Improved Neuromuscular Transmission Following Thymectomy in Juvenile Myasthenia Gravis: A Case Series

Juvenile myasthenia gravis (JMG) patients report symptomatic improvement following thymectomy; however, there is a lack of published literature on biomarkers for interval improvement. This study aimed to investigate the utility of single-fiber electromyography to quantify changes post-thymectomy.

This was a retrospective medical record review of JMG patients who underwent thymectomy at Children's Healthcare of Atlanta between 2014 and 2024. Pre- and post-thymectomy orbicularis oculi jitter values and Myasthenia Gravis Activities of Daily Living (MG-ADL) scores were recorded. A two-sided paired t-test was used to compare results pre- and post-thymectomy and Pearson's correlations were calculated.

Twelve JMG patients (6 female) with a mean age at diagnosis of 12.9 ± 4.5 (range 1.6-17.1) years, positive acetylcholine receptor antibodies, and normal thymus imaging underwent thoracoscopic thymectomy at 15.2 ± 3.3 (range 7.4-18.2) years. Post-thymectomy, there was a statistically significant decrease in mean jitter (interval 7.3 ± 7.4 months, mean difference -33.2 ± 32.6 μs, p = 0.04, n = 7) and MG-ADL scores (interval 2.5 ± 2.1 years, mean difference -2.2 ± 2.5, p = 0.02, n = 11). There were no significant correlations between timing of thymectomy after diagnosis and the change in mean jitter (r = 0.11, p = 0.8, n = 7) and MG-ADL (r = -0.19, p = 0.58, n = 11). No major post-surgical complications were observed.

Thymectomy is well-tolerated and leads to both objective and subjective improvement in JMG patients.