
In the Neuroscience Letters study published in 2014, the authors compared two groups of people with refractory epilepsy: a group where people responded to VNS versus one a group where people did not respond to VNS.
In the Epilepsy & Behavior study published in 2017, the authors analyzed metrics related to quality of life in people who had the VNS implanted for refractory epilepsy. Physicians subjectively assessed outcomes like