Vocal cord paralysis after vagus nerve stimulator battery replacement successfully treated with medialization thyroplasty.

The vagus nerve stimulator (VNS) has been used effectively for partial seizure disorders, however many patients suffer from side effects of alterations in voice. This case describes a new remediable adverse effect of the VNS. A patient with medically intractable epilepsy had improvement of his seizure control with VNS therapy after titrating him to a high output and rapid cycling paradigm with essentially no side effects. After a battery replacement, he was restarted on his previous settings and subsequently developed a hoarse voice. He was found to have complete left vocal cord paralysis, an adverse effect attributed to a rapid titration to his previous high output and rapid cycling paradigm. This side effect has not been previously described in the literature. The patient subsequently had a medialization thyroplasty with resolution of his hoarse voice.