• Dementia facts*
• Introduction to dementia
• What is dementia?
• What are the different kinds of dementia?
• Alzheimer's disease
• Vascular dementia
• Lewy body dementia
• Frontotemporal dementia
• HIV-associated dementia
• Huntington's disease
• Dementia pugilistica
• Corticobasal degeneration
• Creutzfeldt-Jakob disease
• Other rare hereditary dementias
• Secondary dementias
• Dementias in children
• What other conditions can cause dementia?
• What conditions are not dementia?
• What causes dementia?
• What are the risk factors for dementia?
• How is dementia diagnosed?
• Is there any treatment for dementia?
• Can dementia be prevented?
• What kind of care does a person with dementia need?
• What research is being done?
• How can I help research?
• Where can I get more information?
• Patient Discussions: Dementia - Symptoms
• Find a local Neurologist in your town

Types of Dementia

The Different Types of Dementia

Dementing disorders can be classified 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 forms of dementia are classified as either primary or secondary dementia. Examples of primary dementia include:

• Alzheimer's disease
• Vascular dementia
• Lewy body dementia
• HIV-associated dementia
• Huntington's disease
• Creutzfeldt-Jakob disease and more.

Examples of secondary dementia include:

• Progressive supranuclear palsy
• Multiple sclerosis
• ALS dementia
• Normal pressure dementia

Read about all the types and stages of dementia »

Dementia facts*

*Dementia Facts Medically Edited by: Charles P. Davis, MD, PhD

• Dementia is a term that describes a collection of symptoms that include decreased intellectual functioning that interferes with normal life functions and is usually used to describe people who have two or more major life functions impaired or lost such as memory, language, perception, judgment or reasoning; they may lose emotional and behavioral control, develop personality changes and have problem solving abilities reduced or lost.
  
  
• There are different classification schemes for dementias roughly based (and with overlap) on observed problems; some frequently used are cortical (memory, language, thinking, social) , subcortical (emotions, movement, memory), progressive (cognitive abilities worsen over time), primary (results from a specific disease such as Alzheimer's disease and secondary (occurs because of disease or injury).
  
  
• Alzheimer's disease (AD): is the most common cause of dementia in people over age 65 with cause possibly related to amyloid plaques and neurofibrillary tangles; almost all brain functions, including memory, movement, language, judgment, behavior, and abstract thinking, are eventually affected.
  
  
• Vascular dementia: is the second most common cause of dementia caused by brain damage from cerebrovascular or cardiovascular problems (strokes) or other problems that inhibit vascular function; symptoms similar to AD but personality and emotions effected only late in the disease.
  
  
• Lewy body dementia: is common and progressive where cells in the brain's cortex die and other contain abnormal structures (Lewy bodies); symptoms overlap with Alzheimer's disease but also include hallucinations, shuffling gait, and flexed posture with symptoms that may vary daily.
  
  
• Frontotemporal dementia: is dementia linked to degeneration of nerve cells in the frontal and temporal brain lobes and some evidence for a genetic factor (many have a family history of the disease); symptoms in patients (usually ages 40 – 65) have judgment and social behavior problems such as stealing, neglecting responsibilities, increased appetite, compulsive behavior and eventual motor skill problems and memory loss.
  
  
• HIV-associated dementia: is due to infection of the brain with HIV virus; symptoms include impaired memory, apathy, social withdrawal, and concentration problems.
  
  
• Huntington's disease: is a heredity disorder caused by a faulty gene and children of a person with the disorder have a 50% chance of getting the disease; symptoms begin in 30-40 year old people with personality changes such as anxiety, depression and progress to show psychotic behavior severe dementia and chorea - involuntary jerky, arrhythmic movements of the body.
  
  
• Dementia pugilistica: is also termed Boxer's syndrome, is due to traumatic injury (often repeatedly) to the brain; symptoms commonly are dementia and parkinsonism ( tremors, gait abnormalities) and other changes depending where brain injury has happened.
  
  
• Corticobasal degeneration: is a progressive nerve cell loss in multiple areas of the brain; symptoms begin at about age 60 on one side of the body and include poor coordination and rigidity with associated visual-spatial problems that can progress to memory loss, hesitant speech and dysphagia (difficulty swallowing).
  
  
• Creutzfeldt-Jakob disease: is a rare disease that seems related to a gene mutation that causes rapid (death about one year after symptoms begin to develop) degenerative and fatal brain disease in people usually over 60 years old; personality changes and reduced coordination develop, rapidly followed by impaired judgment and vision and many patients develop a coma before they die.
  
  
• Other rare hereditary dementias: – Most of these diseases develop in people between 50 – 60 years old and most have variable symptoms of poor reflexes, dementia, hallucinations, paralysis and most develop coma before death; some of the names of these diseases are Gerstmann-Straussler-Scheinker disease, familial British dementia, familial Danish dementia and fatal familial insomnia.
  
  
• Secondary dementias: These dementias occur in patients with other disorders of movement such as Parkinson's disease or multiple sclerosis and may because by one or more problems listed above; these dementias may share symptoms with any of the above mentioned dementias but researchers are unsure if this is due to disease overlap or other causes.
  
  
• Dementias in children: While infections, trauma and poisoning can lead to dementia in both children and adults, there are some dementias that are unique to children but may result in mental problems, seizures, reduction or loss of motor skills, blindness, neurodegeneration and death; many are inherited disorders such as Niemann-Pick disease, Batten disease, Lafora disease and mitochondrial abnormalities.
  
  
• Other conditions that may cause dementia: Reactions to medications, endocrine and metabolic problems, nutritional deficiencies, infections, subdural hematomas, poisoning, brain tumors, anoxia (lack of oxygen), heart and lung problems.
  
  
• What conditions are not dementia: Although these conditions may resemble some aspects of dementia, they have different causes, usually are treatable and have better outcomes; examples are depression, delirium, mild cognitive impairment and age-related cognitive decline.
  
  
• Dementia causes: All causes of dementia result from death and damage of nerve cells in the brain; genetics and possibly the formation of different types of inclusions in the brain cells are likely the major causes, although some researchers suggest that certain inclusions may be only side effects of an underlying disorder.
  
  
• Risk factors for dementia include advancing age, genetics (family history), smoking, alcohol use, atherosclerosis, high cholesterol, diabetes, high plasma homocysteine levels, mild cognitive impairment, Down syndrome
  
  
• Dementia is diagnosed by using many methods such as patient's medical and family history, physical exam, neurological evaluations, cognitive and neuropsychological testing, CT's, MRI's and other brain scans, mental status exams, electroencephalograms, blood tests, psychiatric evaluations, and even some pre-symptomatic tests are available for some patients that may have a genetic link to dementia.
  
  
• Most treatments for dementia will neither reverse or stop the disease; however, there are treatments and medications that may reduce the symptoms and slow the disease progression; they are tight glucose control by persons with diabetes, intellectual stimulating activities, lowering cholesterol and homocysteine levels, regular exercise, education, controlling inflammation of body tissues, using NSAID's and possibly other medications.

Introduction to Dementia

A woman in her early 50s was admitted to a hospital because of increasingly odd behavior. Her family reported that she had been showing memory problems and strong feelings of jealousy. She also had become disoriented at home and was hiding objects. During a doctor's examination, the woman was unable to remember her husband's name, the year, or how long she had been at the hospital. She could read but did not seem to understand what she read, and she stressed the words in an unusual way. She sometimes became agitated and seemed to have hallucinations and irrational fears.

This woman, known as Auguste D., was the first person reported to have the disease now known as Alzheimer's disease * (AD) after Alois Alzheimer, the German doctor who first described it. After Auguste D. died in 1906, doctors examined her brain and found that it appeared shrunken and contained several unusual features, including strange clumps of protein called plaques and tangled fibers inside the nerve cells. Memory impairments and other symptoms of dementia, which means "deprived of mind," had been described in older adults since ancient times. However, because Auguste D. began to show symptoms at a relatively early age, doctors did not think her disease could be related to what was then called "senile dementia. "The word senile is derived from a Latin term that means, roughly, "old age."

It is now clear that AD is a major cause of dementia in elderly people as well as in relatively young adults. Furthermore, we know that it is only one of many disorders that can lead to dementia. The U. S. Congress Office of Technology Assessment estimates that as many as 6.8 million people in the United States have dementia, and at least 1.8 million of those are severely affected. Studies in some communities have found that almost half of all people age 85 and older have some form of dementia. Although it is common in very elderly individuals, dementia is not a normal part of the aging process. Many people live into their 90s and even 100s without any symptoms of dementia.

Besides senile dementia, other terms often used to describe dementia include senility and organic brain syndrome. Senility and senile dementia are outdated terms that reflect the formerly widespread belief that dementia was a normal part of aging. Organic brain syndrome is a general term that refers to physical disorders (not psychiatric in origin) that impair mental functions.

Research in the last 30 years has led to a greatly improved understanding of what dementia is, who gets it, and how it develops and affects the brain. This work is beginning to pay off with better diagnostic techniques, improved treatments, and even potential ways of preventing these diseases.

What Is Dementia?

Dementia is not a specific disease. It is a descriptive term for a collection of symptoms that can be caused by a number of disorders that affect the brain. People with dementia have significantly impaired intellectual functioning that interferes with normal activities and relationships. They also lose their ability to solve problems and maintain emotional control, and they may experience personality changes and behavioral problems such as agitation, delusions, and hallucinations. While memory loss is a common symptom of dementia, memory loss by itself does not mean that a person has dementia. Doctors diagnose dementia only if two or more brain functions - such as memory, language skills, perception, or cognitive skills including reasoning and judgment - are significantly impaired without loss of consciousness.

There are many disorders that can cause dementia. Some, such as AD, lead to a progressive loss of mental functions. But other types of dementia can be halted or reversed with appropriate treatment.

With AD and many other types of dementia, disease processes cause many nerve cells to stop functioning, lose connections with other neurons, and die. In contrast, normal aging does not result in the loss of large numbers of neurons in the brain.

Next: What are the different kinds of dementia?

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Vascular dementia: A common form of dementia in older persons that is due to cerebrovascular disease, usually with stepwise deterioration from a series of small strokes and a patchy distribution of neurologic deficits affecting some functions and not others. Risk factors include high blood pressure, an unsteady way of walking, and advanced age. Symptoms include confusion, problems with recent memory, wandering or getting lost in familiar places, loss of bladder or bowel control (incontinence), emotional problems such as laughing or crying inappropriately, difficulty following instructions, and problems handling money. The damage is typically so slight that the change is noticeable only as a series of small steps. However, over time, as more small blood vessels in the brain are blocked, there is noticeable gradual mental decline. Vascular dementia commonly begins between the ages of 60 and 75 and affects men more often than women. Also known as multi-infarct dementia. See also CADASIL.