Airway compromise secondary to vagus nerve stimulator: case report and implications for otolaryngologists

Vagus nerve stimulation: a pre-hospital case report

Introduction:

Vagus nerve stimulation (VNS) is an adjunct therapy to anti-epileptics in patients where combination drug therapy alone has failed. The VNS device resembles an implantable defibrillator, and can be found underneath the clavicle on either side of the chest. By using a strong ring magnet, the device can be manipulated to seize function or operate on higher intensities, depending on how it is applied. The use of vagal stimulation is increasingly common and VNS is being explored for a range of other medical complaints.

Case:

This case study discusses the encounter between a paramedic and a woman presenting with a choking sensation, isolated uvular deviation and stable cardiorespiratory functions. Following a short period of observation without adverse events, she was discharged on scene and advised to see her specialist epilepsy nurse.

Conclusion:

Side effects of VNS increase with intensity of stimulation and can manifest throughout any branch of the vagus nerve. Its therapeutic mechanism of action is yet to be fully understood. The symptoms of over-stimulation are often frightening but benign, and although life-threatening events are rare, they require rapid recognition and immediate intervention.

Airway obstruction during general anaesthesia in a patient with a vagal nerve stimulator

For patients with epilepsy refractory to medical management, vagal nerve stimulator implantation may reduce the number of seizures and/or reduce their severity. A 34-year-old woman with epilepsy underwent a change in vagal nerve stimulator battery under general anaesthesia with a supraglottic airway device and total intravenous anaesthesia. During the procedure, she developed clinically significant airway obstruction, which resolved only when the device was disabled. We recommend that anaesthetists and others providing peri-operative care for patients with a vagal nerve stimulator remain vigilant to the possibility of device-related airway obstruction, which may occur even in asymptomatic patients. All patients with a vagal nerve stimulator are provided with a magnet that will disable the device, should complications arise. There is a need to establish a standard approach to the peri-operative care of these patients, including the identification and management of device-related airway obstruction.

Case of Vagal Nerve Stimulator-Induced Stridor After Anterior Cervical Diskectomy and Fusion-Induced Vocal Cord Paralysis

BACKGROUND

Vagal nerve stimulation is a generally safe adjunctive treatment for medically refractory epilepsy. Nevertheless, reports of vocal cord dysfunction during stimulation can be found in the literature. When vagal nerve stimulation-induced vocal cord dysfunction is compounded with contralateral dysfunction, such as that which can occur after anterior cervical diskectomy and fusion, serious pulmonary complications can occur.

CASE DESCRIPTION

A 56-year-old female presented to the emergency department 3 weeks postoperatively from a cervical 7-thoracic 2 anterior cervical diskectomy and fusion through a right-sided approach with new-onset, intermittent stridor. Otorhinolaryngology conducted a fiberoptic laryngoscopy and determined that the patient had a right vocal cord paralysis and intermittent left vocal cord paresis that coincided with activation of the patient's vagal nerve stimulator. The stimulator was shut off, and the patient's stridor disappeared.

CONCLUSIONS

Vagal nerve stimulation-induced vocal cord paralysis is a rare but known complication. Given this potential for vocal cord dysfunction, neurosurgeons should plan further anterior cervical diskectomy and fusions accordingly to ensure that patients do not develop dysfunction of bilateral vocal cords. Should this develop, however, cessation of vagal nerve stimulation can improve or treat the pulmonologic complication that develops.

The role of voice therapy in the treatment of dyspnea and dysphonia in a patient with a vagal nerve stimulation device

Vagal nerve stimulators (VNS) are implanted to treat medically refractory epilepsy and depression. The VNS stimulates the vagus nerve in the left neck. Laryngeal side effects are common and include dysphagia, dysphonia, and dyspnea. The current case study represents a patient with severe dyspnea and dysphonia, persisting even with VNS deactivation. The case demonstrates the use of voice and respiratory retraining therapy for the treatment of VNS-induced dysphonia and dyspnea. It also highlights the importance of a multidisciplinary approach, including laryngology, neurology, and speech-language pathology, in the treatment of these challenging patients.