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Health Letter | Normal Memory Loss and Dementia: How to Tell the Difference

Normal Memory Loss and Dementia: How to Tell the Difference

Health Letter article, September 2013

If you are an older adult, memory problems are probably a regular occurrence in your life. Memory lapses, such as misplacing your keys, forgetting your medication or missing an important appointment, often become more common as you age. Yet such problems can be particularly distressing for elderly adults, because it can be difficult for them to tell the difference between normal memory lapses and the start of a more serious decline into dementia due to Alzheimer’s disease or other causes. Dementia, defined as chronic impairment in thinking and social abilities severe enough to interfere with daily functioning, is a concern for many people as they grow older. About 1 in 5 people who live past 65 will develop dementia in their lifetimes. This risk goes up as people age: More than 1 in 4 people over 85 have dementia, and about 40 percent of those over 90 are estimated to have the condition.

In a small number of cases, dementia is reversible. In others, diagnosing the condition can be an important first step toward putting appropriate social and medical support in place that will provide for a life that is as comfortable and normal as possible as mental function declines.

Read on to learn two simple tests to distinguish between normal memory loss and dementia, and be prepared to talk to a doctor when you or someone you care about may be experiencing problems.

Identifying normal memory loss, mild cognitive impairment and dementia

It is a normal part of healthy aging to experience some difficulty with memory or reasoning, two types of cognitive function. Physicians have developed two medical terms to describe individuals whose cognitive functioning has declined to a point at which it can no longer be considered healthy. When a person has some level of cognitive impairment that can be detected using an assessment test, but that person is nevertheless generally still able to function as normal independently, he or she can be diagnosed with a condition known as “mild cognitive impairment.” The second term, “dementia,” is used when the person’s thinking or behavior becomes so impaired that he or she is no longer able to carry out normal daily activities independently. Since it is not easy to pinpoint the precise line between normal aging and mild cognitive impairment, or between mild cognitive impairment and dementia, physicians often need to diagnose these conditions by offering assessment tests and talking to the patient and family members about concerns with the patient’s thinking or behavior. Cognitive assessment tests measure impairment in several different areas: ability to recall new information (short-term memory), reasoning, visuospatial ability (the ability to draw or arrange objects), language and personality. Impairment in any of these areas can be enough to support a diagnosis of mild cognitive impairment, whereas a dementia diagnosis generally requires identifying impairment in two or more areas, where the impairment also interferes with the person’s ability to function at work or in a social setting.

Not everyone with mild cognitive impairment will go on to develop dementia, and others will develop dementia only very slowly. Each year, about 10 to 15 percent of people with mild cognitive impairment develop dementia caused by Alzheimer’s disease.

Two simple screening tests used by physicians to detect risk for dementia are included in the text box at right. If you or a loved one may be at risk, you should seek a more thorough assessment from a trained physician. Doctors can combine mental assessments with blood tests and other laboratory evaluations to identify causes of mild cognitive impairment or dementia.

Dementia causes, risks and treatments

About 70 percent of dementia patients are diagnosed with Alzheimer’s disease. Other causes of dementia include vascular dementia, caused by restricted blood flow to the brain from stroke or other conditions; Parkinson’s disease; chronic alcoholism; the use of some prescription drugs; and frontal lobe dementia, which is caused by changes to the frontal lobes of the brain.

Some people who experience memory loss do not have dementia. People with depression often complain of memory loss and have difficulty concentrating. Delirium, brought on by a drug reaction or sudden medical condition, can also cause problems with thinking. Both of these potentially treatable conditions can be incorrectly diagnosed as dementia and can also occur simultaneously with dementia.

Dementia is sometimes treatable, but such cases are relatively rare: Only about 1.5 percent of cases of mild to moderate dementia are fully reversible. Certain symptoms help identify these rare cases so appropriate treatment steps can be taken. (See the text box below).

Other cases of dementia are not treatable, but certain factors affect your risk of getting the disease. Having a close relative with Alzheimer’s disease increases your risk of developing Alzheimer’s dementia, as does carrying a specific gene associated with the disease, known as the APOE4 gene. People who complete high school or college are at lower risk for dementia than people with less education. People who live a heart-healthy lifestyle by controlling their blood pressure and eating a healthful diet low in saturated fats and rich in vegetables, beans, fruits, nuts, cereals, fish and olive oil may be less likely to develop the symptoms of Alzheimer’s disease or vascular dementia.

Simple Tests to Screen for Dementia

Here are two simple tests commonly used by physicians to identify patients who may be in need of more thorough assessment to diagnose for dementia. You can ask your family doctor to administer these tests in the office, or try taking them yourself at home.

Test One: Ask the test-taker to name as many animals as possible in 60 seconds. People with a high school education and no impairment should easily be able to name at least 15 animals. However, those with very limited education (for example, those that did not attend middle school or high school) may only be able to name 9 or 12 animals.

Test Two: Ask the test-taker to say three unrelated words (example: chair, Seattle, apricot), draw a picture of a clock set to a particular time (example: ten minutes after 11 o’clock), and then try to repeat the same three words again. The person earns one point for each correct word remembered and two points if the clock drawing includes a circle with all of the correct numbers in the right order and hands pointing at approximately the right positions. If anything is out of place on the clock, it earns zero points. A score of 2 or below is a good indicator of dementia.

Remember: These tests are not the same thing as a medical diagnosis of dementia. If you or your loved one struggles to name 15 animals (or 9 for those with minimal education), or gets a score of 2 or below on the clock test, it’s time to ask your family doctor for help getting a more thorough medical assessment.

Symptoms and Risk Factors for Treatable Dementia

Talk to your doctor if you have identified difficulties with thought, memory or behavior and have one of these symptoms or risk factors, which indicate a rare cause of dementia or mild cognitive impairment that may be treatable.

Potential Diagnosis
Symptom or Risk Factor
Numbness, tingling or weakness in the hands, arms, legs or feet; tongue soreness; weight loss Vitamin B12 deficiency
Shuffling gait, urinary incontinence Abnormal buildup of fluid in the brain
Use of drugs that affect the brain, including benzodiazepines and anticholinergics Side effects from medication
Tiredness, sensitivity to cold, constipation, weight gain, hair loss Hypothyroidism
Recent head injury, headache, seizures, paralysis on one side of the body, swelling behind the eye Bleeding in the spaces around the brain
A history of alcoholism, abnormal eye movements, eyelid drooping or double vision, loss of muscle coordination Wernicke-Korsakoff syndrome (Vitamin B1 deficiency), sometimes due to alcoholism
History of high-risk sexual behavior or illicit drug use Syphilis or HIV-associated dementia

There also is a growing body of evidence that physical and intellectual activity may help delay the onset of dementia symptoms. In particular, one randomized controlled clinical trial recently showed that a six-month program of physical activity offered modest improvements in cognitive performance among elderly subjects who reported memory problems but did not have dementia. (See the text box above.) Moreover, walking and other physical activity carry minimal risks, are widely available at low cost, and have an array of other physical and mental health benefits.

There also is some evidence that controlling hypertension through drugs or lifestyle changes can help prevent the onset of vascular dementia or Alzheimer’s disease, though the evidence is limited that such treatment can reverse cognitive decline in patients already diagnosed with vascular dementia. Treating hypertension has many health benefits, and you should not wait for a dementia diagnosis to get your hypertension under control.

Unfortunately, for most people with dementia, there is no effective treatment available that will restore mental functioning. The FDA has approved several drugs to treat Alzheimer’s disease, but Public Citizen’s WorstPills.org website has categorized each of these therapies as Do Not Use, because none produce meaningful improvements in cognitive or other functions and all carry harmful side effects. Other forms of dementia, such as frontal lobe dementia, also have no known effective treatment. However, therapy or counseling may be helpful in finding strategies to cope with memory loss and other symptoms. Therapy also can help address depression, which is common among elderly people with mild cognitive impairment and dementia and can produce similar symptoms.

Even if dementia symptoms are not treatable, diagnosing and becoming aware of impairment early on can help, because it encourages families to plan for the future. Families may benefit from extra time to develop a plan for obtaining health care, keeping the person with dementia safe and handling financial issues. Families and individuals also can use the diagnosis as an opportunity to talk about important legal decisions while the affected family member is still capable of making choices for themselves, including formulating an advance directive for end-of-life decisions and selecting a person to exercise power of attorney for financial, health and personal care decision-making.

Physical Activity May Improve Cognitive Function

In 2008, the Journal of the American Medical Association published a study showing that a six-month program of physical activity led to modest improvements in cognitive function for adults over age 50 who reported memory problems but did not meet criteria for dementia. The study randomized 170 participants to receive either standard healthy lifestyle advice alone or lifestyle advice plus a home exercise program that encouraged them to complete at least three 50-minute sessions of physical activity per week. Participants chose their own programs, with most selecting walking or other aerobic exercise. Some also did light strength training.

At the end of the program, participants in the physical activity program had improved 1.3 points (on a scale of 0 to 70) on the Alzheimer’s Disease Assessment Scale?Cognitive Subscale (ADAS?Cog), a measure of cognitive performance. By contrast, subjects enrolled in an earlier clinical trial of donepezil (ARICEPT), a drug approved to treat Alzheimer’s dementia, demonstrated an improvement of only 0.5 points on the same scale. Moreover, some of the cognitive benefits of the exercise program could still be seen a year after the program ended, whereas patients who took donepezil for six months had no significant benefits at one year after treatment ended. The benefits of physical activity were similar regardless of whether participants actually met objective criteria for cognitive impairment or simply believed they had memory problems even though their objective performance was normal.

The researchers who conducted the experiment are not certain why exercise improves mental function but believe it may help by assisting with blood flow to the brain or providing a mentally stimulating environment.

Advice for patients

It is normal to experience problems with memory and thinking as you age. The odds are good that these problems are not signs of early dementia. However, if you start to become concerned that a member of your family has reached a level of impairment that is not normal, particularly if it creates difficulties carrying out daily activities, it is time to talk to a doctor about assessing the person for dementia.

You also can test at home for impairments using one of the simple tests identified in the text box on page 2. If the score is low enough to indicate dementia, you should talk about setting up an appointment for a more thorough evaluation.

Tell the doctor if you or a loved one have observed any of the symptoms or risk factors described in the text box. Talking to a doctor about these symptoms as soon as possible will help detect treatable causes of cognitive impairment or dementia and minimize potential harm.