Alzheimer's Disease

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Alzheimer's disease generally affects memory and the ability to think logically. Other important skills that may be impaired include language, complex motor activities, perception, and organizational skills. In its most severe form, Alzheimer's disease can interfere with a person's ability to perform daily tasks, such as dressing, bathing, and eating.

Alzheimer's disease is the single most common cause of dementia. Dementia is a sustained decline in thinking, with memory loss and at least one other area of deficit in great enough degree to interfere with social or occupational activities.

Most patients' symptoms progress slowly over a number of years. Symptoms may not be noticed early on. Sometimes, it is only when family members look back that they realize when the changes started to occur. The symptoms of Alzheimer's disease may resemble those of other medical conditions or problems, so it is important to talk to your doctor for an accurate diagnosis.

This section includes:

  • A list of symptoms of Alzheimer's disease
  • A discussion of memory and normal aging
  • Alzheimer's symptoms

    It is important to visit a doctor if you experience or observe in a loved one any of these symptoms so you can receive the proper evaluation and diagnosis. Other conditions—including depression and head injuries—can also produce many of the following symptoms.

    The changes in the brain associated with Alzheimer's disease can begin long before symptoms appear. But the key warning signs include:

    Impaired memory and thinking. The person has difficulty learning new information and remembering things, including personal information, such as his or her place of birth or occupation.

    Difficulty performing familiar tasks. The person begins to have difficulty performing daily tasks, such as eating, dressing, and showering. A person with Alzheimer's disease might prepare a meal and forget to serve it or even forget that he or she prepared it.

    Problems with language. The person can't recall words or understand the meaning of common words. A person with Alzheimer's disease may substitute inappropriate words, making it difficult to understand what he or she is saying.

    Disorientation and confusion. People with Alzheimer's disease may get lost when out on their own and may not be able to remember where they are or how they got there. They also may not recognize formerly familiar places and situations.

    Inability to follow directions. The person has difficulty understanding simple commands or directions. The person may get lost easily and begin to wander.

    Poor or decreased judgment. The person has difficulty making decisions and cannot fully grasp consequences. People with Alzheimer's disease may leave the house on a cold day without a coat or shoes, or they may go to the store wearing pajamas.

    Problems with abstract thinking. Many people find balancing a checkbook challenging. But someone with Alzheimer's disease may have difficulty recognizing numbers or understanding what to do with them.

    Misplacing things. The person forgets where he or she put things used every day, such as glasses, a hearing aid, keys, etc. The person also may put things in strange places, such as leaving glasses in the refrigerator.

    Changes in mood or behavior. People with Alzheimer's disease tend to have rapid mood swings.

    Changes in personality. The person may experience a dramatic change in personality, becoming suspicious, fearful, angry, or quiet.

    Loss of motivation or initiative. People with Alzheimer's disease may become passive and lose interest in their usual activities. They may require extra encouragement to become involved.

    Social withdrawal. The person begins to spend more time alone and is less willing to interact with others.

    Loss of appetite.

    Normal aging and memory

    Our ability to remember and to recall our past is what links us to our families, our friends, and our communities. As we age, subtle changes in memory occur. Simple forgetfulness (the "missing keys") and delay or slowing in recalling names, dates, and events can be part of the normal process of aging. Most normal changes in memory and thinking are of little importance. Not every memory problem becomes dementia, and not every cause of dementia is Alzheimer's disease. But when memory loss prevents us from performing daily tasks and our accustomed roles in life, it becomes a health concern that needs further evaluation by healthcare professionals.

    Memory has various forms that might be affected differently by aging. As we age, we maintain remote memory, procedural memory (performing tasks), and semantic recall (general knowledge). However, our ability to learn something new and recall it declines.

    Other changes can also occur with normal aging:

    Language comprehension (understanding the rules of language) is preserved as we age, as are vocabulary and one's understanding of syntax—the way in which words are put together. But some modest decline is seen in our ability to dredge up words and in verbal fluency—one's ability to "get the words out."

    While one's vocabulary remains unchanged as one ages, the speed with which one processes information gradually slows. For instance, one's ability to solve problems can decline.

    In normal aging, so-called executive functions (like planning or abstracting) remain normal for everyday tasks but are slowed when one multitasks or is faced with novel tasks.

    A slowing of the speed of cognitive processing and reaction time ("hitting the buzzer") occurs with aging.

    Last reviewed on 10/21/2008

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