What is vascular dementia?

It’s a common misconception that dementia is a disease itself, but this isn’t the case. The word ‘dementia’ is used to describe a group of symptoms, such as memory loss, communication changes and confusion. It happens when brain cells become damaged by underlying diseases. While Alzheimer’s disease is the most well-known, there are other diseases that cause dementia too.

Vascular dementia is the second most common type of dementia. For every five people with dementia, one will have vascular dementia.

 

Our brains are a hungry organ. Despite weighing just 2% of our total body weight, they take up a fifth of all our bodies energy needs. Blood delivers vital oxygen and nutrients to cells around our body including brain cells and helps remove waste too.

Vascular dementia occurs when there is a disruption of blood flow to the brain. This disruption means brain cells can’t get the oxygen and nutrients they need to function properly, and overtime they become damaged and die.

This damage and brain cell death leads to symptoms of dementia, and in vascular dementia this can include:

• Difficulty performing tasks that used to be easy.
• Difficulty learning new information or following instructions.
• Difficulty with paying attention, reading and writing.
• Struggling to find the right words or using the wrong word.
• Slurred speech.
• Changes in personality, behaviour or mood.

Read more information about the symptoms caused by vascular dementia here.

 

But what stops blood flowing to the brain?

There are different underlying conditions that can lead to reduced blood flow in the brain, and in turn vascular dementia. And someone may have more than one of these at the same time.

Stroke and vascular dementia

Around 1 in 3 people with vascular dementia have had a stroke. A stroke occurs when blood flow to part of the brain is cut off. There are different types of stroke:

Haemorrhagic stroke occurs when a blood vessel bursts.

 

Ischaemic strokes occur when a blood clot blocks blood flow to the brain.

Ischaemic strokes can cause single or multi-infarct dementia. The word ‘infarct’ means that an area of the brain has become damaged because it has had its blood supply cut off. Single-infarct dementia occurs when there a is large area of damage in one part of the brain.

Multi-infarct dementia occurs after a series of strokes in different parts of the brain.

Many people have problems with forgetfulness after a stroke and do not develop dementia. However, if somebody has persistent issues with thinking and memory after a stroke or a series of small strokes, they may be diagnosed with post stroke vascular dementia.

The symptoms a person experiences depend on the regions of the brain that are damaged.

Subcortical vascular dementia

Vascular dementia can also occur when there are damaged cells in an area of the brain called white matter – this is sometimes referred to as subcortical vascular dementia.

The brain is made up of white and grey matter. Grey matter is found around the outer edge of the brain. It processes information and sends new information, controlling many functions including movement, speech and memory. White matter is deeper inside the brain and allows different areas of our brain to communicate with each other, and the rest of our body. It helps us to carry out functions such as balancing, learning and problem solving.

If the white matter does not receive blood supply, brain cells in this area die and so the connections across the brain become lost. This can cause a range of dementia symptoms including memory loss and confusion.

Damage to brain cells in the white matter can be caused by small vessel disease (SVD). This is when the small blood vessels become narrow, and blood cannot flow through them. SVD can happen naturally as we age, but conditions like high blood pressure or lifestyle factors like smoking or poor diet can make it more likely at an earlier age.

In contrast to vascular dementia caused by a stroke, SVD might not cause any symptoms initially. But as small vessel damage worsens and spreads over time in the white matter, dementia symptoms may become more noticeable.

There are also a number of other diseases that can cause damage to white matter brain cells, and therefore lead to vascular dementia. For example:

• Lacunar lesions. These occur when a person experiences a type of stroke in the very small arteries deep within the white matter of the brain.
• Subcortical vascular dementia or Binswanger’s disease is characterised by widespread narrowing of arteries in the white matter. which reduces blood flow and causes cell death.

Can I have two different types of dementia?

Yes, you can. This is called mixed dementia, and in many cases people have both Alzheimer’s disease and vascular dementia. You may be diagnosed with mixed dementia if there are clear signs that more than one type of disease is directly contributing to your dementia symptoms.

The relationship between our brains’ blood vessels and dementia is a complex one. Research is investigating how diseases like Alzheimer’s slowly damage blood vessels in the brain overtime, and whether early changes to blood vessels in our eyes may be an indicator of Alzheimer’s.

What can I do to keep my brain healthy?

What makes up our risk of developing dementia is a complex mix of factors that interact over our lifetimes. These factors include our age, genes, health, environment and lifestyle factors. While we cannot change our age or the genes we inherit, we can all take steps to look after our brain health and this can help to reduce our overall risk of developing dementia.

Research has shown that almost half (45%) of dementia cases worldwide could be prevented or delayed by addressing 14 population health and lifestyle factors.

Looking after our heart health can help reduce our risk of dementia. High blood pressure, high cholesterol, obesity and stroke all damage our blood vessels, including those in our brain, and are related to an increased risk of dementia. So, we can reduce our risk if we:

• Stop smoking.
• Are physically active every day.
• Eat a balanced diet.
• Maintain a healthy weight
• Drink alcohol in line with government recommendations.

You can read more about risk factors for dementia and steps you can take to reduce your risk of dementia here.

What research is being carried out?

Alzheimer’s Research UK has funded more than £4.5 million of research to advance our understanding of vascular dementia. Thanks to your support we have funded studies investigating how blood vessels can become damaged in the brain, and how this damage causes the symptoms seen in vascular dementia. Our scientists are also working to develop new ways of preventing and diagnosing vascular dementia.

Researchers at the University of Oxford are investigating why blood vessels behave differently after a stroke. They will work to understand how the brain and blood vessels communicate after a stroke, with the aim of finding new ways to reduce the risk of dementia. Early findings have provided some important information about the health of the brain post-stroke, that may be used to inform future treatment strategies.

A team at the University of Manchester led by Dr Joyce (Yun-Ting) Huang, are investigating whether thiazolidinediones (TZDs), a diabetes drug could be repurposed to treat vascular dementia. Currently, there is no specific treatment available for vascular dementia. This project aims to generate the evidence needed to design a clinical trial to test TZDs for vascular dementia.

You can read more about our projects and initiatives here.

 

How can I take part in dementia research?

Research is the only way to understand more about diseases like vascular dementia, to find effective ways to diagnose it, prevent it and to work towards a cure. And we need people like you to get involved!

There are many different ways to take part in dementia research.  Find out more about how you can play a role in helping scientists change the ending for people with dementia.

 

If have any questions about dementia, dementia research, or want to take part in research, you can contact the Dementia Research Infoline by phone on 0300 111 5111 (9-5pm Monday to Friday) or email infoline@alzheimersresearchuk.org

If you are worried that you are experiencing any signs or symptoms of dementia, it is best to discuss these with your doctor.

Watch Olive’s story to hear from someone living with vascular dementia: