NEURO-IMAGING AND SCHIZOPHRENIA

The techniques of neuro-imaging permit an in vivo approach to schizoph renia. They bring capital elements for the understanding of this disor der psychopathology and etiology. The Magnetic Resonance Imaging (MRI) allows us to evaluate the cerebral morphology, while the PET SCAN (Po sitron Emission Tomography) and the SPECT SCAN (Single Photon Emission Computed Tomography) reflect the blood flow or the cerebral metabolis m. Neuro-imaging in schizophrenic patients brings to light a widening of the cerebral ventricules as well as temporo-limbic and fronto-stria tal alterations. The ventricular widening is an abnormality present at the initial stage of the schizophrenic disorder. It is associated wit h the negative syndrome of schizophrenia and an unfavourable prognosis . The fronto-striatal abnormalities are essentially functional; they a re also correlated with the negative signs of schizophrenia. Finally, the temporo-limbic alterations are revealed by a decrease of the hippo campo-amygdalian volume as well as of certain cortico-temporal furrows , and are correlated with positive symptoms of schizophrenia (hallucin ations, delusion...). Futur research will have to aim at determining t he relations between clinical symptoms and specific cerebral alteratio ns. Moreover, the interactions between the different affected structur es will gain from being better defined.