Alzheimer's Disease: What You Need to Know

Nearly everyone has harmless moments of forgetfulness: What was his name? Where did I put my keys? But what if you forget how to brush your teeth, or where you live? These could be signs of Alzheimer's disease. Here’s what you need to know.

Alzheimer’s disease (AD) is an irreversible, progressive brain disease that slowly destroys memory and thinking skills.

It does so by wiping out neurons and the connections that control memory, then it attacks areas responsible for language and reasoning. Once additional areas of the brain are damaged, a person with AD becomes helpless and unresponsive.

Among older people, it’s the most common cause of dementia. Dementia is the loss of cognitive functioning – thinking, remembering, and reasoning – to such an extent that it interferes with a person’s daily life and activities.

As many as 5.1 million Americans, most over age 60, may have Alzheimer’s. But still much about this disease remains unknown. Scientists continue to investigate what causes it and why it largely strikes older adults.

Here, we answer your basic questions:

What is Alzheimer's disease (AD)?
AD is common among older people, but it isn’t considered a normal part of aging. It initially affects new memories, then gradually spreads to other parts of the brain. Although treatment can slow the progression of AD and help manage its symptoms in some people, currently there’s no cure for this devastating disease.

As nerve cells die throughout the brain, affected regions begin to shrink. By the final stage of AD, damage is widespread and brain tissue has shrunk significantly.
What is dementia?
Dementia is a general term that refers to a decline in cognitive function so extensive that it interferes with daily life and activities. This loss in the ability to think, remember and reason isn’t a disease itself, but a group of symptoms that often accompanies a disease or condition.

Many conditions and diseases cause dementia. Two of the most common causes in older people are AD and vascular dementia, which is caused by a series of strokes or changes in the brain’s blood supply.

Other conditions that cause memory loss or dementia include:

Medication side effects

Chronic alcoholism

Certain tumors and infections in the brain

Blood clots in the brain

Vitamin B12 deficiency

Dehydration

High fever

Some thyroid, kidney, or liver disorders

Many of these conditions are temporary and reversible, but they can be serious and should be treated by a doctor as soon as possible.

What causes AD?
Scientists don’t yet fully understand what causes AD, but it’s clear that it develops because of a complex series of events that take place in the brain over a long period of time. Likely causes include genetic, environmental and lifestyle factors.

Because people differ in their genetic make-up and lifestyle, the importance of these factors for preventing or delaying Alzheimer’s differs from person to person.

What are the symptoms?
Alzheimer's disease develops slowly and causes changes in the brain long before there are obvious changes in a person's memory, thinking, use of words or behavior. Its course isn’t the same in everyone, but symptoms seem to develop over the same general stages.
Mild AD
As AD progresses, memory loss continues and changes in other cognitive abilities appear. Symptoms in this stage can include:

Getting lost at familiar locations

Trouble handling money and paying bills

Repeating questions

Taking longer than usual to complete normal daily tasks

Poor judgment

Losing things or misplacing them in odd places

Mood and personality changes

In most people with AD, symptoms first appear after age 60. AD is often diagnosed at this stage.

Moderate AD
In moderate AD, damage occurs in areas of the brain that control language, reasoning, sensory processing and conscious thought. Symptoms may include:

Increased memory loss and confusion

Problems recognizing family and friends

Inability to learn new things

Difficulty carrying out tasks that involve multiple steps (such as getting dressed)

Problems coping with new situations

Delusions and paranoia

Impulsive behavior

Severe AD
People with severe AD can’t communicate and are completely dependent on others for their care. Near the end, the person with AD may be in bed most or all of the time. Their symptoms often include:

Inability to recognize oneself or family

Inability to communicate

Weight loss

Seizures

Skin infections

Difficulty swallowing

Groaning, moaning or grunting

Increased sleeping

Lack of control of bowel and bladder

How is it diagnosed?
Several methods and tools can determine fairly accurately whether a person with memory problems has “possible Alzheimer’s disease,” “probable Alzheimer’s disease” or another problem. However, a definitive diagnosis of AD can be made only through autopsy after death.
To diagnose Alzheimer’s in a living person, a physician will:

Ask questions about a person’s overall health, past medical problems, ability to carry out daily activities, and changes in behavior and personality.

Give written and oral tests, such as the Mini Mental State Examination, that score memory, problem solving, attention, counting and language skills.

Carry out medical tests, such as tests of blood, urine, or spinal fluid.

Perform brain scans, such as a computed tomography (CT) or positron emission tomography (PET) scan or a magnetic resonance imaging (MRI) test.

These tests may be repeated to give doctors information about how the person’s health and memory are changing over time. Such tests also can help diagnose other causes of memory problems, including mild cognitive impairment and vascular dementia.

What is mild cognitive impairment (or MCI)?
Mild cognitive impairment is a medical condition that causes people to have more memory problems than other people their age. Vascular dementia is a medical condition caused by small strokes or changes in the brain’s blood supply.

Is there treatment for Alzheimer’s?
Only a few medications have been approved by the U.S. Food and Drug Administration (FDA) to help control the memory loss that characterizes AD. Donepezil (Aricept®), rivastigmine (Exelon®), and galantamine (Razadyne®, formerly known as Reminyl® and now available as a generic drug) are prescribed to treat mild to moderate AD symptoms. Donepezil also is approved to treat severe AD.

These drugs stop or slow the action of acetylcholinesterase, an enzyme that breaks down acetylcholine (a neurotransmitter that helps in memory formation).
These meds also help regulate neurotransmitters, the chemicals that transmit messages between neurons. The goal is to help patients carry out everyday activities and slow symptoms related to thinking, memory, or speaking skills. They also may help with certain behavioral symptoms. However, they do not stop or reverse AD and appear to help patients only for several months to a few years.

Memantine (Namenda®) may be prescribed to treat moderate to severe AD symptoms. This drug appears to block receptors for glutamate, another neurotransmitter involved in memory function.

Other medicines, such as antidepressants, help ease behavioral symptoms of AD, such as sleeplessness, anxiety, anger, depression and wandering. They don’t treat AD, but can provide some comfort.

Can symptoms for Alzheimer’s be mistaken for another condition?
Emotional problems, such as stress, anxiety, or depression, can make a person more forgetful and can be mistaken for Alzheimer’s or dementia. Some people with mild cognitive impairment (MCI) have memory losses similar to those with AD, but typically do not have the personality changes or cognitive problems that characterize AD.

Thyroid problems, drug reactions, depression, brain tumors and blood-vessel disease in the brain can also cause Alzheimer’s-like symptoms, but most can be treated successfully.

Is there anything that can be done to prevent the disease?
Although no treatments or drugs have yet been proven to prevent or delay AD, people can take some beneficial steps and that might reduce possible risk factors for AD. For example:

Regular exercise

Eating a healthy diet rich in fruits and vegetables

Engaging in social and intellectually stimulating activities

Controlling type-2 diabetes

Lowering high blood pressure levels

Lowering high blood cholesterol levels

Maintaining a healthy weight

Any new promising research into the causes or cures for AD?
AD research is focusing on ways to better identify high-risk individuals at very early stages of the disease. Efforts to understand more about certain biological compounds, how they work and what causes their levels to change may answer questions about what initiates AD and how it develops.

Learning more about these markers also may help scientists track whether certain medications are effective in early stages of the disease and may some day lead to new prevention strategies.

The use of imaging techniques, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), to measure brain structure and function, is also showing promise in AD research.

How long can a person live with AD?
AD is a slow disease that starts with mild memory problems and ends with severe brain damage. The time from diagnosis to death varies — as little as 3 or 4 years if the person is older than 80 when diagnosed, to as long as 10 or more years if the person is younger.

Other factors that affect how long a person will live with AD include the person’s sex, the presence of other health problems, and the severity of cognitive problems at diagnosis.

To learn more, visit our new Alzheimer's Health Center.

How Much Do You Know About Alzheimer’s?
More than 5 million Americans have Alzheimer’s disease, and that number could climb to 16 million by 2050. Women face a higher risk of developing it than men, and are also more likely to become caregivers.