Pyridostigmine for Reversal of Severe Sequelae From Botulinum Toxin Injection

Objective. Botulinum toxin is used to treat a wide range of dystonias in the head and neck. Occasionally, patients receiving laryngeal botulinum toxin experience severe dysphagia, dyspnea, or even distant and autonomic symptoms. Rarely, these patients may require hospitalization with possible intubation and placement of nasogastric tubes. Botulinum antitoxin is not readily available and ineffective once symptoms have progressed, so patients must wait until the toxin wears off over weeks to months. Pyridostigmine prevents the breakdown of acetylcholine at the neuromuscular junction, thus making more neurotransmitter available for the muscles. Study Design. A retrospective case study of patients receiving botulinum toxin for dystonia in the head and neck from 1998 to 2012 who experienced adverse effects that were successfully treated with pyridostigmine. Methods. Twenty cases were selected and reviewed to demonstrate how pyridostigmine was used to modulate severe dysphagia, breathiness, dyspnea, and some distant/autonomic symptoms. Results. Pyridostigmine was well tolerated and resulted in significant symptom improvement. Only one significant adverse effect, bradycardia, occurred in a patient with severe cardiac disease. Conclusions. Given the safety and efficacy of this medication, pyridostigmine should be considered to modulate severe sequelae of botulinum toxin in select patients when conservative management is deemed insufficient. Also, physicians should be aware that patient complaints of symptoms at distant sites and temporally delayed from the injection may be a result of the botulinum toxin and relieved with pyridostigmine.