title: The psychotic phenomenon in probable Alzheimer's disease: a positron emission tomography study.
abstract: Positron emission tomography was used to examine the mechanisms of the psychotic phenomenon in Alzheimer's disease (AD). Data from 2 patients with delusions and 2 with hallucinations were compared with those of 5 AD patients without psychosis. The patients with paranoid delusions had diminished relative regional cerebral blood flow (rel-CBF) in the left dorsolateral prefrontal and left medial temporal cortices. The patients with visual hallucinations showed diminished rel-CBF in the right parietal, left medial temporal, and left dorsolateral prefrontal cortices. These findings support the hypothesis that a frontal-temporal abnormality is associated with paranoid delusions in AD. By contrast, visual hallucinations are associated with parietal as well as frontal and temporal lobe dysfunction. In these patients, a left prefrontal-temporal cortex dysfunction appears to be a common denominator for the development of the psychotic phenomenon in AD.
authors.affiliation: Alzheimer's Disease Research Center and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: O L
authors.initials: OL
authors.lastname: Lopez
authors.forename: G
authors.initials: G
authors.lastname: Smith
authors.forename: J T
authors.initials: JT
authors.lastname: Becker
authors.forename: C C
authors.initials: CC
authors.lastname: Meltzer
authors.forename: S T
authors.initials: ST
authors.lastname: DeKosky
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply; D003702:Delusions / Q000000981:diagnostic imaging; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006212:Hallucinations / Q000000981:diagnostic imaging; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000000981:diagnostic imaging*; D012039:Regional Blood Flow / Q000502:physiology; D014055:Tomography, Emission-Computed