Dementia with Lewy bodies, the second most frequent cause of dementia in elderly adults, is a neurodegenerative disorder associated with abnormal structures (Lewy bodies) found in certain areas of the brain. Because these structures and many of the symptoms of dementia with Lewy bodies are associated with Parkinson's and Alzheimer's diseases, researchers do not yet understand whether dementia with Lewy bodies is a distinct clinical entity or perhaps a variant of Alzheimer's or Parkinson's disease.
Recent research has revealed that Lewy bodies contain deposits of a protein called alpha-synuclein that is also linked to Parkinson's disease and multiple system atrophy.
Symptoms can range from traditional parkinsonian effects, such as loss of spontaneous movement (bradykinesia), rigidity (muscles feel stiff and resist movement), tremor, and shuffling gait, to effects similar to those of Alzheimer's disease, such as acute confusion, loss of memory, and loss of, or fluctuating, cognition. Visual hallucinations may be one of the first symptoms noted, and patients may suffer from other psychiatric disturbances such as delusions and depression. Onset of the disorder usually occurs in older adults, although younger people can be affected as well. In 1996 scientists published guidelines for the diagnosis of dementia with Lewy bodies (McKeith IG, et al, Neurology, vol 47, pp 1113-1114, Nov 1996).
Scientists continue to search for a specific course of therapy for people with dementia with Lewy bodies. Treatment is symptomatic, often involving the use of medication to control the parkinsonian and psychiatric symptoms. However, patients should be aware that antiparkinsonian medication that may help to reduce tremor and loss of muscle movement may actually worsen such symptoms as hallucinations and delusions. Similarly, neuroleptic drugs prescribed for psychiatric symptoms may in fact markedly worsen the movement symptoms. In general atypical antipsychotic medications are more successful than older drugs such as haloperidol.
Dementia with Lewy bodies is a slowly progressive condition for which there is no cure.