Vascular Dementia: Where the Cardiovascular System Meets the Brain

 Historically, infectious diseases have been at the forefront of public health concern but the rise of advances in health care has meant non-communicable diseases such as heart disease and dementia, are fast becoming the leading health problem of the modern era. By 2050 an estimated 106 million people will be living with dementia (Figure 1). 

(Key words in this article are in Bold – find the descriptions in the Terms Explained section at the end of this article).  

So What is Dementia? 

Dementia is an umbrella term which describes diseases and conditions characterized by decline in cognitive function. There are several misconceptions about dementia, the most common being that it is a singular rather than a family of conditions.  

      Common symptoms range from difficulty in thinking, memory problems and decreased motivation all which affect day to day tasks.  

What is Vascular Dementia? 

    Vascular dementia (VaD) is a common subtype and accounts for 150,000 cases in the UK coming only second to Alzheimer’s diseaseIt is characterised by damage to brain vessels and surrounding tissue – termed cerebral-vascular pathologies.  

Stroke: a major cause of Vascular Dementia

Vascular dementia is caused by several different pathologies usually linked to cardio-vascular risk factors. One of these pathologies is stroke.  

      Strokes can be divided into two subtypes, haemorrhagic and ischemic stroke (Figure 2a-b)Haemorrhagic stroke occurs when a blood vessel ruptures and bleeds into the surrounding brain tissue. Damage to the brain cells is subsequently caused by the pressure from the blood leaking. Ischemic stroke is a result of a blockage of the blood vessel – resulting in cerebral infarcts 

     When a stroke occurs blood supply to the brain is rapidly reduced or cut off and this leads to cell death. Post stroke dementia refers to cognitive decline after the occurrence of a single stroke in critical regions of the brain such as the hypothalamus or frontal lobe.  

Risk factors of Vascular Dementia   

       In all diseases there are factors which may increase the chance of developing the disease or injury – these are called risk factors. VaD risk factors can be put into two categories, factors which cannot be altered such as age, gender, genetic predisposition and conditions which can be modified such as, diabetes, high blood pressure, high cholesterol, hyperlipidaemia, and heart disease. 

Symptoms 

       Vascular dementia has a long list of symptoms and these vary hugely between individuals. The area in the brain where blood flow is impaired often determines which symptoms a sufferer may have. Some of the symptoms of  vascular dementia include problems with memory, confusion, reduced concentration, difficulty in thinking, reasoning and judgement, restlessness and agitation, personality change and perception and orientation to surroundings. When symptoms occur right after a stroke this is called post-stroke dementia.  

Prevention & Treatment 

  1. Drug therapies 

    Unfortunately, there is no licenced drug treatment for vascular dementia, however some  studies have proposed treating the condition with licensed Alzheimer’s disease drugs, such as Cholinesterase inhibitors (Figure 3).  

  1. Prevention 

      With limited treatment options there is therefore a huge focus on preventative measures. Firstly, doctors may try to achieve this through the detecting and managing cardio-vascular risk factors earlier on – this is known as primary prevention.    

      The Rotterdam study showed that management of high blood pressure effectively reduced the risk of developing vascular dementia and similar findings were confirmed in more recent research.  

      High risk individuals such as the elderly, diabetics or those with high blood pressure are given advice on lifestyle changes which hopefully prevent the development of a stroke.  

Unfortunately, this is not always successful. In this case, secondary parameters are put in place to avoid cognitive decline after such an event. 

Further resources: 

Short informative video: https://www.youtube.com/watch?v=OcVPGIMCDTU 

British Heart Foundation: https://www.bhf.org.uk/informationsupport/conditions/vascular-dementia 

Alzheimer’s Society: https://www.alzheimers.org.uk/about-dementia/types-dementia/vascular-dementia 

Educational video: https://www.youtube.com/watch?v=OcVPGIMCDTU 

The Rotterdam study: https://www.bmj.com/content/310/6985/970.long 

Terms explained: 

Non-communicable diseasesa disease that is not transmissible directly from one person to another. NCDs include Parkinson’s disease, strokes, most heart diseases and more  

Cognitive functionmental processes that allow us to carry out any task  

Alzheimer’s diseasea chronic neurodegenerative disease that usually starts slowly and gradually worsens over time 

Cognitive declinewhen a person has trouble remembering, learning new things, concentrating, or making decisions that affect their everyday life 

Cerebral infarctsareas of dead tissue in the brain resulting from a blockage or narrowing in the arteries supplying blood and oxygen to the brain. 

Hyperlipidaemiahigh level of cholesterol or triglycerides in the blood  cholinesterase inhibitors: medications that prevent the breakdown of acetylcholine  

Information in this article was taken from the ‘Vascular Dementia’ resource written & illustrated by Tanyaradzwa Mwamuka. This article was compiled by Jessica Brown on behalf of the LIVE with Scientists team.