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About Dementia
Types of Dementia

Dementia with Lewy Bodies

Dementia with Lewy bodies is one of the more common forms of dementia and can affect as many as one in ten people with dementia. Lewy bodies appear in neurons which are breaking down. When these Lewy bodies are in deep regions of the brain that affect control of movement, they cause Parkinson's disease . Dementia with Lewy bodies occurs when Lewy bodies are in other areas of the brain such as the thinking parts of the brain in the cortex . Especially when this dementia occurs in older adults -say past the the age of 80-it can occur together with Alzheimer's disease . It is no surprise then, that Lewy Body Dementia shares many symptoms with Alzheimer's disease.


Symptoms of Lewy Body Dementia

One way to understand the symptoms of dementia with Lewy bodies is that while they are similar to those of Alzheimer's disease they occur out of order.The symptoms of Alzheimer's disease occur in a fairly characteristic order in relation to the stage of the illness. In Alzheimer's disease, some symptoms are very common when the disease is mild, but others usually do not occur until later, when the dementia is in a moderate or late stage. For example, hallucinations are common in Lewy body dementia. The hallucinations typically consist of seeing things that are not there. in Alzheimer's disease generally, hallucinations occur late ( e.g. in the severe stage), but in dementia with Lewy bodies, they usually occur early when the dementia is in the mild stage. In fact, in Lewy Body dementia, hallucinations can be the first sign of the dementia. (It should be noted that patients with early hallucinations also have particular problems with visuospatial function).

Symptoms that are more specific for dementia with Lewy bodies include large changes in attention and alertness (one day able to hold conversation, next day completely unable). Other indications of fluctuation are episodes of staring blankly, especially if it occurs to such an extent that you find yourself touching or even shaking the person you care for so that they will " snap out of it". Daytime sleepiness can be another sign of fluctuation.

Another important set of symptoms of Lewy Body dementia reflect its overlap with Parkinson's disease. Parkinson-like symptoms (for theses symptoms, doctors often use the term" Parkinsonism " )include bent posture, shuffling walk, and the tendency to fall. In fact, recurrent falls can be an early feature of Lewy body dementia.

People with Lewy body dementia often experience marked sensitivity to anti-psychotic medications, which can only be used with great care. Referred to as the neuroleptic sensitivity syndrome, the sensitivity usually consists of dramatic worsening of Parkinsonism and cognitive function. (This issue is discussed in Aarsland D et al., Neuroleptic sensitivity in Parkinson's disease and Parkinsonian dementias. J Clin Psychiatry. 2005;66:633-7.).

In Lewy Body dementia, a specific sleep disorder is sometimes present. Normally, our brains inhibit movement of muscles during what is known as "Rapid Eye Movement (REM) sleep". REM sleep behaviour disorder can be thought of as people acting out their dreams. They can move about, although often what is seen is thrashing about in bed. The thrashing movements are organized, however, and can include such things as punching, kicking or jumping out of bed. In such states, patients with REM sleep behaviour disorder have been known to injure themselves or others, especially bed partners. The medications that often work best in REM sleep behaviour disorder often are those that commonly are avoided in people with dementia. In consequence, treatment is tricky and often requires a skilled practitioner and careful monitoring by families.


Course of Lewy Body Dementia

Dementia with Lewy bodies is a progressive disease that has an average length of several years from the beginning of symptoms. One of the notable features of Lewy Body dementia is that people can respond very well to treatment with cholinesterase inhibitors ( i.e. rivastigmine, donepezil or galantamine ). The evidence is best for rivastigmine, so that many physicians will start treatment of a patient with Lewy Body dementia with rivastigmine. if for some reason this does not work , the other drugs can be tried. For some patients, the response to a cholinesterase inhibitor is dramatic improvement. In fact, experienced clinicians often will suspect Lewy Body dementia if they see dramatic improvement after starting treatment with a cholinesterase inhibitor for a patient whom they thought had Alzheimer's disease.

The cause of Lewy Body dementia is still unknown,but it is thought that thereare many genes which contribute to the its development,including some that are also thought to cause Alzheimer's disease and Parkinson's disease.


Criteria for Diagnosis of Lewy Body Dementia

The classic criteria for Lewy Body dementia start with dementia, and then distinguish between core features and supportive features:

Core Features

Three core features are defined, and for a diagnosis of probably Lewy body dementia, two need to be present. These are:

  1. Fluctuating cognition and level of consciousness
  2. Visual hallucinations
  3. Parkinsonism (not induced by drugs or stroke )

Supportive features:

Eight supportive features are described, including repeated falls, fainting, other loss of consciousness, sensitivity to neuroleptic medications, delusions, hallucinations other than visual, specific types of sleep disorders and depression .


Additional Information About Lewy Body Dementia

The Alzheimer's Association website has more information about Dementia with Lewy bodies. Two other websites that we recommend are the UK Lewy Body Dementia Association and the US Lewy Body Dementia Organization.

Information about therapeutics can be found in the chapter on dementia with Lewy Bodies by Richard Camicioli and Serge Gauthier in the book Trial Designs and Outcomes in Dementia Therapeutic Research, published in 2005 by Taylor & Francis (London) and edited by Kenneth Rockwood and Serge Gauthier.

Much of the work on Lewy Body dementia has been conducted at the Institute for Ageing and Health at the University of Newcastle in England. Searching for authors from there, especially Ian McKeith, is another way to get reputable information online.


Frequently Asked Questions About Lewy Body Dementia


Exactly what is a Lewy Body?

Early descriptions of Lewy Bodies called them "debris", but a considerable body of work has revealed that they are made up of a particular type of protein called alpha-synuclein. This protein is otherwise an important part of the synapse - i.e., the small space that separates two neurons, by which they "talk" to each other. The "talking" takes the form of releasing neurochemicals across the synapse, which induces an electrical charge in the second neuron (the one receiving the chemical signal) from the first (the one transmitting it). This is what the term "synaptic neurotransmission " means, and is why the chemicals that cross the synapse are called "neurotransmitters".

How should I handle things when the person I care for is telling me about their hallucinations? Should I just play along?

This is always a difficult thing to know, and how a person reacts might vary from one episode to the next. It is easiest to know what to do when the person themselves is aware that what they are seeing is not real. In that case, reassurance and reinforcement that what they are seeing is not real is helpful. It also helps to be sympathetic to their plight. People with Lewy Body dementia report that it can be very frightening to see things which they know their brain is making up, even if what they are seeing is not very frightening in and of itself. Some people are more reassured by a phrase like "your brain is playing tricks on you", which also means, "you are not losing your mind".

If that is the easiest circumstance - the images are not frightening, and the person has awareness - the hardest circumstance is where the images are scary - even horrific - and the person has no insight. In such circumstances, reassurance is essential, but it is often the case that only medication can help.

Do the Symptoms of Lewy Body Dementia Include Depression?


Not always, but depression occurs often enough to be seen as a supporting feature of a Lewy body diagnosis. The symptoms can overlap, but signs of depression (low mood, disrupted sleep, weight loss, poor appetite, inability to enjoy things, inability to think anything positive about the future) should be treated. Which anti-depressant to use in the setting of Lewy Body dementia (or Parkinson's Disease dementia) is not clear. This is where a skilled psychiatrist can be especially useful.


Comments from Dr. Kenneth Rockwood about Dementia with Lewy Bodies


It has been professionally satisfying to see how much progress has been made in understanding Lewy Body dementia. I remember the first case that I saw, when I was still in training. A highly educated man, whose memory was not detectably impaired without special tests, told me about seeing "little green men" standing on his apartment balcony railing each evening. He described this with insight and humour, but it was clear that he was worried. This was in the days before the dementia had been described, and I was puzzled over what was wrong. We investigated him for a brain tumour. He had been sent to the clinic where I was training by his psychiatrist, whom he had consulted first. The man left the area to go live with family, so I never knew what became of him.

A couple of years later, by which time I was a newly minted geriatrician , I had just completed ward rounds when I go an urgent call from the nurses. A patient whom we had seen only a couple of hours earlier was now in a coma. I rushed back to the ward and went through a coma protocol, which at one point necessitated sending the patient for an urgent CT head scan. That was not so easily arranged and involved disrupting the day's planned schedule of tests. Even so, I was a little taken aback by the hostility of the radiologist's tone with me, when he called me back to ask what I thought I was doing. By now, the patient had completely awoken, and was screaming about prison guards coming to get her. (Such an event was understood to mean that she could not have been in a coma, much less in urgent need of a CT scan less than an hour earlier.).

This too was in the days before criteria for Lewy body disease had been described, although there were several papers emerging in the medical literature about similar patients. I remember both the excitement at understanding what it was that I had seen and the frustration an sadness at not being able to use that information to help people, beyond making a diagnosis. Those feelings of frustration intensified over the next few years, as I saw many patients with truly horrific hallucinations, including reliving past traumatic events. I especially recall one man, a true war hero, who spent his last six months constantly seeing in front of him his worst experiences from the war.

By 1997, we had routine access to donepezil (trade name AriceptTM), the first of the cholinesterase inhibitors to become available in Canada. Even so, there was considerable pressure to use it in a strictly "evidence-based" way, as the drug was expensive. One Saturday morning on weekend ward rounds, I was asked to see a patient who was not onmy list of patients, but whoclearly had dementia and terrible hallucinations. Although the patient was still aware that the hallucinations could not be real, they were especially monstrous. As I spoke with the man, he grabbed my lab coat and asked if I could help him. I said I wasn't sure. "Then you must kill me," he said in the most matter of fact way, "because no one is meant to suffer like this". In desperation, I suggested to the nurses that they try donepezil, and then went through the steps to have this cleared with his attending physician. The result was amazing. By the next morning, the hallucinations had been reduced remarkably, and within only a few days, they had entirely disappeared. Based on that experience, I treated eight more patients who had Dementia with Lewy Bodies each time with remarkable results. My colleagues and I wrote up the series of nine cases in a paper which we published in 1999, and which quickly became a "classic", meaning that it has been cited more than 100 times in the medical literature.

I learned a lot from that experience. The first was dramatic reinforcement of how important careful clinical observation can be in making care better. It has only been in the last few years that we have had access in my health facility, to cutting edge neuroimaging. This means I can now mentor and encourage a generation of prospective young clinician scientists that they can do much good by simply looking at what they see - by doing it in an organized and careful way. One thing that looking carefully has also taught me is about how variable the response to treatment can be. Although many patients improve a great deal, some hardly show any effect, which is both puzzling and disappointing. It is not clear why some people do well and some don't respond at all, and it almost never can be guessed ahead of time.

Another way that response varies is in how starting a cholinesterase inhibitor can affect the motor performance of a person with Lewy Body dementa. Remembering that parkinsonism is a core feature of Lewy Body dementia, it is interesting to see how patients' slowness and rigidity, for example, might respond. For technical reasons, one might theoretically expect both to slightly worsen, and while that sometimes happens, in our experience it does not happen very often. Usually there is no effect on motor performance - although walking can improve as apraxia (the brain's problem in integrating what needs to be done) improves. We have also seen some patients' rigidity and slowness get better. All this shows that there is sometimes an important gap between what is generally true for an illness, and how it manifests in particular patients. I have also been impressed by the ability of patients with Lewy Body dementia to tolerate the gradual need for, and to tolerate higher doses of cholinesterase inhibitors - often higher than recommended doses.

The last point has made me think a lot. If we can learn about fundamental aspects of neurobiology by paying attention to what drugs actually work in patients, we have a lot of work to do in how we organize conduct and interpret controlled clinical trials . At present, the idea is very much that we should set specific hypotheses and use the trials to test them. This is essential, but the psychology around what happens next is not optimal for good science. If a drug passes this hurdle, the pharmaceutical companies are naturally hesitant to work with the data any more - they have done their job, at great cost, and additional analysis will necessarily be speculative and might not always be favourable. If the data do not work out as planned, there is little perceived value in investing more in additional analysis.

Variability in response is also a challenge for knowing how to interpret the scientific evidence overall. Some people look at the cholinesterase inhibitor data for dementia and conclude that the drugs are generally not worth it, given a small average effect. But the small average effect hides no differences for some people and big differences for others. Who will do well and who will n ot, cannot be guessed ahead of time, so my general stance is that we should try with individual patients, and then monitor their response carefully.

See Also:
Symptom Library > Physical Changes > Mobility
About Dementia > Types of Dementia > Parkinson's Disease
Symptom Library > Behaviour > Hallucinations
Symptom Library > Thinking & Judgment > Attention/Concentration (lack of)
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Last updated July 23, 2014
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