Functional MRI and DTI Analysis of Post VNS Therapy Rehab Changes
Condition: Stroke Hemorrhagic
MeSH terms: Hemorrhagic Stroke
Study type: Interventional

Summary: 
      The purpose of performing magnetic resonance imaging (MRI) scans on patients undergoing
      stroke rehabilitation therapy in conjunction with vagal nerve stimulators (VNS) is to
      determine if the patients clinical improvement correlates to changes that can be identified
      on MRI of the brain such as degree of blood oxygen level dependent (BOLD) signal, changes in
      resting state connectivity, and corticospinal tract fiber density.

      Subjects will be randomized at implant surgery to either the device treatment (rehabilitation
      and VNS) or control (rehabilitation and Control VNS) groups. All participants of this study
      are also participants of the STU 062017-071 study and chose to participate in this functional
      magnetic resonance imaging (fMRI) sub-study. Rehabilitation is standard of care.

      Both experimental groups and control groups will receive pre-rehabilitation and
      post-rehabilitation fMRI and diffusion tensor imaging (DTI) scans to quantify their white
      matter track density. We will analyze this data using the University of Texas Southwestern
      (UTSW) Advanced Neuroscience Imaging Research (ANSIR) pipeline which can automatically
      quantify white matter track density on both sides of the brain given the appropriate scans.
      In this study the VNS device specifically will not be studied. Rather we will be looking at
      the changes that occur in the brain as a result of using the VNS device during physical
      rehabilitation.

      Once the post-rehabilitation scans are completed the patients in the control group will be
      given the opportunity to crossover into the experimental group and receive physical
      rehabilitation with the VNS implant turned on. They will have a third MRI session after their
      round of rehabilitation with the implant turned on in order to quantify their white matter
      tract density.
    

Detailed description: 
      This study will consist of 2-3 fMRI sessions, depending on group assignment, and span 2 days
      for each session. It will be done at a single site only, at UTSW. The fMRI tasks will
      consists of subjects grasping and releasing a handgrip.

      The VNS implant will be used in this study to determine if having the implant active during
      physical rehabilitation produces white matter tract changes in the brain visible on fMRI. All
      subjects in the STU 062017-071 study will receive a VNS implant. And all subjects in this
      study are also subjects of the STU 062017-071 study. Therefore participants of this study
      will enroll with the implant already in place.

      Methods: After passing routine MRI screening, patients who are enrolled in the VNS-REHAB
      study and consent to participate in the fMRI study will be scanned on a Phillips 3 Tesla
      Research Magnet (Ingenia, Philips Healthcare, Best, the Netherlands). Patients will be
      scanned before therapy and the week after therapy. A subset of patients will be scanned 3
      times, before therapy, after therapy without activation of the vagal nerve stimulator, and
      after therapy with activation of the vagal nerve stimulator.

      Scan Time:

      Scan time is limited to 15 minutes per session to match manufacture FDA guidelines. Patients
      will receive two, 15 minute MRI scans over 2 days.
    

Intervention name(s): fMRI
Intervention type(s): Procedure
Intervention description(s): 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Double blind, randomized, parallel study with partial crossover (control subjects crossover to treatment after randomized portion)
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Diagnostic
Keywords: vagal nerve stimulator; MRI; functional MRI