Dementia is a general term for a decline in mental ability severe enough to interfere with daily life. Memory loss is an example. A person's consciousness is usually not affected. Alzheimer's is the most common type of dementia. Alzheimer's disease accounts for 60 to 80 percent of cases. Vascular dementia, which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies. There is no cure for dementia.
While most changes in the brain that cause dementia are permanent and worsen over time, thinking and memory problems caused by the following conditions may improve when the condition is treated or addressed:
Medication side effects
Excess use of alcohol
Globally, dementia affects 47.5 million people. About 10% of people develop the disorder at some point in their lives. It becomes more common with age. About 3% of people between the ages of 65–74 have dementia, 19% between 75 and 84 and nearly half of those over 85 years of age.
As more people are living longer, dementia is becoming more common in the population as a whole.
It is not a specific disease. People with dementia may not be able to think well enough to do normal activities, such as getting dressed or eating. They may lose their ability to solve problems or control their emotions. Their personalities may change. They may become agitated or see things that are not there.
Memory Loss and other Symptoms of Dementia
While symptoms of dementia can vary greatly, at least two of the following core mental functions must be significantly impaired to be considered dementia:
Communication and language
Ability to focus and pay attention
Reasoning and judgment
People with dementia may have problems with short-term memory, keeping track of a purse or wallet, paying bills, planning and preparing meals, remembering appointments or travelling out of the neighbourhood.
Many dementias are progressive, meaning symptoms start out slowly and gradually get worse. If you or a loved one is experiencing memory difficulties or other changes in thinking skills, don't ignore them. See a doctor soon to determine the cause. Professional evaluation may detect a treatable condition. And even if symptoms suggest dementia, early diagnosis allows a person to get the maximum benefit from available treatments and provides an opportunity to volunteer for clinical trials or studies. It also provides time to plan for the future.
Dementia is caused by damage to brain cells. This damage interferes with the ability of brain cells to communicate with each other. When brain cells cannot communicate normally, thinking, behaviour and feelings can be affected.
The brain has many distinct regions, each of which is responsible for different functions (for example, memory, judgment and movement). When cells in a particular region are damaged, that region cannot carry out its functions normally.
Different types of dementia are associated with particular types of brain cell damage in particular regions of the brain. For example, in Alzheimer's disease, high levels of certain proteins inside and outside brain cells make it hard for brain cells to stay healthy and to communicate with each other. The brain region called the hippocampus is the centre of learning and memory in the brain, and the brain cells in this region are often the first to be damaged. That's why memory loss is often one of the earliest symptoms of Alzheimer's.
Diagnosis of Dementia
There is no one test to determine if someone has dementia. Doctors diagnose Alzheimer's and other types of dementia based on a careful medical history, a physical examination, laboratory tests, and the characteristic changes in thinking, day-to-day function and behaviour associated with each type. Doctors can determine that a person has dementia with a high level of certainty. But it's harder to determine the exact type of dementia because the symptoms and brain changes of different dementias can overlap. In some cases, a doctor may diagnose "dementia" and not specify a type. If this occurs it may be necessary to see a specialist such as a neurologist or gero-psychologist.
Cognitive dementia tests
Today's cognitive dementia tests are widely used and have been verified as a reliable way of indicating dementia. They have changed little since being established in the early 1970s.
The abbreviated mental test score has 10 questions which include:
What is your age?
What is the time, to the nearest hour?
What is the year?
What is your date of birth?
Each correct answer gets one point; scoring six points or fewer suggests cognitive impairment.
The General Practitioner Assessment of Cognition (GPCOG) test includes an added element for recording the observations of relatives and caregivers.
Designed for doctors, this sort of test may be the first formal assessment of a person's mental ability.
The second part of the test probes someone close to the patient and includes six questions to find out whether the patient has:
Become less able to remember recent events or conversations
Begun struggling to find the right words or using inappropriate ones
Found difficulty managing money or medications
Needed more help with transport (without the reason being, for example, injury)
If the test does suggest memory loss, standard investigations are then recommended, including routine blood tests and a CT brain scan.
Clinical tests will identify, or rule out, treatable causes of memory loss and help to narrow down potential causes, such as Alzheimer's disease.
The mini-mental state examination (MMSE) is a cognitive test which measures:
Orientation to time and place
Attention and calculation
The MMSE is used to help diagnose dementia caused by Alzheimer's disease and also to rate its severity and whether drug treatment is needed.
Dementia Treatment and Care
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.
There is also a lot that can be done to enable someone with dementia to live well with the condition. Care and support should be 'person-centred', valuing the person as a unique individual.
Ultimately, the path to effective new treatments for dementia is through increased research funding and increased participation in clinical studies. Right now, volunteers are urgently needed to participate in more than 180+ actively enrolling clinical studies and trials about Alzheimer's and related dementias.
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.
Dementia with Lewy Bodies (DLB)
Symptoms: People with dementia with Lewy bodies often have memory loss and thinking problems common in Alzheimer's, but are more likely than people with Alzheimer's to have initial or early symptoms such as sleep disturbances, well-formed visual hallucinations, and slowness, gait imbalance or other parkinsonian movement features.
Brain changes: Lewy bodies are abnormal aggregations (or clumps) of the protein alpha-synuclein. When they develop in a part of the brain called the cortex, dementia can result. Alpha-synuclein also aggregates in the brains of people with Parkinson's disease, but the aggregates may appear in a pattern that is different from dementia with Lewy bodies.
The brain changes of dementia with Lewy bodies alone can cause dementia, or they can be present at the same time as the brain changes of Alzheimer's disease and/or vascular dementia, with each abnormality contributing to the development of dementia. When this happens, the individual is said to have "mixed dementia."
In mixed dementia abnormalities linked to more than one cause of dementia occur simultaneously in the brain. Recent studies suggest that mixed dementia is more common than previously thought.
Brain changes: Characterized by the hallmark abnormalities of more than one cause of dementia —most commonly, Alzheimer's and vascular dementia, but also other types, such as dementia with Lewy bodies.
In the early stage of dementia, the person begins to show symptoms noticeable to the people around them. In addition, the symptoms begin to interfere with daily activities. The symptoms are dependent on the type of dementia a person has. The person may begin to have difficulty with more complicated chores and tasks around the house. The person can usually still take care of him or herself but may forget things like taking pills or doing laundry and may need prompting or reminders.
The symptoms of early dementia usually include memory difficulty, but can also include some word-finding problems (anomia) and problems with planning and organizational skills (executive function). One very good way of assessing a person's impairment is by asking if he or she is still able to handle his/her finances independently. This is often one of the first things to become problematic. Other signs might be getting lost in new places, repeating things, personality changes, social withdrawal and difficulties at work.
When evaluating a person for dementia, it is important to consider how the person was able to function five or ten years earlier. It is also important to consider a person's level of education when assessing for loss of function. For example, an accountant who can no longer balance a cheque book would be more concerning than a person who had not finished high school or had never taken care of his/her own finances.
In Alzheimer's dementia the most prominent early symptom is memory difficulty. Others include word-finding problems and getting lost. In other types of dementia, like dementia with Lewy bodies and fronto-temporal dementia, personality changes and difficulty with organization and planning may be the first signs.
As dementia progresses, the symptoms first experienced in the early stages of the dementia generally worsen. The rate of decline is different for each person. For example, people with Alzheimer's dementia in the moderate stages lose almost all new information very quickly. People with dementia may be severely impaired in solving problems, and their social judgment is usually also impaired. They cannot usually function outside their own home, and generally should not be left alone. They may be able to do simple chores around the house but not much else, and begin to require assistance for personal care and hygiene other than simple reminders.
People with late-stage dementia typically turn increasingly inward and need assistance with most or all of their personal care. Persons with dementia in the late stages usually need 24-hour supervision to ensure personal safety, as well as to ensure that basic needs are being met. If left unsupervised, a person with late-stage dementia may wander or fall, may not recognize common dangers around them such as a hot stove, and may not realize that they need to use the bathroom or become unable to control their bladder or bowels.
Changes in eating frequently occur. Caregivers of people with late-stage dementia often provide pureed diets, thickened liquids, and assistance in eating, to prolong their lives, to cause them to gain weight, to reduce the risk of choking, and to make feeding the person easier. The person's appetite may decline to the point that the person does not want to eat at all. He or she may not want to get out of bed, or may need complete assistance doing so. Commonly, the person no longer recognizes familiar people. He or she may have significant changes in sleeping habits or have trouble sleeping at all.
How Can I Tell If I Have Dementia?
Becoming a bit more forgetful does not necessarily mean that you have dementia. Many people notice that their memory becomes a bit less reliable as they get older - for example they might forget someone's name. Memory loss can also be a sign of stress, depression or certain physical illnesses.
However, anyone who is worried that their memory is getting noticeably worse, or who has other symptoms such as those listed above, should discuss their concerns with their health care provider.