Regional frontal abnormalities in schizophrenia: A quantitative gray matter volume and cortical surface size study

Background: Previous structural studies of the frontal lobe in schizophreni a have had somewhat inconsistent results, but most of them have measured th e frontal lobe as a single brain structure. To investigate more specific ab normalities in frontal subregions, we measured gray matter volume and corti cal surface size in 10 subregions in drug-naive patients during the early s tages of the illness. Methods: Magnetic resonance imaging was used to measure frontal subregions in 34 healthy male volunteers, and 26 male, drug-naive schizophrenia patien ts at early stages of the illness. Frontal subregions were manually traced using our locally developed parcellation method. Results: Patients with schizophrenia had a significant deficit in cortical surface size in the right straight gyrus and left orbitofrontal cortex. No differences were found in gray matter volumes. Conclusions: Frontal structural abnormalities found in drug-naive schizophr enic patients appear to be subtle and circumscribed to ventral portions. An omalies in the cortical surface size suggest neurodevelopmental abnormaliti es might occur during the early stages of the gyrogenesis. Further investig ations are needed to explore the implications of paralimbic ventral frontal regions (i.e,, straight gyrus and orbitofrontal cortex) in the pathophysio logy of schizophrenia. Biol Psychiatry 2000,48: 110-119 (C) 2000 Society of Biological Psychiatry.