Investigation of frontal lobe subregions in first-episode schizophrenia

The evidence for frontal lobe structural abnormalities in schizophrenia usi ng magnetic resonance (MR) imaging has been mixed, but most studies used ei ther single slice measures or total volumes of a single frontal region, nei ther of which is sensitive to potential volume differences in more specific subregions. This study employed reliable methods for parcellation of the f rontal lobes from MR images based on the sulcal anatomy. Following a cytoar chitectonic theory that distinguishes dorsomedial (archicortically derived) from ventrolateral (paleocortically derived) frontal subregions, we measur ed the superior frontal gyrus, anterior cingulate gyrus, and orbital fronta l region in 19 first-episode schizophrenia patients and 26 healthy comparis on subjects. Results indicated that mall: patients had significantly larger right orbital frontal volume compared to their left orbital frontal volume and compared to healthy men. Among male patients larger right orbital fron tal volume was significantly correlated with smaller right 'archicortical' (i.e. anterior cingulate and superior frontal gyri) volume. Furthermore, th e ratio of right orbital frontal to right 'archicortical' volume was signif icantly and positively correlated with level of delusions among male patien ts. These findings suggest that there may be reciprocal controls on 'archic ortical' and 'paleocortical' neurodevelopment among men with schizophrenia, and that larger paleocortical relative to archicortical volumes may be ass ociated with increased delusions. (C) 1999 Elsevier Science Ireland Ltd. Al l rights reserved.