Parkinson's disease: functional changes in frontal and parietal cortex using 18 F- fluoro-deoxy glucose positron emission tomography/computed tomography.

Abstract

BACKGROUND: In Parkinson's disease (PD) there is increasing evidence to suggest motor function changes of the cerebral cortex occur in addition to the pathological changes in the extrapyramidal system. AIMS: To explore the functional changes in the frontal and parietal cortex in PD cat model. SETTINGS AND DESIGN: Twenty-four healthy male cats were divided into four animal model groups with the injection of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), and one control group. MATERIALS AND METHODS: Cats in both the animal model and control groups were observed for the behavioral changes. They were also examined by 18 F-fluoro-deoxy glucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). Region of Interest (ROI) was determined by 18 F-FDG intensity and semi-quantitative analysis was employed after detecting the standard absorption value (SUV). Statistical Analysis : Statistical significance was evaluated by ANOVA. RESULTS: Compared to control group, the 18 F-FDG intensity and SUV were found normal on both the sides of frontal and parietal cortex in the PD models on the second day (P > 0.05), and on the fifth day, they were reduced significantly on both the sides of frontal cortex exclusively (P < 0.05). Moreover on the eighth day, the SUV of both frontal cortexes was reduced, while it was increased in both parietal cortex (P < 0.05). Finally on the eleventh day, the SUV remained stable in both the frontal cortex, and was back to normal level in both the parietal cortex. CONCLUSIONS: Functional disorders exist in the frontal cortex of PD animals and aggravate with time. Transient functional enhancement in the parietal cortex of PD cats might be a compensation for the dysfunction of frontal cortex.