Correlation Between Non-motor Symptoms And Clinical Characters Of Myasthenia Gravis

Objective1、To investigate the non-motor symptoms such as olfactory function and cognitive function of MG patients,and to compare whether there are differences between MG patients and healthy controls(HC)in olfactory function and cognitive function;2、To analyze the correlation between olfactory function and clinical characters,and to analyze the correlation between cognitive function and clinical characters.MethodsSixty-seven MG patients and thirty-two healthy controls were performed T&T olfactometer test.The clinical information were collected.Fluroimmunoprecipitation assay(FIPA)was applied to detect acetylcholine receptor(ACh R)antibody and muscle specific receptor tyrosine kinase(Mu SK)antibody.Results1、MG patients performed more poorly on olfaction test compared to healthy controls(t=5.50,P<0.01);2、MG patients with abnormal IT performed more poorly on QMG scores and ADL scores.But there is no significant differences in disease course,time and total dose of taking pyridostigmine,serum level of anti-ACh R,serum level of anti Mu SK,serum level of ACh E between MG patients with normal IT and abnormal IT.By Spearman analysis,it was obvious that the disease course(r=0.374,P<0.01),ADL scores(r=0.576,P<0.01),time of taking pyridostigmine(r=0.333,P<0.05),total dose of taking pyridostigmine(r=0.34,P<0.01)were positively correlated to T&T scores.But time of taking prednisone(r=0.084,P=0.053)or time of taking immunodepressants(r=0.153,P=0.251)did not correlate with T&T scores.Also,serum level of ACh R or Mu SK antibody did not correlate with T&T score;3、MG patients performed more poorly on cognitive tests of MMSE(t=5.09,P<0.01),CVLT 5th trial(t=3.60,P<0.01),CVLT total of free recall(t=3.44,P<0.01)CVLT short time delayed free recall(t=2.96,P<0.01),CVLT short time cued free recall(t=4.45,P<0.01),CVLT long time delayed free recall(t=3.95,P<0.01)、CVLT long time delayed cued recall(t=4.72,P<0.01),BVMT 3rd trial(t=2.35,P<0.05)、BVMT delayed recall(t=3.28,P<0.05),SDMT(t=4.83,P<0.05)、 JLO(t=3.10,P<0.05),PASAT(t=3.26,P<0.01),but there was no significant differences between MG patients and HC in BVMT recognition(t=1.90,P=0.06)、 language fluency(t=1.32,P=0.19)or BDI(t=-1.95,P=0.053);4、CVLT short time delayed free and cued recall,language fluency were significantly diffenent between MG patients with normal IT and abnormal IT.All other cognitive tests has no significantly differences between MG patients with normal IT and abnormal IT.BVMT in MG patients was negatively correlated with ADL score(r=-0.278,P=0.035).All of the cognitive tests were not correlated with the disease courses,time of taking pyridostigmine,time of taking prednisone,time of taking antidepressants,serum level of ACh R or Mu SK antibody;5、Identification threshold(IT)of MG patients was negatively correlated with MMSE(r=-0.319,P=0.016),CVLT short time delayed free recall(r=-0.289,P=0.023)、CVLT short time delayed cued recall(r=-0.275,P=0.030)、CVLT long time delayed cued recall(r=-0.262,P=0.048),PASAT(r=-0.309,P=0.016)、SDMT(r=-0.404,P=0.01),CVLT total free recall(r=-0.248,P=0.052),BVMT recognition(r=-0.011,P=0.936),JLO(r=-0.067,P=0.609),or BDI(r=0.230,P=0.08)did not correlated with IT.Conclusions1、Compared to HC,MG patients presents olfactory dysfunction,and olfactory function positively correlated with disease course and ADL score,suggesting that olfactory dysfunction may negatively influenced daily life;2、MG patients performed more poorly on cognitive tests,but BDI score did not significantly higher than HC,suggesting that the ability of working memory and information process may damaged in MG patients;3、IT negatively correlated with several cognitive test scores,suggesting that perhaps central cholinergic system involvement in MG,but the mechamism is still not clear.