Study On The Correlation Between The Changes Of Intrinsic Network Connectivity And The Development Of Visual Hallucinations In Parkinson's Disease

Background: Visual hallucinations are a common non-motor symptom of Parkinson's disease(PD).Its mechanism remains unclear.It has been previously discovered that the abnormal structure and function of intrinsic brain networks in PD patients with visual hallucinations.However,these studies were performed in patients with PD under dopaminergic treatment and with a present history of visual hallucinations.Thus,it is not possible to determine whether their findings were related to chronic dopamine replacement treatment,neuronal reorganization induced by the hallucinated behaviors themselves,or a premorbid pattern predisposing to visual hallucinations.In this study,we intend to explore the intra-and inter-network connectivity changes in PD patients who eventually developed visual hallucinations.Methods: 87 PD patients without visual hallucinations were include in this study.All the patients underwent resting-state functional MRI(RS-fMRI)data acquisition and neuropsychological scale measurements and 36 months follow-up.Those who experienced visual hallucinations during the follow-up were included to PD with visual hallucinations group(VHs+),those who didn't were included to PD without visual hallucinations group(VHs-).The intra-and inter-networkconnectivity of DMN,DAN,VAN and PVC were evaluated by Independent component analysis(ICA).Finally,Cox regression analysis was used to investigate baseline predictors of visual hallucinations development in PD patients.Results: Fifteen PD patients developed visual hallucinations during the follow-up and entered the VHs + group;70 patients didn't develop visual hallucinations,15 age,sex,L-doba equivalent dose(LEDD)and Dopamine agonist(DA)matched non-hallucinated PD patients were included in VHs-.18 healthy people were included in HCs.Decreased connectivity in the DMN and DAN were detected in PD patients with visual hallucinations at follow-up compared with those without.Increased inter-network connectivity between DMN and PVC was significantly associated with visual hallucinations development in PD patients(P <0.05).Conclusions: The development of visual hallucinations in PD patients is related to the abnormal intra-and inter-network functional connectivity inherent in DMN,DAN,VAN,and PVC.And the inter-network connectivity changes between DMN and PVC may be a potential biomarker for visual hallucinations in PD patients.