Abstracts

Rationale: Vagus nerve stimulation (VNS) is an effective method (with ≥ 50% of seizures reduction) for patients with refractory epilepsy that are not suitable candidates for resective surgery. We aim to evaluate its additional benefit for reducing the need of medical assistance in these patients. Methods: Retrospective study of adult epilepsy patients implanted with VNS and ≥ 1 year follow up. We evaluated number of days of hospitalization, number of emergency department attendances and number of consultations regarding their epilepsy, comparing every year after surgery, up to four years, with the year prior to the intervention. Results: We included 44 patients (55% women) aged 40 [30, 51] years old and a median time of evolution of epilepsy of 25 [17, 37] years. 52% had > 20 seizures/month. Good response to VNS was achieved in 44% (n = 44, 1 year), 51% (n = 41, 2 years), 53% (n = 34, 3 years) and 52% (n = 29; 4 years) of patients. Days of hospitalization (preVNS= 5.66 ± 15.80) decreased at 1 year (1.42 ± 9.15, p=0.03), 2 years (0.02 ± 0.16, p=0.01), 3 years (0.76 ± 3.48, p=0.008) and 4 years (1.00 ± 3.18, p=0.03). Attendances to the emergency room were also reduced from 0.86 ± 1.37 days (prior to VNS) to 0.44 ± 0.76 (1 year, p=0.076), 0.32 ± 0.65 (2 years, p=0.005), 0.24 ± 0.61 (3 years, p=0.005) and 0.24 ± 0.61 (4 years, p=0.02). Follow-up visits initially increased from 5.39 ± 2.29 (preVNS) visits to 5.95 ± 2.03 (1 year, p=0.166) and 4.51 ± 1.79 (2 years, p=0.158) and then reduced to 4.9 ± 1.97 (3 years, p=0.008) and 3.93 ± 1.62 (4 years, p=0.004). Conclusions: VNS increases its efficacy over time and it reduces the need for urgent care and hospitalization days in patients with refractory epilepsy.