Dementia with Lewy bodies is a brain disease that causes progressive loss of memory and the ability to think and plan. It is associated with protein deposits called Lewy bodies in brain cells.

The main symptoms of dementia with Lewy bodies are:

• Fluctuating attention and alertness (the person may be alert and then suddenly confused).
• Visual-spatial problems (can't find his or her way around usually familiar places).
• Visual hallucinations that are vivid and detailed.
• Loss of ability to recall long-term memories.
• Repeated falls.

Some symptoms of dementia with Lewy bodies are similar to those of other brain diseases, such as loss of short-term memory or a shuffling walk. Some people may have "Lewy body variant," a combination of Lewy bodies and Alzheimer's disease.