NEUROMUSCULAR JUNCTION RELATED DISORDERS: EP.298 Juvenile myasthenia gravis and determining the causes of delays to diagnosis: a ten-year experience

Abstract

To evaluate our center's experience and determine potential causes of delays to diagnosis as once diagnosed these patients typically have the good response to treatment. We performed a retrospective chart review of 26 patients diagnosed with juvenile myasthenia between January 1, 2010 and December 31, 2020 at Le Bonehur Children's hospital. The baseline characteristics were recorded for each patient. In our cohort, the median age at onset was 5.5 years (18mo - 16years old). We had a 2:1 female to male ratio. The median time to both neurology consultation and diagnosis was 3 months. 46% were less than 5 years of age, 31% between 5-9 years, and 23% were older than 10. 75% were African American, 18% white, and 7% Latino. Prepubertal patients had a less than 4 months’ time to diagnosis on average whereas post-pubertal had 8.5 months to diagnosis on average. 56% were AChR-Ab positive, 12% were MuSK positive and 32% were seronegative. The average time to diagnosis was 18 months in MuSK patients and 3 and 2 months for AChR and seronegative patients respectively. In our cohort, post-pubertal patients had a time to diagnosis on average twice as long as compared to prepubertal patients. MuSK patients had a time to diagnosis on average 3 times as long as compared to AChR patients. Our cohort tended to present at a younger age and we had a higher percentage of MuSK patients then traditionally reported in literature, likely due to our higher African American demographic. We hypothesize that these patients’ predominant bulbar symptoms clouded their clinical picture and accounted for a delay to diagnosis as they were more often referred to ENT and GI. Given general providers decreased awareness of the association with bulbar symptoms and JMG, we sought to better educate providers at our institution regarding this association.