Functional MRI and DTI Analysis of Post VNS Therapy Rehab Changes

All subjects will undergo 2 fMRI sessions. Each of these sessions will span two days, and subjects will spend 15 minutes in the MRI each day. fMRI tasks will consist of subjects grasping and releasing a handgrip. The control arm subjects will be offered a third fMRI session after unblinding and therapy with activation of the VNS.