Dementia

What causes dementia?

Dementia is caused by damage to or loss of nerve cells and their connections in the brain. Depending on the area of the brain that's affected by the damage, dementia can affect people differently and cause different symptoms.

Dementias are often grouped by what they have in common, such as the protein or proteins deposited in the brain or the part of the brain that's affected. Some diseases look like dementias, such as those caused by a reaction to medications or vitamin deficiencies, and they might improve with treatment.

Progressive dementias

Types of dementias that progress and aren't reversible include:

  • Alzheimer's disease. Alzheimer's disease is the most common cause of dementia.

    Although not all causes of Alzheimer's disease are known, experts do know that a small percentage are related to mutations of three genes, which can be passed down from parent to child. While several different genes are probably involved in Alzheimer's disease, one important gene that increases risk is apolipoprotein E4 (APOE).

    Alzheimer's disease patients have plaques and tangles in their brains. Plaques are clumps of a protein called beta-amyloid, and tangles are fibrous tangles made up of tau protein. It's thought that these clumps damage healthy neurons and the fibers connecting them.

    Other genetic factors might make it more likely that people will develop Alzheimer's.

  • Vascular dementia. This second most common type of dementia is caused by damage to the vessels that supply blood to your brain. Blood vessel problems can cause strokes or damage the brain in other ways, such as by damaging the fibers in the white matter of the brain. The most common symptoms of vascular dementia include difficulties with problem-solving, slowed thinking, focus and organization. These tend to be more noticeable than memory loss.
  • Lewy body dementia. Lewy bodies are abnormal balloonlike clumps of protein that have been found in the brains of people with Lewy body dementia, Alzheimer's disease and Parkinson's disease. This is one of the more common types of progressive dementia. Common signs and symptoms include acting out one's dreams in sleep, seeing things that aren't there (visual hallucinations), and problems with focus and attention. Other signs include uncoordinated or slow movement, tremors, and rigidity (parkinsonism).
  • Frontotemporal dementia. This is a group of diseases characterized by the breakdown (degeneration) of nerve cells and their connections in the frontal and temporal lobes of the brain, the areas generally associated with personality, behavior and language. Common symptoms affect behavior, personality, thinking, judgment, and language and movement.
  • Mixed dementia. Autopsy studies of the brains of people 80 and older who had dementia indicate that many had a combination of several causes, such as Alzheimer's disease, vascular dementia and Lewy body dementia. Studies are ongoing to determine how having mixed dementia affects symptoms and treatments.

Other disorders linked to dementia

  • Huntington's disease. Caused by a genetic mutation, this disease causes certain nerve cells in your brain and spinal cord to waste away. Signs and symptoms, including a severe decline in thinking (cognitive) skills, usually appear around age 30 or 40.
  • Traumatic brain injury (TBI). This condition is most often caused by repetitive head trauma. People such as boxers, football players or soldiers might experience TBI.

    Depending on the part of the brain that's injured, this condition can cause dementia signs and symptoms such as depression, explosiveness, memory loss and impaired speech. TBI may also cause parkinsonism. Symptoms might not appear until years after the trauma.

  • Creutzfeldt-Jakob disease. This rare brain disorder usually occurs in people without known risk factors. This condition might be due to deposits of infectious proteins called prions. Creutzfeldt-Jakob disease usually has no known cause but can be inherited. It may also be caused by exposure to diseased brain or nervous system tissue, such as from a cornea transplant.

    Signs and symptoms of this fatal condition usually appear after age 60.

  • Parkinson's disease. Many people with Parkinson's disease eventually develop dementia symptoms (Parkinson's disease dementia).

Dementia-like conditions that can be reversed

Some causes of dementia or dementia-like symptoms can be reversed with treatment. They include:

  • Infections and immune disorders. Dementia-like symptoms can result from fever or other side effects of your body's attempt to fight off an infection. Multiple sclerosis and other conditions caused by the body's immune system attacking nerve cells also can cause dementia.
  • Metabolic problems and endocrine abnormalities. People with thyroid problems, low blood sugar (hypoglycemia), too little or too much sodium or calcium, or problems absorbing vitamin B-12 can develop dementia-like symptoms or other personality changes.
  • Nutritional deficiencies. Not drinking enough liquids (dehydration); not getting enough thiamin (vitamin B-1), which is common in people with chronic alcoholism; and not getting enough vitamins B-6 and B-12 in your diet can cause dementia-like symptoms. Copper and vitamin E deficiencies also can cause dementia symptoms.
  • Medication side effects. Side effects of medications, a reaction to a medication or an interaction of several medications can cause dementia-like symptoms.
  • Subdural hematomas. Bleeding between the surface of the brain and the covering over the brain, which is common in the elderly after a fall, can cause symptoms similar to those of dementia.
  • Poisoning. Exposure to heavy metals, such as lead, and other poisons, such as pesticides, as well as recreational drug or heavy alcohol use can lead to symptoms of dementia. Symptoms might resolve with treatment.
  • Brain tumors. Rarely, dementia can result from damage caused by a brain tumor.
  • Anoxia. This condition, also called hypoxia, occurs when organ tissues aren't getting enough oxygen. Anoxia can occur due to severe sleep apneas, asthma, heart attack, carbon monoxide poisoning or other causes.
  • Normal-pressure hydrocephalus. This condition, which is caused by enlarged ventricles in the brain, can cause walking problems, urinary difficulty and memory loss.

Risk factors

Many factors can eventually contribute to dementia. Some factors, such as age, can't be changed. Others can be addressed to reduce your risk.

Risk factors that can't be changed

  • Age. The risk rises as you age, especially after age 65. However, dementia isn't a normal part of aging, and dementia can occur in younger people.
  • Family history. Having a family history of dementia puts you at greater risk of developing the condition. However, many people with a family history never develop symptoms, and many people without a family history do. There are tests to determine whether you have certain genetic mutations.
  • Down syndrome. By middle age, many people with Down syndrome develop early-onset Alzheimer's disease.

Risk factors you can change

You might be able to control the following risk factors for dementia.

  • Diet and exercise. Research shows that lack of exercise increases the risk of dementia. And while no specific diet is known to reduce dementia risk, research indicates a greater incidence of dementia in people who eat an unhealthy diet compared with those who follow a Mediterranean-style diet rich in produce, whole grains, nuts and seeds.
  • Heavy alcohol use. If you drink large amounts of alcohol, you might have a higher risk of dementia. While some studies have shown that moderate amounts of alcohol might have a protective effect, results are inconsistent. The relationship between moderate amounts of alcohol and dementia risk isn't well-understood.
  • Cardiovascular risk factors. These include high blood pressure (hypertension), high cholesterol, buildup of fats in your artery walls (atherosclerosis) and obesity.
  • Depression. Although not yet well-understood, late-life depression might indicate the development of dementia.
  • Diabetes. Having diabetes may increase your risk of dementia, especially if it's poorly controlled.
  • Smoking. Smoking might increase your risk of developing dementia and blood vessel (vascular) diseases.
  • Sleep apnea. People who snore and have episodes where they frequently stop breathing while asleep may have reversible memory loss.
  • Vitamin and nutritional deficiencies. Low levels of vitamin D, vitamin B-6, vitamin B-12 and folate may increase your risk of dementia.

Complications

Dementia can affect many body systems and, therefore, the ability to function. Dementia can lead to:

  • Poor nutrition. Many people with dementia eventually reduce or stop eating, affecting their nutrient intake. Ultimately, they may be unable to chew and swallow.
  • Pneumonia. Difficulty swallowing increases the risk of choking or aspirating food into the lungs, which can block breathing and cause pneumonia.
  • Inability to perform self-care tasks. As dementia progresses, it can interfere with bathing, dressing, brushing hair or teeth, using the toilet independently, and taking medications accurately.
  • Personal safety challenges. Some day-to-day situations can present safety issues for people with dementia, including driving, cooking and walking alone.
  • Death. Late-stage dementia results in coma and death, often from infection.

Prevention

There's no sure way to prevent dementia, but there are steps you can take that might help. More research is needed, but it might be beneficial to do the following:

  • Keep your mind active. Mentally stimulating activities, such as reading, solving puzzles and playing word games, and memory training might delay the onset of dementia and decrease its effects.
  • Be physically and socially active. Physical activity and social interaction might delay the onset of dementia and reduce its symptoms. Move more and aim for 150 minutes of exercise a week.
  • Quit smoking. Some studies have shown that smoking in middle age and beyond may increase your risk of dementia and blood vessel (vascular) conditions. Quitting smoking might reduce your risk and will improve your health.
  • Get enough vitamins. Some research suggests that people with low levels of vitamin D in their blood are more likely to develop Alzheimer's disease and other forms of dementia. You can get vitamin D through certain foods, supplements and sun exposure.

    More study is needed before an increase in vitamin D intake is recommended for preventing dementia, but it's a good idea to make sure you get adequate vitamin D. Taking a daily B-complex vitamin and vitamin C may also be helpful.

  • Manage cardiovascular risk factors. Treat high blood pressure, high cholesterol, diabetes, and high body mass index (BMI). High blood pressure might lead to a higher risk of some types of dementia. More research is needed to determine whether treating high blood pressure may reduce the risk of dementia.
  • Treat health conditions. See your doctor for treatment if you experience hearing loss, depression or anxiety.
  • Maintain a healthy diet. Eating a healthy diet is important for many reasons, but a diet such as the Mediterranean diet — rich in fruits, vegetables, whole grains and omega-3 fatty acids, which are commonly found in certain fish and nuts — might promote health and lower your risk of developing dementia. This type of diet also improves cardiovascular health, which may help lower dementia risk. Try eating fatty fish such as salmon three times a week, and a handful of nuts — especially almonds and walnuts — daily.
  • Get quality sleep. Practice good sleep hygiene, and talk to your doctor if you snore loudly or have periods where you stop breathing or gasp during sleep.

Last updated on 05-01-20

How is dementia diagnosed?

Diagnosing dementia and its type can be challenging. People have dementia when they have cognitive impairment and lose their ability to perform daily functions, such as taking their medication, paying bills and driving safely.

To diagnose the cause of the dementia, the doctor must recognize the pattern of the loss of skills and function and determine what a person is still able to do. More recently, biomarkers have become available to make a more accurate diagnosis of Alzheimer's disease.


Your doctor will review your medical history and symptoms and conduct a physical examination. He or she will likely ask someone close to you about your symptoms as well.

No single test can diagnose dementia, so doctors are likely to run a number of tests that can help pinpoint the problem.

Cognitive and neuropsychological tests

Doctors will evaluate your thinking (cognitive) function. A number of tests measure thinking skills, such as memory, orientation, reasoning and judgment, language skills, and attention.

Neurological evaluation

Doctors evaluate your memory, language, visual perception, attention, problem-solving, movement, senses, balance, reflexes and other areas.

Brain scans

  • CT or MRI. These scans can check for evidence of stroke or bleeding or tumor or hydrocephalus.
  • PET scans. These can show patterns of brain activity and whether the amyloid protein, a hallmark of Alzheimer's disease, has been deposited in the brain.

Laboratory tests

Simple blood tests can detect physical problems that can affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland. Sometimes the spinal fluid is examined for infection, inflammation or markers of some degenerative diseases.

Psychiatric evaluation

A mental health professional can determine whether depression or another mental health condition is contributing to your symptoms.

Last updated on 05-01-20

How is dementia treated?

Most types of dementia can't be cured, but there are ways to manage your symptoms.

Medications

The following are used to temporarily improve dementia symptoms.

  • Cholinesterase inhibitors. These medications — including donepezil (Aricept), rivastigmine (Exelon) and galantamine (Razadyne) — work by boosting levels of a chemical messenger involved in memory and judgment.

    Although primarily used to treat Alzheimer's disease, these medications might also be prescribed for other dementias, including vascular dementia, Parkinson's disease dementia and Lewy body dementia.

    Side effects can include nausea, vomiting and diarrhea. Other possible side effects include slowed heart rate, fainting and sleep disturbances.

  • Memantine. Memantine (Namenda) works by regulating the activity of glutamate, another chemical messenger involved in brain functions, such as learning and memory. In some cases, memantine is prescribed with a cholinesterase inhibitor.

    A common side effect of memantine is dizziness.

  • Other medications. Your doctor might prescribe medications to treat other symptoms or conditions, such as depression, sleep disturbances, hallucinations, parkinsonism or agitation.

Therapies

Several dementia symptoms and behavior problems might be treated initially using nondrug approaches, such as:

  • Occupational therapy. An occupational therapist can show you how to make your home safer and teach coping behaviors. The purpose is to prevent accidents, such as falls; manage behavior; and prepare you for the dementia progression.
  • Modifying the environment. Reducing clutter and noise can make it easier for someone with dementia to focus and function. You might need to hide objects that can threaten safety, such as knives and car keys. Monitoring systems can alert you if the person with dementia wanders.
  • Simplifying tasks. Break tasks into easier steps and focus on success, not failure. Structure and routine also help reduce confusion in people with dementia.

Lifestyle and home remedies

Dementia symptoms and behavior problems will progress over time. Caregivers might try the following suggestions:

  • Enhance communication. When talking with your loved one, maintain eye contact. Speak slowly in simple sentences, and don't rush the response. Present one idea or instruction at a time. Use gestures and cues, such as pointing to objects.
  • Encourage exercise. The main benefits of exercise in people with dementia include improved strength, balance and cardiovascular health. Exercise may also be helpful in managing symptoms such as restlessness. There is growing evidence that exercise also protects the brain from dementia, especially when combined with a healthy diet and treatment for risk factors for cardiovascular disease.

    Some research also shows that physical activity might slow the progression of impaired thinking in people with Alzheimer's disease, and it can lessen symptoms of depression.

  • Engage in activity. Plan activities the person with dementia enjoys and can do. Dancing, painting, gardening, cooking, singing and other activities can be fun, can help you connect with your loved one, and can help your loved one focus on what he or she can still do.
  • Establish a nighttime ritual. Behavior is often worse at night. Try to establish going-to-bed rituals that are calming and away from the noise of television, meal cleanup and active family members. Leave night lights on in the bedroom, hall and bathroom to prevent disorientation.

    Limiting caffeine, discouraging napping and offering opportunities for exercise during the day might ease nighttime restlessness.

  • Keep a calendar. A calendar might help your loved one remember upcoming events, daily activities and medication schedules. Consider sharing a calendar with your loved one.
  • Plan for the future. Develop a plan with your loved one while he or she is able to participate that identifies goals for future care. Support groups, legal advisers, family members and others might be able to help.

    You'll need to consider financial and legal issues, safety and daily living concerns, and long-term care options.

Alternative medicine

Several dietary supplements, herbal remedies and therapies have been studied for people with dementia. But at this time there is no convincing evidence for any of these.

Use caution when considering taking dietary supplements, vitamins or herbal remedies, especially if you're taking other medications. These remedies aren't regulated, and claims about their benefits aren't always based on scientific research.

While some studies suggest that vitamin E supplements may be helpful for Alzheimer's disease, the evidence is not convincing and large doses may pose risks. Vitamin E supplementation is not currently recommended, but including vitamin E in the diet through foods such as nuts is suggested to promote brain health.

Other therapies

The following techniques may help reduce agitation and promote relaxation in people with dementia.

  • Music therapy, which involves listening to soothing music
  • Light exercise
  • Watching videos of family members
  • Pet therapy, which involves use of animals, such as visits from dogs, to promote improved moods and behaviors in people with dementia
  • Aromatherapy, which uses fragrant plant oils
  • Massage therapy
  • Art therapy, which involves creating art, focusing on the process rather than the outcome

Coping and support

Receiving a diagnosis of dementia can be devastating. Many details need to be considered to ensure that you and those around you are as prepared as possible for dealing with a condition that's unpredictable and progressive.

Care and support for the person with the disease

Here are some suggestions you can try to help yourself cope with the disease:

  • Learn as much as you can about memory loss, dementia and Alzheimer's disease.
  • Write about your feelings in a journal.
  • Join a local support group.
  • Get individual or family counseling.
  • Talk to a member of your spiritual community or another person who can help you with your spiritual needs.
  • Stay active and involved, volunteer, exercise, and participate in activities for people with memory loss.
  • Spend time with friends and family.
  • Participate in an online community of people who are having similar experiences.
  • Find new ways to express yourself, such as through painting, singing or writing.
  • Delegate help with decision-making to someone you trust.

Helping someone with dementia

You can help a person cope with the disease by listening, reassuring the person that he or she still can enjoy life, being supportive and positive, and doing your best to help the person retain dignity and self-respect.

Caregiver support

Providing care for someone with dementia is physically and emotionally demanding. Feelings of anger and guilt, frustration and discouragement, worry, grief, and social isolation are common. If you're a caregiver for someone with dementia:

  • Learn as much about the disease as you can and participate in caregiver education programs
  • Find out about supportive services in your community, such as respite care or adult care, which can give you a break from caregiving at scheduled times during the week
  • Ask friends or other family members for help
  • Take care of your physical, emotional and spiritual health
  • Ask questions of doctors, social workers and others involved in the care of your loved one
  • Join a support group

Last updated on 05-01-20

Mayo Clinic. Dementia Reference Link

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