Unit title:

Learning outcomes:

• Identify the most common types of dementia• List the most common causes of dementia• Describe the signs and symptoms of the most common causes

of dementia• Explain the risk factors for the most common causes of dementia• Identify prevalence rates for different types of dementia

Dementia awareness

Most common types of dementia and their causes

2

Most common types of dementia and their causes

Dementia is the term used to describe a group of related symptoms, caused by diseases that damage the brain.

3

Introduction 4

Alzheimer’s disease (AD) 5

Vascular dementia (VaD) 7

Dementia with Lewy bodies (DLB) 8

Fronto-temporal dementia (FTD) 9

Other types of dementia

Further information

10

11

Contents

Licenced photography is being used for illustrative purposes only and person(s) depicted in the material is a model.

4

Most common types of dementia and their causes

These symptoms may include problems with memory, thinking, language, mood or movement and can lead to difficulties in carrying out daily activities.

In 2017, dementia affects about 850,000 people within the UK.

This guide introduces the four most common types of dementia and outlines the prevalence, risk factors (where known), and signs and symptoms for each type.

Introduction

Dementia is the term used to describe a group of related symptoms which are caused by damage to the brain.

The four main types of dementia are:

• Alzheimer’s disease

• Vascular dementia (VaD)

• Dementia with Lewy bodies (DLB)

• Fronto-temporal dementia (FTD)

Research has identified that is possible for individuals to live with two types of dementia, this is known as mixed dementia. For example, an individual may live with Alzheimer’s disease (AD) and vascular dementia simultaneously.

5

Alzheimer’s disease is the most common form of dementia, affecting about 520,000 people in the UK. Dr Alois Alzheimer first discovered the disease in 1906, when he identified abnormal changes to the brain of a woman whilst carrying out a post-mortem.

Alzheimer’s disease (AD)

Alzheimer’s disease is a progressive condition which is linked to a build-up of proteins within the brain. People in the early stages of the disease often experience memory problems and have problems finding the right words. Over time, more parts of the brain are damaged and further symptoms develop.

The exact cause of Alzheimer’s disease is not yet known, but there are a number of factors which increase the risk of developing the condition.

Risk increases with age or a family history of the condition. Previous severe head injuries where a person has suffered concussion or a lack of consciousness may also play a part in causing the disease.

Lifestyle factors that increase the risk of cardiovascular disease may also heighten the risk of Alzheimer’s disease. These include high blood pressure, smoking, high cholesterol, being overweight or lack of exercise.

Current research suggests social isolation, reduced participation in activities requiring cognitive skills may also increase the likelihood of Alzheimer’s disease.

Risk factors

In AD the brain shows evidence of increased proteins, known as

amyloid tau. These disrupt the function of nerve cells, causing

brain cell death.

6

Most common types of dementia and their causes

Signs and symptoms

The symptoms of Alzheimer’s disease are not just about memory loss. It can also affect the way a person speaks, thinks, feels and behaves. Symptoms may include:

Problems with speech and language

Mood swings, such as bursting into tears for no reason

Personality changes such as becoming aggressive, demanding and suspicious of others

Walking about, particularly in the middle of the night

Confusion and disorientation such as getting lost in familiar places

Seeing or hearing things that aren’t there and believing things that are untrue

Loss of inhibitions – inappropriate behaviour

Neglect of personal hygiene

7

It is caused when blood vessels in the brain are damaged, causing the oxygen supply to be reduced.

The lack of oxygen can result in a series of mini-strokes, causing small blood vessels in the brain to become blocked. As brain cells are starved of oxygen they eventually die. Mini-strokes have a cumulative effect on the brain and symptoms can occur quite suddenly or over a period of time.

A sudden stroke can cause immediate death of brain cells, compared to the more progressive brain cell death associated with mini-strokes.

Vascular dementia (VaD)

Vascular dementia (VaD) is the second most common form of dementia after Alzheimer’s disease. In 2017, it is estimated to affect around 150,000 people in the UK.

Risk factors

Conditions such as high blood pressure and diabetes can make mini-stroke more likely, as there is an increased risk of damage to blood vessels.

Lifestyle factors, such as smoking, low physical activity, heart disease, stress and substance misuse can make stroke, or mini-stroke more likely. Tackling these issues might reduce the risk of vascular dementia in later life, however, not all risk factors are modifiable and this is more prominent as we reach the later life.

• Memory loss

• Depression and anxiety

• Loss of bladder and bowel control

• Visual mistakes and misperceptions (for example, seeing a rug as a patch of grass)

• Changes in behaviour (such as restlessness)

• Psychological symptoms (such as becoming more obsessive)

• Problems with the speed of thinking, concentration and communication

• Problems with planning or organising, making decisions or solving problems

• Difficulties following a series of steps (e.g. cooking a meal)

• Problems concentrating, including short periods of sudden confusion

Signs and symptoms

As well as cognitive symptoms, it is common for someone with early vascular dementia to experience mood changes, such as apathy, depression or anxiety. The signs and symptoms of vascular dementia will differ from person to person, dependent on the area of the brain that has experienced cell death.

8

Most common types of dementia and their causes

It is called Lewy bodies; a particular type of abnormal protein which builds up inside the brain cell, causing degeneration of the affected part of the brain. Friederich H. Lewy discovered this type of dementia in the early 1900s, whilst researching Parkinson’s disease.

Dementia with Lewy bodies shares characteristics with both Alzheimer’s and Parkinson’s diseases. People who suffer from it may also develop the symptoms of Parkinson’s disease, such as slowness, muscle stiffness and trembling of the limbs.

Dementia with Lewy bodies (DLB)

In 2017 dementia with Lewy bodies (DLB), also known as Lewy body dementia, is estimated to affect more than 100,000 people in the UK.

Risk factors

It’s not clear what causes the build-up of Lewy bodies within the brain or how exactly they inflict damage. The disease does not appear to have a genetic element and usually appears in people with no previous family history of the disease. It is rarely diagnosed in people under the age of 65. People with Parkinson’s disease may go on to develop dementia with Lewy bodies.

Signs and symptoms

The symptoms that a person has will vary, depending on which part of the brain is affected. Symptoms include:

• Problems with understanding, thinking and memory loss – this is similar to Alzheimer’s disease, although memory may be less affected

• Loss of facial expression

• Sleep disorders – restless, disturbed nights with confusion, nightmares and hallucinations. Falling asleep easily during the day

• Shaking and trembling of arms and legs

• Problems with attention and alertness with periods of confusion or sleepiness

• Difficulties with judging distances and perceiving objects in three dimensions

• Decline in problem solving; for example, finding it difficult to plan ahead

• Persistent and detailed hallucinations – seeing things that are not there

• Fluctuations in abilities daily or even hourly

• Fainting, falling or having ‘funny turns’

9

Signs and symptoms

The signs and symptoms of the disease are linked to the damage to the frontal and temporal lobes which control personality, behaviour and language. These include:

• Language problems – speaking slowly, getting words in the wrong order, using words incorrectly or struggling to make the right sounds

• Aggression

• Lack of insight – even early on within the course of the disease, people lack awareness about what is happening to them

• Increased interest in sex

• Becoming easily distracted and struggling with planning and organisation

Fronto-temporal (FTD) dementia is a less common form of dementia. Doctors sometimes use different names for this type of dementia, such as: Pick’s disease, frontal dementia, fronto-temporal lobar degeneration, primary progressive aphasia, progressive non-fluent aphasia or semantic dementia.

Fronto-temporal dementia (FTD)

Fronto-temporal dementia mainly affects the front and sides of the brain, which are called the frontal and temporal lobes.

Fronto-temporal dementia tends to start at a younger age, with most cases diagnosed between the ages of 45 to 65. It is caused by clumps of abnormal proteins forming inside brain cells within the frontal and temporal lobes. It is not fully understood what causes

Risk factors

this build-up of proteins but there may be a genetic link as, in about 20% of cases, the person inherits the disease from a parent. Motor neurone disease (MND) is sometimes linked to this type of dementia.

• Loss of inhibitions and acting impulsively

• A decline in personal hygiene

• Compulsive or repetitive behaviour, such as humming or foot-tapping or walking the same route constantly

• Agitated or blunt emotions – such as an inability to sympathise with others

10

Most common types of dementia and their causes

Other types of dementia

There are also some less common types of dementia. Here are some of the other types of dementia.

Dementia in adults with a learning disability

Alcohol-related dementia, also called Korsakoff’s Syndrome

Creutzfeldt-Jakob Disease (CJD)

Dementia linked to motor neurone disease (MND)

Dementia linked to Huntington’s disease

HIV-related dementia

11

Further information

You can find more information about dementia from the following organisations:

• Dementia UK: www.dementiauk.org/

• Young Dementia UK: www.youngdementiauk.org/

• The Alzheimer’s Society: www.alzheimers.org.uk/

• Alzheimer Scotland http: www.alzscot.org/

Most common types of dementia and their causes

Knowledge guide