19 February 2020

Dementia and Alzheimer's disease: causes, symptoms, diagnosis, treatment & prevention

This resource is relevant to anyone wishing to learn more about dementia, including those caring for a loved one and healthcare professionals.

Dementia can be frightening for both people with the condition and for their families and friends. Additionally, the misinformation surrounding dementia can lead to unnecessary confusion. Our guide to dementia covers the most common types of dementia, their symptoms, causes, diagnosis, treatments and prevention.

What is Dementia?

Though often understood as such, dementia is not a single condition: in fact, the term is used as an umbrella for symptoms displayed by a range of illnesses and diseases. Often recognised through its association with Alzheimer’s disease, dementia occurs when damage occurs in the brain.  It is a progressive condition, ultimately resulting in loss of life.

Dementia is especially prevalent in people over the age of 65 but can occur in early onset cases at a younger age, with some rarer forms of dementia occurring in children as well as adults. There are 42,000 people in the UK, under the age of 65, living with dementia. As such, the planning of care must be personalised for residents and loved ones according to their age and the progress of the condition.

How does dementia affect people?

A person will experience different symptoms depending on which part of their brain has been affected. That said, memory loss is generally associated with most types of dementia, as the nerve cells and their connections within the brain become gradually damaged by the disease. People with dementia can also experience changes in behaviour and cognitive function depending on which type they have.

Types of Dementia, causes and symptoms

Alzheimer’s Disease

What causes Alzheimer’s Disease?

Almost 60% of diagnosed cases of dementia in the UK are caused by Alzheimer’s Disease, making it the most common source of dementia-associated symptoms.

It’s caused when one abnormal protein surrounds a brain cell and another damages its internal structure: these are known as ‘plaques’ and ‘tangles’. This happens to multiple brain cells. Although the reason why they behave this way isn’t yet fully understood, we do know that the chemical connections between brain cells are lost, causing them to begin to die.

Symptoms of Alzheimer’s Disease

As it disrupts chemical changes in the brain, thus causing information to be transmitted inefficiently, one of the first noticeable symptoms of Alzheimer’s is increasing problems with day-to-day memory.

As the condition progresses, people begin to have difficulty in finding the right words, solving problems, making decisions, and other tasks which require complex mental effort. These progress over time and can result in slow speech, confusion and disorientation.

People with Alzheimer’s disease can also experience slow, muddled or repetitive speech as the condition progresses.

Vascular Dementia

What causes vascular dementia?

After Alzheimer’s disease, vascular dementia is the second most common diagnosis amongst the over 65s. It’s broadly caused by problems with blood circulation, as when the oxygen supply to the brain is reduced, some brain cells become damaged or die. Symptoms can appear after a large stroke or a Transient Ischaemic Attack (TIA), where small clots block blood vessels and reduce oxygen flow to the brain.

Vascular dementia can also be caused by a disease that affects the small blood vessels deep in the brain, known as subcortical vascular dementia, which presents similar symptoms.

Symptoms of vascular dementia

Many symptoms overlap with other forms of dementia, especially that of Alzheimer’s Disease, where people have difficulty with their memories or problem-solving. Vascular dementia can also progress suddenly - after a large stroke - or can develop after a series of smaller strokes. Though it varies, many people with vascular dementia find it hard to think quickly or concentrate, and can become very confused for short periods of time.

What is mixed dementia?

As dementia is an umbrella term rather than a disease in and of itself, it’s possible for a person to have more than one type of dementia and a mixture of the associated symptoms. It is common for someone to have both Alzheimer’s disease and vascular dementia together: at least one in ten people with dementia are found to have more than one type.

Care for people with mixed dementia depends on whether one type is predominant as well as which types of dementia they have.

Dementia with Lewy bodies

What causes dementia with Lewy bodies?

A complex form of dementia that involves tiny, abnormal structures in the brain cells, dementia with Lewy bodies can often be mistaken for Alzheimer’s disease in the early stages due to similarities in symptoms. It occurs as tiny structures are formed from clumps of protein (Lewy bodies), which then begin to disrupt brain chemistry, leading to the death of brain cells.

Dementia with Lewy bodies is a progressive disease accounting for roughly 10-15% of dementia cases in the UK.

Symptoms of dementia with Lewy bodies

There are two subtypes of this kind of dementia, diagnosed based on which symptoms present themselves first: dementia with Lewy bodies and Parkinson’s disease dementia. Early symptoms of the first subtype include varying levels of alertness throughout the day, hallucinations, and difficulty judging distances. Crucially, Parkinsonian dementia tends to display the rigidity of movement and slowness typical of the condition, with cognitive changes following later. It’s important to note that not all people with Parkinson’s disease develop dementia, but as the condition progresses the risk of developing symptoms increases.

Dementia with Lewy bodies can, in the initial stages, be mistaken for Alzheimer’s disease: however, people are less likely to have issues with their day-to-day memory with this type of dementia.

Frontotemporal dementia and Pick’s disease

What causes frontotemporal dementia?

A group of conditions in which a person’s frontal and temporal (side) lobes become damaged, frontotemporal dementia is caused by the degeneration of nerve cells and pathways in these areas of the brain. This kind of dementia is the second-most common type that occurs in younger age groups, although it’s less common in the over 65s. It can be split into two main subtypes:

  • Pick’s disease, which affects behavioural signals and social cues. This is the most common type of frontotemporal dementia, accounting for almost half of all cases.
  • Primary progressive aphasia, which affects communication and progresses over several years.

Symptoms of frontotemporal dementia

Changes in a person’s personality or behaviour may be the most obvious signs of this progressive dementia. Depending on where damage has occurred in the brain language fluency may be lost, and as the disease progresses, social inhibitions can become impaired.

People with frontotemporal dementia may also experience shifts in judgement, such as binge eating or inappropriate behaviours, so care for loved ones and residents with this dementia should take steps to address these symptoms in the early stages.

Rarer forms of dementia and linked diseases

These are the most common diagnoses of dementia in the UK, but other types of progressive dementia can be caused by conditions such as:

  • Creutzfeldt-Jakob disease
  • Huntingdon’s disease
  • Corticobasal degeneration (CBD)
  • Multiple Sclerosis (MS)
  • Parkinson’s disease
  • Posterior cortical atrophy
  • Alcohol-related brain damage
  • Niemann-Pick disease type C
  • Down’s Syndrome, which can lead to dementia in later life

These rarer forms of dementia account for only 5% of all cases and are most likely to affect people under the age of 65.

Dementia can often mean that people find it frightening to cope with changes to their daily lives. With our dementia home care and support network, our staff are fully trained to work across a range of dementia types, including those mentioned above. A person-centric approach, this allows loved ones and people with the condition to receive the care and support they need in familiar surroundings.

Dementia testing and diagnosis

People who suspect they have dementia or a related condition often have concerns about memory lapses and forgetfulness. For an accurate diagnosis, it’s important to consult a GP as soon as possible in order to rule out other, treatable conditions which can have similar onset symptoms, such as:

  • Thyroid problems
  • Stress
  • Vitamin deficiencies
  • Infections
  • Medicine interaction
  • Depression.

How do you test for dementia?

Once these have been ruled out, the GP will then carry out a specific set of mental tests. A reliable way of indicating dementia since their introduction over forty years ago, these doctor-led cognitive tests involve a scored question and answer session to assess long and short-term memory and concentration / alertness levels. Language, communication and awareness of time or place are also tested within these initial assessments.

Specialists and memory clinics

If the results of these tests indicate a likelihood of dementia, the GP will refer people on to a cognitive specialist or memory clinic for a more in-depth examination. Discussions will be held with family, friends and loved ones about an individual’s symptoms as well as any difficulties they may be facing in order to best determine which kind of dementia the person has, and how far the condition has progressed.

This is followed by a detailed assessment of the brain, either through a CT (computed tomography) or MRI (magnetic resonance imaging) scan. Both procedures create very detailed images of the inside of the brain, allowing specialists to assess if damage is present, and whereabouts this damage is located within the brain. An important stage in dementia diagnosis, working with a specialist to assess these scans informs people of the type of dementia they have, which in turn informs the range of available treatments for the condition.

Once a diagnosis is reached, help and support can be given to people and loved ones to explain the issues which may develop as the disease progresses.

Late stage dementia symptoms

As dementia progresses, symptoms may become more severe as the person approaches the end of their life. It’s hard to define these exactly as each person experiences the condition differently, but common indicators for later stage dementia include:

Severe memory loss

As the brain degenerates, the memory loss associated with dementia can progress to the point where it becomes difficult to recall recent memories - such as breakfast - or to recognise people and places that are familiar.

Increasing disorientation

Concentration, planning and organisation can become muddled in the later stages of dementia, and a person with the disease may only be able to carry out simple activities. This can be accompanied by a limited understanding of time or place.

Lack of mobility

Dementia and associated conditions often have a big physical impact: it’s not always the case, but people can become reluctant to move around, or can become unable to get themselves out of bed or walk around.

Communication and behaviour

Verbal communication can begin to lapse in the later stages of dementia, resulting in a loss of fluency or understanding in conversation. This can also be accompanied by a reduction in the understanding of social norms and other behavioural changes.

Keeping comfortable in the later stages

People with dementia respond well to familiar environments and recognisable comforts. Our end of life care services provide care in the home to reduce stress, maintain regular access to friends and family and to allow people to spend their final days in comfort. Many of the symptoms of late stage dementia can be alleviated by meaningful activities, conversation and interests present in the home.

Dementia treatments

Dementia is a progressive condition that leads to eventual loss of life. Although there is no cure, certain medications may be prescribed which can help manage symptoms by working to prevent the breakdown of acetylcholine in the brain, a chemical messenger that helps nerves communicate with one another. Three options are available:

  • Donepezil (also known as Aricept)
  • Rivastigmine (also known as Exelon)
  • Galantamine (also known as Reminyl)

Called acetylcholinesterase inhibitors, these medicines are used to treat Alzheimer’s disease as the most common form of dementia, but there is evidence to support their use in cases of dementia with Lewy bodies, Parkinson’s disease dementia, and for people with a mixed dementia diagnosis.

Additionally, another medicine called Memantine can be used in cases where a person is unable to tolerate cholinesterase inhibitors. Working by blocking the effects of too much of a chemical called glutamate in the brain, this medicine can help people show some improvement with memory and attention as well as linguistic fluency.

How to prevent dementia

There’s no concrete way to prevent the onset of dementia, but living healthily is an important choice that helps reduce the risk of developing Alzheimer’s disease or a similar condition. Additionally, healthy living can help slow the progression of the disease by looking after the heart; studies have shown that people can improve brain function and general health by eating a balanced diet, stopping smoking and exercising for 150 minutes per week.

By taking care of the heart in this way, risks can be reduced for cardiovascular diseases, which are themselves risk factors for the most common types of dementia: Alzheimer’s and vascular dementia.

Additional resources:

Activities to stimulate & entertain people with an Alzheimer’s or dementia diagnosis