Although delusions are a frequent finding in patients with Alzheimer's
disease (AD), their mechanism is not well known. We carried out Tc 99
m HMPAO single-photon emission computed tomography studies in 16 AD pa
tients with delusions and 29 kD patients without delusions comparable
in age, years of education, duration of illness, and severity of demen
tia. Although we found no significant between-group differences in per
formance on neuropsychological tasks, AD patients with delusions had s
ignificantly lower mean cerebral blood flow in both the left and right
temporal lobes.