Dementia is a loss of brain function that occurs with certain diseases. Alzheimer disease is one form of dementia. It affects memory, thinking, and behavior.
Senile dementia - Alzheimer type (SDAT); SDAT; Dementia - Alzheimer
The exact cause of Alzheimer disease (AD) is not known. Research shows that certain changes in the brain lead to AD.
You are more likely to develop AD if you:
Are older. 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.
The following may also increase the risk:
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.
AD symptoms include difficulty with many areas of mental function, including:
Emotional behavior or personality
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 remembering the names of familiar objects
Losing interest in things previously enjoyed and being in a flat mood
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
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.
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 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
Although there is no proven way to prevent AD, there are some measures that may help prevent or slow the onset of AD:
Stay on a low-fat diet and eat foods high in omega-3 fatty acids.
Get plenty of exercise.
Stay mentally and socially active.
Wear a helmet during risky activities to prevent brain injury.
Peterson R, Graff-Radford J. Alzheimer disease and other dementias. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. Philadelphia, PA: Elsevier; 2016:chap 95.
Joseph V. Campellone, MD, Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Internal review and update on 09/01/2016 by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.