Dementia facts*

*Dementia facts medical author: 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 reduced or lost problem solving abilities.
  • 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).
  • There are many types of dementia, examples include:
    • 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. S ymptoms are similar to AD but personality and emotions are affected only late in the disease.
    • Lewy body dementia is common and progressive where cells in the brain's cortex die and others contain abnormal structures (Lewy bodies). Symptoms overlap with AD 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. Affected individuals are usually ages 40 to 65 and many have a family history (genetic contribution) of the disease. Symptoms include judgment and social behavior problems such as stealing, neglecting responsibilities, increased appetite, compulsive behavior, and eventually, problems with motor skills and
    • HIV-associated dementia is due to infection of the brain with human immunodeficiency virus (HIV). Symptoms include impaired memory, apathy, social withdrawal, and concentration problems.
    • Huntington's disease is a heredity disorder caused by a faulty gene. Children of those with the disorder have a 50% chance of getting the disease. Symptoms begin in those 30 to 40 years of age, beginning with personality changes such as anxiety and depression. Symptoms progress to 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, 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. Many patients develop a coma before they die.
    • Other rare hereditary dementias Gerstmann-Straussler-Scheinker disease, familial British dementia, familial Danish dementia , and fatal familial insomnia. Most of these diseases develop in people between 50 to 60 years old and most have variable symptoms of poor reflexes, dementia, hallucinations, paralysis, and most develop coma before death.
    • Secondary dementias occur in patients with other disorders of movement such as Parkinson's disease or multiple sclerosis and may be caused 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.
  • Dementia in children may result in mental problems, seizures, reduction or loss of motor skills, blindness, neurodegeneration, and death. Infections, trauma, and poisoning can lead to dementia in both children and adults. Inherited disorders such as Niemann-Pick disease, Batten disease, Lafora disease, and mitochondrial abnormalities may cause dementia in children.
  • Other conditions that may cause dementia include reactions to medications, endocrine and metabolic problems, nutritional deficiencies, infections, subdural hematomas, poisoning, brain tumors, anoxia (lack of oxygen), and heart and lung problems.
  • 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, and 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, 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. CT scan, MRI, and other brain scans are useful in diagnosis.
  • 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. These include engaging in intellectually stimulating activities, lowering cholesterol and homocysteine levels, performing regular exercise, controlling inflammation of body tissues, and using NSAIDs and possibly other medications. Furthering one's education and getting tight glucose control by persons with diabetes may also help.
Medically Reviewed by a Doctor on 9/18/2015

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