AChR+ Ocular Myasthenia and Facial Hemispasm: A Case Report of Unusual Association and Botulinum Toxic Type A Safety and Efficacy.

Introduction: Hemifacial spasm represents segmental myoclonus of muscles innervated by the facial nerve, which is usually and successfully treated with botulinum toxin. Botulinum toxin (BTX) acts as an acetylcholine release inhibitor at presynaptic cholinergic junctions and therefore is considered contraindicated (or administrable with caution) in patients with neuromuscular disorders like Myasthenia Gravis (MG). Moreover, to date, the association of hemifacial spasm and ocular MG is extremely rare and only a few cases have been described.

Case presentation: We report the case of a 73 years old man with a 3-year history of ocular MG who developed a left hemifacial spasm. The patient underwent hemispasm, treatment with BTX type A (abobotulinum toxin-A, total dose of 50 IU) that resulted in safe and successful 6 months re-evaluation.

Conclusion: Our results suggest that in selected cases with concomitant MG and conditions characterized by orbicularis oculi spasms or hemispasm, BTX therapy may not be contraindicated and could be given at longer intervals due to prolonged effects.