What is Lewy body dementia?

Lewy body dementia (LBD) is one of the most common types of dementia. LBD is characterised by the abnormal deposition of a protein called alpha-synuclein in certain parts of the brain. These protein deposits are called ‘Lewy bodies’ and can be very dangerous because their accumulation can change how the brain works, causing problems with thinking, memory, behaviour and mood.¹

People usually show symptoms of LBD when they are aged 50+ years, although sometimes younger people are affected too. LBD is a progressive condition, meaning that the symptoms will get worse over time. The speed at which symptoms worsen depends on various factors, including overall health, age and lifestyle. As a result, the progression of LBD varies a lot between individuals.¹

In the early stages of LBD, symptoms are usually mild, and those affected by LBD can function relatively normally. However, as the disease progresses, people with LBD will require more help due to a decline in cognition and movement abilities. In the later stages of the disease, people with LBD often depend entirely on others for assistance in navigating everyday life.¹

Signs and symptoms of lewy body dementia

The most common symptoms of LBD are changes in cognition, motor abilities, sleep and behaviour.¹ People with LBD do not need to experience every symptom to achieve a diagnosis, and any sudden change in any of these abilities should be discussed with a healthcare professional.

• Cognitive symptoms: some people with LBD experience hallucinations, the most common of which are visual hallucinations. Additionally, people with LBD may struggle with concentration, organised thought, memory and language. Sometimes people with LBD also experience paranoia and delusions. It is common for an individual’s cognitive state to fluctuate, with periods of cognitive coherence and periods where cognition is more severely challenged
• Movement: there are several different challenges people may experience with their movement, ranging from mild to severe, including muscle rigidity/stiffness, shaking, slow movement, balance problems, stooped posture, smaller handwriting, reduced facial expressions, difficulty swallowing and a weaker voice than usual
• Sleep: a lot of people affected by LBD experience problems with their sleep. Some of the sleep disorders experienced include REM sleep behaviour disorder, excessive daytime sleepiness, insomnia, and restless leg syndrome
• Behavioural and mood symptoms: the behaviour of people with LBD may start to change as the disease progresses. Such changes include experiencing feels of depression, apathy towards things which would usually be of interest, anxiety and, agitation
• Other symptoms: the accumulation of lewy bodies in LBD can cause more widespread effects in the nervous system, for example changes in internal body temperature, blood pressure, sexual dysfunction, impaired sense of smell, constipation, urinary incontinence, dizziness and fainting. These features of LBD can be very dangerous for the affected individual’s health, and may require additional support from healthcare professionals in order to manage them

Importance of prevention

There is currently no cure for LBD, meaning that the question of whether LBD can be prevented in the first place is a significant one, with far reaching implications which touch the lives of many. Currently, there is no definitive way to prevent LBD¹. However, scientists have suggested that looking after your brain can be helpful in reducing the chances of developing LBD and other forms of dementia too.²

To promote brain health, the following lifestyle options are generally recommended:

• Regular physical exercise
• Regular mental exercise
• Avoiding smoking
• Monitor your weight
• Have a balanced diet
• Limit alcohol consumption

You can learn more about reducing your risk of developing dementia here.

It is important to remember that none of these lifestyle options will stop you from getting LBD; these factors just reduce the probability. Unfortunately, it is possible to do everything ‘right’ and still get LBD.

What causes Lewy body dementia?

It is difficult to precisely name one singular cause for LBD, so there are many potential avenues for LBD research in the future.

What we currently know is that the buildup of Lewy bodies in the brain disrupts signalling processes inside the brain. The disruption in signalling between brain regions important for cognitive and behavioural functions causes some common symptoms of LBD.

It is not yet known exactly why Lewy bodies build up in the brains of some people and not others, although scientists are exploring genes, evironmental influences and the natural process of ageing as possible features of the LBD mechanism. Two genetic risk factors of particular interest are variants in the APOE and GBA genes.

The accumulation of Lewy bodies is associated with the loss of neurons which produce dopamine and acetylcholine³. Dopamine and acetylcholine are both neurotransmitters (chemical messengers). Dopamine is important for movement, motivation and mood. Acetylcholine has an important role in memory and learning. When the numbers of these neurons dwindle, these functions become less effective.

Risk factors for Lewy body dementia

A risk factor is any feature of your life which can increase the likelihood of you developing a certain disease. There are several known risk factors for LBD, including the following:

• Age: the older you are, the more likely you are to develop LBD
• Health: Parkinson’s disease is linked to a higher risk of LBD
• Genetics: a family history of LBD may increase a person's risk of developing the condition. Variants in two genes in particular — APOE and GBA — have been associated with an increased risk of LBD

To read more about LBD and associated risk factors, see here.

Potential Prevention Strategies for Lewy body dementia

There is no known way to prevent the onset of LBD.¹

Challenges in Lewy body dementia prevention

There is no way to prevent the development of LBD, and this is a difficult area of research because it is not understood what causes the formation of Lewy bodies.

Additionally, the genetic markers associated with Lewy body dementia are not fully understood, and the existence of a genetic predisposition for Lewy body dementia does not guarantee you will get the condition, so it’s difficult for researchers to know how to prevent the condition when the exact underlying mechanisms are still unclear.

Furthermore, age is arguably the most significant risk factor for Lewy body dementia, and the ageing process is not something that anyone can change.

Compared to Alzheimer’s disease, LBD is less well-known because it is slightly less common. This lack of awareness leads to less funding and research attention, slowing research progress in prevention efforts.

Treatment and management of lewy body dementia

Even though LBD can’t be cured or prevented, there are several options available to help manage the condition. Some of which include:

• Cholinesterase inhibitors: these can help to manage the cognitive symptoms of LBD. Examples of cholinesterase inhibitors include rivastigmine, galantamine and donepezil
• Melatonin: these can help alleviate the sleep disturbances associated with LBD
• Antidepressants: depression can be an effect of LBD, antidepressants can help to manage this. SSRIs are a commonly prescribed antidepressant
• Physiotherapy: physiotherapy can help with the motor difficulties in LBD. Physiotherapy is commonly an effective form of treatment for several conditions where movement becomes difficult

To find out more about managing LBD, see here.

Summary 

• Lewy body dementia (LBD) is a type of dementia caused by the buildup of lewy bodies (clumps of proteins) in parts of the brain important for cognition, behaviour and mood
• There is no way to prevent LBD
• There is no cure for LBD
• It is unclear why lewy bodies accumulate, but there is likely a genetic influence
• In cases of LBD, it is usually neurons which produce dopamine and acetylcholine which are most severely affected. This has severe consequences because dopamine and acetylcholine are very important chemicals: dopamine has a vital role in motivation, sleep, and movement while acetylcholine is important for memory and learning
• LBD is a progressive condition, meaning that the symptoms will get worse over time
• The most common symptoms of LBD are changes in cognition, motor abilities, sleep and behaviour
• Risk factors for LBD include genetics, overall health, and age
• Some of the treatment options for LBD include: cholinesterase inhibitors for the cognitive symptoms, melatonin to help with sleep problems, antidepressants, and physiotherapy for any movement problems