Analysis Of Metabolic Characteristics Of ¹⁸F-FDG And ¹⁸F-DOPA In Multiple System Atrophys

Objective:To analyze the ¹⁸F-deoxyglucose positron emission tomography and ¹⁸F-dopa positron emission tomography metabolic characteristics and clinical characteristics of patients with multiple system atrophy.Methods:From January 2016 to December 2020,28 patients with MSA who were treated in the Department of Neurology of Shenzhen Second People’s Hospital（Shenzhen Second Hospital of Anhui Medical University）were collected as the research objects.Among them,there were 14 cases in the MSA-P group and 14 cases in the MSA-C group.Eleven healthy subjects who were treated in the First Affiliated Hospital of Sun Yat-sen University who matched the age and sex of MSA patients were selected as the control group.Collect baseline clinical data of MSA patients and healthy subjects,namely:name,gender,age,course of disease,smoking history,and clinical symptoms.MSA patients underwent ¹⁸F-FDGPET examination during the clinical evaluation,and then completed ¹⁸F-DOPA PET imaging.The healthy control group completed imaging examinations during the same period.¹⁸F-FDG image application SPM will perform a two-sample t-test based on voxel level on ¹⁸F-FDGPET target images of healthy control group,MSA-P subgroup and MSA-C subgroup respectively.That is to compare the radioactivity counts of each voxel point in the corresponding positions in the two sets of data,and perform FDR correction on the results.Use the xj View toolbox to view the MNI coordinates of each brain area.The results were superimposed on the MNI52 brain template with MRIcro MTL software to visually display the area and range of ¹⁸F-FDG metabolic changes.The uptake index of ¹⁸F-DOPA striatum was statistically analyzed by Graphpad Prism8software,and the comparison of SOR between groups was performed by two-sample t test.P<0.05 was considered statistically significant.Results:The clinical symptoms of the MSA-P group were mainly Parkinson’s symptoms,and about 86%of patients showed retardation;The prominent symptom in the MSA-C group was cerebellar ataxia,and the most common one was unstable walking（about 64%）.The MSA-P subgroup and the MSA-C subgroup had similar clinical age of onset,and the difference was not statistically significant（P>0.05）.The clinical symptoms of motor retardation and cerebellar ataxia between the two groups were statistically significant（P<0.05）.The MSA-P subgroup was more common in motor retardation,while the MSA-C subgroup was more common in cerebellar ataxia.In addition,there was no significant difference in smoking history between MSA patients and healthy controls（P>0.05）.The brain regions of patients with MSA-P whose ¹⁸F-FDG metabolism is reduced mainly include the cerebellum,frontal lobe and putamen.The metabolism of ¹⁸F-DOPA in the striatum is significantly lower than that of normal people,and the left and right caudate nucleus and putamen are reduced,and there is no laterality.The ¹⁸F-FDG metabolism of MSA-C patients is mainly concentrated in the cerebellum,and the ¹⁸F-DOPA metabolism of the striatum is also reduced compared with normal people.However,the substantia nigra dopaminergic damage in the posterior part of the putamen is not as severe as in MSA-P patients,and there is no laterality.Conclusion:（1）The average age of MSA patients is 52-64 years old,and the disease is mainly in middle-aged and elderly people.The MSA-P subgroup and MSA-C subgroup have basically the same average age of onset.（2）There is no statistically significant difference in smoking history between MSA patients and healthy controls.It is still unclear whether smoking is a protective factor or a risk factor for MSA.（3）The combination of ¹⁸F-FDG metabolic changes and striatal 18F-DOPA uptake index analysis has reference significance for the diagnosis of MSA patients.