[Acute psychotic productivity in cerebral imaging]

Regional cerebral blood flow (rCBF) was analysed in 24 neuroleptically never treated schizophrenics by 99m-Tc-HMPAO-SPECT. Psychopathological symptoms (PANSS) were correlated with rCBF-measures using multidimensional scaling (MDS). Highest degrees of correlation were found for ideas of grandiosity and formal thought disorders compared to different regions of interest (ROIs). An adynamic cluster was defined by basic symptoms which showed signs of deficiency. This cluster was by the highest degree correlated with a cluster defined by rCBF compared to four different clusters of basic symptoms. A fMRI-study was performed in schizophrenic patients with auditive hallucinations in comparison to healthy controls. We offered simple acoustic stimuli perceived as coming from the outside versus inside. For the outside condition, controls activated the medial temporal gyrus on the left side and the rightsided precuneus and postcentral gyrus which represent the auditive source locating and the stimulus processing systems, for inside, they activated the left insula. Hallucinating schizophrenic neither activated the one nor the other system. We discussed the findings as a possible explanation of the schizophrenics' tendency to misinterpret hallucinations as real perceptions.