Dementia by Lewy Bodies: Symptoms, Causes and Treatment

The Dementia by Lewy bodies Is a degenerative disease, very similar to Alzheimer's dementia, but with specific characteristics that Become a very particular dementia syndrome.

In fact, until a few years ago, it did not"exist." That is to say, this type of disorder had not been discovered and the people who They were diagnosed with Alzheimer's disease (AD).

Dementia of Lewy bodies

However, in 1980, psychiatrist Kenji Kosaka coined the concept of"Lewy Body Disease"by witnessing a very Similar to Alzheimer's dementia, but with certain differences.

In fact, this characteristic name (Lewy bodies) refers to the particles that were discovered in the neurons of patients with this type Of disorder, which are responsible for producing brain degeneration.

Thus, although Alzheimer's dementia and DCL share many characteristics, these particles do not Neurons, so the cause of both types of dementia seems to be different.

However, currently many patients with Lewy body dementia remain"misdiagnosed"of Alzheimer's.

To try to clarify a little the properties of the DCL, below we will comment on all its characteristics and which of them make it different from the d Alzheimer's disease.

Characteristics of Dementia by Lewy Bodies

The main symptom of Lewy body dementia is cognitive impairment, which includes memory problems, problem solving, Planning, abstract thinking, concentration, language, etc.

Also, another important feature of this disorder are cognitive fluctuations.

This means that patients with DCL do not always have the same cognitive performance. In other words, sometimes they appear to be older Mental and intellectual abilities, and sometimes appear to have a more advanced deterioration.

These variations in their performance are explained by the alterations in the processes of attention and concentration that people with this type present Of dementia.

In DCL, attention and concentration undergo unpredictable changes. There are days or times of the day in which the person can be attentive and concentrated, and There are other days when your concentration may be completely deactivated.

Thus, when the person with DCL has greater attention and concentration, their cognitive performance increases, and performs more effectively Mental activities, has a better functioning, speaks in a more fluid way, etc.

However, when attention and concentration appear more deteriorated, their cognitive performance decreases sharply.

Another relevant symptom in Lewy body dementia is the motor signs: stiffness, muscle tightening, tremor and slowness of Movements, which are practically the same as Parkinson's disease .

Finally, the third main symptom of DCL is hallucinations, which are usually Visual .

Older DCL sufferers often hear and interpret voices that do not exist, and sometimes see hallucinatory elements.

Thus, by way of summary, the four main characteristics of CDL are: cognitive impairment, fluctuations in such deterioration, presence of Parkinsonian symptoms and the appearance of Hallucinations .

However, other symptoms such as:

  • REM sleep behavioral disorder : This disorder is characterized by very intense living dreams, which can become In violent actions and attitudes.

  • Significant changes in autonomic nervous system : Regulation of temperature, blood pressure, digestion, dizziness, fainting, sensitivity to Heat and cold, sexual dysfunction, urinary incontinence, etc.

  • Excessive somnolence during the day, possible mood alterations, loss of consciousness, apathy , Anxiety or delusions.


The diagnosis of dementia by Lewy bodies is highly controversial because of its multiple similarities with type dementia Alzheimer's .

However, in order to delimit its diagnosis as much as possible, the DCL consortium concluded in 1996 established the Following criteria:

  1. The central feature is progressive cognitive impairment of sufficient magnitude to interfere with normal social or work function. In the Early stages there may not be a noticeable and persistent memory disorder, but it is usually evident as you progress. They can be especially The accusations of attention.

  2. Two of the following primary features are required for the probable diagnosis of DCL and one for the possible diagnosis DCL:

  1. Cognitive fluctuations with noticeable variations in attention and alertness.

  2. Recurrent visual hallucinations, typically well structured and detailed.

  3. Features spontaneous motors of Parkinson's.

  1. The following features support the diagnosis:

  1. Repeated falls.

  2. Syncope (fainting)

  3. Transient loss of consciousness

  4. Sensitivity to Antipsychotics (Bad reaction when taking these drugs).

  5. Systematic delusions.

  1. The diagnosis of DCL is less likely in the presence of:

  1. Cerebrovascular disease manifests as focal neurological signs.

  2. Evidence on the physical or complementary examination of another general or cerebral disease capable of explaining the clinical picture.

Thus, the diagnosis of DCL is not yet detailed and differentiated from Alzheimer's disease through Probability mechanisms.

Differences of Alzheimer's disease and Dementia by Lewy Bodies

Despite the multiple similarities, there are also divergent aspects between both diseases, therefore, in many cases it is possible to differentiate one DCL from Alzheimer's dementia.

The main differences are:

  1. In Alzheimer's disease, memory impairment is early and prominent; memory loss in DCL is more variable and, therefore, General, less important.

  1. In DCL visuomotor abilities (such as writing or picking up an object) are very deteriorated, whereas in Alzheimer's this deficit is not usually Be very noticeable.

  1. The same happens with visuoconstructive deficits (ability to plan and make movements). They are very marked in the DCL and are less Important in EA.

  1. On the other hand, patients with DCL tend to have better verbal memory during the course of their disease than Patients with Alzheimer's disease.

  1. The DCL has the unique characteristic of presenting fluctuations in the cognitive deterioration, this in the EA does not happen.

  1. In DCL hallucinations occur frequently, they are very common and may already be present at the onset of the disease. In Alzheimer's Are rare and usually only appear at very advanced stages.

  1. The same is true of delusions, quite common in DCL, and rarely seen in Alzheimer's dementia.

  1. Other major symptoms of DCL are stiffness, trembling, and typical signs of Parkinson's. Patients with AD rarely present these Symptoms and if they do, they present them at very advanced stages of the disease.

  1. Sometimes demented patients present with hallucinations, a fact that usually requires the use of antipsychotics. When a person with EE takes a Antipsychotic drug usually has a good therapeutic response, when it takes a person with DCL usually has a very bad physical and Psychological.

  1. In DCL, the famous Lewy bodies (cytoplasmic inclusions) are present in the neurons, which cause neuronal death and Cognitive impairment. In Alzheimer's disease this does not happen.

About us

Dementia by Lewy bodies is the third cause of dementia behind Alzheimer's disease and the Vascular dementia .

In fact, Lewy bodies have been observed in the neurons of patients with dementia in approximately 20-30% of autopsies performed.

There are studies that have found that the prevalence of CDL among people over 65 is 0.7%.

The onset of the disease varies between 50 and 90 years of age, and the life prevalence of patients with this type of dementia is usually very high. short.

In people with DCL, it usually takes 6 to 10 years between the onset of their illness and their death, being thus one of the dementias that worse Forecast present.


DCL originates when the famous Lewy bodies appear in the neurons of the person.

Lewy bodies are cytoplasmic inclusions that are constituted through different proteins, especially alpha-synuclein.

That is to say, brain Of the patients with DCL suffers an alteration in the synthesis of this protein, therefore, this one is united to the nucleus of neurons , Y Thus constitutes the bodies of Lewy.

Therefore, in the neurons of the patient, these bodies begin to appear, which collaborate in the dead neuron itself and initiate the Cognitive impairment .

Likewise, the Lewy body is distributed by the neurons of different regions of the brain, producing a great number of alterations and provoking Cognitive deficits in many different areas.

The cause of DCL, that is, why they begin to"put together"Lewy bodies in neurons, today is unknown.

However, there seems to be some consensus that there is a genetic component in the development of this disease.

Genes as the gene for Apolipoprotein Or the Cytochrome P450 Seem to be involved in DCL. Likewise, the former appears to be also Related to Alzheimer's and the second with Parkinson's, a fact that could explain the characteristic symptoms of Parkinson's and AD Also present in the DCL.

However, these genetic patterns alone would not explain the development of the disorder.

As far as the environment is concerned, there are no conclusive studies on what the risk factors for dementia by Lewy bodies might be, without However the following seem to bear some relation:

  1. Age : As in most dementia syndromes, the longer they are, the more likely they are to have MCI.

  2. Cholesterol : Although there are no studies that prove this clearly, suffering from cholesterol could be a risk factor.

  3. The alcohol : High alcohol consumption may increase the risk of developing DCL, although moderate consumption may reduce it.

  4. Diabetes : Similarly, although there is no aetiological evidence, there are authors who defend that diabetes can be a factor that collaborates in the Development of DCL.

  5. He Mild cognitive impairment : This disorder markedly increases the risk of developing dementia as the age increases. From 65 The risk can be increased up to 40%.

How can it be treated?

DCL has a wide range of symptoms, so it is important to perform different therapeutic interventions.

As far as cognitive impairment is concerned, it is important to carry out cognitive stimulation activities to try to maximize the progress of the illness.

Working with patient deficits such as attention, concentration, memory, language or visual construction can Their cognitive abilities.

As far as hallucinations are concerned, they should only be treated when they produce anxiety or agitation in the patient. Conventional antipsychotics As the Haloperidol Are contraindicated for their strong side effects.

In those cases where it is imperative to treat hallucinations, atypical antipsychotics such as Risperidone .

Finally, parkinsonian symptoms are also often difficult to treat since antiparkinsonian drugs are often ineffective and produce Many side effects in patients with DCL.

When tremor or stiffness is very high, small doses of L-dopa .


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