Mild cognitive impairment (MCI) is a slight decline in memory or the ability to think clearly. It’s noticeable to the person experiencing it and to their loved ones. It’s also measurable on cognitive tests.
Doctors don’t consider MCI a form of dementia because it’s not severe enough to interfere with your daily routine or with your ability to function independently.
The Alzheimer’s Association claims that 10 to 20 percent of people over the age of 65 may have MCI.
MCI has two broad categories of symptoms. The first category primarily affects memory. For example, forgetting certain details such as doctor’s appointments or not being able to recall the name of a good friend. This type of impairment is known as “amnestic MCI.”
The second category of symptoms has to do with thought process, such as planning and completing a complex task like balancing a checkbook or exercising good judgment in risky situations. This type of impairment is known as “nonamnestic MCI.”
Both types of symptoms may occur in the same person.
According to the Mayo Clinic, the causes of MCI aren’t clearly understood. Current evidence suggests that MCI often occurs due to lesser degrees of the same types of brain damage found in Alzheimer’s disease and other forms of dementia. These changes include:
- beta-amyloid plaques with protein tangles
- dementia with Lewy bodies
- reduced blood flow to the brain
- damage caused by multiple small strokes
- shrinkage of parts of the brain associated with memory
- enlargement of the ventricles, which are fluid-filled spaces
- less use of glucose in key thinking regions
According to the Alzheimer’s Association, a medical workup for MCI should include at least seven core areas. Your doctor shouldn’t diagnose any kind of cognitive impairment until they perform all of the following:
- an assessment of your medical history, including your family history of dementia and any illnesses or medications that could be causing cognitive symptoms
- an assessment of your ability to function independently
- an assessment of input from those familiar with you to help catch symptoms you might miss
- a series of simple mental status tests
- a neurological exam in their office
- a careful evaluation of your mood and behavior because mental illnesses like schizophrenia, bipolar disorder, and major depression can cause symptoms that mimic dementia
- blood tests to help your doctor rule out infections
- brain imaging tests to determine whether or not any other disorders may be causing the MCI or dementia
No medications have been approved for use in the treatment of MCI, but some lifestyle changes may help slow or even reverse the progression of the disease. According to the Alzheimer’s Association, these changes include:
- exercising regularly
- controlling cardiovascular risks by stopping smoking
- changing one’s diet to include fresh fruits and vegetables, whole grains, and lean proteins
- participating in mentally and socially stimulating activities
A study published in the British Journal of Psychiatry suggests that 60 to 65 percent of people with MCI will go on to develop clinical dementia. Depending on the cause of the impairment, taking the steps to modify your lifestyle in the ways listed may give you more control over the progression of MCI into full dementia.
The chief complication associated with MCI, according to the National Institute on Aging, is developing Alzheimer’s disease or a related form of progressive dementia.
Because so little is known about the causes of MCI, definitive guidelines for prevention aren’t available. Some agencies suggest maintaining good cardiovascular health, but no evidence confirms that this prevents MCI.