title: Regional brain atrophy in patients with mild Alzheimer's disease and delusions.
abstract: OBJECTIVE
  The pathophysiology and the neurobiology of the behavioral disturbances in Alzheimer's disease (AD) are far from understood. The aim of the study was to assess whether delusional AD patients have a specific pattern of regional brain atrophy.
  
  
  METHODS
  The setting of the study was the outpatient facility of a memory clinic. Subjects were 41 AD patients with mild dementia severity (Mini-Mental State Exam score of 22 +/- 3, range 18 to 27). Delusions were assessed with the pertinent subscale of the UCLA Neuropsychiatric Inventory (NPI). Nondelusional (n = 22) AD and delusional (n = 19) AD were defined on the basis of absence (NPI delusions subscale = 0) or presence (NPI delusions subscale = 1 or higher) of delusions. Thirteen (68%) of the delusional patients had isolated theft delusions, and 6 (32%) had theft associated with another paranoid delusion (of jealousy or persecution). None of the patients had misidentifications or other delusions of nonparanoid content. Temporal lobe and frontal lobe atrophy were assessed with linear measures (radial width of the temporal horn, rWTH, and frontal index, FI) taken from computed tomographic films. Temporal and frontal asymmetries were computed as right/left ratio of the rWTH and FI.
  
  
  RESULTS
  AD patients without delusions had symmetrical enlargement of both temporal (8.1 +/- 3.9 vs. 8.5 +/- 4.5) and frontal horns (35.8 +/- 4.8 vs. 35.9 +/- 4.6). On the contrary, AD with delusions showed temporal horns larger to the right (9.1 +/- 3.3 vs. 7.7 +/- 3.1, p = .06) and the frontal horn to the left (35.7 +/- 4.3 vs. 37.5 +/- 4.2, p = .02). This different pattern was confirmed with a gender-adjusted repeated measures analysis of variance model interaction term between asymmetry and group: F1,38 = 5.5, p = .03).
  
  
  CONCLUSIONS
  AD patients with delusions are characterized by a specific pattern of frontal and temporal asymmetry of brain atrophy, whereas nondelusional patients are symmetric. Because the asymmetry pattern of the delusional patients is similar to the physiological pattern of asymmetry of individuals without dementia, the data indicate that the absence of theft delusions in the mild stage of AD rather than their presence is associated with an abnormal asymmetry pattern.
authors.affiliation: Laboratory of Epidemiology & Neuroimaging, IRCCS San Giovanni di Dio-FBF, Brescia, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Geroldi
authors.forename: Lorena
authors.initials: L
authors.lastname: Bresciani
authors.forename: Orazio
authors.initials: O
authors.lastname: Zanetti
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Frisoni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D001284:Atrophy; D002552:Cerebral Ventricles / Q000473:pathology; D003702:Delusions / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000473:pathology*