Vagus nerve stimulation for epilepsy activates the vocal folds maximally at therapeutic levels

Repeated assessment of larynx compound muscle action potentials using a self-sizing cuff electrode around the vagus nerve in experimental rats

“…The shape was identical, but longer latencies and higher amplitudes were reported (Ardesch et al, 2010). Activation of the larynx in humans was obtained by applying a VNS pulse of 0.5 mA and 130 s, while in our experiments maximal muscle activation was already reached at approximately 65 A and 100 s.…”

“…During the second part of this study a new self-sizing cuff electrode for combined stimulation and recording was designed and used to record VNS-induced LCAMP on a daily basis and for several weeks after implantation of the stimulation electrode. In humans, intraoperative VNS-induced LCAMP was described (Ardesch et al, 2010), but no studies, animal nor human, report chronic LCAMP recordings.…”

Lead breakage and vocal cord paralysis following blunt neck trauma in a patient with vagal nerve stimulator

“…Depending on the stimulus parameters, a strong contraction of the left arytenoid and thyroarytenoid muscles occurs resulting in hoarseness which disappears immediately during the rest interval. Ardesch et al noted significant dysfunction of the vocal folds on laryngoscopy, even at the lowest stimulation parameters [14]. These prominent effects on the vocal cords may not result in clinical changes in voice [2].…”

“…This is usually limited to periods of vagal nerve stimulation and typically improves or resolves over time or with decrease in setting parameters [13]. The temporal relationship of VNS stimulation and hoarseness has been well described and is thought to occur as a result of coactivation of the efferent fibers of the recurrent laryngeal nerve [14]. Depending on the stimulus parameters, a strong contraction of the left arytenoid and thyroarytenoid muscles occurs resulting in hoarseness which disappears immediately during the rest interval.…”

Bioinspired Design of Peripheral Nerve Devices

“…85,91 Similarly, differences in the anatomy or sensitivity of the laryngeal nerve may variably impact vocal function. 81,92,93 Biomechanically, scarring and fibrosis are not unexpected, but can compress the nerve or induce tension during neck movement, 94−97 resulting in diminished nerve function. In addition to scar-induced tethering, connecting leads to the stimulator can also exert injurious traction on the nerve, or break outright.…”