What is Lewy Body Dementia? Months after actor and comedian Robin Williams committed suicide in August 2014, autopsy results revealed that he suffered from Lewy body dementia (LBD). Unlike Alzheimer’s disease and even frontotemporal dementia, this brain disorder has remained largely unknown. However, Dr. Stephen Gomperts, a visiting professor of neurology at Harvard College of Medicine and director of the Lewy Body Dementia Unit at Harvard-affiliated Massachusetts General Hospital, says attempts are being made to change this.
Perhaps surprisingly, LBD is the second leading cause of neurodegenerative dementia after Alzheimer’s disease. How do the symptoms differ? Who is at risk? How is it diagnosed and treated?
What is Lewy Body Dementia?
First, it is important to understand that dementia is classified into two types. One is known as dementia with Lewy bodies (DLB). A second type, known as Parkinson’s disease dementia, or PDD, can develop late in the course of the illness.
These disorders result from an abnormal buildup of protein deposits in the brain known as Lewy bodies. The deposits, made of a protein called alpha-synuclein, accumulate in brain areas that affect thinking, behaviour, perception, and movement.
LBD, like Alzheimer’s disease, is progressive and fatal. However, while the median lifespan of people with this illness is seven years, Dr. Gompers notes that the duration of the disease varies greatly. “Many people respond well to medicines that aim to improve their ability to function and quality of life.”
How common is this?
More than a million Americans have Lewy body dementia. Others who are likely to have the disease may have avoided seeking treatment or been misdiagnosed, according to Dr. Gompers.”Previously, LBD was usually referred to as ‘dementia’ or ‘Alzheimer’s. It is still considerably underdiagnosed, but the situation is improving.
How does Lewy body dementia compare with Alzheimer’s disease?
Like Alzheimer’s, LBD impairs a person’s ability to think, remember details, solve problems, focus on tasks, and, eventually, care for themselves. “The most common feature between the two is gradually progressive difficulty with thinking. This has no immediate impact on daily activities, but it does in the long run,” he explains.
How does Lewy body dementia vary from Alzheimer’s disease?
Memory problems are typically the first and most serious symptoms of Alzheimer’s disease. In contrast, in LBD, problems with problem-solving or spatial problems tend to emerge before memory issues. However, these symptoms might appear alone or in combination and may differ.
Perception is frequently affected, which can result in visual hallucinations.
Other differences include:
- Acting out dreams. Individuals with LBD may act out their dreams. This condition, REM sleep behavioural disorder, frequently occurs before thinking problems develop.
- Movement changes occur. People with Lewy body dementia frequently move slowly and stiffly, exhibiting tremors and gait changes and being prone to falls. Progressive movement problems are common among people with PDD. This symptom prompts the initial diagnosis of Parkinson’s disease. Movement is frequently affected by DLB, but not always.
How do experts differentiate PDD and DLB?
Everything depends on when key symptoms appear.
PDD is diagnosed when a person with Parkinson’s disease develops memory and thinking problems that interfere with daily activities more than a year after their movement problems begin.
DLB is diagnosed when cognitive problems appear first or do not coincide with movement problems.
“But this one-year rule is somewhat arbitrary,” Dr. Gomperts adds.
Who is at risk of Lewy body dementia?
Age is regarded as the most significant risk factor for the disease. Most cases have no known cause, but a few gene mutations can predispose someone to LBD.
Several lifestyle factors, including diet, lack of exercise, and toxic exposure, have been linked to an increased risk of Parkinson’s disease. However, little research has been done to determine whether these factors are associated with LBD. People who have experienced head trauma appear to have a higher risk of developing LBD and Parkinson’s. Both conditions disproportionately affect men. “We think that’s telling us something important, but it’s not yet clear what,” according to Dr. Gomperts.
How is Lewy Body Dementia diagnosed?
DLB is diagnosed when essential clinical symptoms such as trouble thinking, cognitive fluctuations, movement abnormalities, and REM sleep behavioural disturbance appear in the absence of other reasons.
Early symptoms of DLB are frequently confused with those of other brain or psychiatric disorders, making diagnosis difficult. According to Dr. Gomperts, many people do not receive an accurate diagnosis until their symptoms have advanced significantly.
A variety of tests and imaging exams are used to differentiate LBD from other conditions that can cause similar symptoms, such as Alzheimer’s disease, vascular disease, thyroid disorders, or vitamin B12 deficiency.
“Not every scenario are clear-cut and not all medical professionals are skilled at making the diagnosis,” he told me. “Accuracy is also lower in early disease.”
Are there any treatments for Lewy body dementia?
Yes. Although there is no cure, medications, physical therapy, and counselling can help with specific LBD symptoms such as cognitive impairment, hallucinations, and sleep disturbances. Some Parkinson’s medications can also help with LBD-related movement symptoms. This makes it easier to walk and perform other tasks.
“We’ve also learned that various drugs can cause or worsen certain symptoms, such as confusion, delusions, and movement problems,” the physician explains. “Some drugs that treat hallucinations and delusions regularly impair motor function and can even be deadly in LBD. “They should be avoided.”
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