• Home

Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Dementia

• Overview
• Symptoms
• Treatment
• Prevention

Definition:

Dementia is a loss of brain function. It is not a single disease. Instead, dementia refers to a group of illnesses that involve memory, behavior, learning, and communicating problems. The problems are progressive, which means they slowly get worse.

Alternative Names:

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

Causes, incidence, and risk factors:

The two major causes of degenerative (non-reversible) dementia are Alzheimer's disease and vascular dementia (loss of brain function due to a series of small strokes). The two conditions often occur together.

Dementia with Lewy bodies (DLB) is a leading cause of degenerative dementia in elderly adults. This condition is linked to abnormal protein structures in certain areas of the brain. The structures and symptoms of DLB are associated with Alzheimer's disease, but it is uncertain whether DLB is a sub-type of Alzheimer's or 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 normal pressure hydrocephalus , brain tumors, and dementia due to metabolic causes , thyroid conditions, low vitamin B12 levels, and infections.

Dementia may be diagnosed when a patient has two or more problems in brain function. 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. Other symptoms may only be seen during a medical exam or with cognitive tests.

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

References:

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 . 2nd ed. St. Louis, Mo: WB Saunders; 2003: 705-708.

• Review Date: 5/10/2006
• Reviewed By: Daniel Kantor, M.D., Director of the Comprehensive MS Center, Neuroscience Institute, University of Florida Health Science Center, Jacksonville, FL. Review provided by VeriMed Healthcare Network.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.