A case of acute pulmonary complication due to botulinum toxin: Patient with central pontine myelinolysis developed acute respiratory distress syndrome after botulinum neurotoxin type A injection into spastic lower extremity muscles.

Chemodenervation with botulinum neurotoxin type A (BoNTA) is the preferred method for focal spasticity management among various treatment options. While BoNTA injection is considered safe, its widespread use and increasing evidence raise safety concerns. In this paper, we present a patient with central pontine myelinolysis, a rare disease, who developed acute respiratory distress syndrome on the third day after BoNTA application to the spastic gastrocnemius muscle group and required intubation in the intensive care unit due to this complication. To our knowledge, this is the first case reported in the literature to develop an acute pulmonary complication after BoNTA injection into spastic lower extremity muscles.