Neuromyotonia in a 16-year-old female with dramatic improvement after IVIG therapy: Case report and literature review.

Neuromyotonia, also known as Isaac syndrome, is a rare neurological disorder characterized by continuous muscle activity, stiffness, and spontaneous muscle contractions, it is very rare in children. We report a 16-year-old female patient with neuromyotonia. She presented with pain, stiffness, autonomic symptoms and muscle myokymia in both lower limbs. The patient was treated with a short course of methylprednisolone, IVIG over the course of 4 weeks, and symptomatic management which resulted in a dramatic improvement and relief of symptoms. A literature review for pediatric patients with neuromyotonia was conducted revealing 10 reported cases so far. All pediatric patients with neuromyotonia showed favorable prognosis despite using different treatment modalities. Although the association between neuromyotonia and malignancy is known in adult population, this has not been seen in the reported pediatric cases. Indeed, given the scarcity of data, we still do recommend screening for malignancy in pediatric patients with neuromyotonia.