Clinical management of voice and breathing problems in two patients with vagus nerve stimulation therapy

We report two cases highlighting the diversity of vagal nerve stimulation (VNS)-related effects on voice and breathing in patients with refractory epilepsy. The patients had both implantation and stimulation-related side effects, which lasted for several months, impacting on their quality of life. The adverse effects appear to be due to recurrent laryngeal nerve paralysis-related vocal cord hypofunction and stimulation-related vocal fold spasms, however, their inter-relationship is complex. In one of the patients, we were able to utilize the novel programming capabilities of the VNS device to reduce the laryngeal side effects without compromising therapeutic efficacy. [Published with video sequences].