A Retrospective Study On260Patients Of Childhood Myasthenia Gravis With A Minimum Follow-up Of Five-year

Object：To study the clinical characteristics, treatment, outcome and factors that affected theoutcomes of myasthenia gravis of childhood onset.Methods：Case records of260patients with diagnosed myasthenia gravis who were14yearsof age or less at disease onset at Tongji Hospital from Jan,1999to Nov,2013with aminimum follow-up of5years were reviewed. The data of demography, clinicalcharacteristics, outcomes, the factors affected the outcomes and the effect of prednisonewere analyzed by SPSS19.0.Results：There were142girls and118boys, mean age of onset was5.4±3.5years and meanfollow-up period was11.1years (range from5~45years). The gender ratio is1.2:1(female:male).17out of260patients had the risk factors of onset, such as upper respiratory infectionand brain injury. The positive family history is5.4%.42patients had associated autoimmunedisease, mostly were hyperthyroid. Unselected126patients received Chest scan,49patientswere normal,66patients were thymic hyperplasia,11patients were thymoma. Seropositivityto acetylcholine receptor antibodies was found in34out of85patients (85%). According tothe symptoms and response to therapy, most patients were treated with pyridostigmine andprednisone. Thymectomy was performed in16patients. At the end of follow-up,78patients(17.3%) remained no change,27patients (6.0%) got worse and277patients (61.4%)exacerbated. And the27patients who got worse transformed from OMG patients (11.9%) toGMG. The factors inducing exacerbation were analyzed, it showed that drug withdrawal wasthe dominant one. By analyzing the risk factors (age of onset, familiar history, complication,the course of disease and the use of prednisone)of the transformation, we found only thecourse of disease was related to the outcomes. Nevertheless，there is statistical difference of remission rate by Chi-square test between the group of patients who had used prednisoneand the one who had not. It is proved that the use of prednisone induced remission rate ofthe OMG patients while it was not related to the progression.Conclusion： Generalization to systemic disease is not frequent in OMG children. It isproved that the use of prednisone induces remission rate of the OMG patients while it wasnot related to the progression to GMG. The myasthenia crisis and the fatalities occurs at amuch lower rate than in adults.