Objective: The aim of the present study was to evaluate cortical hypometabolism of the F-18- fluorodeoxyglucose positron emission tomography (FDG-PET) based on a diagnostic cutoff point of the mini-mental state examination (MMSE) in de novo PD.Methods: We recruited 24 PD patients and 15 healthy controls to analyze FDG-PET. We divided the patients into two groups by the diagnostic cutoff point of MMSE for diagnosing dementia, with scores of>25 vs. < 25. FDG-PET was processed using statistical parametric mapping (SPM) 8 running on Matlab 11. Results: Patients with a MMSE < 25 presented lower score in time orientation, serial sevens, language and pentagon copying of MMSE compared to patients with a MMSE >25. Compared to healthy controls, patients with a MMSE> 25 and < 25 showed a fronto-temporo-parietal hypometabolism, which was more extended in patients with a MMSE < 25. Difference in cortical hypometabolism between patients with a MMSE >25 and < 25 was found in the right inferior parietal lobule. Conclusions: In the comparison by cutoff point of MMSE (25/24), hypometabolism in the right inferior parietal lobule suggests that the posterior cortical deficit is the main region ofde novo PD with cognitive impairment. Hypometabolism of right inferior parietal lobule is related to the damage of cerebral networkin de novo PD.
Parkinson Disease