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

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

The two major causes of nonreversible (degenerative) dementia are:

• Alzheimer's disease
• Loss of brain function due to a series of small strokes (vascular dementia)

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:

• Brain tumors
• Dementia due to metabolic causes
• Infections
• Low vitamin B12 levels
• Normal pressure hydrocephalus
• Thyroid conditions

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:

• Incontinence
• Swallowing problems

The following tests and procedures may be done:

• B12 level
• Blood ammonia levels
• Blood chemistry (chem-20)
• Blood gas analysis
• Cerebrospinal fluid (CSF) analysis
• Drug or alcohol levels (toxicology screen)
• Electroencephalograph (EEG)
• Glucose test
• Head CT
• Liver function tests
• Mental status test
• MRI of head
• Serum calcium
• Serum electrolytes
• Thyroid function tests
• Thyroid stimulating hormone level
• Urinalysis

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

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

• 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):763-776.

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.