Value Of Auxiliary Examination In Diagnosis And Clinical Application Of Myasthenia Gravis In Children

Objective:To investigate the diagnostic value and clinical application of clinically used auxiliary examination methods in children with newly diagnosed myasthenia gravis.Methods:Retrospective analysis of 104 cases of newly diagnosed children with MG(Myasthenia gravis,MG)Clinical and laboratory examination data,such as gender,age,onset symptoms,family history,auxiliary examination results,including neostigmine test,repeated nerve electrical stimulation,AChR(Acetylcholine receptor)antibody detection,cytokines and chest MRI/CT and so on.To compare the positive rate and difference in children with newly diagnosed myasthenia gravis,another 21patients with non-MG who had ptosis were used as a control group to understand the value of the above-mentioned examination for the diagnosis and differential diagnosis of MG children.Results:1.General information:104 children with newly diagnosed MG,(1)by gender:male group,34 cases(32.7%),female group 70 cases(67.3%),male:female=1:2,The youngest is 6 months,the maximum is13 years old,the average age is 4.8±3.3 years old;(2)Grouped by age,50cases in infant group(?3 years old),26 cases in preschool group(>3-?7years old),and 28 cases in School-age group(?7 years old).(3)Grouped according to clinical type:96 cases(92.3%)of MG I type,2 cases(1.9%)of MGIIa type,5 cases(4.8%)of MGIIb type,and 1 case(1.0%)of MGIII type.In the control group,14 males(66.7%)and 7 females(33.3%),male:female=2:1,maximum 16 years old,minimum August,mean age 4.7±3.7 years old.2.Completion of all auxiliary examinations,104 children with MG:(1)All children underwent neostigmine test(100%),positive 98cases(94.2%);(2)102(98.1%)cases complete Repeated nerve electrical stimulation test,14 cases(13.7%)were positive,3 cases(2.9%)were suspicious,so 17 cases(16.67%)were positive totally;(3)AchR-Ab,Musk-Ab,RyR-Ab,Titin-Ab test showed 103 cases(99.0%),54 cases(51.9%),56 cases(53.8%),and 65 cases(62.5%).The abnormalities were70 cases(67.9%)and 0 cases(0 cases).%),17 cases(30.3%),18 cases(27.6%),the overall positive rate of antibody screening was 78.6%;(4)25cases of children were tested for cytokines,13 cases were positive(52.0%);(5)all The child underwent chest MRI/CT examination,3 cases(2.88%)with positive;(6)100 cases complete head MRI/CT,16 cases of positive(16.0%);(7)20 cases of non-MG children were tested for neostigmine test,1 case was positive(5.0%),2 cases(10.0%)suspected positive,3 cases were abnormal totally(15.0%),and 20 cases complete repeated nerve stimulation,positive in 1 case(5.0%),other related auxiliary examinations have a low positive rate.3.The multivariate analysis of the above results showed that there was a significant difference in the sensitivity between the neostigmine test,repeated neuroelectric stimulation,antibody detection,cytokine examination and chest MRI/CT examination.(1)Neostigmine test test was significantly different from the repeated nerve electrical stimulation,antibody detection,cytokine,chest MRI/CT,and head MRI/CT results(?~2=125.627,P=0.000<0.01;?~2=10.753,P=0.001<0.01;?~2=29.938,P=0.000<0.01,?~2=173.702,P=0.000<0.01,?~2=126.553,P=0.000<0.01).(2)Repeated nerve stimulation was significantly different from antibody detection,cytokine,and chest MRI/CT findings(?~2=78.886,P=0.000<0.01;?~2=13.894,P=0.000<0.01;?~2=11.158,P=0.001<0.01).There was no significant difference between repeated nerve stimulation and head MRI/CT(?~2=0.016,P=0.898>0.05).(3)There were significant differences in antibody detection compared with cytokines,chest MRI/CT,and head MRI/CT(?~2=7.319,P=0.007<0.01;?~2=123.166,P=0.000<0.01;?~2=79.794,P=0.000<0.01).(4)The overall positive rate of MG children was 100%,and the overall positive rate of non-MG group was 33.3%.The overall positive rate of MG children and non-MG related tests was very significant(?~2=78.078,P=0.000<0.01).(5)The sensitivity of neostigmine test and acetylcholine receptor antibody detection is high(67.9%-94.2%),while maintaining high specificity(85.0%-88.8%).The sensitivity of repeated nerve electrical stimulation,Musk-Ab,RyR-Ab,Titin-Ab is low(0-30.3%),and the specificity of each auxiliary examination is high(80%-100%).Conclusion:1.Children with myasthenia gravis is as same as adult MG,more female patients than males,which is consistent with more women in autoimmune diseases;2.The initial diagnosis of children with MG should be based on typical clinical manifestations,combined with pharmacological tests,electricity Physiological examination,antibodies and cytokines detection,chest MRI/CT examination for comprehensive analysis and judgment for differentiation with non-MG children;3.In laboratory examination of MG children:neostigmine test sensitivity is highest,It should be recommended as an early screening test;the sensitivity of repetitive nerve electrical stimulation is low,but maintains high specificity;serum antibody and cytokines,chest MRI/CT,etc.are required under conditions.All these examinations have important clinical significance and use value for the judgment of the condition of the children with MG and the guidance of the treatment plan.