Does Mild Cognitive Impairment (MCI) Lead to Dementia?

If you have mild cognitive impairment (MCI), you may be worried that your condition will progress to dementia. But rest assured, the shift to dementia is not necessarily inevitable.

It depends on what’s causing the impairment, says Elizabeth Bevins, MD, PhD, a neurologist and assistant professor of neurosciences at the University of California in San Diego. Sometimes it’s caused by disease, such as Alzheimer’s or a vascular disease, and other times it’s the result of things going on in your life or health that make it difficult for your brain to function at its highest level, she explains.

Here’s what you need to know about the link between MCI and dementia, including what you can do to reduce your risk.

The causes of MCI can vary widely. Some culprits are degenerative brain conditions that worsen with time, such as Alzheimer’s disease, Lewy body dementia, or frontotemporal dementia, says Douglas Scharre, MD, a professor of clinical neurology and psychiatry at The Ohio State University Wexner Medical Center in Columbus.

Others include chronic kidney or liver disease. Your kidneys and liver remove toxins from your blood, he explains, and if those organs aren’t working well, the toxins can reach your brain and cause damage.

Some other causes of MCI are less progressive. For example, if you develop MCI after a series of ministrokes, it might stay steady as long as you don’t have another stroke.

• Depression can cause thinking changes that might resolve once treated.
• A vitamin B12 deficiency can cause cognitive changes until the deficiency is corrected.
• Sleep apnea robs your brain of the oxygen needed for thinking, which can improve once treated with continuous positive airway pressure.
• Chemotherapy for cancer treatment can cause thinking changes that improve after treatment.
• Heavy drinking can cause MCI.
• Some medications, such as diphenhydramine for allergies, can have cognitive side effects.

“There are hundreds of causes,” Dr. Scharre notes. “If there’s a change in your cognition, you should make an appointment with your primary care doctor.” They can do blood tests and brain scans to figure out what’s going on.

“We’re getting better and better at being able to determine which mild cognitive impairment is due to an underlying progressive or neurodegenerative brain disease,” says Dr. Bevins.

If MCI is due to a neurodegenerative disease, such as Alzheimer’s disease, Lewy body dementia, or frontotemporal dementia, abnormal proteins build up in the brain. “Over time, these proteins accumulate and start killing brain cells,” Scharre explains. An amyloid PET scan or cerebral spinal fluid test can spot these proteins.

These degenerative conditions are not curable, but early intervention still matters. There are now ways to diagnose Alzheimer’s early, in the MCI stage, and start treatment with medications that might slow cognitive changes.

“If it’s a mild cognitive impairment due to Alzheimer’s disease, that is actually our most effective time to intervene and to get someone started on these disease-modifying treatments, which are more effective the earlier you get them started.”

It’s not always possible to prevent dementia, but with the right interventions, you may be able to slow down the process.

Work with your doctor to find the cause. “The earlier you identify the cause of why your brain’s not working well, the more treatment choices you’ll have and the better your outcomes will be,” says Scharre.

Complete a cognitive assessment to track changes. Ask your doctor to administer a cognitive test, such as the Self-Administered Gerocognitive Exam, and track your results over time. You can also do the test yourself to establish a baseline and repeat it yearly. Tell your doctor if you drop two or three points.

Address heart risk factors. Your brain needs good blood flow to function, so protect your blood vessels. Ask your doctor to check your blood pressure, cholesterol, and blood sugar, and take steps to control them if they’re too high. And if you smoke, now is the time to quit.

Use it or lose it. Build up your cognitive reserve, which is your starting point for thinking and memory. Read, do puzzles, play the piano — whatever activities will exercise your brain. “You’re building up new connections,” says Scharre. “You have more reserves. So if you do have any kind of degenerative disorder or anything else, you have a buffer.”

Move your body. Physical activity challenges the brain in addition to the muscles, says Scharre. Your brain monitors your muscle and lung activity and helps you set your pace.

Be social. “Maintaining a good community and staying in touch with family and friends as you get older has been shown to be really important,” says Bevins. Conversation is like a workout for your brain. “Someone makes a comment, you’re interpreting it, your brain is working,” says Scharre. Even sitting on a bench and watching people walk by can stimulate your mind.

Alert your doctor to any changes in your thinking. Here are a few common ones:

Clueing problems: When you find misplaced objects, do you remember how they ended up there? For example, you might recall setting them down to go to the bathroom or greet the dog. That’s clueing. If you find the item and have no idea how it got there, you aren’t clueing — and that’s not normal, says Scharre.

Repeating yourself: If you ask the same question over and over and don’t remember doing it, that can be a sign of impaired cognition.

Forgetting the names of objects: If you often forget the names of common objects, such as a spatula when you’re flipping pancakes, you should see a doctor, says Scharre.

Problems managing daily responsibilities: “As it progresses from mild cognitive impairment to more of a major cognitive impairment, it starts to impact your daily life,” says Bevins. Common signs include difficulty managing medications (forgetting to take pills or taking multiple doses of the same pills), managing personal finances (such as forgetting to pay your bills), and shopping (like buying multiples of the same item), as well as losing track of appointments and plans.

If you notice any of these changes, alert your doctor right away.

• Not all mild cognitive impairment will progress to dementia. Work with your doctor to find the cause of the MCI, so you can take steps to slow or possibly reverse it.
• MCI can develop into neurodegenerative diseases such as Alzheimer’s disease, Lewy body dementia, or frontotemporal dementia.
• Alert your doctor if you notice your thinking and memory problems getting worse — for example, forgetting the names of common objects or being told that you’re asking the same question over and over.