"Lewy body dementia" (LBD) is a term that includes two related diagnoses: Dementia with Lewy bodies (DLB) and Parkinson's disease dementia.

According to the Lewy Body Dementia Association:

  • A person with DLB will develop dementia and other LBD symptoms, including possible changes in movement like a tremor.
  • A person with Parkinson's disease dementia will first experience changes in movement, then may develop dementia years later.

Key features of Lewy body dementia

  • The pattern of cognitive decline in Lewy body dementia, including both dementia with Lewy bodies and Parkinson's disease dementia, can involve memory impairment, poor judgment and confusion.
  • Apathy may be more prominent in Lewy body dementia than in Alzheimer's.
  • Severity of cognitive symptoms and alertness may fluctuate from day to day. Patients may experience excessive daytime sleepiness.
  • Other common symptoms include non-threatening visual hallucinations and such Parkinsonian symptoms as "mask-like" face, rigidity, stiffness, shuffling gait and problems with balance.
  • About 50% of Lewy body dementia patients experience rapid eye movement (REM) sleep behavior disorder. In this disorder, the normal suppression of voluntary muscle movement during REM sleep fails to occur, leading to vivid and sometimes violent acting out of dreams. REM sleep disorder in a person with dementia may be diagnostic for Lewy body dementia.


  • No drugs are currently approved for treatment of dementia with Lewy bodies by the FDA.
  • Lewy body dementia may be the most responsive of any dementia to treatment with cholinesterase inhibitors, but they are not approved for this purpose.
  • Parkinsonian symptoms may be treated with drugs for Parkinson's disease.
  • Treatment with antipsychotic drugs may lead to worsening of both cognitive and Parkinsonian symptoms.


Lewy bodies, which characterize this pathology, are abnormal deposits that consist largely of a protein called alpha-synuclein. Lewy bodies occur inside brain cells across a spectrum of other neurodegenerative disorders, including Parkinson's disease and some cases of Alzheimer's. The spectrum of disorders involving Lewy bodies is sometimes referred to as "synucleinopathies."

For your patients and families: Dementia with Lewy bodies