Vagus nerve stimulation shows unprecedented recovery rates in spinal cord injuries

The unprecedented results position the UT Dallas scientists to proceed with a pivotal trial - the final hurdle on the road to potential Food and Drug Administration (FDA) approval of vagus nerve stimulation for treatment of upper-limb impairment due to spinal cord injury.

The trial involved 19 participants with chronic, incomplete cervical spinal cord injury. Each person performed 12 weeks of therapy, playing simple video games to trigger specific upper-limb movements. The implant was activated upon successful movements, resulting in significant benefits for arm and hand strength.

The study served as both a Phase 1 and Phase 2 clinical trial and included randomized placebo control in its first phase, in which nine of the 19 participants received sham stimulation rather than active treatment during the first 18 therapy sessions, then received CLV in the latter 18 sessions.

The participants ranged in age from 21 to 65 and were from one to 45 years post-injury. Neither of those factors, nor the severity of the impairment in those with any hand movement, influenced the degree of response to treatment.

"It is remarkable from a medical standpoint," said Wigginton, who planned the clinical interactions and patient protections for the trial.

Wigginton said the latest results are especially exciting because they help people for whom there is no existing solution.

"The people in this study have now gained the ability to do things that are meaningful for them and impactful in their lives."

The newest generation of the implantable CLV device, designed by Rennaker, is approximately 50 times smaller than their version from three years ago. It does not prevent patients from receiving MRIs, CT scans or ultrasounds.

A Phase 3 pivotal trial will include 70 participants at multiple U.S. institutions that specialize in spinal cord injury.

"Prior to this study, no person with spinal cord injury had ever received CLV," he said. "This is the first evidence that gains can be made. Now we will set about determining how we make this optimally effective."

Hays cautioned that it is not a foregone conclusion that the therapy will make it to patients after the next trial.

"We still have a long road ahead. For many reasons - financial, regulatory or scientific - this could still die on the vine," he said. "But we have positioned ourselves to succeed."

The research team emphasized the importance of the dozens of people involved in the work - both the patients and TxBDC's partners at Baylor University Medical Center, Baylor Scott & White Research Institute and Baylor Scott & White Institute for Rehabilitation.

"This has been the hardest working, most altruistic group of professionals, and that has been incredibly impactful," Wigginton said.

Noting that even outpatient surgery is complex for those with impaired mobility, Rennaker added, "These patients said, 'Put that device in me' - that's a huge commitment. They deserve credit for paving the path for others."

Kilgard has a financial interest in MicroTransponder Inc., which markets vagus nerve stimulation therapy for stroke. Rennaker is the founder and CEO of XNerve, which developed the device used in this study.

Source:

University of Texas at Dallas

Journal reference: