What is Mild Cognitive Impairment?

GINA SHAW wrote . . . . . . . . .

As athletic director for Free State High School in Lawrence, KS, Steve Grant supervised a staff of 60 coaches and countless games, tournaments, and other events in basketball, football, soccer, volleyball, swimming, wrestling, track, golf, tennis, and gymnastics. A campus fixture known as “Mr. Free State,” Grant could be walking down the hallway and be asked by a student, coach, or teacher about a game or practice time, and he would answer in detail without hesitation. “I set up all the games, hired the coaches, and dealt with the officials, and I knew all that stuff off the top of my head,” says Grant, now 74 and “semi-retired” from his lifelong education career. (He still substitute-teaches and volunteers as a golf coach.)

When Grant began referring to his calendar more frequently, he and his wife, Mary, knew something was off. “That might have been totally normal for someone else, but not for Steve,” says Mary, a retired second-grade teacher in the Lawrence public schools.

At first, the family physician was unconcerned and reassured the couple and their three grown children that lapses in Steve’s mastery of complicated scheduling were likely just due to normal aging. But then Steve and his family began noticing more signs of trouble: Steve’s reaction time when driving slowed down, especially at night, and his golf game deteriorated. “I was never a great golfer, but I could always shoot in the 80s, and my scores were getting much worse,” he says.

In late 2022, the Grants were referred to the Alzheimer’s Disease Research Center at the University of Kansas (KU) Medical Center, where Steve underwent a full neurologic exam and a series of tests to assess memory, executive function, and visuospatial abilities. Based on the results, he was diagnosed with mild cognitive impairment (MCI) in February 2023. “That was a blow,” Steve says. “I knew something was wrong, but I wasn’t expecting that.”

Approximately 12 to 18 percent of Americans ages 60 or older have mild cognitive impairment, according to the Alzheimer’s Association. This slight but noticeable decline in mental abilities can be a precursor to Alzheimer’s disease and is more severe than the normal memory loss that may come with aging. “Most of us don’t run quite as fast as we used to as we get older, and we don’t think quite as fast as we used to either,” says Jeffrey Burns, MD, co-director of the KU Alzheimer’s Disease Research Center. “These kinds of changes are expected. What we do not expect are changes that interfere with daily function.”

In February 2020, at the age of 50, Adriane Crouse of Jefferson City, MO, was diagnosed with young-onset MCI. She had been struggling the previous year to retain newer facts and information. As secretary of the senate for the state of Missouri, Crouse had deftly juggled duties involving the senate’s procedural rules and legislative process, and in a previous job for the state senate, she helped lawmakers draft their bills and amendments. So when she could not recall the name of a former co-worker who came to visit, “that was a real concern,” says Crouse, who went to a neurologist for an evaluation.

Crouse has since taken a job on the senate research staff that has fewer responsibilities. “Her long-term memories are still strong, but she’s been given easier jobs that she can handle,” says her husband, Brian, who is vice president of education for the Missouri Chamber of Commerce.

Signs of MCI vary from person to person, says Nicole Anderson, PhD, director of Baycrest’s Ben & Hilda Katz Interprofessional Research Centre in Geriatric and Dementia Care in Toronto. “When we assess someone for MCI, it’s important to talk with family members or others who know the person well, who can tell us what specific changes they’ve noticed and how the person is different from how he or she was previously.”

Neurologists don’t make comparisons with age-matched controls on memory tests, says Barbara Joy Snider, MD, PhD, FAAN, professor of neurology at Washington University School of Medicine in St. Louis. Instead, they look for what has changed specifically about that person’s memory. “Some people have incredibly detailed memories, so if that slips a little bit, they may still perform far above other people their age, but someone who knows them well will see that they have declined,” says Dr. Snider, who also works at Washington University’s Knight Alzheimer Disease Research Center.

The Grants’ experience is an example of this. Most people wouldn’t be able to remember a complicated schedule as Steve did for years. But when he lost that ability, he and his wife sensed that something was wrong.

Differences Worth Noting

Behaviors that could be a sign of MCI, rather than normal aging, include repeating yourself in a single conversation. “We may forget to whom we told that great joke and tell it to them again a few weeks later,” Dr. Anderson says. “But telling the same joke in the same conversation is not normal healthy aging.”

Neither is misplacing things or forgetting where you put them. “We all put the car keys down somewhere strange from time to time because we’re distracted,” says Dr. Anderson. “But if that starts happening a lot more frequently or with items that you never used to misplace, that may be a sign of MCI.”

The ways that behavior changes also could signal MCI, she says. For example, if you’ve typically left your eyeglasses in random places and you begin doing so more frequently as you age, that probably isn’t a concern. But if you always put the glasses on your nightstand and lately you’ve been leaving them in a kitchen cupboard or the refrigerator, that is a concern.

Another sign is when a particular mental task starts becoming difficult. “If you’re finding the tax forms much more challenging than in the past or having trouble organizing your bills when you always did those easily, that can be a red flag,” Dr. Burns says.

The difference between MCI and dementia is subtle, but people with MCI generally have memory loss or other cognitive problems that do not substantially interfere with their daily activities, says Dr. Burns. It may take people with MCI longer to do multi-step activities such as shopping for groceries or paying bills, but they are still mostly independent. It’s when cognitive impairments significantly interfere with the ability to function at work or do usual activities at home that neurologists generally consider people to have progressed from MCI to dementia.

The condition is typically an interim phase between normal aging and early-stage dementia, although in some cases MCI does not progress—or progresses extremely slowly—to dementia. Most people with MCI go on to develop worsening dementia, especially if it is due to a neurologic condition such as Alzheimer’s disease. For about one-third of people with MCI, it happens within five years of their diagnosis. Steve Grant, for instance, was told he had Alzheimer’s disease only six months after his MCI diagnosis, based on results of PET scans that revealed beta-amyloid plaques, which are one of the hallmarks of Alzheimer’s disease.

Other Possible Causes

Sometimes symptoms of MCI might be caused by overmedication, says Dr. Snider. A study involving people in their sixties, published in the International Journal of Clinical Pharmacy in 2018, found significantly higher rates of cognitive impairment among those on five or more medications. For people concerned about their cognitive function, a physician can do a full review of their medications and possibly eliminate unnecessary or duplicative ones.

Other causes of mild but noticeable memory problems include sleep disturbances, anxiety or depression, deficiency of certain vitamins (such as B12), and an underactive thyroid or other hormonal disruption.

A recent heart attack, stroke, or head injury also can affect cognitive function. “Often, a person who has had a heart attack or open-heart surgery has experienced a brief period when the brain was deprived of oxygen, and the hippocampus—a part of the brain that is vital for learning and memory—is very sensitive to oxygen,” says Dr. Anderson. “A transient ischemic attack or bigger stroke also can affect cognition. In general, though, these are one-time insults to the brain, and any associated mild cognitive impairment typically does not get any worse unless there are further strokes or cardiac events.”

The Value of a Diagnosis

A person experiencing memory changes that affect daily functioning should see a neurologist, who will take a thorough history, conduct a physical examination, and likely order blood work. Depending on the results, the neurologist may recommend one or more standardized cognitive tests—to assess memory, reasoning, attention, language, and visual, motor, and social functions—as well as various imaging studies, such as MRI and PET scans.

“We want to know what has been changing and the characteristics and timing of those changes,” says Dr. Burns. “We also want to know how patients function today compared to how they were a few years ago.” The cognitive tests help corroborate what the neurologist observed in the exam, says Dr. Burns. “Someone with MCI often will do fairly well across the board on a battery of memory and thinking tests, but their short-term memory will be impaired. That’s the classic story.”

An early diagnosis means people can be treated sooner, and many new treatments work best in the earliest stages of the disease, says Dr. Snider. In 2023, the FDA approved lecanemab (Leqembi) for the treatment of MCI and mild Alzheimer’s disease in people with evidence of elevated beta-amyloid in their brains. In clinical trials that led to the drug’s approval, lecanemab reduced the amount of amyloid plaques and slowed patients’ decline by 27 percent, based on performance on several standard cognitive and functional tests.

Source: Brain&Life