Cortical thinning pattern in Parkinson's disease stages

It has been well described the subcortical areas are the first affected; however, the progression to cortical involvement and how it correlates with disease severity are still unclear. 56 patients with PD (59.52 ± 9.9) according to the UK Parkinson's Disease Society Brain Bank criteria were compared with 27 healthy controls (HC) (57.77 ± 10.06). Anatomical T1-weighted MRI images were obtained on a 3 T scanner. We used the civet pipeline and the SurfStat toolbox on MatlabR2012b to process and analyze the images. We divided patients into 3 groups according to disease severity measured by H&Y scale and compared each group with healthy controls (HC). We also correlated patients' cortical thickness with H&Y, NMS, UPDRS, UPDRS III and SCOPA scores. There was a correlation between patients CT and UPDRS scores in the right superior temporal gyrus (p < 0.05). The comparison between group 1 and HC revealed decreased cortical thickness in left superior temporal gyrus, left gyrus rectus and left olfactory cortex (p < 0.05); Regarding the group 2, the areas with lower CT were right postcentral gyrus, right supplementary motor area and right inferior frontal gyrus (p < 0.05). For group 3 significant lower CT was found in left inferior frontal gyrus, left precentral and postcentral gyrus, left SMA, left inferior frontal gyrus, left gyrus rectus, right temporal pole, right fusiform gyrus, right middle temporal gyrus, and right occipital gyrus (p < 0.05). Our results show that there is an increase in cortical thinning across PD stages; Progression of PD has been well demonstrated using other neuroimaging methods and cortical thickness measure is also a useful tool to assess disease stages.