Aktueller Überblick über strukturelle Magnet-resonanztomographie bei Schizophrenie

Abstract

Non-invasive morphologic imaging (computer tomography, magnetic resonance imaging, MRT) has contributed significantly to our understanding of schizophrenic disorders as diseases of the brain. Improved MRT techniques enable us to analyse anatomical substructures. The present overview evaluates peer-reviewed MRT studies published between 1994 and July 2000 and provides a comparison with our own results. Chronic schizophrenic patients most frequently show an enlargement in the ventricular system along with a reduction in grey matter. A more detailed subdivision into cortical and subcortical regions additionally shows the noted volume reduction to be limited to specific areas within the brain rather than being distributed equally throughout the brain. Within the area of the temporal lobes the two most frequently affected areas are the hippocampus and the gyrus temporalis superior. Alterations within these areas correlate with clinical symptoms such as hallucinations or thought disorders. Within the frontal cortex nearly 70% of all studies show a decrease in overall volume, while 63% note a reduction in size within the thalamus and 60% in the cerebellum. Morphologically speaking these structures therefore play the greatest role in the pathophysiology of schizophrenia and the onset of clinical symptoms. More recent studies also showed a specific progression in subgroups of patients pointing toward a neurodegenerative process. Additionally there are a number of differential antipsychotic effects following longterm treatment with typical neuroleptics as compared to atypical antipsychotics. Based on these findings future longitudinal studies should examine to what extent such a progressive decrease in volume might be influenced by treatment with modern antipsychotics.