Microtransponder has announced the publication of new findings in the journal Stroke validating the beneficial long-term outcomes of paired vagus nerve stimulation (VNS) therapy via its Vivistim system for chronic stroke recovery. The findings demonstrate that stroke survivors treated with paired VNS for upper-extremity deficits post-stroke had improvements in symptoms of motor impairment, as well as activity, participation in daily life and quality of life, for at least one year after completing therapy.
‘Long-term outcomes of vagus nerve stimulation paired with upper-extremity rehabilitation after stroke’, as published in Stroke, is a long-term analysis of VNS-REHAB—a pivotal, multicentre, triple-blinded randomised controlled clinical trial previously published in The Lancet that served as the basis for US Food and Drug Administration (FDA) premarket approval of the Vivistim paired VNS system in 2021.
One year after completing paired VNS therapy alongside post-stroke upper-extremity rehabilitation, participants maintained significant and clinically meaningful improvements in motor impairment and functional activity as measured by the Fugl-Meyer assessment—upper extremity (FMA-UE) and the Wolf motor function test (WMFT). Average improvements from baseline were 5.23 and 0.5, respectively. Microtransponder also notes in a press release that 66.2% of 74 participants responded positively to paired VNS therapy.
Additional patient-reported outcomes demonstrated improvements in activity, participation in daily life and quality of life across multiple validated measures, including motor activity log; stroke impact scale—activities of daily living; stroke impact scale—hand; stroke-specific quality-of-life scale; and overall health-related quality of life (EQ-5D).
“These long-term clinical and quality-of-life outcomes of paired VNS therapy are particularly notable because sustained, comprehensive benefits are rarely shown in chronic stroke recovery,” said Teresa Jacobson Kimberley (Massachusetts General Hospital [MGH] Institute of Health Professions, Boston, USA), the lead researcher on the study. “Most stroke survivors need improved hand and arm function because it is essential for nearly every task in daily life, and Vivistim may be the boost that helps get them there.”
Microtransponder’s press release states that, in current clinical practice, the Vivistim device is implanted in stroke survivors, enabling therapists to use a wireless remote that communicates with the device to pair VNS with high-repetition, goal-oriented functional activities to increase neuroplasticity. The standard protocol is for stroke survivors to participate in in-clinic Vivistim therapy during 90-minute sessions three times per week for six weeks. In-clinic paired VNS therapy is complemented by self-initiated Vivistim therapy, which allows stroke survivors to swipe a magnet across the implant to activate VNS while doing daily activities at home or in the community.
The company further claims that this one-year study analysis demonstrates that self-initiated paired VNS therapy may facilitate the continued refinement and consolidation of behaviourally relevant activities, resulting in long-term, persistent improvements.
“The growing clinical and real-world evidence supporting Vivistim emphasises that stroke recovery needs to extend beyond acute intervention. While patients who have lost mobility in their hands and arms following ischaemic stroke have previously been limited in their treatment options, the Vivistim paired VNS therapy is a breakthrough intervention in establishing a new standard in the stroke continuum of care,” said Richard Foust, Microtransponder’s chief executive officer (CEO). “With these data, healthcare professionals—including neurologists, physiatrists, neurosurgeons, occupational therapists and physical therapists—can confidently pursue Vivistim therapy as an evidence-based, clinically proven intervention for ischaemic stroke survivors who are six months or more post-stroke.”
The pivotal VNS-REHAB trial was conducted between October 2017 and June 2022. Researchers note that some therapy and assessments occurred during the COVID-19 pandemic, but improvements were sustained in spite of the potentially unfavourable impact the pandemic may have had on participants’ lives. Sex, age, side of stroke, and time since stroke, did not significantly impact FMA-UE or WMFT outcomes, and no long-term serious adverse events related to therapy or stimulation were reported.
