What is Lewy body dementia (LBD)? That is a question we hear often, and the answer can be a bit confusing. The basic explanation is that Lewy body dementia is an umbrella term for two related kinds of dementia: dementia with Lewy bodies (DLB) and Parkinson’s disease with dementia (PDD). Until 2006, when specialists agreed that the cognitive symptoms of DLB and PDD were essentially the same, the terms Lewy body dementia and dementia with Lewy bodies were used interchangeably. However, they are now recognized as separate diseases and, although some people continue to use a single term, the correct names are:

  • Lewy body dementia, which describes both DLB and PDD;
  • Dementia with Lewy bodies, which describes the kind that starts with mental symptoms; and
  • Parkinson’s disease with dementia, which describes the kind that starts with motor symptoms.

Over time, people with either type of Lewy body dementia will develop very similar cognitive, motor, physical, sleep, and behavioral symptoms, including hallucinations, insomnia, and acting out. LBD is a multisystem disease and may require a comprehensive treatment approach with a collaborative team of physicians from varying specialties. In all Lewy body disorders, tiny abnormal round structures called Lewy bodies develop in regions of the brain involved in thinking and/or movement.

Quick Facts

Lewy body dementia is:

  • Different from Alzheimer’s disease and related to Parkinson’s disease
  • Degenerative—not curable, but it can be slowed
  • Caused by microscopic Lewy bodies in the cognitive and motor areas of the brain
  • More common in men than women
  • A disease that comprises two types of dementias that start with different symptoms but are very similar: DLB, which starts with cognitive symptoms; and PDD, which starts with motor symptoms
  • A multifaceted disease with cognitive, physical, perceptual, behavioral, and motor symptoms