Abnormal memory loss in
the United States is commonly caused by dementia. Dementia
can be the result of vascular disease in the brain (i.e.
strokes) or Parkinson’s disease, but in the majority of
cases it is the result of Alzheimer’s disease (AD).
For many medical problems, doctors can make a diagnosis with
simple blood tests (as with high cholesterol) or a simple
procedure like measuring our blood pressure. Unfortunately,
AD is a clinical diagnosis, meaning it is one that a doctor
makes with various pieces of information combined.
The only definitive way to diagnose AD is with a brain
biopsy that shows the typical amyloid plaques and tangles;
this is only done in research and with autopsy.
While there are a number of companies selling tests for AD,
the best test is still a history, physical exam and a brief
neuropsychological test. Laboratory tests are often sent to
rule out other rare causes of memory loss, such as abnormal
thyroid function or vitamin B12 deficiency (2% of the
cases). Depression is typically screened for as it can cause
memory loss when it is severe and undiagnosed. Brain scans
are often sent to rule out prior strokes and other
abnormalities. Ask to see a neurologist or a geriatrician if
you feel your doctor is not comfortable addressing your
memory concerns.
In general, there are no medications or treatments that can
change the course of Alzheimer’s disease, but early
diagnosis enables us to use current treatments that will
slow the course of the disease. In other words, if a person
is going to develop AD as a result of genetics and their
environment, there is nothing doctors can do to prevent it
from developing, but the progression of the disease can be
slowed.
The following are some of the known states that place
patients at higher risk of developing Alzheimer’s disease:
-
Familial Alzheimer’s disease (due to chromosomal
mutation). Patients inherit this problem and develop
memory loss at a young age, in their late forties or
fifties.
-
Down’s Syndrome, a common form of mental retardation.
When people with Down’s Syndrome live long enough, they
are all at risk of developing AD. Brain biopsies show
the same amyloid plaques and tangles see in older adults
with AD.
-
Epsilon 4 allele of apolipoprotein E gene, a
“susceptibility gene.” Patients who carry this gene
abnormality may or may not develop AD, just as a smoker
is at higher risk of lung cancer, though it is not
guaranteed they will develop lung cancer. Clinical
testing for this gene is only available in research
settings.
-
Patients who are diagnosed by their physician with “Mild
Cognitive Impairment” are considered at high risk of
going on to develop AD. Often this group of patients is
treated aggressively, and in many cases they are offered
medications used to treat AD in order to delay the
development of AD.
Here are
some questions you may have:
Question: If I am worried about memory loss, how
might my doctor detect it early, before I show signs of
memory loss?
Answer: In 2004 Medicare approved the use of PET
(positron emission tomography) scanning to detect dementia
in patients who demonstrate certain signs which typically
precede the symptoms of AD. A PET scan looks at energy usage
in areas of the brain that correlate with memory and
learning such as the parietal and temporal lobes.
Question: What can I do now to lower my chances of
developing AD?
Answer: Talk with your doctor, make sure they are
aware of every medication you are taking. Below is a
detailed list of what therapies are known to increase your
risk, decrease risk or have no impact.
Increased Risk of Dementia
-
The
Women’s Health Initiative (WHI) Memory study proved that
estrogen does not decrease women’s risk of dementia, but
rather increases it.
-
Some
studies show that high cholesterol can increase the risk
of AD, this is currently being studied at Boston
University (CLASP trial).
-
Several uncontrolled studies have shown greater risk of
dementia among smokers, but one showed smokers had a
lower risk. In general, there are many reasons to quit
smoking.
No
Effect on Risk of Dementia
-
There
is no convincing data for routine use of Vitamin E for
AD prevention.
-
While
Ginko Biloba has some promise from uncontrolled trials,
it is a nutritional supplement and is therefore not
regulated by the FDA, so the other additives are
unknown. Tell your doctor if you are taking it as there
is a known increase in bleeding risk with Ginko.
-
While
promising in mice, studies of a vaccine for AD were
stopped when a number of patients developed
encephalitis.
-
At
this time, a large study of vitamins is underway called
VITAL (vitamins to slow AD). Similarly, a very large
study of the use of non-steroidal anti-inflammatory
agents (NSAIDS) to prevent AD was stopped this year when
there were safety concerns of naproxen and increased
cardiovascular death rates. So neither vitamins nor
NSAIDS can be recommended to prevent Alzheimer’s
disease.
Reduced Risk of Dementia
In
summary, Alzheimer’s disease is a progressive neurological
disease which should be detected as early as possible.
Doctors can slow the progression of the disease, but it
cannot be stopped. Make sure that if you or a loved one has
memory concerns, that they are fully evaluated. Don’t settle
for “you’re getting old” if you have serious concerns.
Speak with your primary care doctor and ask for a geriatric
or neurological evaluation if you think you show signs of
abnormal memory loss. |
