Pharmacologic treatment expectations in the management of dementia with Lewy bodies.

Recently recognized as an entity separate from Alzheimer's disease (AD) and Parkinson's disease with dementia, dementia with Lewy bodies (DLB) is a frequent cause of dementia. It is characterized by progressive cognitive decline and attention deficits, but in contrast to AD, the cognitive changes typically fluctuate over time. Patients with DLB often experience Parkinson-like spontaneous motor features as well as recurrent visual hallucinations. Another frequent finding in DLB is rapid eye movement (REM) sleep disorder. Ideally, each of the major symptom domains associated with DLB (behavioral, motor, and cognitive) would be treated, but drug interactions in these patients are a serious concern. In addition, many patients with DLB are hypersensitive to neuroleptics, which can induce severe extrapyramidal and other symptoms--sometimes ending in death. Compared with conventional neuroleptics, the newer atypical antipsychotic agents may be associated with lower rates of extrapyramidal side effects. Cholinergic deficits in DLB are even more severe than in AD, whereas the extent of cerebral atrophy and neuronal damage may be less. These observations and emerging clinical data support the treatment of DLB with acetylcholinesterase inhibitors. Encouraging results have been obtained from studies of DLB patients treated with rivastigmine, donepezil, and galantamine, but large-scale, controlled trials are needed to confirm the efficacy and safety of acetylcholinesterase inhibitors in patients with DLB.