Dementia
Dementia describes a group of symptoms associated with a decline in memory, reasoning or other thinking skills. Many different types of dementia exist, and many conditions cause it. Mixed dementia is a condition in which brain changes of more than one type of dementia occur simultaneously. Alzheimer’s disease is the most common cause of dementia, accounting for 60-80% of dementia cases.
Dementia is not a normal part of aging. It is caused by damage to brain cells that affects their ability to communicate, which can affect thinking, behavior and feelings.
Dementia is not a single disease; it’s an overall term — like heart disease — that covers a wide range of specific medical conditions, including Alzheimer’s disease. Disorders grouped under the general term “dementia” are caused by abnormal brain changes. These changes trigger a decline in thinking skills, also known as cognitive abilities, severe enough to impair daily life and independent function. They also affect behavior, feelings and relationships.
Alzheimer’s disease accounts for 60-80% of cases. Vascular dementia, which occurs because of microscopic bleeding and blood vessel blockage in the brain, is the second most common cause of dementia. Those who experience the brain changes of multiple types of dementia simultaneously have mixed dementia. There are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.
Dementia is often incorrectly referred to as “senility” or “senile dementia,” which reflects the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.
Signs of dementia can vary greatly. Examples include:
- Problems with short-term memory.
- Keeping track of a purse or wallet.
- Paying bills.
- Planning and preparing meals.
- Remembering appointments.
- Traveling out of the neighborhood.
Many conditions are progressive, which means that the signs of dementia start out slowly and gradually get worse. If you or someone you know 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, behavior 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 center 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.
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:
- Depression.
- Medication side effects.
- Excess use of alcohol.
- Thyroid problems.
- Vitamin deficiencies
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 behavior 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, psychiatrist, psychologist or geriatrician.
Treatment of dementia depends on its cause. In the case of most progressive dementias, including Alzheimer’s disease, there is no cure, but one treatment — aducanumab (Aduhelm™) — is the first therapy to demonstrate that removing amyloid, one of the hallmarks of Alzheimer’s disease, from the brain is reasonably likely to reduce cognitive and functional decline in people living with early Alzheimer’s. Others can temporarily slow the worsening of dementia symptoms and improve quality of life for those living with Alzheimer’s and their caregivers. 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. Right now, volunteers are urgently needed to participate in clinical studies and trials about Alzheimer’s and other dementias.
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.
Research reported at the 2019 Alzheimer’s Association International Conference® suggests that adopting multiple healthy lifestyle choices, including healthy diet, not smoking, regular exercise and cognitive stimulation, may decrease the risk of cognitive decline and dementia.
Alzheimer’s Disease
Alzheimer’s is a degenerative brain disease that is caused by complex brain changes following cell damage. It leads to dementia symptoms that gradually worsen over time. The most common early symptom of Alzheimer’s is trouble remembering new information because the disease typically impacts the part of the brain associated with learning first.
As Alzheimer’s advances, symptoms get more severe and include disorientation, confusion and behavior changes. Eventually, speaking, swallowing and walking become difficult.
Though the greatest known risk factor for Alzheimer’s is increasing age, the disease is not a normal part of aging. And though most people with Alzheimer’s are 65 and older, approximately 200,000 Americans under 65 are living with younger-onset Alzheimer’s disease.
The most common early symptom of Alzheimer’s is difficulty remembering newly learned information.
Just like the rest of our bodies, our brains change as we age. Most of us eventually notice some slowed thinking and occasional problems with remembering certain things. However, serious memory loss, confusion and other major changes in the way our minds work may be a sign that brain cells are failing.
Alzheimer’s changes typically begin in the part of the brain that affects learning. As Alzheimer’s advances through the brain it leads to increasingly severe symptoms, including disorientation, mood and behavior changes; deepening confusion about events, time and place; unfounded suspicions about family, friends and professional caregivers; more serious memory loss and behavior changes; and difficulty speaking, swallowing and walking.
People with memory loss or other possible signs of Alzheimer’s may find it hard to recognize they have a problem. Signs of dementia may be more obvious to family members or friends. Anyone experiencing dementia-like symptoms should see a doctor as soon as possible. If you need assistance finding a doctor with experience evaluating memory problems, your local Alzheimer’s Association can help. Earlier diagnosis and intervention methods are improving dramatically, and treatment options and sources of support can improve quality of life. Two helpful support resources you can tap into are ALZConnected, our message boards and online social networking community, and Alzheimer’s Navigator, a web tool that creates customized action plans, based on answers you provide through short, online surveys.
Researchers believe there isn’t a single cause of Alzheimer’s disease. It likely develops from multiple factors, such as genetics, lifestyle and environment. Scientists have identified factors that increase the risk of Alzheimer’s. While some risk factors — age, family history and heredity — can’t be changed, emerging evidence suggests there may be other factors we can influence.
- Age
- Family history
- Genetics (heredity)
