Early effects of treatment on regional cerebral blood flow in first episode schizophrenia patients evaluated with 99Tc-ECD-SPECT.

OBJECTIVES: Altered regional cerebral blood flow (r-CBF) is mentioned as one of possible etiological factors or as a consequence of schizophrenia. Perfusion scintigraphic brain studies with SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) can detect areas of the brain with altered perfusion during the disease. Conflicting data exist on follow-up after treatment. The aim of our study was to evaluate r-CBF in acute first-episode schizophrenia and early effect of antipsychotic drugs on r-CBF.

DESIGN AND SETTING: Clinical criteria for schizophrenia were met according to International Classification of Diseases-10th Edition (ICD-10). Psychic status and severity of the disease in each patient were evaluated with psychiatric interview, Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression (CGI) on the same day as the scintigraphic study. Brain perfusion SPECT was performed 20 minutes after 99mTc-ECD application. R-CBF was measured in 9 first-episode schizophrenic male patients 2-7 (median 6) days after the beginning of antipsychotic treatment and 8-15 (median 9) weeks later. Semiquantitative analysis of r-CBF was performed with cerebellum as the reference region. R-CBF was evaluated for 12 regions in each study.

RESULTS: Decrease in perfusion in comparison to cerebellum was detected in left (90%) and right (93%) frontal lobes. Increase in perfusion between the first (t1) and the second (t2) investigation was significant (p<0.05) for both frontal regions (left 94%, right 97%). Significant decrease in PANSS (p<0.05) and CGI (p<0.001) scores was noted and correlated well with the increase of r-CBF.

CONCLUSIONS: Our findings implicate that patients with first-episode schizophrenia have significant left hypoperfusion relative to the right in dorsolateral frontal lobes. Increased blood flow was observed bilaterally in dorsolateral frontal lobes after 10 weeks of antipsychotic medication. Significant amelioration of r-CBF correlated with clinical improvement.

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