Types of Dementia

What Are the Different Kinds of Dementia?

Dementing disorders can be classified in many different ways. These classification schemes attempt to group disorders that have particular features in common, such as whether they are progressive or what parts of the brain are affected. Some frequently used classifications include the following:

• Cortical dementia - dementia where the brain damage primarily affects the brain's cortex, or outer layer. Cortical dementias tend to cause problems with memory, language, thinking, and social behavior.
  
• Subcortical dementia - dementia that affects parts of the brain below the cortex. Subcortical dementia tends to cause changes in emotions and movement in addition to problems with memory.
  
• Progressive dementia - dementia that gets worse over time, gradually interfering with more and more cognitive abilities.
  
• Primary dementia - dementia such as AD that does not result from any other disease.
  
• Secondary dementia - dementia that occurs as a result of a physical disease or injury.
  

Some types of dementia fit into more than one of these classifications. For example, Alzheimer's Disease is considered both a progressive and a cortical dementia.

• Alzheimer's disease (AD)
  
• Vascular dementia (VD)
  
• Lewy body dementia (LBD)
  
• Frontotemporal dementia (FTD)
  
• Primary progressive aphasia (PPA)
  
• HIV-associated dementia (HAD)
  
• Huntington's disease (HD)
  
• Dementia pugilistica (DP)
  
• Corticobasal degeneration (CBD)
  
• Creutzfeldt-Jakob disease (CJD)

Other rare hereditary dementias include Gerstmann-Straussler-Scheinker (GSS) disease, fatal familial insomnia, familial British dementia, and familial Danish dementia. Symptoms of GSS typically include ataxia and progressive dementia that begins when people are between 50 and 60 years old. The disease may last for several years before patients eventually die. Fatal familial insomnia causes degeneration of a brain region called the thalamus, which is partially responsible for controlling sleep. It causes a progressive insomnia that eventually leads to a complete inability to sleep. Other symptoms may include poor reflexes, dementia, hallucinations, and eventually coma. It can be fatal within 7 to 13 months after symptoms begin but may last longer. Familial British dementia and familial Danish dementia have been linked to two different defects in a gene found on chromosome 13. The symptoms of both diseases include progressive dementia, paralysis, and loss of balance.

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More on Dementia

What is Dementia

Types of Dementia

Secondary Dementia

Dementia in Children

Causes of Dementia

Other Causes of Dementia

Conditions That Are Not Dementia

Risk Factors for Dementia

Dementia Diagnosis

Treatment for Dementia

Dementia Prevention

Care For Dementia Patient

Research On Dementia

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Sources:

National Institutes of Health
9000 Rockville Pike
Bethesda, Maryland 20892
www.nih.gov
Tel: 301-496-4000
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National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
www.ninds.nih.gov
Tel: 800-352-9424
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National Institute of Mental Health
6001 Executive Blvd. Rm. 8184, MSC 9663
Bethesda, MD 20892-9663
www.nimh.nih.gov
Tel: 301-443-4513
Fax: 301-443-4279
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Alzheimer's Disease Education and Referral Center
P.O. Box 8250
Silver Spring, MD 20907-8250
www.alzheimers.nia.nih.gov
Tel: 800-438-4380
Fax: 301-495-3334
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The Alzheimer's Research Trust of U.K.
The Stables
Station Road
Great Shelford
Cambridge
CB22 5LR - UK
www.alzheimers-research.org.uk
Tel: 01223 843899
Fax: 01223 843325