MYASTHENIA GRAVIS IN IRANIAN CHILDREN

This study was undertaken to evaluate the clinical spectrum of myasthenia gravis in children and determine factors that help the clinician in his/her diagnosis and management. Materials & Methods A retrospective review was performed on all pediatric patients suffering from myasthenia gravis (M.G) admitted in the department of pediatric neurology of the Mofid Hospital of the Shaheed Beheshti University, between 1994 and 2002. Results Of the thirty-two children with M.G. enrolled in our study, seven were suffering from the congenital type while the remaining (25 cases) had the juvenile M.G. Initial symptoms of congenital M.G were ptosis (7/7), limitation of eye movement (2/7) and mild generalized weakness (6/7). Although the Tensilon test was positive in 85% of congenital M.G cases, no myasthenia crisis or spontaneous remission was observed in any of them. In children with juvenile M.G, the age of presentation was 1.2 to 12.5 years, mean age 5.7+4.2 years (15 girls and 10 boys). The most common presenting symptoms in juvenile group were ptosis in 96% and generalized weakness in 76%. Eight of them (32%) had had at least one myasthenia crisis. EMG was diagnostic in 83% and one case the tensilon test was positive in 84%. One patient had hyperthyroidism and had already been diagnosed with hypothyroidism; two of them were epileptics. Eight patients underwent thymectomy microscopically; in specimens examined, five (62%) showed thymic follicular hyperplasia while in remaining three results were normal. One patient (12.5%) recovered completely after thymectomy with no need for medication during the follow up. Four patients (50%) showed relative improvement and in three cases (37%) improvement was negligible. Conclusion The results showed a female to male ratio of 1.5/1 which was correlated to adult M.G. The most common presenting symptoms consisted of ophtalmoplegia, with bilateral ptosis being the most significant. Although this study revealed that thymectomy lacks any remarkable prognostic influence, all patients had thymectomy after two years of disease onset. Some reports have indicated positive results if surgery was performed within two years of onset of disease.