18F-FDG PET/CT Evaluation of Regional Cerebral Metabolic Activities in Childhood Onset Schizophrenia

Abstract

Introduction: Functional neuro-imaging with FDG PET CT in schizophrenic patients have reported certain patterns of increased or decreased metabolism in specific areas of the brain. Frontal lobe is one of the cortical areas consistently associated with schizophrenia and the activity levels have been reported to vary with the symptomatology at presentation. Predominantly positive symptoms cause and underlying hyperfrontality and negative symptoms are associated with hypofrontality. This study aims to assess the imaging patterns in unmedicated pediatric patients with a diagnosis of schizophrenia and predominantly positive symptoms.

Patients and methods: 48 pediatric patients with a diagnosis of schizophrenia (all unmedicated, 38 never medicated) and 10 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: Children with schizophrenia and positive symptoms had a pattern of diffuse hyper-metabolism involving the bilateral frontal cortices and could be demonstrated 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 these patients when compared to controls.

Conclusion: Diffuse frontal hypermetabolism or hyperfrontality is observed in children with schizophrenia 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 in experimentally induced models of psychosis.