Abnormal Functional Connectivity And Visual Pathway Of SLD In Parkinson's Disease With Rapid Eye Movement Sleep Behavior Disorder:An Rs-fMRI Study

REM(rapid eye movement)sleep behavior disorder(RBD)is a sleep disturbance described as increased muscle tone and violent limb movements and is a non-motor symptom of Parkinson's disease(PD).PD patients with RBD represent faster motor and cognitive dysfunction progression.However,there are limited studies on possible structural brain changes underpinning this disorder.Sublaterodorsal nucleus(SLD)play a central role in generating REM sleep.Abnormal functional connectivity of SLD may cause RBD.By using rs-fMRI,we expected to find the functional connectivity alterations in the SLD of PD-RBD patients.Our study was performed as following two parts.Part one.Abnormal functional connectivity of SLD in Parkinson ‘disease with and without REM sleep behavior disorderObjective To investigate the abnormal functional connectivity(FC)between SLD and the whole brain in PD patients with RBD(PD-RBD)and PD patients without RBD(PDnRBD)by rs-fMRI,which may shed new light on the neural mechanism of RBD.Methods 23 patients of PD-RBD,20 patients of PD-nRBD and 21 age,sex-matched normal controls(control group))recruited in the Department of Neurology,Henan Provincial People's Hospital were enrolled in this study according to international diagnosis criteria.All subjects were examined by motor functional tests,cognitive tests and rfMRI.Resluts The FCs between bilateral SLDs and the whole brain have significant differences among PD-RBD group,PD-nRBD group and NC group.Compared with the control group,the FC analysis in PD-RBD showed reduced correlations between the left SLD and bilateral fusiform gyrus,bilateral lingual gyrus,bilateral inferior temporal gyrus,bilateral precuneus,right midbrain,right orbital middle frontal gyrus,left parahippocampal gyrus,left cerebellum and left cingulate gyrus,and between the right SLD and the left inferior and middle temporal gyrus,left inferior occipital gyrus,left cingulate gyrus,left precentral gyrus,right postcentral gyrus,bilateral precuneus and bilateral cerebellum and vermis.The FC analysis in PD-nRBD showed increased correlations between the right SLD and right cerebellum but reduced correlations between the left SLD and right postcentral gyrus and right inferior temporal gyrus.Compared with the PD-nRBD group,the FC analysis in PD-RBD showed reduced correlations between the left SLD and bilateral cerebellum,bilateral thalamus and posterior limb of internal capsule.The FC also reduced between the right SLD and left inferior and middle temporal gyrus,left precentral gyrus,left inferior occipital gyrus,left precuneus,left thalamus and bilateral cerebellum.All the results corrected by Alpha Sim(p<0.005).The correlations between the left SLD and left cerebellum,right midbrain,left inferior temporal gyrus and between the right SLD and left cingulate gyrus,left middle frontal gyrus,left precentral gyrus,left temporal-occipital gyrus were negative correlated with the motor functional tests.Conclusions There were abnormal FCs between SLD and cognitive and motor areas in PD-RBD patients,to lead to clinical symptoms such as cognitive deterioration and movement disorder.Part two The visual pathway concluding SLD in idiopathic RBD,Parkinson ‘disease with RBD and Parkinson ‘disease without RBDObjective To explore the visual pathway consisted by SLD,lateral geniculate body,cuneus,fusiform gyrus and lingual gyrus in iRBD,PD-RBD,PD-nRBD and normal controls.Methods 19 patients of iRBD,23 patients of PD-RBD,20 patients of PD-nRBD and 21 age,sex-matched normal controls(control group))recruited in the Department of Neurology,Henan Provincial People's Hospital were enrolled in this study according to international diagnosis criteria.All subjects were examined by rs-fMRI.Resluts The SLD-lateral geniculate body-visual cortex pathway was existed in iRBD,PDRBD,PD-nRBD and normal controls.The number and intensity of correlation between either ROI was decreased in PD-RBD group.Conclusions there was a special visual pathway concluded SLD in iRBD,PD-RBD,PDnRBD and normal controls.But it was injured when PD-RBD appeared,which could lead to the impairment of visuospatial function and visual hallucination.