Effect of thymectomy in elderly patients with non-thymomatous generalized myasthenia gravis

  • Seung Woo Kim
  • Young-Chul Choi
  • Seung Min Kim
  • Hyo Sup Shim
  • Ha Young ShinEmail author
Original Communication


Whether thymectomy is beneficial in elderly patients with myasthenia gravis (MG) is unclear. Thus, we assessed whether conducting thymectomy in MG patients aged ≥ 50 years is beneficial. This retrospective cohort study included patients with MG between 1990 and 2018. Thymectomy and control cohorts were selected from among the population of MG patients with an age at onset of ≥ 45 years and elevated concentrations of acetylcholine-receptor antibodies. Patients with evidence of thymic malignancy were excluded. Of these patients, those who underwent thymectomy at the age of ≥ 50 years were designated as the thymectomy group and those who received only medical treatment were designated as the medical treatment group. We compared the Myasthenia Gravis Foundation of America post-intervention status between the thymectomy and medical treatment groups. Landmark analysis was conducted with the landmark set at 24 months. A total of 34 and 105 patients were classified into the thymectomy and medical treatment groups, respectively. Before landmark analysis, the thymectomy group had a higher cumulative incidence of pharmacologic remission (p = 0.009) and complete stable remission (p = 0.022) than the medical treatment group. After landmark analysis, the thymectomy group had a 2.22-fold (95% confidence interval 1.01–4.80) increased chance of achieving pharmacologic remission compared to the medical treatment group after adjustment for age, sex, and disease severity. No significant difference was observed in the rate of relapse after pharmacological remission between the thymectomy (16.7%) and medical treatment groups (21.4%). In conclusion, thymectomy may have a beneficial effect in elderly patients with non-thymomatous generalized MG.


Myasthenia gravis Thymectomy Remission Prognosis 



This work was supported by the National Research Foundation of Korea funded by the Korean government (MSIP) (No. 2016R1C1B1010120).

Compliance with ethical standards

Conflicts of interest

None of the authors has any conflicts of interest to disclose.

Ethics approval

The study including human participants has been approved by the Severance Hospital Institutional Review Board (Approval No. 4-2018-0869) and has, therefore, been performed in accordance with the Declaration of Helsinki.

Supplementary material

415_2019_9222_MOESM1_ESM.pdf (36 kb)
Supplementary material 1 (PDF 35 KB)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Seung Woo Kim
    • 1
  • Young-Chul Choi
    • 1
  • Seung Min Kim
    • 1
  • Hyo Sup Shim
    • 2
  • Ha Young Shin
    • 1
    Email author
  1. 1.Department of NeurologyYonsei University College of MedicineSeoulSouth Korea
  2. 2.Department of PathologyYonsei University College of MedicineSeoulSouth Korea

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