A retrospective study of 859 patients followed by a Shanghai hospital for Myasthenia gravis diagnosed before the age of 14 found :
- an ocular form in 97.8% of cases, which only generalized in 14% of patients;
- 21.7% were in stable complete remission, 15.3% in pharmaceutical remission, and 42% of patients had achieved minimal manifestation status by the time of their last consultation, five to 16 years after the onset of the disease;
- of the 2.1% of patients who had at least one myasthenic attack, none died;
- the onset of myasthenia before puberty is predictive of a favorable outcome.
A second multicenter study conducted in the United States on 451 children with myasthenia, 238 of them treated with thymectomy, confirmed the efficacy of this procedure, with :
- from one year before thymectomy to three years after,
- a reduction in drug treatment, myasthenia-related hospitalizations and associated costs.
It should be noted that the surgical approach does not appear to influence the outcome of thymectomy.