Therapy will take place over six weeks and long-term assessment of safety will be performed twice yearly for up to 2 years.
Pre-Therapy: During the first six weeks, participants will undergo consent, assessment, surgical implantation, and group assignment. Participants must wait a minimum of two weeks after surgery to start rehabilitation.
Phase 1: The Immediate Start VNS group will receive rehabilitation and active stimulation for 18 in-office sessions over the course of approximately 6 weeks. The Delayed Start VNS group will receive equivalent rehabilitation with placebo stimulation. Assignments for placebo or active stimulation in Phase 1 are random. An assessment will be performed approximately one week after the completion of the 18 sessions of rehabilitation.
Phase 2: Subjects who do not exit the study at the end of Phase 1 will participate in an open-label extension consisting of an additional 18 sessions of in-office rehabilitation with active VNS over the course of approximately 6 weeks. All participants will receive active stimulation. Participants will be assessed approximately 1 week after the conclusion of the additional 18 sessions of therapy.
Long-term Follow Up: Safety will be assessed in all participants, regardless of whether they elect to exit after Phase 1 or continue into the Phase 2 open-label extension, twice per year for up to 2 years after the date of the implant. Participants will have the option to leave the device implanted, and participants may be offered the opportunity to participate in a follow-on study during this period. Aside from participation in a follow-on study, there is no plan to stimulate during this period. Safety assessments will only report on the presence of the implanted device and/or participant status during this period. Participants who experience a serious device-related adverse event will be removed from the identified risk but will continue to be monitored for 2 years or longer if the event has not been resolved.