Observation And Intervention Of Binocular Rivalry In Parkinson’s Disease

When bistable stimulus is presented to each eye,perceptual awareness changes without any change in retinal stimulation,a phenomenon known as binocular rivalry.Binocular rivalry is a spontaneous alternation of visual perception.Paradigms of binocular rivalry have been widely used in the study of bistable perception and have been applied to many mental disorders.In this thesis,we focused on the binocular rivalry in patients with Parkinson’s disease(PD)using the binocular rivalry paradigm.Background:(1)Non-motor symptoms of PD often exist several years before the appearance of motor symptoms and have a negative impact on social function and quality of life.Studies have shown that PD patients have reduced perceptual abilities,however,the exploration of bistable perception is lacking.In this study,we used the binocular rivalry paradigm to observe the average switching rate of binocular rivalry in PD.(2)Repetitive transcranial magnetic stimulation(rTMS)is an effective intervention for PD,which can improve the motor symptoms of PD patients,but reports differ on the efficacy of non-motor symptoms.In order to explore the effect of rTMS on binocular rivalry in PD patients,we stimulated the supplementary motor area(SMA)and observed the effect of intervention.Methods:(1)We recruited 40 PD patients and 20 healthy controls(HCs).The PD patients were randomly divided into a medication group and temporary withdrawal group.All of the subjects took the binocular rivalry paradigm test and received a background assessment,including the Mini–Mental State Examination(MMSE),Hamilton Anxiety scale(HAMA),Hamilton Depression scale-17(HAMD-17),Unified Parkinson’s Disease Rating Scale Ⅲ(UPDRS Ⅲ),and Modified Hoehn and Yahr staging of disease.(2)A total of 12 PD patients were enrolled in this study.We stimulated the SMA of PD patients with persistent theta-burst stimulation for 14 days.All of the subjects performed the binocular rivalry paradigm test and background evaluation(including HAMA,HAMD-17,UPDRS Ⅲ,and Modified Hoehn and Yahr staging of disease)before and after the intervention.Results:(1)The average switching rates of binocular rivalry in the medication group and temporary withdrawal group were significantly slower than that in the HCs(F = 27.289,P < 0.001).There was no significant difference in the average switching rates of binocular rivalry between the medication group and temporary withdrawal group(P = 0.271).(2)After rTMS treatment,the average switching rates of binocular rivalry increased(t =-2.671,P = 0.022)and the scores of UPDRS Ⅲ decreased(t = 2.644,P = 0.023).There was no statistically significant difference in the scores of HAMA(t = 1.074,P = 0.306)and HAMD-17(t = 1.225,P = 0.246)before and after the rTMS treatment.Conclusion:(1)PD patients have slower alternation in binocular rivalry than HCs.(2)rTMS of the SMA can increase the alternation of binocular rivalry and improve the motor symptoms in PD patients.