What is Mild Cognitive Impairment?
Memory loss, often seen among older adults, can manifest in several ways. For some, it’s a normal aspect of aging that doesn’t interfere with daily function. Others may experience complaints about memory loss without any detectable issues on brain function tests, which is known as subjective cognitive impairment. Some people might also be diagnosed with mild cognitive impairment (MCI) or even dementia.
MCI, first fully studied in the late ’90s, refers to memory problems that are more severe than those expected for a person’s age. However, they aren’t severe enough to be classified as dementia. The concept of MCI changed over time when it became clear that memory impairment wasn’t the only cognitive aspect affected in some cases and not all cases progressed to dementia. Thus, MCI was eventually recognized as a bridge between normal aging and early dementia.
By 2003, a clearer definition of MCI was established, considering cognitive complaints, deficits in any cognitive area (not just memory), preserved but struggling overall function, and absence of dementia. This more comprehensive concept of MCI helped doctors monitor their patients more closely.
In 2013, the American Psychiatry Association’s guidebook classified MCI as a type of neurocognitive disorder (NCD), characterized by a decline in one or more cognitive areas that doesn’t interfere with everyday activities and isn’t caused by delirium or other psychiatric conditions. The World Health Organization also adopted this definition in 2018.
MCI’s classification follows the patterns through which cognitive areas are affected. It’s either labeled as ‘amnestic’ (featuring predominant memory loss) or ‘non-amnestic’ (with memory relatively intact). Amnestic MCI is common and may progress to Alzheimer’s disease, whereas non-amnestic MCI is less common and might develop into dementia unrelated to Alzheimer’s.
In terms of subtypes, amnestic MCI can affect just memory or multiple domains, while non-amnestic MCI affects one or multiple cognitive domains, but memory remains intact. A more extensive classification system was developed to better represent the diverse nature of MCI, covering memory issues (amnestic), problems in varying cognitive areas (mixed), impairments in attention and spatial functions but intact memory (dysexecutive), and difficulties in visual construction (visuospatial).
Clerly, classifying MCI based on various factors, including associated symptoms and test results can guide doctors in identifying probable MCI cause and predicting its course. For instance, those with the ‘dysexecutive’ type of MCI are less likely to develop Alzheimer’s disease and more likely to experience a stroke.
What Causes Mild Cognitive Impairment?
Certain factors can increase your risk of mild cognitive impairment (MCI), a condition that affects your memory and thinking skills.
A few factors that you can’t change include getting older – as this is the biggest risk factor for MCI. Others include being male, having a family history of memory loss, and having a specific gene known as apolipoprotein E (APOE) allele. This particular gene is often connected to MCI progressing into Alzheimer’s. However, not all studies agree with this, meaning it’s hard to use this gene to predict who will progress from MCI to Alzheimer’s.
There are also risk factors that can be changed or treated.
Certain long-term health conditions and having multiple health conditions at once can increase your risk of MCI. These include high blood pressure, high cholesterol, heart disease, and stroke. If you have any four long-term health conditions, especially two of those mentioned, your risk of MCI increases. Other conditions like chronic obstructive pulmonary disease and diabetes can also raise your risk.
Taking multiple medications or certain types of medications can also increase your risk for MCI as they can negatively affect your memory. These can include both prescription and over-the-counter drugs, such as painkillers, anxiety medication, sleeping pills, muscle relaxants, and epilepsy medication. Other medications, such as allergy medication, antidepressants, medicine for urinary incontinence, antipsychotics, and blood pressure medication, can also affect your thinking skills.
Mental health conditions like depression and anxiety, medical conditions like an underactive thyroid or Vitamin B12 deficiency, dehydration, high or low blood sugar, and infections like urinary tract infections can all affect your thinking skills. However, these can be treated easily.
Sleep disorders like obstructive sleep apnea can lead to daytime fatigue and, if not treated, can affect your thinking skills. Using the Continuous Positive Airway Pressure (CPAP) device may help.
Conditions such as Normal Pressure Hydrocephalus, which results from an accumulation of brain fluid, can lead to issues with balance, bladder control, and thinking skills. Spotting and treating this condition early can reverse these changes.
In some instances, MCI can be an early sign of dementia. Certain conditions, like Parkinson’s disease, traumatic brain injury, Huntington disease, HIV infection, and stroke, can first show memory loss and thinking difficulties.
On the other hand, there are factors that can help protect you from developing MCI or delay its onset. These include higher levels of education, being bilingual, and engaging in brain-stimulating activities. A healthier lifestyle can also help, such as following a Mediterranean diet, staying physically active, quitting smoking, drinking alcohol in moderation, and staying socially active.
Risk Factors and Frequency for Mild Cognitive Impairment
Mild Cognitive Impairment (MCI) is a condition that can have a wide range of impacts on a person’s cognitive abilities and daily functions. There are no universally agreed-upon criteria for the diagnosis of MCI, which leads to a wide range of estimates for how common this condition is. However, it’s widely understood that MCI is quite common among older adults and the likelihood of developing it increases with age.
- The American Academy of Neurology reported that about 6.7% of people aged 60-64 have MCI, increasing to 25.2% for those aged 80-84.
- Other research shows that as many as 22% of older adults living independently, and up to 40% of older adults in memory care facilities, may have MCI.
- MCI is more prevalent among individuals with less education.
- MCI impacts both men and women, but some studies report a higher prevalence in men.
- Different studies, methods and populations can lead to a wide range of estimates for how common MCI is.
- In comparison to the US, European studies report a lower prevalence of MCI. However, US studies conducted in urban areas or among non-Caucasian groups tend to report higher prevalence.
- A recent study from China estimated the prevalence of MCI among Chinese adults to be about 15.5%.
- There are fewer studies focusing on how often new cases of MCI occur. Estimates range from 5.1 to 168 cases per 1000 person-years. For a subtype of MCI known as A-MCI, this estimation is between 10 and 14 cases per 1000 person-years.
Signs and Symptoms of Mild Cognitive Impairment
Cognitive disorders are conditions that affect mental processes such as learning, memory, perception, and problem solving. Diagnosing cognitive disorders involves a detailed examination and understanding of a patient’s history, often provided by family members or caregivers. Patients may find it hard to recognize their memory loss, so it’s sometimes necessary to consult their close acquaintances to gather accurate information. Cognitive issues may come to light through forgetting appointments, difficulty following simple instructions, or confusing medication routines. Sometimes a change in behavior or mood like anxiety, depression, or apathy might trigger the need for an evaluation.
During the evaluation, the gradual onset and progression of symptoms are noted. They could be mistaken for normal ageing, but any memory issues should be investigated to determine if they indicate mild cognitive impairment (MCI) and not just age-related changes. The aim is to differentiate between MCI, dementia, and normal ageing and to see if there are any treatable causes for the cognitive deterioration. It is also useful to understand the patient’s educational background and occupation when assessing their base level function.
Notably, cognitive issues should reflect a change from the patient’s normal. Some examples of how impairments may show up in daily life could be:
- Getting easily distracted, being slow to complete tasks, having to simplify tasks, difficulty doing mental arithmetic
- Struggling with multi-tasking, planning, organization, or following conversations
- Repeatedly misplacing items, repeating questions or conversations, forgetting recent events, relying more on lists
- Having difficulty finding words, using incorrect words, making grammatical mistakes, struggling to understand speech or written material
- Experiencing difficulty with using familiar appliances or getting lost in familiar places
- Displaying apathy and lack of empathy, or behaving inappropriately in social situations
A thorough functional assessment should be carried out to distinguish MCI from dementia. This includes detecting any changes in complex functions such as managing finances or driving. MCI patients usually maintain function despite cognitive decline. A detailed review of all the medications the patient is taking, both prescribed and over-the-counter, is essential. Certain medications may also contribute to cognitive impairment.
Neuropsychiatric symptoms such as depression, anxiety, sleep disturbances, and changes in eating behaviour are commonly seen in MCI patients, with varying degrees of severity. A comprehensive neurological examination, including cranial nerve tests, coordination checks, and gait analysis, should also be performed. This could point out potential causes for the cognitive issues, including stroke, vitamin deficiency, or diseases like Normal Pressure Hydrocephalus (NPH) or Parkinson’s Disease (PD).
Testing for Mild Cognitive Impairment
To diagnose Mild Cognitive Impairment (MCI), a common condition that causes slight but noticeable memory problems, your doctor would typically use certain standard assessments. These tests can include the Montreal Cognitive Assessment (MOCA), the Saint Louis University Mental Status Examination (SLUMS), and the Mini-Mental State Exam (MMSE). Just having memory concerns is not enough to diagnose MCI – you require a formal assessment using one of these approved tools.
The MOCA is a 30-question test designed specifically to spot MCI. It takes about 10 minutes, tests various areas of cognitive function, and has been validated in multiple languages. If someone has had less than 12 years of education, they’re given an extra point. Using a cut-off score of 25-26, the MOCA has been shown to be around 80-100% accurate in detecting MCI. The MMSE is also a 30-question test, but it’s less good at spotting MCI than the MOCA.
The MMSE can be less accurate in people with very high or low education levels, as these could give misleading results. Additionally, the MMSE is copyrighted, meaning it’s not freely available. The SLUMS is another 30-question test which is more effective at spotting specific types of cognitive loss often seen in MCI, making it a better tool for detecting MCI than the MMSE. The SLUMS is also free to use.
When diagnosing MCI, doctors use scores that are significantly below what we’d expect for someone’s age and level of education. These scores provide guidance but are not hard cut-off points for diagnosing MCI. If the cognitive losses are subtle, doctors may refer the patient for further neuropsychology testing.
Doctors can also gather information about your cognitive function from people who know the patient well using standardized questionnaires. These can be used to assess cognitive decline and the severity of any dementia symptoms.
After MCI is diagnosed via a clinical examination and cognitive testing, other diagnostic tests are ordered to determine why the cognitive losses are occurring and whether any reversible causes can be identified. These tests can include checks for blood count, thyroid function, vitamin levels, and glucose and renal function. Additional tests can be ordered based on clinical suspicion.
Tests to study markers of disease in the body can be helpful but are not routinely used due to a lack of standardized methods and clear cut-off scores. Studies of the brain’s structure, such as MRI or CT brain scans, can help rule out conditions like stroke or tumors. They can also highlight changes that might suggest cognitive impairment due to vascular dementia.
MCI is a clinical diagnosis, meaning it’s based on a health care provider’s observations instead of test results alone. Regular clinical checks are needed to monitor the progress of the condition. The guidelines also suggest referring the patient to a specialist if doctors are not experienced in treating cognitive impairment.
Treatment Options for Mild Cognitive Impairment
Treating conditions that can be reversed should be the first step as they can often lead to improvement in cognitive function. These conditions might include sleep disorders like obstructive sleep apnea (OSA), depression, thyroid deficiency, vitamin deficiency, and excessive use of medication. It’s also important to address factors that could potentially worsen the blood flow to your brain, like high cholesterol, high blood pressure, diabetes, irregular heartbeat, and smoking and drinking.
At present, the U.S. Food and Drug Administration (FDA) hasn’t approved any treatment specifically for mild cognitive impairment (MCI). Several drugs, including some used for Alzheimer’s disease, have been tested but have shown no substantial results in improving MCI.
Current medical guidelines from the American Academy of Neurology (AAN) advise against using medicines or diet supplements for MCI. If a physician wants to prescribe such treatments off-label (meaning they were approved for other conditions, but not MCI), it’s important they discuss the reasons with you in detail. They should also let you know about any ongoing clinical trials if you’re interested in drug treatment.
Non-drug treatments like exercise and mental training have shown potential in treating MCI. A study indicated that regular resistance training exercises twice a week could improve cognitive function. Participating in activities that stimulates your brain, like crossword puzzles or card games, and staying socially active can also help slow down the progression of MCI. The AAN suggests regular exercise and cognitive training as part of managing MCI because of their general health benefits and low risk.
Since MCI can potentially progress into a more serious condition like dementia, it’s crucial for doctors to educate patients about this. They should encourage them to plan for the future, such as by designating someone to make medical and financial decisions for them if they become unable to do so. Other potential safety issues like driving, handling of firearms, and susceptibility to scams should also be discussed.
Making sure your vision and hearing are at their best is essential, as untreated problems can contribute to cognitive decline. It’s also beneficial to work on improving balance and walking to help prevent falls. Since the changes associated with MCI can be stressful for caregivers, it’s essential they receive support and help that caters to their particular needs.
What else can Mild Cognitive Impairment be?
Mild Cognitive Impairment (MCI) needs to be distinguished from the normal process of aging, as well as from dementia. If you or a caregiver notices changes in your memory or thinking skills, this could be a sign of MCI. It’s also crucial to consider if the MCI could be due to other reversible causes, such as depression or obstructive sleep apnea (OSA), which need to be looked for and treated if present. MCI could be an early sign of various kinds of dementia, and the specific subtype of MCI might help indicate the underlining cause.
Alzheimer’s disease can exhibit as any of the four MCI types – single or multiple domain MCI with memory loss (A-MCI), or single or multiple domain MCI without memory loss (NA-MCI). Depression can seem like MCI with memory loss. Frontotemporal dementia (FTD) often appears as single domain MCI without memory loss. Vascular cognitive issues can show up in any subtype of MCI. Dementia with Lewy bodies typically appears as multiple domain MCI without memory loss. In Parkinson’s disease, a single domain MCI without memory loss is usually noticed.
What to expect with Mild Cognitive Impairment
The future health outcomes of Mild Cognitive Impairment (MCI) are unpredictable. The condition can develop into dementia at different rates, with annual conversion rates (how often MCI turns into dementia yearly) reported between less than 5% and as high as 20%. Between 40% to 70% of people with MCI may not develop dementia for more than ten years, while around 15%-20% might find their cognitive abilities improve over 1 to 2 years. However, even those who see improvement remain at risk of cognitive decline in the future.
The risk factors that could make MCI progress include a type of MCI where memory loss is the main symptom (amnestic MCI), old age, stroke, diabetes, and low educational levels. On the other hand, factors that could help return to normal cognitive function include a type of MCI where memory loss is not the main symptom (non-amnestic MCI), being younger, having high cognitive function, and high educational levels.
Predicting who will progress from MCI to dementia is not accurate at present. Current models predicting risk are unreliable and limited in their capacity to forecast progression to dementia. Models for predicting risk in the future need to consider other health factors like heart disease and cancer that could cause death before dementia develops.
Possible Complications When Diagnosed with Mild Cognitive Impairment
The main issue with Mild Cognitive Impairment (MCI) is that it can potentially worsen to dementia. It’s crucial to diagnose and treat MCI early. Early treatment helps patients to prepare for their future and also avoids crisis situations or late-stage issues. By identifying and treating possible causes that can be reversed, it might be possible to stabilize or even improve the cognitive changes.
Common Complications:
- Progression to dementia
- Emergencies or late-stage complications if left untreated
- Potential cognitive changes
Preventing Mild Cognitive Impairment
At this time, there are no specific treatments to lessen the risk of Mild Cognitive Impairment (MCI), which is a stage between the expected cognitive decline of normal aging and the more serious decline of dementia. However, managing factors that affect your blood vessels can be helpful. For instance, controlling your blood pressure can lower the risk of developing MCI and the likelihood of getting dementia. It’s also important to manage other conditions that affect your cardiovascular system, such as diabetes, high cholesterol, and obesity, by following general guidelines on heart and brain health.
Combination treatments are necessary if you have other conditions such as Obstructive Sleep Apnea (a serious sleep disorder where breathing repeatedly stops and starts), depression, underactive thyroid gland, use of multiple medications, and hearing loss.
Educating oneself and family members about what MCI is and its progression risks is crucial. Doctors will share that it’s challenging to predict who will move from MCI to dementia, emphasizing that regular check-ups are necessary. Talk about long-term care plans as early as possible and spell out your care goals depending on the stage of MCI. It can be helpful to understand the differences between MCI, dementia, and Alzheimer’s disease to reduce stress. Direct patients to websites like the Alzheimer’s Association and the National Institute on Aging for more resources and further information.
Living a healthy lifestyle is vital too. Encourage activities that promote physical movement, eating a balanced diet, and engaging socially or in activities that stimulate the mind.
Lastly, caregivers should be encouraged to care for themselves, both physically and mentally, to reduce the stress that comes from caring for a person with MCI.
