institutes of
Health and the Robert H. and Clarice Smith
and Abigail Van Buren Alzheimer’s Disease
Research Program of the Mayo Foundation.
The American Academy of Neurology, an
association of more than 24,000 neurologists
and neuroscience professionals, is dedicated
to promoting the highest quality
patient-centered neurologic care. A
neurologist is a doctor with specialized
training in diagnosing, treating and
managing disorders of the brain and nervous
system such as Alzheimer’s disease, stroke,
migraine, multiple sclerosis, brain injury,
Parkinson’s disease and epilepsy.
For more information about the American
Academy of Neurology, visit http://www.aan.com.
