Late onset laryngeal and facial pain in previously asymptomatic vagus nerve stimulation patients

Abstract

Early common side effects following vagus nerve stimulator (VNS) implantation include voice alteration, throat pain, cough, dyspnea, headache, vomiting, and parasthesias.1 We report two patients with delayed VNS side effects that occurred with previously well-tolerated VNS parameter settings. Patient 1 is an 8-year-old girl with tuberous sclerosis and medically refractory seizures. She had multiple seizure types with a frequency of 15 to 30 seizures per day. A VNS stimulator was implanted. No aberrant nerve branches were noted by the neurosurgeon. Intraoperative testing documented a DC Conversion Code of 0. The VNS settings were gradually increased until, at 9 months after implantation, the VNS settings were programmed to 1.25-mA, 30-Hz, 500-μsec, 30-sec on, 5-minute off. Seizure frequency decreased to 5 to 6 per day. The patient tolerated this setting without signs of discomfort. This nonverbal patient began demonstrating signs of pain in her left cheek 2 months after …