Dementia is a collective term used to describe various symptoms of cognitive decline, such as forgetfulness. It is a symptom of several underlying diseases and brain disorders.
What is Dementia?
Dementia is not a single disease in itself, but a general term to describe symptoms such as impairments to memory, communication, and thinking.
While the likelihood of having dementia increases with age, it is not a normal part of aging.
Light cognitive impairments, such as poorer short-term memory, can happen as a normal part of aging. This is known as age-related cognitive decline rather than dementia because it does not cause significant problems.
Dementia describes two or more types of symptom that are severe enough to affect daily activities.
- Just over a tenth of people aged 65 years or more have Alzheimer’s disease
- This proportion rises to about a third of people aged 85 and older
- Alzheimer’s accounts for 60-80 percent of all cases of dementia
Causes of Dementia
Dementia is caused by gradual changes and damage in the brain. The most common causes of dementia include diseases in which the brain cells degenerate and die more quickly than they would as part of the normal ageing process. The changes usually happen because of a build-up of abnormal proteins in the brain.
This damage leads to a decline in a person’s mental and, sometimes, physical abilities.
The abnormal proteins are different in each type of these kinds of dementia. In most cases, dementia is not inherited directly from family members. However, frontotemporal dementia can sometimes run in families.
Causes of vascular dementia
Vascular dementia is caused when the brain’s blood supply is interrupted.
Like all organs, the brain needs a constant supply of oxygen and nutrients from the blood to work properly. If the supply of blood is restricted or stopped, the brain cells will begin to die, leading to brain damage.
If the blood vessels inside the brain narrow and harden, the brain’s blood supply can gradually become interrupted. The blood vessels usually narrow and become hard when fatty deposits build up on the blood vessel walls, restricting blood flow. This is called atherosclerosis, and is more common in people who have high blood pressure, type-1 diabetes and those who smoke.
Atherosclerosis in the smaller blood vessels in the brain will also cause them to clog up gradually, depriving the brain of blood. This is known as small vessel disease.
If the brain’s blood supply is interrupted rapidly during a stroke, this can also damage brain cells.
Not everyone who has had a stroke will go on to develop vascular dementia. However, if you have had a stroke or you have been diagnosed with small vessel disease, you may have an increased risk of developing vascular dementia.
Types of Dementia
Alzheimer’s disease, vascular dementia, dementia with lewy bodies, mixed dementia and Parkinson’s disease are common types of dementia. Frontotemporal dementia, Creutzfeldt-Jakob disease, Huntington’s disease and Wernicke-Korsakoff syndrome are also types of dementia, according to the Alzheimer’s Association.
Dementia is split into two major categories: cortical and subcortical dementia, says WebMD. Alzheimer’s disease and Creutzfeldt-Jakob disease are part of cortical dementia, while Huntington’s disease and Parkinson’s disease are part of subcortical dementia
Treatment of dementia depends on its cause. In the case of most progressive dementias, including Alzheimer’s disease, there is no cure and no treatment that slows or stops its progression. But there are drug treatments that may temporarily improve symptoms. The same medications used to treat Alzheimer’s are among the drugs sometimes prescribed to help with symptoms of other types of dementias. Non-drug therapies can also alleviate some symptoms of dementia.
Ultimately, the path to effective new treatments for dementia is through increased research funding and increased participation in clinical studies.
- Where possible, the underlying cause of dementia should be treated
- In case the disease cannot be cured, the goal of treatment is to improve and/or control the symptoms of dementia
- A combination of psychotherapy, environmental modifications, and medication is the best approach, but this can still be complemented by other therapies
Treatment of dementia begins with the treatment of the underlying disease, where possible. The underlying causes of nutritional, hormonal, tumour-caused or drug-related dementia may be reversible to some extent. For many other diseases, such as Alzheimer’s disease (AD), no cure has yet been discovered. However, improvement of cognitive and behavioural symptoms can be achieved through a combination of appropriate medications and other treatments, including psychotherapy.
The goal of treatment is to slow down the progression of dementia-related impairments and to control behavioral symptoms, which may be treated with a combination of psychotherapy, environmental modifications, and medication1.
Psychotherapy, in particular behavioral approaches, can be used to reduce the frequency or severity of problematic behaviors, such as aggression or socially inappropriate conduct. Identifying what might be triggering a problematic behavior and then devising an intervention that either changes the person’s environment or the caregiver’s reaction to the behavior can be effective. Other strategies may include breaking down complex tasks, such as dressing, into simpler steps, or reducing the amount of activity in the environment to avoid confusion and agitation.
Modifying the environment can increase safety and comfort while decreasing agitation. Home modifications for safety include removal or lock-up of hazards such as sharp knives, dangerous chemicals, and tools. Child-proof latches may be used to limit access. Bed rails and bathroom safety rails can be important safety measures as well. Another example is lowering the hot water temperature, which reduces the risk of burning or disabling the stove and/or using stove childproof knobs may be necessary to prevent cooking accidents.
Medication can be prescribed to reduce dementia symptoms. There are a number of drugs available today for improving brain function. Typically, anti-dementia or other psychotropic drugs are prescribed.
The more recent anti-dementia agents belong to the so-called acetylcholinesterase inhibitors. Acetylcholine is one of the chemical substances that allow brain cells to communicate with one another, the so-called neurotransmitters. Research suggests that acetylcholine is reduced in the brain of AD patients. These kinds of drugs prevent acetylcholine being eliminated too quickly, prolonging its ability to conduct chemical messages between brain cells. It could be shown in clinical trials that, with these kinds of drugs, the deterioration of the disease could be delayed by at least 12 months. Apart from preserving and partially improving mental capacities, and coping with daily activities, a delayed onset of behavioral disturbances and a reduction in caring time could also be demonstrated.
Psychotropic drugs: can be used as a supportive therapy in the treatment of behavioral problems in dementia. For instance, antipsychotic medications (typically used to treat disorders like schizophrenia) can be effective in reducing persistent aggression, and in patients who have been unresponsive to non-pharmacological approaches, and where there is a risk of harm to themselves or others; however, such treatments should be used on a short-term up to six weeks rather than a systematic basis.
Anti-anxiety medications (typically used to treat anxiety disorders) can also be prescribed to help treating agitation and restlessness. Likewise, antidepressant medication can be prescribed to alleviate symptoms of depression. Treating depression symptoms is particularly important, as depression makes it harder for a person with dementia to remember things and enjoy life. It also adds to the difficulty of caring for someone with dementia. Significant improvements can be made by treating depression, as the patient’s mood and their ability to participate in activities may be improved5.
In general, medications should be administered very cautiously to patients with dementia and in the lowest possible effective doses, to minimize side effects. Supervision of taking medications is generally required. With each of these medications, there are associated side effects and risks. Therefore, a careful risk-benefit evaluation should be conducted before treatment initiation and on a regular basis throughout treatment. However, one must bear in mind that these medications do not cure dementia or reverse someone’s symptoms. There is no evidence that life is prolonged by taking medications. Rather, these medications can help some patients functioning better for a longer period of time6.
Dementia risk and prevention
Some risk factors for dementia, such as age and genetics, cannot be changed. But researchers continue to explore the impact of other risk factors on brain health and prevention of dementia. Some of the most active areas of research in risk reduction and prevention include cardiovascular factors, physical fitness, and diet.
Cardiovascular risk factors: Your brain is nourished by one of your body’s richest networks of blood vessels. Anything that damages blood vessels anywhere in your body can damage blood vessels in your brain, depriving brain cells of vital food and oxygen. Blood vessel changes in the brain are linked to vascular dementia. They often are present along with changes caused by other types of dementia, including Alzheimer’s disease and dementia with Lewy bodies. These changes may interact to cause faster decline or make impairments more severe. You can help protect your brain with some of the same strategies that protect your heart – don’t smoke; take steps to keep your blood pressure, cholesterol and blood sugar within recommended limits; and maintain a healthy weight.
Physical exercise: Regular physical exercise may help lower the risk of some types of dementia. Evidence suggests exercise may directly benefit brain cells by increasing blood and oxygen flow to the brain.
Diet: What you eat may have its greatest impact on brain health through its effect on heart health. The best current evidence suggests that heart-healthy eating patterns, such as the Mediterranean diet, also may help protect the brain. A Mediterranean diet includes relatively little red meat and emphasizes whole grains, fruits and vegetables, fish and shellfish, and nuts, olive oil and other healthy fats.