Volumetric analysis of the pre-frontal regions: findings in aging and schizophrenia

Frontal lobe dysfunction is thought to be involved in schizophrenia and age -associated cognitive decline. Frontal lobe volume changes have been invest igated in these conditions using MRI, but results have been inconsistent. F ew volumetric MRI protocols exist that divide the pre-frontal cortex into i ts sub-regions. In the present article, we describe a new method, which all ows assessment of the superior, middle and inferior frontal gyrus, as well as the orbitofrontal and cingulate regions. The method uses multiple planes to help guide the anatomical decisions and combines this with a geometric approach utilizing readily apparent anatomical landmarks. Using this protoc ol, the frontal lobe volumes in young healthy subjects were contrasted with those of young schizophrenic patients and elderly healthy subjects (nine m ale subjects per group). The results showed that the method could be reprod uced with high reliability (r(icc) greater than or equal to 0.88-0.99). Sch izophrenic as well as old subjects had specific significant reductions in t he superior frontal gyrus and orbitofrontal regions compared with the young group. However, old and schizophrenic subjects did not differ from each an other. No volume differences were observed in the other three regions asses sed. Whether or not these volume reductions reflect a common pathological p rocess remains to be investigated in future studies. (C) 2001 Elsevier Scie nce Ireland Ltd. All rights reserved.