Management of vagus nerve stimulation–related complications in drug resistant epilepsy: a system-based review

• Epilepsy is one of the most common chronic neurological disorders, affecting approximately 1–3 % of the global population and representing a major cause of long-term neurological morbidity worldwide. • Vagus nerve stimulation (VNS) is an established adjunctive therapy for drug-resistant epilepsy (DRE). • While generally safe, stimulation of the cervical vagus nerve may be associated with adverse events involving multiple organ systems, necessitating accurate risk contextualisation and patient-centred management. • Stimulation-related airway symptoms including hoarseness, cough, dyspnoea, stridor, and sleep-disordered breathing were the most frequently reported adverse effects and were typically transient or reversible through adjustment of output current, pulse width, duty cycle, or temporary magnet-controlled suspension. • VNS provides meaningful seizure reduction for a substantial proportion of patients with DRE. Optimal long-term outcomes depend on realistic communication of complication risks, careful differentiation between common stimulation-related effects and rare surgical or device failures, and timely, patient-centred adjustment of therapy throughout the device lifespan. Vagus nerve stimulation (VNS) is an established adjunct for drug-resistant epilepsy (DRE), yet its “wandering” effects across organ systems generate a wide range of adverse events. To collate published VNS-related complications and present pragmatic, system-based management guidance. PubMed, Scopus, and Web of Science were searched from inception to 30 June 2025 for human studies reporting surgical, device-related, or stimulation-linked problems after cervical VNS in DRE or treatment-resistant depression. Two reviewers independently screened, extracted, and synthesised data in this narrative review. Airway sequelae—hoarseness, cough, dyspnoea, stridor and sleep apnoea—were the most typical reactions; most resolved after reducing output current, pulse width or duty-cycle, or by magnet-controlled pauses. Device failures comprised lead fracture (up to 11.9 % in paediatric cohorts), generator battery depletion prompting replacement in 15–27 % of long-term users, and infections in 2–6 % of implants. Rare but serious cardiac events—bradycardia or intra-operative asystole (manufacturer estimate 0.1–1 %)—were reversible when stimulation ceased. Isolated neurological, psychiatric, and gastrointestinal events (pain, tremor, mania, intractable hiccups, diarrhoea) were typically mitigated by parameter adjustment or explantation. Roughly half of DRE patients attain ≥50 % seizure reduction with VNS, but durable benefit hinges on vigilant, system-specific surveillance and early tailored interventions. A structured, organ-oriented approach helps multidisciplinary teams balance seizure control, safety, and quality of life throughout the device’s lifespan