About Dementia

 

Dementia is a general term for a decline in cognitive function that affects daily life. It impacts memory, thinking, reasoning, and decision-making. Dementia is not a single condition but a group of related conditions, with over 200 different types.

Some risk factors of dementia include:

  1. Age (most common in older adults)
  2. Family history and genetics (e.g. APOE ε4 gene in Alzheimer’s)
  3. Cardiovascular conditions (e.g. hypertension, diabetes, obesity)
  4. Lifestyle factors (e.g. smoking, sedentary behaviour, poor diet)
  5. Chronic inflammatory conditions or prolonged stress

Identifying the specific type of dementia is important because different types may require different treatments and care plans.

 

 

Common Types of Dementia

 

Alzheimer’s Disease

The most common form of dementia, making up about two-thirds of dementia cases.

Is increasingly common with age - typically affects people over 65.

The exact cause of Alzheimer’s isn’t fully understood, but it occurs when brain proteins stop working properly. This damages brain cells (neurons), breaking their connections and eventually causing them to die.

Early signs include:

  1. Short-term memory loss (forgetting names, appointments, conversations, or misplacing items).
  2. Difficulty following conversations or repeating conversations.
  3. Difficulties with memory, orientation, activities of daily living, decision making, judgement & hobbies.

Symptoms gradually worsen over months or years but can vary from 3 to 20 years.

Life expectancy after diagnosis is usually 8-10 years.

 

Vascular Dementia

The second most common type of dementia.

It’s caused by reduced blood flow to the brain.

Can develop suddenly after a stroke, although strokes don’t always lead to vascular dementia, depending on the severity and location in the brain.

Can develop slowly due to ongoing damage to blood vessels which can reduce circulation of blood, depriving the brain of oxygen and nutrients.

Risk factors include:

  1. Heart disease
  2. High blood pressure
  3. High cholesterol
  4. Smoking

Early signs include:

  1. Difficulty with judgement, decision-making and concentration.
  2. Confusion, poor attention & concentration, restlessness, agitation.
  3. Problems with balance and movement (increased risk of falls).
  4. Mood changes, including depression.

Differs from Alzheimer’s Disease, where difficulty with short-term memory is the most prevalent early symptom.

Some people with vascular dementia also have Alzheimer’s disease, known as mixed vascular and Alzheimer’s disease.

 

Dementia with Lewy Bodies (DLB)

DLB is the third most common type of dementia.

The exact cause of DLB is not yet known, however scientists believe it’s because of abnormal protein deposits (Lewy bodies) in the brain. These proteins interfere with brain function by reducing important chemical messengers. One of these chemicals, acetylcholine, helps with memory and learning, while another, dopamine, affects movement, mood, sleep, motivation, and thinking. Scientists don’t yet know exactly why Lewy bodies form, but they are linked to both dementia and Parkinson’s disease - up to 80% of people with Parkinson’s disease will go on to develop dementia.

DLB can be hard to diagnose because early symptoms can mirror those of psychiatric disorders.

Symptoms are similar to Alzheimer’s disease but with more of a fluctuation in thinking and reasoning.

Early signs include symptoms such as:

  1. Hallucinations (seeing things that aren’t there).
  2. Delusions and paranoia.
  3. Movement issues, including a shuffling gait and loss of coordination (increased risk of falls).
  4. Poor sleep and confusion.

People with DLB are very sensitive to antipsychotic medications, which can cause unwanted side effects.

 

Frontotemporal Dementia (FTD)

Also known as Frontal Lobe dementia

The cause of FTD is not yet known but is linked with the presence of Pick bodies, tiny structures that hold an abnormal amount or type of proteins, in the brain cells.

It is a group of disorders that occur when there is damage to the frontal and temporal parts of the brain, which control behaviour, personality, and language. There is a loss of nerve cells resulting in shrinkage of the frontal lobes.

It’s more common in younger people, often appearing before age 65, and is also more common in women.

Like Alzheimer’s, FTD has a gradual onset and is progressive. Unlike Alzheimer’s, memory loss appears later in the disease.

Early signs include:

  1. Personality and behaviour changes (e.g., lack of empathy, impulsive actions, inappropriate social behaviour, decreased self-awareness).
  2. Loss of motivation and energy.
  3. Emotional withdrawal.
  4. Easily agitated with frequent mood changes.
  5. Difficulty speaking or understanding language (aphasia).
  6. Reduced personal hygiene.
  7. Swearing or inappropriate sexual behaviour.

The common types of frontotemporal dementia are:

  1. Behavioural variant FTD – affects personality and behaviour, leading to impulsivity, loss of motivation, and neglect of personal care.
  2. Primary progressive aphasia (PPA) – affects communication, with two subtypes:
    1. Non-fluent aphasia – difficulty speaking.
    2. Semantic dementia – trouble understanding and using language.

 

Other Types of Dementia

There are many other types of dementia not covered in this list, which outlines the more common types. Each type affects people differently, and the right care depends on the specific diagnosis.