Diffusion Index Of Along The Perivascular Space In Hypoxic Sleep Of Patients With Parkinson’s Disease

Objective:Parkinson’s disease(PD)is the second largest central nervous system degenerative disease.The main pathological changes are the loss of dopaminergic neurons in substantia nigra and the deposition of Lewy body in brainstem,limbic system and neocortex.The misfolding ofα-synuclein(α-syn)and the formation of Lewy body play a central role in the pathogenesis of Parkinson’s disease.Glymphatic system is a waste removal system running in the brain,which can remove misfolded proteins such asα-syn and promote the convective exchange of cerebrospinal fluid and interstitial fluid.A lot of evidence shows that the decline of glymphatic system leads to the deposition of abnormal proteins in and out of cells,which eventually leads to the occurrence and development of PD.Previous studies have found that the protein content of cerebrospinal fluid from central nervous system in patients with obstructive sleep apnea hypopnea syndrome(OSAHS)is decreased.In recent years,through the analysis of diffusion tensor imaging(DTI)data,it was found that the diffusion index of Along the Perivascular Space(ALPS index)decreased in OSAHS patients,suggesting that hypoxia can cause changes in glymphatic system,but the changes of glymphatic system in PD patients during hypoxia have not been reported.The purpose of this study is to verify the changes of glial lymphoid system in patients with PD and the functional changes of glymphatic system in patients with PD during sleep hypoxia,and finally to explore the influencing factors of glial lymphatic system function,in order to attract attention to the changes of glymphatic system function in PD patients during hypoxia sleep,and to provide possible new ideas for the treatment of PD disease.Methods:A total of 25 PD patients and 11 controls who were hospitalized in the Department of Neurology of our hospital from March 2021 to November 2022 and underwent cranial DTI and polysomnography(PSG)were included.The ALPS index was obtained by image processing of baseline DTI.The general neuropsychological evaluation was performed in the control group and the PD group,and the PD motor and non-motor symptoms were evaluated in the PD group.The differences of basic data,hematological index,clinical scale score,PSG data and ALPS index between the two groups were analyzed.Furthermore,PD group was divided into PD group with AHI≤15 and PD group with AHI>15 according to apnea hypopnea index(AHI)=15.The differences of basic data,hematological index,clinical scale score,PSG and ALPS index between the two groups were analyzed.Finally,the influencing factors of ALPS index are discussed by simple linear regression analysis and multiple linear regression model analysis.Results:Compared with control group,the scores of Hamilton anxiety scale(HAMA)(P=0.010)and Hamilton depression scale(HAMA)(P=0.013)in PD group were significantly higher.The left ALPS index(P=0.012),right ALPS index(P=0.000)and total ALPS index(P=0.000)in PD group were significantly lower than those in HC group.The left ALPS index(P=0.010),right ALPS index(P=0.041)and total ALPS index(P=0.015)of PD group with AHI≤15 were significantly higher than those of PD group with AHI>15.Simple linear regression analysis showed that there was no correlationbetweentheUnifiedParkinson’sDiseaseRating Scale(UPDRS)(R~2=0.091,P=0.143),AHI(R~2=0.077,P=0.101)and levodopa equivalent daily dose(R~2=0.124,P=0.084)and the total ALPS index.Multiple linear regression model(R~2=0.735,P=0.011)found that age(P=0.001),duration of disease(P=0.017),average blood oxygen saturation during sleep(P=0.014)and decreasing index of blood oxygen saturation≥3%(P=0.011)had significant negative effect on total ALPS index,Health Questionnaire-15(P=0.042)had significant positive effect on total ALPS index,while OSASH,HAMD,MMSE,Mo CA and total hypopnea time had no effect on total ALPS index.Conclusion:The decline of glymphatic system function in PD patients,especially in PD patients with moderate to severe OSAHS.Age,course of disease and blood oxygen saturation will affect the function of glymphatic system.