People with mild cognitive impairment are more forgetful
than normal for their age, but they don't experience other cognitive problems
associated with dementia, such as disorientation or confusion about routine
activities.
Routine
tasks such as paying bills, shopping, and meal preparation may become
challenging. People with mild cognitive impairment may take more time doing
these things and they may make more mistakes. They are generally able to live
independently but may be less active socially.
About
one in five older adults has some type of mild cognitive impairment. In a 2010
study of nearly 2,000 people, about 16 percent of dementia-free people over age
70 were suffering from mild cognitive impairment. Men were more likely to
suffer than women, although women may simply experience dementia at a later
age. In the study, risk factors included being a carrier of the APOE e4 gene (a
known risk factor for late-onset Alzheimer's disease), never having married,
and having less than nine years of education.
In
a 2011 study of nearly 1,300 women age 85 and older, 23 percent were diagnosed
with mild cognitive impairment. The researchers recommend that women this age
should be screened for cognitive problems.
The
National Institute on Aging-Alzheimer's Association workgroup has come up with
new diagnostic guidelines for mild cognitive impairment due to Alzheimer's
disease. With mild cognitive impairment, people experience gradual cognitive
decline due to Alzheimer's-related brain changes.
What to look for:
A
person is thought to suffer from mild cognitive impairment if he or she meets
the following criteria:
·
A
friend, family member, doctor, or the person in question is concerned about a
change in his or her cognition compared to the previous level.
·
The
person is experiencing more difficulties in one or more cognitive areas such as
memory, attention, and language than would be expected for his or her age or
educational background. Difficulty learning and retaining new information is
most common in mild cognitive impairment patients who develop Alzheimer's related
dementia.
The
person is having trouble performing complex tasks such as paying bills,
preparing a meal, or shopping. He or she may take more time, be less efficient,
and make more mistakes than in the past. Still, he or she maintains his or her
independence with minimal assistance.
·
There's
no evidence of significant impairment in social or occupational functioning.
· There
should be objective evidence of progressive cognitive decline over time.
Cognitive testing can assess the degree of impairment. Scores for people with
mild cognitive impairment are usually 1 to 1.5 standard deviations below the
mean for their age and education level.
Some formal cognitive
tests that assess both immediate and delayed recall can help identify mild
cognitive impairment patients who are likely to progress to Alzheimer's
dementia within a few years. They include the Free and Cued Selective Reminding
Test, the Rev Auditory Verbal Learning Test and the California Verbal Learning
Test.
Other tests can
determine impairment in problem-solving, reasoning and language. Doctors may
also assess a person's cognitive function using informal techniques, like
asking a patient to learn a street address and then remember it after a delay.
Vascular,
traumatic, and medical illnesses that could explain the decline in cognition
must be ruled out. The goal is to increase the likelihood that the underlying
cause of mild cognitive impairment is probably Alzheimer's.
· If
a person is known to carry a genetic defect, such as a mutation in APP, PS1 or
PS2, he or she is most likely suffering from mild cognitive impairment due to
Alzheimer's disease. Most of these carriers develop Alzheimer's before age 65.
A person who meets the diagnostic criteria for mild cognitive impairment and
carries the apolipoprotein E gene is more likely to progress to Alzheimer's
dementia within a few years than someone without this gene.
Biomarkers such as
proteins that can be measured in spinal fluid as well as imaging tests like
positron-emission tomography (PET) scans are being studied or used to increase
accuracy in diagnosing mild cognitive impairment.
Doctors are looking
for specific proteins beta-amyloid and tau which are found in the brain of a
person affected by Alzheimer's disease. Identifying these proteins could help
doctors pinpoint the underlying cause of mild cognitive impairment, which could
lead to the best treatment and determine whether a person will progress to a
more severe stage of mild cognitive impairment or dementia.
What may help
Researchers
have discovered that activities such as exercise and computer use may prevent
mild cognitive impairment. In a 2010 Mayo Clinic study, adults between ages 70
and 90 who participated in moderate physical exercise like brisk walking or
biking and used a computer were less likely to develop mild cognitive
impairment.
Another
Mayo Clinic study found that consuming more heart-healthy mono and
polyunsaturated fats reduced the risk of mild cognitive impairment among people
age 70 and older. These fatty acids which are found in olive oil, nuts,
seafood, and vegetable oils appear to prevent inflammation and reduce the risk
of blood clots, stroke, and heart disease.
Many
experts believe that mild cognitive impairment may be an early warning sign of
memory disorders later in life. Studies show that up to 15 percent of people
with mild cognitive impairment progress to Alzheimer's disease each year,
compared with a rate of 1 to 2 percent a year for the general older population.
Large-scale
studies are testing whether therapies can halt or slow the conversion from mild
cognitive impairment to Alzheimer's disease. By intervening at the first signs
of memory trouble, doctors hope to delay Alzheimer's disease, or prevent it
altogether.
In
a study published in Neurology, moderate drinking defined as up to one drink
per day (mostly wine)—slowed the rate of progression from mild cognitive
impairment to dementia by 85 percent compared with those who abstained from
alcohol.
Research
on medications for staving off dementia has been discouraging, though. For
example, in a recent study of people with mild cognitive impairment,
researchers found no significant benefit from early intervention with the
Alzheimer's drug donepezil (Aricept) or vitamin E.
(Source: UC Berkeley Health and
Wellness Alerts, November 2017)
