Lopez O L, Smith G, Becker J T, Meltzer C C, DeKosky S T
Alzheimer's Disease Research Center and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
J Neuropsychiatry Clin Neurosci. 2001 Winter;13(1):50-5. doi: 10.1176/jnp.13.1.50.
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.
