Long-term outcome of vagus nerve stimulation for refractory partial epilepsy.

We assessed 1- and 2-year outcomes of specific seizure types, quality of life, depression, and anxiety among patients treated with vagus nerve stimulation (VNS) for refractory partial epilepsy. Patients completed a seizure questionnaire, the Quality of Life in Epilepsy-89 (QOLIE-89) questionnaire, the Beck Anxiety Inventory (BAI), and the Beck Depression Inventory (BDI) at baseline and 1 year, and 2 years after activation of VNS. VNS was associated with >or=50% reduction in total seizure frequency in 54% of patients at 1 year and 61% of patients 2 years post-VNS activation compared with baseline. No statistically significant changes from baseline to 12 or 24 months were found in mean quality of life, depression, or anxiety measures in the overall study population. Patients with at least 50% reduction in seizures had significant improvement in anxiety at 12 and 24 months compared with patients who did not have the same degree of seizure reduction.