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

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.

To explore the functional changes in the frontal and parietal cortex in PD cat model.

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.

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.

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.

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.