The Study Of Lateralization Of Attention In Patients With Parkinson's Disease

Background: Parkinson's disease(PD)is a movement disorder characterized by degeneration and death of dopaminergic neurons in the substantia nigra and relatively enhanced cholinergic system function.Recently,the non-motor symptoms of Parkinson's disease have also received a lot of attention.Even in the early stage of the disease,studies show that there may be cognitive deficits,among which the impairment of attention function is prominent.Attention is the process of active processing of partial information from infinite information.Posner et al.proposed to divide attention network into three sub-networks: alertness,orientation and execution.A large number of evidences show that the normal left and right brain attention function exists asymmetry.In recent years,more and more scholars have studied the lateralization of attention function in the left and right hemispheres from three aspects: orientation,alertness and executive control of attention network system.At the population level,brain atypical lateralization exists in neuropsychiatric disorders,including autism and schizophrenia,which may reflect brain abnormal development.Previous studies have found that the functional advantage of left-hemisphere orientation networks disappears in schizophrenia patients compared with the general population.Previous studies on attention network have shown that the orientation network is impaired in Parkinson's disease,but the effect of Parkinson's disease on the lateralization of attention network remains unclear.The lateralized attention network test(LANT)assesses the efficiency of attention in the brain's hemispheres and the hemispheric state of each attention network.Therefore,the LANT was used in this study to investigate the lateralized attention network and its mechanism in Parkinson's disease.Objective: To investigate whether there are differences between Parkinson's disease patients and normal people in attentional lateralization,and the related mechanism of such differences.Method: The study included 33 patients with Parkinson's disease and 28 matched healthy controls.Neuropsychological background tests were performed on all subjects,and the lateralized attention network test paradigm was used to compare whether there was hemispheric lateralization in the orientation,alertness and executive function networks by calculating the mean response time(RT)and error rate(ERR)of the two groups of subjects in the left and right visual fields.The attention network effect of one side field represents the attention network function of the contralateral cerebral hemisphere.Finally,all the data were analyzed by Spss20.0 software.Result: In the orientation network,the average response time of the left visual field in the Parkinson's disease group was longer than that on the right,with a statistically significant difference(t=2.923,p=0.006),while the average response time of the right visual field in the healthy control group was longer than that on the left,with a statistically significant difference(t=4.751,p <0.001).In the alertness network,the main effect of left visual field alertness disappeared in the Parkinson's disease group,while the average response time of left visual field and right visual field in the healthy control group was not statistically significant.In the executive network,there was no significant difference in the mean reaction time between the left and right visual field in the two groups.In addition,there was no statistically significant difference in response error rates between the left and right visual fields in the three networks of the two groups.Conclusion: The healthy control group showed the dominance of oriented function in the left hemisphere,while the Parkinson's disease group changed to the dominance of oriented function in the right hemisphere.Besides,the alertness function in the right hemisphere was impaired in the Parkinson's disease group.These changes may be related to asymmetric secretion of neurotransmitters in the left and right hemispheres of Parkinson's disease,impaired neural circuits,and asymmetric damage to the frontal and parietal cortex.