Work

Effects of VNS paired with rehabilitation for chronic upper limb recovery post stroke: cross-over response

Year: 2021

Type: article

Abstract: Long-term loss of arm function is a common outcome after stroke. Vagus Nerve Stimulation (VNS) in conjunction with intense rehabilitation is a promising intervention that may reduce arm impairment after chronic stroke. The VNS-Rehab trial was a randomized, triple-blinded, sham-controlled study with 108 participants at 19 sites. All participants were implanted at the start of the study and randomized to Active-VNS (n=53) or Sham-VNS (n=55) paired with rehabilitation. Participants received 6 weeks of in-clinic therapy followed by 3 months of home therapy paired with Sham- or Active-VNS. At the end of the randomized phase, participants in the Active-VNS group showed a significant and clinically meaningful improvement in arm impairment (Upper Extremity Fugl-Meyer Assessment: FMA-UE ≥ 6 points) compared to the Sham-VNS group. At the end of the randomized phase, participants, therapists, and assessors were unblinded. The Sham-VNS group then crossed over to receive 6 weeks of in-clinic Active-VNS (n=49) followed by 3 months of home-based Active-VNS (n=43). We report the results of the Sham-VNS/Crossover group here. Following the Sham-VNS phase, FMA-UE score increased from [mean (SD)] 35.65 (7.98) at baseline to 38.71 (9.71)(n=49, p<0.001). After in-clinic, Active-VNS FMA-UE further increased to 41.52 (9.67)(n=49, p<0.001), and maintained at 40.86 (10.42) in the 43 people that completed the 90-day follow-up at 3-months (post Active-VNS home exercise program) (p<0.001). 24% of participants showed a clinically meaningful response after Sham-VNS which increased to 44% after receiving Active-VNS in the cross-over phase. There were no related adverse or serious adverse events reported due to the Sham- or Active-VNS. Participants initially receiving Sham-VNS with rehabilitation demonstrated additional improvement in arm impairment after receiving Active-VNS. In summary, VNS may be a promising novel intervention strategy that can help mitigate arm impairment after chronic stroke. Keywords: rehabilitation, VNS, stroke, clinical trial

Source: Brain stimulation

DOI: 10.1016/j.brs.2021.10.419