In addition to Alzheimer's disease, there is also a type of dementia called Lewy body dementia!

Author: Xiao Weizhong, Chief Physician, Peking University Third Hospital

Reviewer: Wang Lixiang, Chief Physician, Third Medical Center, PLA General Hospital

Everyone is familiar with Alzheimer's disease and often calls it senile dementia. This is because the main group of people suffering from Alzheimer's disease are the elderly. In fact, if the elderly have dementia symptoms, they do not necessarily have Alzheimer's disease.

Common in the elderly, other dementia-related diseases include frontotemporal dementia, Parkinson's dementia, and Lewy body dementia. The incidence of Lewy body dementia is second only to Alzheimer's disease.

Dementia with Lewy bodies (DLB) is a type of dementia and also a degenerative disease. It is mainly caused by the pathological structure of Lewy bodies found in the human brain. The disease is named in honor of its discoverer, British neurologist Friedrich Lewy.

Although there is no authoritative data on the incidence of Lewy body dementia, based on the development and clinical manifestations of Lewy body dementia and existing clinical experience, the elderly are more susceptible to the disease than other groups. Of course, people with cognitive impairment are also more likely to develop dementia in the future.

Due to my country's large population base, extended life expectancy and accelerating aging trend, the clinical prevention and treatment situation of Lewy body dementia is also quite severe. Many people do not even know what Lewy body dementia is, let alone actively treat it.

In addition to dementia, what situations in life should make patients and their families highly suspicious of Lewy body dementia?

1. What symptoms should lead to a high suspicion of Lewy body dementia?

As we mentioned earlier, there are many types of dementia, such as Alzheimer's disease, Parkinson's dementia, frontotemporal dementia, etc. As long as it is dementia, there must be symptoms of dementia. The diagnostic criteria for dementia include memory loss, decreased cognitive ability, and the resulting decreased ability to live.

Lewy body dementia has three core symptoms: fluctuating cognitive impairment, visual hallucinations, and Parkinson's-like symptoms.

Figure 1 Original copyright image, no permission to reprint

Fluctuating cognitive disorder means that the condition gets better and worse within a day, a week, or a month. When it is good, the patient can be the same as a normal person, but when it is bad, the patient may suffer from dementia. The condition may even relapse several times within a day. This is called fluctuating cognitive disorder.

Visual hallucination means that he sees some vivid and bright colors, very deep and bright figures or small animals. This is called visual hallucination.

Parkinson's-like symptoms may include stiffness, lack of movement, slow walking, leaning forward when walking, or difficulty starting and being unable to stop, similar to the symptoms of Parkinson's disease.

To suspect Lewy body dementia, the prerequisite is that there must be symptoms of dementia. If two of these three core symptoms appear, then Lewy body dementia can be considered. If only one symptom appears, then there is a possibility of Lewy body dementia.

2. How is Lewy body dementia diagnosed?

When memory loss occurs but has not yet affected social functions, the patient's family or people who know the situation should send the patient to the hospital's memory clinic for diagnosis and treatment as soon as possible.

The doctor will do a series of tests, ask about the medical history, do a physical examination, and do a cognitive assessment, that is, a scale test, to see if there is memory loss or early dementia. Then some related tests should be done, such as biochemical tests, thyroid function tests, vitamin B12, folic acid tests, immune index tests, etc., to rule out other causes of dementia. Imaging examinations are very important, and CT, magnetic resonance imaging, PET-CT or PET-MRI examinations should be done. These examinations can basically confirm the diagnosis. The gold standard for diagnosis is pathological examination. Lewy bodies must be seen in pathology to be truly diagnosed as Lewy body dementia.

As Lewy body dementia progresses, memory loss and a decline in daily living ability occur. The patient may get lost when going out and may also develop some mental symptoms. The patient is particularly prone to falling. For the elderly, the consequences of falling are very serious.

Now that we know about Lewy body dementia and the dangers of Lewy body dementia, is there any way to treat Lewy body dementia? How should it be treated?

3. How to treat Lewy body dementia?

To treat Lewy body dementia, the first thing to do is to treat the symptoms of dementia. For the three major symptoms of fluctuating cognitive impairment, visual hallucinations, and Parkinson's-like symptoms, appropriate nursing guidance and treatment should be given.

The current treatment methods are, first, drug treatment, and second, non-drug treatment. Drug treatment mainly relieves symptoms and provides symptomatic treatment.

There are two major categories of drugs commonly used in clinical practice for dementia symptoms. One is cholinesterase inhibitors, such as donepezil and rivastigmine. Evidence shows that rivastigmine can be used as the drug of choice. The other is excitatory amino acid receptor antagonists, such as memantine.

For Parkinson's-like symptoms, use drugs for treating Parkinson's disease. The most commonly used ones in clinical practice are dopamine hydrazine or dopamine receptor agonists. There are also other drugs for treating Parkinson's disease that can be chosen.

For symptoms of visual hallucinations, if the hallucinations are very obvious, or there are delusions, comprehensive treatment is generally used first. After anti-dementia treatment, if the patient's mental symptoms are still very obvious, small doses of atypical antipsychotics can be used for treatment, such as clozapine, Risperdal, and olanzapine. These can all be chosen. Be sure to pay attention to side effects of this type of drug, and do blood tests regularly. After the symptoms are controlled, the drug dosage should be reduced quickly, and the dosage should be stopped when the symptoms improve. The dosage can be increased appropriately if the symptoms worsen.

There are many non-drug treatment methods, including language training, memory function training, limb function gait, balance training, and cognitive training. Different rehabilitation modes are selected according to the condition. Through rehabilitation training and cognitive training, the quality of life of patients can be improved, which is very meaningful.

For example, when you have a balance disorder and are prone to falling, Tai Chi is a very good exercise to maintain balance. When you have a poor memory and cognitive impairment, playing mahjong is also a very good choice, but of course you can't play mahjong for too long. Listening to music, recalling the past, looking at photos, sunlight, and other stimulations can help restore memory.

In general, Lewy body dementia requires holistic treatment and full-process management. Holistic treatment includes medication and non-drug treatment. Of course, Chinese medicine can also be tried, combining Chinese and Western medicine. Because there is no specific treatment method, comprehensive treatment is needed. A single treatment method has been proven to be ineffective.

Do patients with Lewy body dementia need to take medication for life? When the disease reaches the late stage and the medication cannot achieve the therapeutic purpose, it is recommended to stop taking the medication, as it will not have much effect.

**4.** Is Lewy body dementia hereditary?

Whether dementia is hereditary is a question that everyone is concerned about.

According to current medical knowledge, Alzheimer's disease is an autosomal dominant trait with a nearly 5% inheritance probability.

Based on clinical experience, the probability of inheriting Lewy body dementia is lower than that of Alzheimer's disease. Currently, there is no specific test for the heritability of Lewy body dementia, and there is no relevant data to support it.

Regardless of whether it is hereditary or not, it is recommended to seek treatment as soon as possible once it is discovered.