"Hyperfrontality" as seen on FDG PET in unmedicated schizophrenia patients with positive symptoms.

ABSTRACT

INTRODUCTION: Decreased frontal activity has been reported widely in unmedicated schizophrenic patients with predominantly negative symptoms. Not many studies have assessed the frontal lobe status in unmedicated patients with positive symptoms. PATIENTS AND METHODS: Fifty-one patients with schizophrenia (all unmedicated, 38 never medicated) and 12 healthy age-matched controls were evaluated with FDG PET CT. The patients met ICD-10 and DSM-IV criteria for schizophrenia, and all reported psychotic, "positive" symptoms when tested. RESULTS: Schizophrenic patients with positive symptoms had a hypermetabolic frontal metabolic pattern on quantification by region to occipital ratio comparison. Associated statistically significant differences were also found when comparing ratios of occipital to thalamic, striatal and temporal cortex in schizophrenic patients. CONCLUSION: The finding of a hyperfrontality in unmedicated and never medicated psychotic schizophrenic patients is observed when there is a predominance of positive symptoms. There could be a possible disruption of cortico-striato-thalamic feedback loops causing hyperfrontality as seen in experimentally induced models of psychosis .