Dementia

Dementia is a general term used to describe a decline in cognitive function severe enough to interfere with daily life and activities. It is not a single disease but rather a group of symptoms that affect memory, reasoning, problem-solving, language and other thinking abilities. Dementia is caused by damage to brain cells, which interferes with their ability to communicate with each other. This loss of brain function can lead to changes in behavior, emotions and the ability to perform basic tasks.

8 Categories of Dementia

1. Alzheimer’s Disease
Alzheimer’s is the most common form of dementia, accounting for 60-80% of dementia cases. It is a progressive disease that causes the brain cells to degenerate and die, leading to continuous decline in thinking, behavioural and social skills.

Key Characteristics: Memory loss is the primary symptom, especially short-term memory, along with confusion, difficulty in communicating, impaired judgment, disorientation and behaviour changes.

Causes: Alzheimer’s is believed to be caused by a combination of genetic, environmental and lifestyle factors, including abnormal protein build-up in the brain (amyloid plaques and tau tangles).

2. Vascular Dementia
This type of dementia is caused by damage to the blood vessels in the brain, often as a result of stroke, high blood pressure or other cardiovascular conditions. When blood flow is reduced, brain cells do not receive enough oxygen and nutrients, leading to cell death and cognitive decline.

Key Characteristics: Problems with planning, decision-making, slowed thinking, difficulty focusing and memory loss. Symptoms may vary depending on the area of the brain affected by the vascular injury.

Causes: It is linked to conditions such as stroke, heart disease, high cholesterol, diabetes and lifestyle factors like smoking and obesity.

3. Lewy Body Dementia (LBD)
Lewy Body Dementia is characterized by the abnormal build up of proteins (Lewy bodies) in brain cells, which are also found in Parkinson’s disease. It shares symptoms with both Alzheimer’s and Parkinson’s, making diagnosis more challenging.

Key Characteristics: Fluctuating attention and alertness, visual hallucinations, movement difficulties (similar to Parkinson’s), sleep disturbances and cognitive impairment.

Causes: The exact cause is unknown but the accumulation of Lewy bodies disrupts brain function by impairing how brain cells communicate.

4. Frontotemporal Dementia (FTD)
Frontotemporal dementia primarily affects the frontal and temporal lobes of the brain, which are responsible for personality, behaviour and language. It often affects people at a younger age compared to Alzheimer’s.

Key Characteristics: Changes in personality, socially inappropriate behaviour, apathy, language difficulties and emotional detachment. Memory is typically not affected in the early stages.

Causes: FTD is associated with abnormal deposits of proteins such as tau and TDP-43, which damage brain cells in the affected areas.

5. Mixed Dementia
In mixed dementia, more than one type of dementia occurs simultaneously, often a combination of Alzheimer’s disease and vascular dementia. This is more common in people over the age of 80.

Key Characteristics: Symptoms vary depending on the combination of dementia types but generally include a mix of memory loss, confusion, difficulty with language, and impaired judgment.

Causes: It is caused by the combined effects of different types of brain damage such as the plaques and tangles of Alzheimer’s, along with vascular issues.

6. Parkinson’s Disease Dementia
Parkinson’s disease dementia occurs in people with Parkinson’s disease, a progressive disorder that affects movement. Over time, some people with Parkinson’s develop dementia as the disease progresses.

Key Characteristics: Slow thinking, difficulty with memory and problem-solving, hallucinations and mood changes. It also includes the motor symptoms of Parkinson’s, such as tremors and muscle stiffness.

Causes: It is linked to the same Lewy body protein build up that causes Lewy Body Dementia but starts as a movement disorder before affecting cognitive functions.

7. Huntington’s Disease
Huntington’s disease is a genetic disorder that causes the progressive breakdown of nerve cells in the brain. This leads to movement, cognitive, and psychiatric disorders, with dementia typically developing in the later stages of the disease.

Key Characteristics: Uncontrolled movements (chorea), memory problems, difficulty organizing thoughts, mood swings, and impaired judgment.

Causes: It is caused by a defective gene that produces an abnormal version of the huntingtin protein, which gradually damages brain cells.

8. Creutzfeldt-Jakob Disease (CJD)
Creutzfeldt-Jakob Disease is a rare and rapidly progressing form of dementia caused by an abnormal infectious protein known as a prion.

Key Characteristics: Rapid cognitive decline, memory problems, personality changes, jerky movements and hallucinations. It progresses much faster than other types of dementia.

Causes: CJD is caused by the build up of prions, which are misfolded proteins that accumulate in the brain, leading to brain cell death.

Key Takeaways

Dementia is progressive and irreversible but early diagnosis and treatment can help manage symptoms and improve quality of life.

Dementia encompasses various diseases and conditions, with each type affecting different areas of the brain and leading to unique sets of symptoms.

Alzheimer’s disease is the most common form but other types like vascular dementia, Lewy body dementia and frontotemporal dementia are also prevalent.

Some forms of dementia, like vascular dementia and Alzheimer’s, can coexist, leading to a diagnosis of mixed dementia.