Hallucinations and signs of parkinsonism help distinguish patients with dementia and cortical Lewy bodies from patients with Alzheimer's disease at presentation: a clinicopathological study.

OBJECTIVES To compare, in a retrospective clinicopathological study, the presentation features of patients with dementia and cortical Lewy bodies (Lewy body dementia) with those of patients with Alzheimer's disease. METHODS From a population of 426 cases from the dementia brain bank, 39 cases of Lewy body dementia and 61 cases of Alzheimer's disease with presentation details were identified. RESULTS The Lewy body dementia group had significantly more frequent hallucinations (23% v 3%, P = 0.006) and signs of parkinsonism (41% v 5%, P < 0.0001) than the Alzheimer's disease group. The Lewy body dementia group also had a greater proportion of men (62% v 34%, P = 0.013). CONCLUSION Hallucinations and signs of parkinsonism help distinguish Lewy body dementia from Alzheimer's disease at presentation. These indicators may not be very sensitive, because they were reported for less than half of the patients with Lewy body dementia.