What is Lewy body dementia? Lewy body dementia (LBD) is a type of progressive dementia. Lewy bodies are microscopic clumps of a protein, alpha-synuclein, in the brain. The name comes from the doctor, Frederich H. Lewy, who discovered the abnormal deposits. LBD affects about 1.4 million Americans. It accounts for up to 25% of dementia cases. Other common forms of dementia include Alzheimer’s disease and vascular dementia. Lewy bodies build up in areas of the brain that affect memory, thinking, and motor skills. This leads to problems with reasoning, behavior and cognition. It also causes movement and autonomic body function problems. Autonomic functions are things you don’t have to think about—they happen automatically. They include things like blood pressure, digestion, and temperature control. These physical symptoms of LBD overlap with another closely related condition, Parkinson’s disease. Making matters more complicated, Parkinson’s disease can also lead to dementia. In fact, many experts consider LBD to be an umbrella diagnosis that includes Parkinson’s dementia and dementia with Lewy bodies. LBD typically starts after age 50 and tends to affect men more often than women. Most people who develop LBD do not have a family history of the disease. However, your risk increases if you have a family member with LBD or Parkinson’s disease. There is no cure for LBD. Instead, treatment focuses on relieving symptoms and managing behaviors. Doctors use a combination of medications, therapy, and other strategies. See your doctor if you, or a loved one, are having symptoms consistent with dementia. LBD is a progressive disease that will eventually be fatal. However, you can improve quality of life by seeking an early diagnosis and treatment.