The Correlation Studies Between Cholinergic System Related Cognitive Impairment Of Parkinson's Disease And The Cortex Thickness Of Brain

BACKGROUDParkinson disease(PD)cognitive impairment include PD Mild cognitive impairment(PD-MCI)and Parkinson disease dementia(PDD).With the development of Parkinson's disease,mild cognitive impairment in Parkinson's disease will progress to dementia with Parkinson's disease,therefore,early recognition of Parkinson's disease mild cognitive impairment is very important for the treatment of Parkinson's disease.The pathogenesis of cognitive impairment of Parkinson's disease remains unclear.More and more studies have found that cognitive impairment of PD involves a variety of neurotransmitter systems including dopaminergic and cholinergic systems.In 2012,the Movement Disorder Society divided mild cognitive impairment in Parkinson's disease into five cognitive domains(attention and working memory,executive function,language,memory,visuospatial function).However,it is unclear whether a single neurotransmitter pathway damage is associated with impairment of a particular cognitive domain in Parkinson's disease.The Dual Syndrome Hypothesis think that dysfunction of the fronto-striatal dopaminergic system is mainly related to impairment of cognitive domains such as executive function,while dysfunction of the occipito-parietal,occipito-temporal cholinergic system is mainly related to impairment of cognitive domains such as visuospatial function,memory,and attention.OBJECTIVETo investigate the correlation between cognitive domain impairment such as visuospatial,memory,attention in PD-MCI and cortical thickness in brain regions of the brain projected by the cholinergic neurotransmitter system.METHODSSeventy patients with Parkinson's disease who were hospitalized and outpatient from June 2015 to January 2018 were collected.The clinical data such as age,sex,course of disease,UPDRS-III,the classification of H&Y,MMSE,MoCA,HAMA and HAMD were collected.For each patient with Parkinson's disease,a combination of comprehensive cognitive assessment and assessment of five cognitive domains was used.According to the Level-? level in the diagnostic criteria for mild cognitive impairment in Parkinson's disease(PDMCI)as published by Movement Disorder Society,all non-dementia patients with Parkinson's disease were divided into three groups:PD-NC group(35 cases)and PD-MCI group(35 cases).PD-MCI group was further divided into PD-MCI-EL group(PDMCI with executive function or/and language cognitive domain impairment group)(17 cases)and PD-MCI-NEL group(PD-MCI was not associated with executive function or/and language cognitive domain impairment group)(18 cases)according to the impairment of cognitive domain.All subjects underwent 3.0T GE MR whole brain imaging.Freesurfer image analysis software were used to compare the cortical thickness between PD-NC and PD-MCI and PD-MCI-NEL patients(P<0.01).Patients,in the PD-MCI-EL,who all had impaired cognitive domains,such as memory,visuospatial,and attention,and no single cognitive domain(executive and/or language)impairment.So,comparison of the differences thicknesses in PD-NC vs PD-MCI-ELwas not performed.RESULTSPD-NC vs PD-MCI,PD-NC vs PD-MCI-NEL had no statistical significance in clinical data such as age,sex,education level,course of disease,UPDRS-III,H&Y grade,HAMA and HAMD(P>0.05).Global cognitive function assessment showed that patients with PD-MCI had lower MMSE and MoCA scores than PD-NC(MMSE Z=-4.276,P<0.001,MoCA Z=-3.649,P=0.001).PD-NC vs PD-MCI(P<0.01):PD-MCI patients mainly in frontal lobe,temporal lobe,parietal lobe and parts of occipital lobe of the left and right hemisphere appears cortex thinning area.PD-NC vs PD-MCI-NEL(P<0.01):Patients in PD-MCI-NEL group had cerebral cortex thinning in inferiorparietal,parsopercularis,rostralmiddlefrontal,superiorparietal of the left hemisphere and in superiorfrontal,parahippocampal,superiortemporal,bankssts,inferiorparietal,caudalmiddlefrontal,parsopercularis,parstriangularisof the right hemisphere.CONCLUSIONCognitive domains impairments such as memory,visuospatial and attention in PD-MCI is closely related to the cerebral cortical atrophy projected by the brain cholinergic neurotransmitter system.