Lewy Body Dementia
Lewy body dementia accounts for 15% of dementia cases.
It is the third most common cause of dementia.
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Dementia Statistics Hub
Lewy body dementia is also known as dementia with Lewy bodies (DLB) and formerly known as Pick's disease. The structures that are said to cause DLB are named after the Neurologist, Frederic Lewy.
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DLB is closely related to Alzheimer's and Parkinson's disease. The early symptoms of DLB are more similar to Alzheimer's disease. These cognitive symptoms include difficulty with memory, focusing, speech and experiencing hallucinations. Symptoms involving memory may be pronounced much less severe than in Alzheimer's disease. The later motor symptoms are more similar to Parkinson's disease, including difficulty with movement, rigidity in the limbs, reduced facial expressions, resting tremors and disrupted sleep.
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People can have both dementia and Parkinson's disease at the same time. If cognitive symptoms appear before or at the same time as Parkinson's symptoms it is diagnosed as DLB. If motor symptoms develop at least one year before cognitive symptoms it is diagnosed as Parkinson's disease dementia (PDD).
Lewy bodies form within the brain when changes in a protein called alpha-synuclein cause them to fold together and collect (aggregate) to form deposits.
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Similar to neurobrillary tangles in Alzheimer's disease, Lewy bodies deposit within neurons and cause the cells to die. In people with mixed dementia, Lewy bodies, amyloid plaques and neurobrillary tangles can be found within the brain
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Hallucinations
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Symptoms of Lewy body dementia tend to fluctuate from day to day, or even hour to hour. People living with DLB can experience hallucinations or delusions. Other types of dementia, such as Alzheimer's disease can also cause hallucinations, but it is most common in DLB. Hallucinations can be described as experiencing something that is not there. This can affect any of the senses, but visual hallucinations are the most common. Visual hallucinations can range in complexity from simple flashing lights to detailed visuals such as a person or an animal. Auditory hallucinations are more common for people with hearing-loss and people who live alone. Hallucinations can be frightening and the person should be reassured and spoken to calmly. It is important that environments are designed or adapted with this in mind. Heavy shadows and complex patterns may make hallucinations more likely and should be avoided. To learn more about the design implications of sensory challenges and dementia, see the Design section.
Further resources
Shining a Light on Lewy Body Dementia - The Lewy Body Society
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Living with Lewy Body Dementia - Book by Judie Town Jennings
Lewy Body Dementia - Rare Dementia Support
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Perception and Hallucinations - Alzheimer's Society
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The Progression of Dementia with Lewy Bodies - Alzheimer's Society
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