Sep 21, 2020

Lewy body dementia: why is it so hard to diagnose?

Lewy body disease, a form of degenerative dementia, has proven extremely difficult to accurately diagnose. This is due to its similarities to other diseases and the impossibility of finding Lewy bodies through brain scans and other diagnosis methods. 

Despite these challenges, it is vital that this disease is diagnosed as early as possible, as inappropriate treatment has been seen to worsen the condition. 

What is Lewy body?

Lewy body disease is a form of dementia. It is caused by the degeneration and death of nerve cells in the brain, and shares many similarities with Alzheimer’s disease. Lewy bodies are abnormal spherical structures which develop inside nerve cells and are thought to contribute to the death of brain cells. They are named after Dr Frederic Henry Lewy, who discovered them in the early 1900s.

Lewy body disease is the second most common form of degenerative dementia, after Alzheimer’s. There is no known cause of Lewy body disease, and as yet no risk factors have been identified. There is no evidence that it is an inherited disease and it is present in both men and women, although more common in men.

Why is diagnosis difficult?

Lewy body disease has proven difficult to diagnose due to its close similarities to Vascular dementia and Alzheimer’s disease. It also presents in a similar way to Parkinson’s disease. Lewy bodies can only be identified by examination of brain tissue after death, although a brain scan of living patients may reveal brain degeneration.

Lewy body disease is diagnosed through developing a history of the pattern of symptoms and excluding other possible causes. 

There are three cardinal symptoms of Lewy body disease, and two of these must be present to make a diagnosis:

  • Visual hallucinations
  • Parkinsonism (including tremors and stiffness)
  • Fluctuation in mental state

This fluctuation occurs over a period of hours or even minutes, leaving patients appearing lucid and clear at one time and then rapidly becoming confused, disoriented and bewildered.

Other common symptoms seen in Lewy body disease patients include difficulty with concentration and attention, extreme confusion, and difficulties judging distances, which can result in falls. Many patients exhibit behavioural and mood symptoms, such as depression, apathy and paranoia.

Lewy body disease typically progresses more rapidly than Alzheimer’s. The average lifespan after the onset of symptoms is about seven years, with patients usually dying as a result of another illness such as pneumonia or an infection.

The importance of early and accurate diagnosis

There is no cure for Lewy body disease. Treatment consists of medications to control different aspects of the disease, such as medications to reduce depression, or treatment to help with problems of movement.

However, some of these medications can adversely affect other aspects of a patient’s Lewy body disease symptoms.  For example, medications that can reduce hallucinations can increase the Parkinsonism symptoms of muscle tremors and stiffness. Conversely, drugs used to treat Parkinson can increase the frequency and severity of hallucinations.

This is why an early and accurate diagnosis is crucial: to ensure that medications are administered appropriately and that treatment options that can worsen Lewy body disease symptoms are not used. Lewy body disease patients have been shown to react differently to medications than people living with Alzheimer’s or Parkinson’s. They are very sensitive to side effects from medication, and all medications should be closely supervised by a specialist.

Traditional anti-psychotic medications, sometimes prescribed to people living with Alzheimer’s, can have a severe reaction in Lewy body disease patients, leading to a worsening of movement and a potentially fatal condition known as neuroleptic malignant syndrome. 

More research is needed to continue to combat this disease and find improved ways of diagnosis and treatment. There is some emerging evidence that cholinesterase inhibitor drugs may be used to manage the disease. Doctors are also using exercise, diet, and sleep management to help patients retain motor function. 

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  1. My father who is a couple of weeks shy of 87 constantly complains of his hands being dirty or fluffy, he says when he washes them they just get worse also complains of handtowels being wet and unable to become dry. Any idea what this would fall under? I feel it is getting to the stage where he thinks said grime will come off and go unto his cutlery and end up in his mouth. He already thinks it’s coming off and going onto other surfaces.

  2. This sounds like my mom. She is 98yrs old. She is in a nursing home. While this is hard on her, it is very hard on family. Ma hallucinate most of the time. Not lucid very often. She is mean, really mean. She throws things at us, or throws to the floor, her meals, water etc. I still visit and will continue to do so. She can’t help it, and she is my mother. But I don’t stay as long anymore, it is not only hard, it is very sad.


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