Magnetic Resonance Imaging On Alterations Of Cortex In Right-onset Versus Left-onset Mild-moderate Parkinson’s Disease

Purpose:There is increasing evidence to show that motor symptom lateralization in Parkinson’s disease(PD)is linked to non-motor features,progression,and prognosis of disease.However,the mechanisms involved in PD asymmetry have not yet been elucidated.The study aimed to investigate the differences of cortical changes in Left-onset and Right-onset mild-moderate PD using Voxel-based morphometry(VBM)and Surface-based morphometry(SBM).Materials and Methods:A total of 104 patients with primary PD were collected.According to the onset side of the motor symptoms,patients with PD are divided into Left-onset PD(LPD)and Right-onset PD(RPD).According to the Hoehn and Yahr scale(H-Y scale),patients with PD were divided into mild(H-Y scale≤1.5)and moderate(2≤H-Y scale≤2.5).According to the above classification,patients with PD were divided into mild LPD(N=24,Male=13,Female=11,Age: 55.75 ± 8.08 years),mild RPD(N=38,Male=24,Female=14,Age: 55.49±7.95 years),moderate LPD(N=20,Male=10,Female=10,Age: 59.95 ± 7.95 years),and moderate RPD(N=20,Male=12,Female=8,Age: 58.25±8.08 years).57 people were enrolled in the Health Control(HC)group.The subjects underwent clinical assessment,neuropsychological assessment and magnetic resonance scan.Neuropsychological assessment included Mini-Mental State Examination(MMSE)and Hamilton depression scale(HAMD).Then,based on Cat12/SPM12 software,the T1 structure image data was preprocessed,and the differences of brain structure were compared and analyzed by VBM and SBM for mild LPD,mild RPD and HC((N=37,Male=17,Female=20,Age: 54.72±6.81 years);moderate LPD,moderate RPD and HC((N=20,Male=9,Female=11,Age: 57.66 ± 5.10 years);mild LPD and moderate LPD;mild RPD and moderate RPD,respectively.The SBM indicators include cortical thickness,gyrification index,fractal dimension and sulcal depth.Finally,the correlation between the different brain regions obtained between the groups was analyzed with Unified Parkinson’s Disease Rating Scale(UPDRS),UPDRS-III,MMSE and HAMD.Results:In the VBM analysis,compared with the HC group,the mild LPD group showed gray matter volume(GMV)atrophy in the right temporal lobe.Compared with HC,the mild RPD group were found GMV atrophy in the right temporal lobe,left frontal lobe,and left cingulate gyrus.Compared with mild LPD group,the mild RPD group showed GMV atrophy in the left cingulate gyrus and the right temporal gyrus.In the mild LPD and RPD group,the right middle temporal gyrus was inversely correlated with the HAMD score.In the VBM analysis,GMV atrophy occurred in the moderate LPD group compared with the HC group in a broad brain region involving the frontal,parietal,temporal and occipital lobe.Compared with the HC group,GMV atrophy occurred in the parietal,temporal,and frontal lobes in the moderate RPD group.The moderate LPD group had a more pronounced decline in the right frontal GMV compared with the moderate RPD group.In the moderate LPD and RPD group,the right superior orbital frontal gyrus was positively correlated with MMSE,and the left central posterior gyrus was inversely correlated with the HAMD score.In the VBM analysis,the moderate LPD group showed GMV atrophy in the bilateral cerebelum crus 2,the left lingual gyrus and the right inferior occipital gyrus compared with mild LPD.Moreover,compared with mild LPD,the moderate LPD group showed GMV increase in the bilateral cerebellar 9.Among them,the GMV of bilateral cerebellar 9 was positively correlated with UPDRS and UPDRS-III and the left lingual gyrus was negatively correlated with UPDRS-III.In the VBM analysis of,moderate RPD showed GM atrophy in the left central posterior gyrus compared with mild RPD.The left central posterior gyrus is negatively correlated with UPDRS and UPDRS-III.In the analysis of cortical thickness and complexity based on SBM,no obvious statistical differences were found between groups.Conclusion:There are differences in GMV changes in patients with motor symptoms on different sides onset and different degrees of PD.VBM can detect abnormal cortical changes in patients with early PD,suggesting that it can be used as a potential imaging detection method to assist in the early diagnosis of PD.SBM did not found the difference among mild-moderate LPD and RPD in brain structure,suggesting that the value of applying SBM to detect changes in cortical structure in mild to moderate LPD and RPD might be limited.