Lewy body dementia: Case report and discussion

Background: Lewy body dementia is a common but frequently underdiagnosed cause of dementia often mistaken for the more familiar entity of Alzheimer disease. Clinically the distinction is important, because it can have profound implications for management. Methods: The medical literature was searched using the keywords "Lewy bodies," "Lewy body dementia," "Alzheimer dementia," and "parkinsonian disorders." A case of Lewy body dementia is described. Results: An elderly man had long-standing diagnoses of Alzheimer disease and Parkinson disease. After he was evaluated thoroughly, the diagnosis was revised to Lewy body dementia, leading to changes in treatment that were associated with dramatic improvement in the patient's mental status. Evidence from the literature suggests that Lewy body dementia can be diagnosed in primary care settings based on clinical criteria. The physician should be alert to this diagnosis, and special attention should be paid to dementia patients who exhibit parkinsonism, hallucinations, fluctuating cognition, or prominent visuosperceptual deficits. Conclusions: The diagnosis of Lewy body dementia has important implications. It is associated with a high incidence of neuroleptic sensitivity, necessitating great caution in the use of these common antipsychotic agents. Early studies indicate cholinesterase inhibitors can be beneficial for treating the hallucinations and behavior disturbances that afflict these patients and might also improve cognition.