Lewy body dementia, also known as dementia with Lewy bodies, is a cortical type of dementia. It is the third most common type of progressive dementia after Alzheimer's disease and vascular dementia.
Dementia is a term used to describe a general decline in a person’s cognitive abilities, that is their thinking, memory, language, usually due to disease which results in degeneration of the brain. Lewy body disease is thought to be the second most common kind of dementia and is currently incurable.
"Cortical" refers to the cortex or grey matter which is the outer layer of the brain and plays a critical role in memory and language. People with cortical dementias usually have severe memory loss with associated problems affecting their ability to remember words or understand language.
Lewy body dementia shares characteristics with both Alzheimer's disease and Parkinson's disease. It is more common in older age, affecting around 20 percent of those with dementia worldwide.
Lewy body dementia is caused by the accumulation of abnormal microscopic protein deposits in the brain, which interrupt the brain's normal functions, causing it to slowly deteriorate.
Because Lewy body dementia symptoms closely resemble other diseases, it can be particularly difficult to diagnose correctly. This can create problems for the individual affected, as early diagnosis allows for key early treatment that can extend a person’s freedom and quality of life.
Individuals with Lewy body dementia lose cognitive function, which are those functions of the brain associated with language, memory, planning and attention. However they are less likely to have short-term memory loss which is associated with Alzheimer’s disease.
Lewy body dementia sufferers experience more problems with their executive function, which is their ability to be logical, flexible, or to make judgements or decisions to plan, organize and carry out usual day-to-day activities.
Their capacity to concentrate, to multitask, to be alert or react to changing circumstances are affected. So is their ability to cope with noisy environments.