PSYCHOMETRIC AND SPECT STUDIES IN ALZHEIMERS-DISEASE WITH AND WITHOUTDELUSIONS

Delusions are common in Alzheimer's disease (AD), but their pathophysi ological basis is poorly understood. Fifteen patients meeting NINCDS-A DRDA criteria for probable AD were studied with psychometric assessmen t and brain-dedicated SPECT (xenon-133 and HMPAO). None of the subject s had delusions at the start of the study. One year later, psychometri c testing and SPECT were repeated. Three patients had developed Capgra s syndrome, and three others had developed non-Capgras delusional diso rders in the interval. Psychometric and rCBF measures at baseline and at one year were compared. At baseline rCBF was significantly higher i n the right temporal regions in the patients who developed delusions ( p < 0.05). One year later, rCBF in the right temporal regions had decl ined in the psychotic patients. AD patients who developed delusions sh owed deterioration in right anterior temporal rCBF compared to AD with out delusions. In the setting of AD, right temporal function deteriora tion may contribute to the development of delusions.