Lewy Body Disease

Information for patients and carers

What is Lewy Body Disease

Lewy Body Disease is a progressive disease of the brain that can lead to alterations in thinking and behaviour. It also causes physical symptoms such as shaking, stiffness and walking problems. When people have significant memory, thinking and behavioural problems in Lewy Body Disease which interfere with day to day activities, they are said to have a “Dementia with Lewy Bodies” (DLB) or a “Lewy Body Dementia”.

The disease is named for the clumps of protein which build up in certain parts of the brain, causing the symptoms. These clumps are called “Lewy Bodies”.

Why haven’t I heard of Lewy Body Disease before?

It is only relatively recently that it has been recognised as a specific entity. It is less common than other neurodegenerative diseases like Alzheimer’s Disease, but it is still the third most common cause of dementia in the UK.

What are the symptoms?

People with Lewy Body Disease often have problems with concentration and memory.  They may have difficulty in paying attention to things and remembering information about their day to day life.

It is common for the thinking skills of people with Lewy Body Disease to fluctuate: they may seem confused and incoherent at times, but quite aware and attentive at others. 

The person’s language is usually not affected very much. During periods of confusion they may say things  which seem off the point and irrelevant, and they may have difficulty finding the words they want to use, but they usually use real words and pronounce them correctly.

People might also experience visual hallucinations: they may believe that other people are in the house, or they may see animals that aren’t there.

Why do people with Lewy Body disease have hallucinations?

We still aren’t completely sure.  However, we think they partly relate to problems with visual perception.  The regions at the back of the brain are particularly important for processing visual information and making sense of what we see.  This part of the brain can be damaged in Lewy Body Disease. People can still see (i.e. their eyesight is not affected), but they have problems in interpreting visual information and sometimes misidentify things (e.g. they may think that a pattern in a curtain or carpet is the face of a person).

Are the cognitive symptoms the same as in Alzheimer’s disease?

Some of the cognitive changes are similar and there is a recognised overlap between the two conditions.  However, the fluctuations and distractibility mentioned above are particularly characteristic of Lewy Body Disease.  Hallucinations are also more common in Lewy Body Disease than Alzheimer’s disease.

Are people with Lewy Body Disease sometimes thought to have Alzheimer’s disease initially?

Yes, it can be difficult for doctors to tell the two diseases apart. The reason is that there is an overlap between the two disorders. Alzheimer’s disease and Lewy Body Disease share some of the same cognitive symptoms and there are some common brain changes. As a person’s symptoms develop over time it may become easier to tell which disease is causing them.

Are the mental changes the only symptoms?

No.  People with Lewy Body Disease often also slowed down physically and can develop stiffness of the limbs.  The physical symptoms are similar to those of Parkinson’s disease.

It can be different from person to person.  Some people develop changes in thinking first and may have no physical symptoms for months or years.  Other people develop the physical changes or Parkinson’s disease first, with no cognitive symptoms, and then develop cognitive changes only much later.  People in the second group will normally be diagnosed with Parkinson’s disease until the mental changes develop.

Does that mean that Lewy Body disease is a form of Parkinson’s disease?

Yes.  The difference is that whereas in Parkinson’s disease the brain changes are confined to deep structures within the brain important for the control of movement, Lewy Body Disease also affects the “cortex” – the outer parts of the brain important for thinking.  Lewy Body Disease tends to damage the back part of the cortex, responsible for making sense of what we see.

Will the symptoms become worse?

The disease is progressive, so symptoms do get worse over time.  However, people can be quite different in the speed of progression.  Some people show little decline over the course of a year whereas others change more quickly.  Usually, monitoring a person’s progress over a year or so will give a good guide as to the likely future rate of progression.

At what age do people become affected?

Lewy Body Disease becomes more common as we grow older, although it can also affect people in middle age.

What is the cause?

The disorder is a degenerative condition of the brain. This means that cells in certain parts of the brain gradually stop functioning correctly and can die off, which is why symptoms develop. The cause of this degeneration is not fully understood yet and is the key question for current research.

We do know that a particular protein, alpha-synuclein can build up and form clumps inside brain cells. We call these clumps “Lewy Bodies” after the man who discovered them.

We also know that this condition is not caused by external environmental or lifestyle factors, such as diet, occupational exposure or head injury. It can affect people from all walks of life and is not simply the result of ‘over-use’ or ‘under-use’ of the brain.

Is Lewy Body Disease inherited?

No, not typically. Cases of inherited Lewy Body Disease are extremely rare.

Are there any treatments?

Yes, there are drugs available that can help with some of the symptoms. Unfortunately there is no treatment that can cure the underlying disease. Any treatment options will be discussed with you in the clinic. A doctor in your local area, will prescribe the appropriate drugs so that their effects can be closely monitored.

Is there any research into Lewy Body Disease?

Yes, certainly. The interest in this area of research increases each year. The aim is to understand the mechanisms that underlie this disorder, so that better treatments can be developed. Our department is an active contributor to research in Lewy Body Disease and other degenerative disorders. If you would like to find out more about the research carried out in our unit, please ask when you attend the clinic.