Myasthenia Gravis Attack after Oral Risperidone Treatment: A Case Report

Area of Science:

• Pediatric Neurology
• Clinical Pharmacology
• Autoimmunology

Background:

• Myasthenia gravis (MG) is an autoimmune neuromuscular disease.
• Anticholinergic agents can potentially trigger or exacerbate MG symptoms.
• Comorbid psychiatric conditions in children necessitate careful medication management.

Observation:

• A 6-year-old female with ADHD and conduct disorder presented with fatigue and ptosis after initiating short-acting methylphenidate and risperidone.
• Ocular myasthenia gravis was suspected, and pyridostigmine treatment led to symptom resolution.
• Discontinuation of risperidone and subsequent re-initiation of long-acting methylphenidate did not result in MG symptom recurrence.

Findings:

• The Naranjo scale suggested a possible association between risperidone use and the development of myasthenia gravis symptoms.
• The patient's MG symptoms improved upon withdrawal of risperidone.
• Long-acting methylphenidate treatment did not trigger a relapse of MG.

Implications:

• This case highlights the potential for certain psychotropic medications, specifically risperidone, to induce or unmask autoimmune conditions like MG in pediatric patients.
• Clinicians should consider drug-induced autoimmune syndromes in the differential diagnosis of new-onset neuromuscular symptoms in children on psychotropic medications.
• Further research is warranted to explore the immunomodulatory effects of risperidone and its potential role in pediatric autoimmune diseases.