Temporal lobe asymmetry in patients with Alzheimer's disease with delusions
- Cristina Geroldia,b,
- Nabil Maalikjy Akkawic,
- Samantha Galluzzia,
- MariaChiara Ubeziob,
- Giuliano Binettib,
- Orazio Zanettib,
- Marco Trabucchib,
- Giovanni B Frisonia
- aLaboratory of Epidemiology and Neuroimaging, IRCCS San Giovanni di Dio, FBF, via Pilastroni 4, 25125 Brescia, Italy , bAlzheimer's Unit, cDepartment of Neurology, University of Brescia, Italy
- Dr Giovanni B Frisoni
- Received 4 October 1999
- Revised 29 February 2000
- Accepted 12 April 2000
OBJECTIVE To test the hypothesis that delusions are associated with asymmetric involvement of the temporal lobe regions in Alzheimer's disease.
METHODS Temporal lobe atrophy was assessed with a linear measure of width of the temporal horn (WTH) taken from CT films. Temporal asymmetry was computed as the right/left (R/L) ratio of the WTH in 22 non-delusional and 19 delusional patients with Alzheimer's disease. Delusional patients had paranoid delusions (of theft, jealousy, persecution). None of the patients had misidentifications or other delusions of non-paranoid content.
RESULTS The R/L ratio indicated symmetric temporal horn size in the non-delusional (mean 1.05 (SD 0.20), and right greater than left temporal horn in the delusional patients (mean 1.30, (SD 0.46); t=2.27, df=39, p=0.03). When patients were stratified into three groups according to the R/L ratio, 47% of the delusional (9/19) and 14% of the non-delusional patients (3/21; χ2=5.6, df=1, p=0.02) showed right markedly greater than left WTH.
CONCLUSIONS Predominantly right involvement of the medial temporal lobe might be a determinant of paranoid delusions in the mild stages of Alzheimer's disease.