Mild cognitive
impairment (MCI) falls somewhere between age-associated memory impairment and
early dementia. 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 but can still be performed. People with MCI
may take more time doing these activities 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 MCI.
In a 2010 study of nearly 2,000 people, about 16 percent of dementia-free
people over age 70 were suffering from MCI. 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 ε4 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 MCI. 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 MCI due to Alzheimer’s disease. With MCI, people experience gradual cognitive decline due to Alzheimer’s-related brain changes. A person is thought to suffer from MCI 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 MCI 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 MCI 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 MCI patients
who are likely to progress to Alzheimer’s dementia within a few years. 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 MCI is probably Alzheimer’s.
• If a person is known to carry a genetic defect, such
as a mutation in APP, PS-1 or PS-2, he or she most likely has MCI due to
Alzheimer’s disease. Most of these carriers develop Alzheimer’s before age 65.
A person who meets the diagnostic criteria for MCI and carries a variant of the
Apolipoprotein E (APOE) gene is more likely to progress to Alzheimer’s dementia
within a few years than someone without it.
Researchers have discovered that activities such as
exercise and computer use may prevent MCI. 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 MCI.
Another Mayo Clinic study found that consuming more heart-healthy mono- and
polyunsaturated fats reduced the risk of MCI 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 MCI may be an early warning
sign of memory disorders later in life. Studies show that up to 15 percent of
people with MCI progress to Alzheimer’s disease each year, compared with a rate
of 1 to 2 percent a year for the general older population.
(Source: Health After 50, 14 April 2016)
