Dementia causes the gradual deterioration of mental functioning that effects memory, mood, thinking, concentration, and judgment. These changes often affect a person’s ability to perform normal daily activities.
Common problems include confusion, and changes in the way a person behaves and communicates.
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Cognitive symptoms of dementia can include poor problem solving, difficulty learning new skills, and impaired decision making. Behavior changes can include fear, insecurity, anger, and often, depression like symptoms.
Topic - Memory Care
Dementia is caused by various diseases and conditions that result in damaged brain cells. Brain cells can be destroyed by brain diseases, such as Alzheimer’s disease, or strokes (called vascular or multi-infarct dementia), which decrease blood flow to the brain.
Alzheimer's disease is the most common cause of dementia.
The decline in cognitive abilities must be severe enough to interfere with daily life.
Different types of dementia are associated with distinct symptom patterns and distinguishing microscopic brain abnormalities.
Common Types of Dementia and Their Typical Characteristics
1. Alzheimer’s Disease
Alzheimer’s Disease is the most common type of dementia; accounts for 60 to 80 percent of cases.
Difficulty remembering names and recent events is often an early clinical symptom; later symptoms include impaired judgment, disorientation, confusion, behavior changes and trouble speaking, swallowing and walking.
Hallmark abnormalities are deposits of the protein fragment beta-amyloid (plaques) and twisted strands of the protein tau (tangles).
2. Lewy Body Dementia
Dementia with Lewy Body. Pattern of decline may be similar to Alzheimer’s, including problems with memory, judgment and behavior changes.
Alertness and severity of cognitive symptoms may fluctuate daily.
Visual hallucinations, muscle rigidity and tremors are common.
Hallmarks include Lewy bodies (abnormal deposits of the protein alphasynuclein) that form inside nerve cells in the brain.
Topic - Coping with Dementia
3. Frontotemporal Dementia
Frontotemporal Dementia Involves damage to brain cells, especially in the front and side regions of the brain.
Typical symptoms include changes in personality and behavior and difficulty
with language.
No distinguishing microscopic abnormality is linked to all cases.
Pick’s disease, characterized by “Pick’s bodies,” is one type of frontotemporal
dementia.
4. Vascular Dementia
Vascular Dementia is considered to be the second-most-common type of dementia.
Impairment is caused by decreased blood flow to parts of the brain, often due to a series of small strokes that block arteries.
Symptoms often overlap with those of Alzheimer’s, although memory may not be as seriously affected.
5. Normal Pressure Hydrocephalus
Normal pressure hydrocephalus (NPH) is caused by the buildup of fluid in the brain. Symptoms include difficulty walking, memory loss and inability to control urine.
NPH can sometimes be corrected with surgical installation of a shunt in the brain to drain excess fluid.
6. Mild cognitive impairment (MCI)
Mild cognitive impairment is an intermediate stage between the expected cognitive decline of normal aging and the more-serious decline of dementia. It can involve problems with memory, language, thinking and judgment that are greater than normal age-related changes.
This is a condition in which a person has problems with memory, language or another essential cognitive function that are severe enough to be noticeable to others and show up on tests, but not severe enough to interfere with daily life.
Some people with mild cognitive impairment go on to develop dementia. For others, the symptoms of mild cognitive impairment do not progress to dementia, and some people who have mild cognitive impairment at one point in time later revert to normal cognitive status.
7. Mixed dementia
Mixed dementia is characterized by the presence of the hallmark abnormalities of Alzheimer’s and another type of dementia, most commonly vascular dementia, but also other types, such as dementia with Lewy bodies, frontotemporal dementia and normal pressure hydrocephalus.
8. Parkinson’s disease
Parkinson’s disease. Many people who have Parkinson’s disease develop dementia in the later stages of the disease.
The hallmark abnormality is Lewy bodies (abnormal deposits of the protein alpha-synuclein) that form inside nerve cells in the brain.
9. Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease disease is a degenerative brain disorder that leads to dementia and, ultimately, death. Symptoms of Creutzfeldt-Jakob disease (CJD) can resemble those of other dementia-like brain disorders, such as Alzheimer's. But Creutzfeldt-Jakob disease usually progresses much more rapidly.
“Variant Creutzfeldt-Jakob disease” is believed to be caused by consumption of products from cattle affected by “mad cow disease” - contaminated beef.
Caused by the misfolding of prion protein throughout the brain.
Note: there are more than 100 types of dementia. Those listed here are the most common.
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