Botulinum Toxin Injection in Acute Sixth Nerve Palsy in a 1-Year-Old Child: Case Report, Management Strategy, and Review of Literature.

Abstract

Sixth nerve palsy in children is a rare yet clinically significant condition that can result in strabismus and developmental complications. The acute onset of sixth nerve palsy can lead to esotropia, a sudden inward deviation of the eye due to impaired abduction. While most cases resolve spontaneously, botulinum toxin injection is gaining ground as a therapeutic intervention, particularly in pediatric patients with persistent or severe misalignment.

Objective: To evaluate the effectiveness of botulinum toxin injection in managing acute sixth nerve palsy in a 1-year-old child with esotropia. The therapeutic outcomes and a review of current evidence are discussed, focusing on the efficacy, safety, and timing of botulinum toxin therapy in pediatric sixth nerve palsy. Methods: We report the case of a 1-year-old child diagnosed with acute sixth nerve palsy and treated with botulinum toxin injection to the medial rectus muscle. Follow-up assessments were conducted at 1 week, 3 weeks, and 8 weeks to monitor ocular alignment and visual development. Results: At the one-week follow-up, esotropia decreased from 50 to 20 prism diopters, with moderate upper eyelid ptosis. At eight weeks, ocular alignment was normal, with mild residual ptosis and improvement in amblyopia.

Discussion: Sixth nerve palsy in children is uncommon but can arise from various underlying causes. In most cases, it resolves within a few months, but in severe or persistent cases, therapeutic interventions such as botulinum toxin injections can alleviate symptoms. The clinical case highlights that early intervention with botulinum toxin is a safe and effective method for improving ocular alignment.

Conclusion: Botulinum toxin injection effectively improved ocular alignment and facilitated amblyopia recovery in this pediatric case of sixth nerve palsy, supporting its use as a safe adjunctive treatment in early intervention.