Dementia with Lewy bodies (DLB), previously called Lewy body dementia (LBD), is a type of dementia of unknown cause that gradually worsens over time. Additional symptoms may include fluctuations in alertness, seeing things that other people do not, slowness of movement, trouble walking, and rigidity. Excessive movement during sleep and mood changes, such as depression, are also common.

The cause is unknown. There is typically no family history among those affected. The underlying mechanism involves the buildup of Lewy bodies, clumps of alpha-synuclein protein in neurons. It is classified as a neurodegenerative disorder. A diagnosis may be suspected based on symptom, with blood tests and medical imaging done to rule out other possible causes. The differential diagnosis includes Parkinson's and Alzheimer's.

There is no cure for DLB. Treatments try to improve mental, psychiatric, and motor symptoms. Acetylcholinesterase inhibitors, such as donepezil, may provide some benefit. Some motor problems may improve with levodopa. Antipsychotics, even for hallucination, should generally be avoided due to side effects.

DLB is the most common cause of dementia after Alzheimer's and vascular dementia. It typically begins after the age of 50. Males appear to be more commonly affected than females. Life expectancy following diagnosis is around 8 years.

Friedrich Heinrich Lewy (1885-1950) is credited with the recognition in 1912 of the inclusion bodies that bear his name.

Adapted from Wikipedia, the free encyclopedia. Internet. Accessed on October 11, 2016.