Relationship of prefrontal and temporal lobe MRI measures to neuropsychological performance in chronic schizophrenia

This preliminary study focused on the relationship between prefrontal and temporal lobe MRI measures and neuropsychological performance in chronic schizophrenia. Seventeen schizophrenic inpatients received an MRI and a neuropsychological test battery after clinical stabilization, on average 2 months after admission. The central finding was a significant inverse correlation between neurocognitive measures of prefrontal function and dorsolateral prefrontal cortex (DLPFC) area, strongest in the left hemisphere. Neurocognitive performance did not correlate significantly with orbital frontal area or toral temporal lobe volume. The correlations of neuropsychological performance with total frontal volume and whole brain volume were generally not significant, although the pattern was similar to that associated with the DLPFC. Because a number of executive-attention and abstraction measures were significantly associated with the DLPFC, dysfunctions of this region may underlie a syndrome of cognitive dysfunctions. Longterm memory functions were also significantly correlated with the DLPFC, raising the possibility that recall memory defects in schizophrenia are, in part, associated with prefrontal contributions of attention, abstract reasoning, and executive function. This study needs replication with a larger sample of patients and more comprehensive volumetric morphometric analyses.