OBJECTIVE: The authors compared clinical findings of Alzheimer's disease and the so-called Lewy body variant of Alzheimer's disease. METHOD: Available data were analyzed on the clinical features of 58 patients with Alzheimer's disease and 24 patients with the Lewy body variant of Alzheimer's disease who underwent postmortem examination. RESULTS: The proportion of men was significantly larger in the Lewy body variant group than in the Alzheimer's disease group (66.7% versus 34.5%), and, concordantly, the Lewy body variant group was slightly taller. The prevalence of hallucinations and delusions was significantly higher in Lewy body variant subjects than the Alzheimer's disease subjects, but there were no significant differences between the two groups in educational attainment, family history of dementia, age at onset, duration of illness, cognitive impairment, overall severity of illness, or neuropsychological findings. Patients with the Lewy body variant of Alzheimer's disease tended to experience more frequent extrapyramidal side effects of neuroleptics than did the patients with Alzheimer's disease, but for patients in the two groups who were not exposed to neuroleptics, there was little difference in frequency of extrapyramidal side effects. CSF concentration of homovanillic acid (HVA) was significantly lower in the Lewy body variant patients, even when correction was made for height. CONCLUSIONS: The Lewy body variant of Alzheimer's disease may be suspected in elderly male dementia patients who otherwise meet criteria for Alzheimer's disease but who manifest significant psychiatric symptoms and neuroleptic-induced extrapy-ramidal side effects and have low levels of CSF HVA.Abstract Teaser