Safe administration of botulinum neurotoxin type A for facial nerve palsy sequelae in a patient with myasthenia gravis.

Botulinum neurotoxin type A (BoNT-A) is an effective treatment for facial nerve palsy sequelae; however, its use in patients with myasthenia gravis (MG) is generally contraindicated due to the risk of exacerbating neuromuscular blockade. We report a female in her 40 s with a 10-year history of generalized, seronegative MG who presented with facial tightness and mild synkinesis due to facial nerve palsy sequelae. As BoNT-A is contraindicated for MG patients in Japan, we obtained approval for off-label use from the Division of Patient Safety Management in our hospital. Under a predefined risk management protocol established to meet the approval conditions, a reduced dose of BoNT-A (3 units) was administered to the affected side. Safety measures included pre- and post-injection vital sign monitoring, frequent follow-ups, and advance information sharing with the on-call otolaryngologists. The patient experienced no respiratory failure or systemic MG exacerbation. At 2 months post-injection, objective grading (Sunnybrook Facial Grading System) and patient-reported outcomes (Facial Clinimetric Evaluation scale) demonstrated sustained improvement, particularly in facial tightness and psychological well-being. This case supports the cautious use of BoNT-A for facial palsy sequelae in patients with underlying MG when a predefined risk management protocol and low-dose strategy are employed.