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Alzheimer disease

Dementia is a loss of brain function that occurs with certain diseases. Alzheimer disease (AD) is one form of dementia. It affects memory, thinking, and behavior.

Causes

The exact cause of Alzheimer disease (AD) is not known. Research shows that certain changes in the brain lead to AD developing.

You are more likely to develop AD if you:

  • Are older. But developing AD is not a part of normal aging.
  • Have a close relative, such as a brother, sister, or parent, with AD.
  • Have certain genes linked to AD.
Alzheimer disease

The following may also increase the risk:

  • Being female
  • Having heart and blood vessel problems due to high cholesterol
  • History of head trauma

There are two types of AD:

  • Early onset AD: Symptoms appear before age 60. This type is much less common than late onset. It tends to get worse quickly. Early onset disease can run in families. Several genes have been identified.
  • Late onset AD: This is the most common type. It occurs in people age 60 and older. It may run in some families, but the role of genes is less clear.

Symptoms

AD symptoms include difficulty with many areas of mental function, including:

  • Emotional behavior or personality
  • Language
  • Memory
  • Perception
  • Thinking and judgment (cognitive skills)

AD usually first appears as forgetfulness.

Mild cognitive impairment (MCI) is the stage between normal forgetfulness due to aging, and the development of AD. People with MCI have mild problems with thinking and memory that do not interfere with daily activities. They are often aware of the forgetfulness. Not everyone with MCI develops AD.

Symptoms of MCI include:

  • Difficulty performing more than one task at a time
  • Difficulty solving problems
  • Forgetting recent events or conversations
  • Taking longer to perform more difficult activities

Early symptoms of AD can include:

  • Difficulty performing tasks that take some thought, but used to come easily, such as balancing a checkbook, playing complex games (bridge), and learning new information or routines
  • Getting lost on familiar routes
  • Language problems, such as trouble finding the name of familiar objects
  • Losing interest in things previously enjoyed and flat mood
  • Misplacing items
  • Personality changes and loss of social skills

As AD becomes worse, symptoms are more obvious and interfere with the ability to take care of oneself. Symptoms may include:

  • Change in sleep patterns, often waking up at night
  • Delusions, depression, and agitation
  • Difficulty doing basic tasks, such as preparing meals, choosing proper clothing, and driving
  • Difficulty reading or writing
  • Forgetting details about current events
  • Forgetting events in one's life history and losing self-awareness
  • Hallucinations, arguments, striking out, and violent behavior
  • Poor judgment and loss of ability to recognize danger
  • Using the wrong word, mispronouncing words, or speaking in confusing sentences
  • Withdrawing from social contact

People with severe AD can no longer:

  • Recognize family members
  • Perform basic activities of daily living, such as eating, dressing, and bathing
  • Understand language

Other symptoms that may occur with AD:

Exams and Tests

A skilled health care provider can often diagnose AD with the following steps:

  • Complete physical exam, including nervous system exam
  • Asking about the person's medical history and symptoms
  • Mental function tests (mental status examination)

A diagnosis of AD is made when certain symptoms are present, and by making sure other causes of dementia are not present.

Tests may be done to rule out other possible causes of dementia, including:

CT or MRI of the brain may be done to look for other causes of dementia, such as a brain tumor or stroke. Sometimes, a PET scan can be used to rule out AD.

The only way to know for certain that someone has AD is to examine a sample of their brain tissue after death.

Treatment

There is no cure for AD. The goals of treatment are:

  • Slow the progression of the disease (although this is difficult to do)
  • Manage symptoms, such as behavior problems, confusion, and sleep problems
  • Change the home environment to make daily activities easier
  • Support family members and other caregivers

Medicines are used to:

  • Slow the rate at which symptoms worsen, though benefit with these drugs may be small
  • Control problems with behavior, such as loss of judgment or confusion

Before using these medicines, ask the provider:

  • What are the side effects? Is the medicine worth the risk?
  • When is the best time, if any, to use these medicines?
  • Do medicines for other health problems need to be changed or stopped?

Support Groups

Having AD or caring for a person with the condition may be a challenge. You can ease the stress of illness by seeking support through AD resources. Sharing with others who have common experiences and problems can help you not feel alone.

Outlook (Prognosis)

How quickly AD gets worse is different for each person. If AD develops quickly, it is more likely to worsen quickly.

People with AD often die earlier than normal, although a person may live anywhere from 3 to 20 years after diagnosis.

Families will likely need to plan for their loved one's future care.

The final phase of the disease may last from a few months to several years. During that time, the person becomes totally disabled. Death usually occurs from an infection or organ failure.

When to Contact a Medical Professional

Call the health care provider if:

  • AD symptoms develop or a person has a sudden change in mental status
  • The condition of a person with AD gets worse
  • You are unable to care for a person with AD at home

Prevention

Although there is no proven way to prevent AD, there are some measures that may help prevent or slow the onset of AD.

These include keeping a low-fat diet and eating foods high in omega-3 fatty acids. Getting physical exercise and staying mentally and socially active also seem to help.

Alternative Names

Senile dementia - Alzheimer type (SDAT); SDAT

References

Alzheimer's Association. 2014 Alzheimer's Disease Facts and Figures. Washington, DC: Alzheimer's Association. Available at: www.alz.org/downloads/Facts_Figures_2014.pdf. Accessed November 5, 2014.

Apostolova LG, DeKosky ST, Cummings JL. Dementias. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds.Bradley's Neurology in Clinical Practice

Bayer A. Presentation and clinical management of dementia. In: Fillit HM, Rockwood K, Woodhouse K, eds.Brocklehurst's Textbook of Geriatric Medicine and Gerontology

Camicioli R, Rockwood K. Dementia diagnosis. In: Fillit HM, Rockwood K, Woodhouse K, eds.Brocklehurst's Textbook of Geriatric Medicine and Gerontology

Update Date 11/5/2014

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