What are Lewy bodies

What are Lewy bodies 

In 1912, while Frederick Lewy was examining the brains of people with Parkinson's disease, he discovered irregularities in the cells in the mid-brain region. These abnormal structures (microscopic protein deposits found in deteriorating nerve cells) became known as Lewy bodies. Since that time, the presence of Lewy bodies in the mid-brain has been recognized as a hallmark of Parkinson's disease. In the 1960s, researchers found Lewy bodies in the cortex (the outer layer of gray matter) of the brains of some people who had dementia. Lewy bodies in the cortex are known as cortical Lewy bodies or diffuse Lewy bodies. (That's why Lewy body disease is sometimes called cortical Lewy body disease or diffuse Lewy body disease.) Cortical Lewy bodies were thought to be rare, until the 1980s when improved methodologies showed that Lewy body disease was more common than previously realized.

People with Lewy body disease have Lewy bodies in the mid-brain region (like those with Parkinson's disease) and in the cortex of the brain. It's believed that they usually also have the "plaques and tangles" of the brain that characterize Alzheimer's disease. Conversely, it's believed that many people with Alzheimer's disease also have cortical Lewy bodies. Because of the overlap, it's likely that many people with Lewy body disease are misdiagnosed (at least initially) as having either Parkinson's disease or Alzheimer's disease. A big factor in the misdiagnosis might be that Lewy body disease is relatively unknown.