Overview
Mild cognitive impairment (MCI) is the stage between the expected cognitive decline of normal aging and the more serious decline of dementia. It can involve problems with memory, language, thinking and judgment that are greater than normal age-related changes.
If you have mild cognitive impairment, you may be aware that your memory or mental function has “slipped.” Your family and close friends also may notice a change. But these changes aren’t severe enough to significantly interfere with your daily life and usual activities.
Mild cognitive impairment may increase your risk of later developing dementia caused by Alzheimer’s disease or other neurological conditions. But some people with mild cognitive impairment never get worse, and a few eventually get better.
Types of Mild Cognitive Impairment
A doctor may diagnose an affected individual with one of the following MCI subtypes:
- Amnestic vs. Non-Amnestic MCI: In amnestic MCI, memory is significantly impaired. Other cognitive functions are spared. Alzheimer’s disease is believed to cause amnestic MCI. In non-amnestic MCI, memory remains intact, but one (single domain) or more (multiple domain) other cognitive abilities (e.g., language, visual-spatial skills, executive functioning) are significantly impaired.
- Single Domain vs. Multiple Domain MCI: In single domain MCI, only memory or one other domain of cognition is impaired. In multiple domain MCI, memory plus one or more other cognitive abilities are affected.
Pathophysiology
In mild cognitive impairment (MCI), cognitive impairment exceeds the normal expected age-related changes, but functional activities are largely preserved; thus, MCI does not meet the criteria for dementia. Different subtypes of MCI are recognized. One common classification distinguishes between amnestic and nonamnestic forms of MCI.
Amnestic MCI, in which memory impairment predominates, is often a precursor of clinical Alzheimer disease (AD). Nonamnestic forms of MCI are characterized by a variety of cognitive impairments, the most common of which is probably impaired executive function. A substantial number of patients with MCI may be judged to have normal cognition on follow-up visits.
The pathophysiology of MCI is multifactorial. Most cases of amnestic MCI result from pathologic changes of AD that have not yet become severe enough to cause clinical dementia. At least in specialty research populations, autopsies done on amnestic MCI patients have found the neuropathology to be typical of AD. Nonamnestic MCI may be associated with cerebrovascular disease, frontotemporal dementias (as a precursor), or no specific pathology.
What causes mild cognitive impairment?
All possible causes of mild cognitive impairment have not been completely discovered. In a small number of cases, another condition may be causing the symptoms seen in mild cognitive impairment. Some of the possible conditions include:
- Depression, stress, and anxiety
- Thyroid, kidney or liver problems
- Sleep apnea and other sleep disorders
- Diseases or conditions that affect blood flow in the brain (tumors, blood clots, stroke. traumatic brain injury, and normal pressure hydrocephalus)
- Low vitamin B12 levels or other nutrient levels
- Eye or hearing problems
- An infection
- Side effects of certain prescription (for example, anticholinergic drugs used to treat bladder conditions, Parkinson’s disease and depression) or illegal drugs
- History of alcoholism
Many of these causes of mild cognitive impairment are treatable.
Most cases of MCI, however, are due to a variety of diseases, such as Alzheimer’s or Parkinson’s disease. (Similarly, like dementia is due to a variety of diseases such as Alzheimer’s or Parkinson’s disease, dementia with Lewy bodies, vascular dementia, frontotemporal dementia, and other causes.)
Risk factors
The strongest risk factors for MCI are:
- Increasing age
- Having a specific form of a gene known as APOE-e4, also linked to Alzheimer’s disease — though having the gene doesn’t guarantee that you’ll experience cognitive decline
Other medical conditions and lifestyle factors have been linked to an increased risk of cognitive change, including:
- Diabetes
- Smoking
- High blood pressure
- Elevated cholesterol
- Obesity
- Depression
- Lack of physical exercise
- Low education level
- Infrequent participation in mentally or socially stimulating activities
What are the Symptoms of Mild Cognitive Impairment?
- Patients with mild cognitive impairment are at high risk of developing depression. Depression also plays a role in the conversion of mild cognitive impairment to dementia.
- Anxiety is the common symptoms in the patient suffering from mild cognitive impairment. Anxiety in these patients is increased due to the memory problem and risk of public embarrassment.
- Memory Problems. Memory problem is the primary feature of mild cognitive impairment. The person with mild cognitive impairment has a higher risk of developing Alzheimer’s disease and other forms of dementia.
- Poor Concentration. Mild cognitive impairment also results in poor concentration. It may be due to the reduced flow of blood in the brain. As the blood supply is reduced, the energy level of the neurons decreases leading to poor concentration.
- Anger and Irritability. The patient with mild cognitive impairment has poor emotional health. These people have difficulty in managing their anger and impulsiveness. They get easily irritated and have impulsive actions.
- Apathy is the condition which occurs when the mild cognitive impairment is progressing in Alzheimer’s disease. Thus, patients with apathy as a symptom in mild cognitive impairment are at higher risk of developing Alzheimer’s disease.
- Poor Decision Making. The ability of the person suffering from mild cognitive impairment has cognitive decline. The condition is characterized by reduced leaning and thinking skills. The ability of the patient to take a logical decision is reduced.
- Social Isolation. The patient with mild cognitive impairment develops social isolation. The patient feels uncomfortable in public places and does not able to talk to other people. Social isolation further increases the severity of symptoms such as depression and anxiety.
- Reduced Mental Ability. The patient with mild cognitive impairment has reduced mental ability. The patient feels difficult to perform routine activities.
How is mild cognitive impairment diagnosed?
MCI is diagnosed through a clinical assessment done by a qualified doctor or other healthcare professional.
A clinical assessment should usually include:
- Interviewing the patient regarding his concerns, and inquiring about difficulties managing life tasks
- Assessing whether family members and other observers have noticed anything concerning
- Evaluating cognitive abilities using a short office-based test, such as the Montreal Cognitive Assessment
- Checking prescribed and over-the-counter medications, to see if any are known to make thinking worse (see 4 Types of Brain-Slowing Medication to Avoid if you’re Worried about Memory)
- Evaluating for medical conditions, including mental health conditions and sleep disorders that can worsen thinking or can mimic early dementia
Laboratory work is often necessary, to check for problems such as thyroid disorders, vitamin B12 deficiency, and electrolyte imbalances.
After this initial assessment, a person might be referred for additional neuropsychological testing. These tests provide a more in-depth assessment of specific memory and thinking skills. They can help further categorize MCI as “amnestic” (meaning the problems are mainly with memory) versus non-amnestic.
Ultimately, the process of diagnosing MCI is similar to diagnosing dementia: it requires documenting concerns and difficulties, objectively assessing cognitive abilities, and ruling out other medical problems (including medication side-effects and delirium) that might be interfering with brain function.
But in MCI, the cognitive impairments should not be severe enough to interfere with daily life.
Treatments
Medications
Unfortunately, there isn’t a cure for MCI, and there are no medications that are FDA-approved to treat it. However, doctors sometimes prescribe cholinesterase inhibitors for people whose main MCI symptom is memory loss. (For more on cholinesterase inhibitors and other dementia medications, click here.)
Clinical trials are underway to determine if other medications might help with MCI. Among the medications being tested in trials are curcumin and pioglitazone.
Therapy
If psychiatric symptoms are experienced in addition to MCI, especially anxiety, therapy may help. Since anxiety can affect a person’s cognitive abilities (problem solving, attention), in some individuals therapy has improved both the anxiety and the symptoms of MCI.
Sleeping problems like insomnia and sleep apnea (where a person keeps holding their breath while asleep) can cause thinking problems similar to MCI, and are treatable with therapy.
Exercise
Exercise has been shown in studies as effective for helping older adults with symptoms of cognitive impairment. Exercise improves thinking ability in people with dementia, easing memory problems and psychological health problems like depression and anxiety. Exercise helps prevent decline in the first place, and when MCI becomes an issue, it is a powerful tool for helping symptoms.
Exercise obviously is not as rigorous for older adults, but almost any physical activity can be helpful. Click here for caregiver tips to help get your loved one more active.
Blood Pressure Management
Researchers have found evidence that an effective form of prevention against MCI is for an individual to control their blood pressure. When thousands of people with high blood pressure were studied over years, those who took more intense measures to control their high blood pressure had fewer cases of MCI later in life.
Exercising on a regular basis, avoiding smoking and heavy drinking, losing excess weight, limiting caffeine, reducing stress, and eating a diet low in fat, cholesterol, and sodium all have been shown to reduce blood pressure.
Suggestions for Family Members / Caregivers
- Remain positive and encouraging toward loved ones with MCI.
- Be patient. Don’t interrupt your loved ones and allow them enough time to recall information.
- Continue to treat your loved ones like adults. This includes the way you speak to them. Don’t leave them out of conversations when you are talking about them, and avoid talking down to them.
- When loved ones repeat a question or story, respond as if it’s the first time you’ve heard it.
- Your loved one will benefit from continued physical and social interaction and feelings of independence and usefulness. Pets, plants and household tasks can help him/her feel needed and useful.
General strategies that help caregivers support their loved one with dementia are good to keep in mind when interacting with someone who has MCI. There are proven communication techniques, ways to encourage socialization, and coping methods for emotional and behavioral issues that make day-to-day life easier for someone who is having a harder time thinking because of MCI.
Preventing Mild Cognitive Impairment
Prevention of mild cognitive impairment is focused around protective factors such as eating a balanced diet rich in vegetables and fish, exercising regularly for at least 30 minutes, five times a week, and keeping the brain active by engaging in challenging activities such as learning a new language or learning to play an instrument.
It is also important to care for people with suspected MCI because this condition is considered to be an intermediate stage between normal aging and dementia, with memory changes leading to the development of severe deficits thereby making independent living impossible.
While mild cognitive impairment affects not only older adults, nonetheless, this population has higher risk for developing this condition. Therefore, it is essential that family members and friends who notice memory problems or problems in any other mental abilities, consult with a specialist—preferably a geriatrist—who can provide the necessary attention to each case.