Dados do Trabalho

Título

**CHARACTERIZATION OF DIFFERENT MYASTHENIC SYNDROMES IN PEDIATRIC PATIENTS**

Introdução

Myasthenic syndromes affect the neuromuscular junction, leading to symptoms like fatigability and fluctuating muscular weakness. In pediatric cases, differentiating between juvenile myasthenia gravis and congenital myasthenic syndromes can be challenging and requires comprehensive clinical and laboratory evaluation.

Objetivo

To describe the clinical, laboratory, electrophysiological and therapeutic characteristics of patients with pediatric autoimmune and congenital myasthenia followed at a pediatric neurology referral center.

Método

A retrospective, cross-sectional, non-interventional study analyzed the medical records of patients diagnosed with autoimmune and congenital myasthenia at pediatric neuroimmunology and neuromuscular diseases clinics from January of 2010 to November of 2023.

Resultados

Preliminary evaluation included 86 patients, 60% of whom were female. 38% were diagnosed with myasthenia gravis (MG) and 62% with congenital myasthenia (CM). MG: Symptoms started between 0 and 13 years (mean 6.8 years). Ankle dorsiflexion weakness was noted in 1 case. Ptosis was observed in 30 cases, 9 of which with symmetrical presentation. Extraocular muscle involvement was seen in 21 cases, and fatigability in 24. Fluctuating weakness was present in 26 cases. Palate and facial muscles were not affected. A myasthenic crisis occurred in 10 patients. Current disability was mild in 7 patients. Anti-AChR autoantibodies were present in 21 patients, and an electromyographic (EMG) study showed more than 10% of decrement in 6 of 18 cases. Pyridostigmine was used in 30 patients with a positive response. Thymectomy was performed in 14 patients, with 9 showing improvement. CM: Symptoms began between 0 and 14 years (mean 1.4 years). Ankle dorsiflexion weakness was present in 18 patients. Ptosis was found in 43 cases, 16 symmetrically. Extraocular muscle involvement occurred in 37 cases, with 16 having persistent symptoms and 2 fluctuating. Fatigability was observed in 32 patients and fluctuating weakness in 29. Palate and facial muscles were generally unaffected. A myasthenic crisis occurred in 2 cases. Current disability was mild in 5 and important in 7 patients. EMG showed more than 10% of decrement in 16 cases. Pyridostigmine was administered to 48 patients, with positive response in 41.

Conclusão

This study offers a detailed overview of the clinical aspects of a pediatric population with myasthenic syndromes. Accurate differentiation between autoimmune and congenital forms is crucial for effective treatment.

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Palavras Chave

MYASTHENIC SYNDROMES; myasthenia gravis; Congenital myasthenia