Dementia with Lewy bodies (DLB), or Lewy body dementia, is the second most common type of dementia in the general population, affecting an estimated 1.4 million individuals and their families in the United States. DLB is a progressive form of dementia caused by the degeneration of brain tissue. Individuals with DLB accumulate abnormal protein particles, known as Lewy bodies, within their brain tissue. These are also observed in patients with Parkinson’s disease (PD) and Alzheimer’s disease (AD).

The condition begins primarily with cognitive and behavioral changes, which are later accompanied by movement issues similar to those seen in classical Parkinson’s disease. The movement difficulties in DLB mirror the motor symptoms of Parkinson’s, including stiffness and gait troubles, a set of symptoms often referred to as Parkinsonism.

While the exact cause of the buildup of Lewy bodies in the brain remains unclear, these protein clumps interfere significantly with the function of brain cells, leading to the symptoms associated with the disease. These symptoms not only involve motor challenges but also encompass problems with problem-solving, memory loss, and visual processing difficulties.

Advanced age is a common risk factor for most dementias, and genetics can also play a role. Despite the increasing knowledge, the science behind what causes dementia and who is at risk continues to evolve.

Lewy body dementia was more widely recognized in 1996, when a group of physicians and scientists established a consensus for its diagnostic criteria. Before that, although Lewy body proteins were discovered in the early 1900s, the understanding of their impact on cognitive health wasn’t as clear.

For more detailed information on dementia with Lewy bodies, visit Baylor Medicine, Memory and Aging Center, the Health Encyclopedia of the University of Rochester, Harvard Health, the Patient’s Guide to Dementia by UCSF, Emory University, and Ohio State Medical Center.