Structural magnetic resonance imaging in schizophrenia: An overview

Non-invasive morphologic imaging (computer tomography, magnetic resonance i maging, MRT) has contributed significantly to our understanding of schizoph renic disorders as diseases of the brain. Improved MRT techniques enable us to analyse anatomical substructures. The present overview evaluates peer-r eviewed MRT studies published between 1994 and July 2000 and provides a com parison with our own results. Chronic schizophrenic patients most frequentl y show an enlargement in the ventricular system along with a reduction in g rey matter. A more detailed subdivision into cortical and subcortical regio ns 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 affec ted areas are the hippocampus and the gyrus temporalis superior. Alteration s within these areas correlate with clinical symptoms such as hallucination s 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 with in the thalamus and 60% in the cerebellum. Morphologically speaking these s tructures therefore play the greatest role in the pathophysiology of schizo phrenia and the onset of clinical symptoms. More recent studies also showed a specific progression in subgroups of patients pointing toward a neurodeg enerative process. Additionally there are a number of differential antipsyc hotic effects following longterm treatment with typical neuroleptics as com pared to atypical antipsychotics. Based on these findings future longitudin al studies should examine to what extent such a progressive decrease in vol ume might be influenced by treatment with modern antipsychotics.