ABSTRACTIntroduction/AimsStimulated jitter analysis (stim‐JA) involves analyzing the variation in time intervals between stimulations and action potentials, expressed as the mean consecutive difference (MCD). The MCD upper limits are derived from adult populations and warrant a re‐evaluation in children to accurately diagnose neuromuscular junction (NMJ) defects.MethodsA retrospective chart review was conducted which analyzed orbicularis oculi stim‐JA studies performed on children between January 2014 and December 2021. The clinical profile, acetylcholine receptor (AChR), and muscle‐specific kinase (MuSK) antibody status as well as stim‐JA study results were retrieved. Bootstrapping was applied to the stim‐JA studies to derive de novo MCD upper limits.ResultsTwenty‐seven stim‐JA studies were performed on patients aged 3–19 years with either definite myasthenia gravis presentations and NMJ defects (n = 19, 17 AChR+, 2 MuSK+) or those with normal neurological examinations who were seronegative (n = 8). Four hundred ninety‐nine apparent single fiber action potentials (ASFAPs) were analyzed with the individual and mean MCD significantly higher in children with autoimmune myasthenia (p < 0.05). Bootstrapping analysis revealed that MCD upper limits of 39 μs for individual MCD and 24 μs for mean MCD significantly improved specificity (p < 0.05) while maintaining sensitivity of the test in distinguishing definite MG NMJ defect from normal NMJ function.DiscussionStim‐JA using revised upper limits may help clinicians avoid the over‐diagnosis of NMJ disorders in children. Stim‐JA is a safe and well‐tolerated method to screen for definite MG in children over 2 years.