Health Illustrated Encyclopedia



Dementia is a loss of brain function that occurs with certain diseases.

Alternative Names

Chronic brain syndrome; Lewy body dementia; DLB; Vascular dementia 


The two major causes of non-reversible (degenerative) dementia are:

The two conditions often occur together.

Dementia with Lewy bodies (DLB) is a leading cause of dementia in elderly adults. People with this condition have abnormal protein structures in certain areas of the brain.

The structures and symptoms of DLB are similar to those of Alzheimer's disease, but it is not clear whether DLB is a form of Alzheimer's or a separate disease. There is no cure for DLB or Alzheimer's.

Conditions that damage blood vessels or nerve structures of the brain can also lead to dementia.

Treatable causes of dementia include:

Dementia usually occurs in older age. It is rare in people under age 60. The risk for dementia increases as a person gets older.


Problems may involve language, memory, perception, emotional behavior or personality, and cognitive skills (such as calculation, abstract thinking, or judgment). Dementia usually first appears as forgetfulness.

Symptoms include:

  • Changed feeling (sensation) or perception
  • Changed sleep patterns
    • Change in sleep-wake cycle
    • Insomnia
    • Need for increased sleep
  • Decrease in problem-solving skills and judgment
  • Disorientation
    • Confused about people, places, or times
    • Unable to pick up cues from the environment
  • Disorders of problem-solving or learning
    • Trouble making calculations
    • Unable to learn
    • Unable to think abstractly
    • Unable to think in general terms
  • Impaired recognition (agnosia)
    • Trouble recognizing familiar objects or people
    • Trouble recognizing things through the senses
  • Lack of or poor language ability (aphasia)
    • Unable to form words
    • Unable to name objects
    • Unable to read or write
    • Unable to repeat a phrase
    • Unable to speak (without muscle paralysis)
    • Unable to understand speech
    • Have impaired language skills
    • Repeat phrases
    • Speak poorly (enunciation)
    • Use slang or the wrong words
  • Memory problems
    • Unable to remember new things (short-term memory problems)
    • Unable to remember the past (long-term memory problems)
  • Motor system problems
    • Gait changes
    • Impaired skilled motor function (apraxia)
      • Unable to copy geometric figures
      • Unable to copy hand positions
      • Unable to dress self
    • Inappropriate movements
    • Other motor system problems
  • Seeing or hearing things that aren't there (hallucinations) and having false ideas (delusions)
  • Severe confusion
  • Personality changes
    • Anxiety
    • Decreased ability to care for oneself
    • Decreased interest in daily living activities
    • Depression
    • Inappropriate mood or behavior
    • Irritability
    • No mood (flat affect)
    • Not flexible
    • Only concerned with self (self-centered)
    • Poor temper control
    • Unable to function or interact in social or personal situations
    • Unable to keep a job
    • Unable to make decisions
    • Withdrawal from social interaction
  • Unable to be spontaneous
  • Unable to concentrate

Other symptoms that may occur with dementia:

Exams and Tests

The following tests and procedures may be done:


The goal of treatment is to control the symptoms of dementia. Treatment depends on the condition causing the dementia. Some people may need to stay in the hospital for a short time.

Stopping or changing medications that make confusion worse may improve brain function. Medicines that contribute to confusion include:

Treating conditions that can lead to confusion can often greatly improve mental functioning. Such conditions include:

Medications may be needed to control behavior problems. Possible medications include:

  • Antipsychotics
  • Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) for Alzheimer's-type dementia
  • Dopamine blockers (haloperidol, risperdal, olanzapine, clozapine)
  • Mood stabilizers (fluoxetine, imipramine, citalopram)
  • Serotonin-affecting drugs (trazodone, buspirone)
  • Stimulants (methylphenidate)

A person's eyes and ears should be checked regularly. Hearing aids, glasses, or cataract surgery may be needed.

Psychotherapy or group therapy usually does not help because it may cause more confusion.


A person with dementia may need monitoring and help at home or in an institution. Possible options include:

  • Adult day care
  • Boarding homes
  • Convalescent homes
  • In-home care

Family members can get help caring for the person with dementia from:

  • Adult protective services
  • Community resources
  • Homemakers
  • Visiting nurses or aides
  • Volunteer services

In some communities, support groups may be available (see elder care - support group). Family counseling can help family members cope with home care.

Other tips for reducing disorientation:

  • Have familiar objects and people around
  • Keep lights on at night
  • Provide environmental and other cues with reality orientation
  • Reward appropriate behaviors and ignore inappropriate ones to control unacceptable or dangerous behaviors
  • Stick to a simple activity schedule

Advance directives, power of attorney, and other legal actions may make it easier to decide about the care of the person with dementia. Seek legal advice early in the course of the disorder, before the person with dementia is unable to make such decisions.

Outlook (Prognosis)

Dementia usually gets worse and often decreases quality of life and lifespan.

Possible Complications

Complications depend on the cause of the dementia, but may include the following:

  • Abuse by an overstressed caregiver
  • Increased infections anywhere in the body
  • Loss of ability to function or care for self
  • Loss of ability to interact
  • Reduced life span
  • Side effects of medications used to treat the disorder

When to Contact a Medical Professional

  • Call your health care provider if dementia develops or a sudden change in mental status occurs.
  • Call your health care provider if the condition of a person with dementia gets worse.
  • Call your health care provider if you are unable to care for a person with dementia at home.


Most causes of dementia are not preventable.

You can reduce the risk of vascular dementia, which is caused by a series of small strokes, by quitting smoking and controlling high blood pressure and diabetes. Eating a low-fat diet and exercising regularly may also reduce the risk of vascular dementia.


Alva G. Alzheimer disease and other dementias. Clin Geriatr Med. 2003; 19(4): 763-76.

American Academy of Neurology. About Dementia. Neurology. 2004; 63(10); E20.

Moore DP, Jefferson JW. Handbook of Medical Psychiatry. 2nd ed. St. Louis, Mo: Mosby; 2004:283-286.

Goetz, CG. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders; 2007.

Farlow MR, Cummings JL. Effective pharmacologic management of Alzheimer's disease. Am J Med, 2007;120:388-397.

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Review Date: 2/13/2008
Reviewed By: Luc Jasmin, MD, PhD, Departments of Anatomy & Neurological Surgery, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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