Childhood myasthenia gravis − clinical characteristics, diagnostic modalities, treatment strategies, and outcome

Abstract

Background Childhood myasthenia gravis (CMG) is MG occurring in childhood or adolescence (i.e. <18 years of age). Aim The aim of the work was to identify different clinical presentations and classifications of CMG, current diagnostic modalities, treatment strategies, and outcome to provide a profile of CMG among a cohort of Egyptian children attending Alexandria University Children’s Hospital as a tertiary pediatric center. Patients and methods All children diagnosed as having CMG who attended Pediatric Neurology Clinic at Alexandria University Children’s Hospital from January 1, 2010 to December 31, 2019 were included. A questionnaire for parents or caregivers including demographic data was administered. Clinical examination, clinical scoring system for MG, MG Foundation of America (MGFA) clinical classification system, electrophysiological studies, laboratory investigations, and clinic records review were done. Results Male : female ratio was 1 : 2.75. Mean age at start of symptoms was 4.97±3.78 years. Ptosis was presented in all (100%) patients, swallowing difficulty and choking in 40% of the patients, generalized weakness in 40% of the patients, and slurred speech and nasal tone in 33.3% of the patients. Overall, 46.7% of the patients were classified as pure ocular myasthenia gravis (MGFA class I), 20.0% as MGFA class II (mild generalized), 26.7% as MGFA class III (moderate generalized), and 6.7% as MGFA class IV (severe generalized). Pyridostigmine was used by 100% of the patients, prednisolone by 60% of the patients, and azathioprine by four (26.7%) patients. Pyridostigmine was the commonest single drug used by 40% of the patients. The common combinations were pyridostigmine with prednisolone alone or with added azathioprine. The comparison between the MG-Activities of Daily Living scale profile scores in first and last visits for patients was statistically significant. There was a significant improvement in the class of diseases, with remission in 70% of the patients. Failure rate of management was found in 20% of the patients. Conclusion Ocular myasthenia gravis was the most common subclass of CMG; ptosis was the most common presenting symptom. All patients received pyridostigmine as the first-line treatment. Remission occurred in 70% of the patients.