Treatment of spastic dysphonia without nerve section

Spastic dysphonia is a disorder characterized by strained, constricted phonation with excessively adducted vocal cords. Despite initial success with recurrent laryngeal nerve section, the search for other treatment continues. Our clinical study involved inserting a needle electrode percutaneously into the region of the recurrent laryngeal nerve in five patients with spastic dysphonia. Electrical stimulation resulted in dramatic improvement in three patients and minimal improvement in two. Our experimental study was designed to create an animal model for an implantable nerve stimulator to be used on a long-term basis. A Medtronic spinal cord stimulation system was implanted into a dog, and a cuff electrode was positioned around the recurrent laryngeal nerve. Vocal cord position could be altered by varying the stimulus frequency. Long-term stimulation of the recurrent laryngeal nerve was relatively safe and effective. Eventually, we plan to implant nerve stimulators into spastic dysphonia patients who respond well to percutaneous stimulation.