Study protocol for a pivotal randomised study assessing vagus nerve stimulation during rehabilitation for improved upper limb motor function after stroke

Background. Transcutaneous auricular vagus nerve stimulation (taVNS) is regarded as a potential method for recovery in stroke. The effectiveness of taVNS in acute and subacute stroke should be further discussed as previously, only a few small-scale trials have focused on chronic stroke patients. The objective of this study is to investigate the effect and safety of taVNS on upper limb motor function in subacute ischemic stroke patients. Methods. Twenty-one subacute ischemia stroke patients with single upper limb motor function impairment were enrolled and randomly assigned to conventional rehabilitation training with real or sham taVNS, delivered for 15 consecutive days. Electrodes were fixed to the cymba conchae of the left ear with or without electrical stimulation. Conventional rehabilitation training was performed immediately after the end of real or sham taVNS by the same therapists. Baseline assessments were performed on day 0 of enrollment, and posttreatment evaluations were performed at 15 days, 4 weeks, and 12 weeks after the first intervention. The assessment included the upper limb Fugl-Meyer assessment (FMA-U), the Wolf motor function test (WMFT), the Functional Independence Measurement (FIM), and Brunnstrom stage. Heart rate (HR) and blood pressure (BP) were measured before and after each taVNS intervention. At the same time, any adverse effects were observed during the procedure. Outcomes were assessed by a blind evaluator. Results. There were no significant differences in FMA-U, WMFT, FIM, and Brunnstrom scores between the two groups at baseline (P>0.05). At the endpoint, the FMA-U, WMFT, and FIM scores were significantly higher than before treatment (P<0.05), and there was a significantly greater improvement of those measurements in taVNS group compared with sham-taVNS group (P<0.05). Significant improvements in FMA-U score were found between groups at follow-up. Only one case of skin redness occurred during the study. Conclusions. This study revealed that taVNS appeared to be beneficial to the recovery of upper limb motor function in subacute ischemia stroke patients without obvious adverse effects. Trial registration. This trial is registered with ChiCTR1800019635 on 20 November 2018 (http://www.chictr.org.cn/showproj.aspx?proj=32961).

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Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Stroke: One-Year Follow-up

Neurorehabilitation and Neural Repair ◽

10.1177/1545968320924361 ◽

2020 ◽

Vol 34 (7) ◽

pp. 609-615

Author(s):

Jesse Dawson ◽

Navzer D. Engineer ◽

Cecília N. Prudente ◽

David Pierce ◽

Gerard Francisco ◽

...

Keyword(s):

Ischemic Stroke ◽

Vagus Nerve ◽

Upper Limb ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Exercise Program ◽

Home Exercise ◽

Home Exercise Program

Background. Vagus nerve stimulation (VNS) paired with rehabilitation may improve upper-limb impairment and function after ischemic stroke. Objective. To report 1-year safety, feasibility, adherence, and outcome data from a home exercise program paired with VNS using long-term follow-up data from a randomized double-blind study of rehabilitation therapy paired with Active VNS (n = 8) or Control VNS (n = 9). Methods. All people were implanted with a VNS device and underwent 6 weeks in clinic therapy with Control or Active VNS followed by home exercises through day 90. Thereafter, participants and investigators were unblinded. The Control VNS group then received 6 weeks in-clinic Active VNS (Cross-VNS group). All participants then performed an individualized home exercise program with self-administered Active VNS. Data from this phase are reported here. Outcome measures were Fugl-Meyer Assessment—Upper Extremity (FMA-UE), Wolf Motor Function Test (Functional and Time), Box and Block Test, Nine-Hole Peg Test, Stroke Impact Scale, and Motor Activity Log. Results. There were no VNS treatment–related serious adverse events during the long-term therapy. Two participants discontinued prior to receiving the full crossover VNS. On average, participants performed 200 ± 63 home therapy sessions, representing device use on 57.4% of home exercise days available for each participant. Pooled analysis revealed that 1 year after randomization, the FMA-UE score increased by 9.2 points (95% CI = 4.7 to 13.7; P = .001; n = 15). Other functional measures were also improved at 1 year. Conclusions. VNS combined with rehabilitation is feasible, with good long-term adherence, and may improve arm function after ischemic stroke.

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Effect of vagus nerve stimulation paired with rehabilitation for upper limb function improvement after stroke

International Journal of Rehabilitation Research ◽

10.1097/mrr.0000000000000509 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Kehong Zhao ◽

Jiaen Yang ◽

Jiapeng Huang ◽

Ziqi Zhao ◽

Yun Qu

Keyword(s):

Vagus Nerve ◽

Upper Limb ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Limb Function ◽

Upper Limb Function

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Vagus Nerve Stimulation as a Potential Adjuvant to Rehabilitation for Post-stroke Motor Speech Disorders

Frontiers in Neuroscience ◽

10.3389/fnins.2021.715928 ◽

2021 ◽

Vol 15 ◽

Author(s):

Robert A. Morrison ◽

Seth A. Hays ◽

Michael P. Kilgard

Keyword(s):

Synaptic Plasticity ◽

Vagus Nerve ◽

Upper Limb ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Speech Therapy ◽

Speech Disorders ◽

Motor Speech ◽

Motor Speech Disorders ◽

Post Stroke

Stroke often leaves lasting impairments affecting orofacial function. While speech therapy is able to enhance function after stroke, many patients see only modest improvements after treatment. This partial restoration of function after rehabilitation suggests that there is a need for further intervention. Rehabilitative strategies that augment the effects of traditional speech therapy hold promise to yield greater efficacy and reduce disability associated with motor speech disorders. Recent studies demonstrate that brief bursts of vagus nerve stimulation (VNS) can facilitate the benefits of rehabilitative interventions. VNS paired with upper limb rehabilitation enhances recovery of upper limb function in patients with chronic stroke. Animal studies reveal that these improvements are driven by VNS-dependent synaptic plasticity in motor networks. Moreover, preclinical evidence demonstrates that a similar strategy of pairing VNS can promote synaptic reorganization in orofacial networks. Building on these findings, we postulate that VNS-directed orofacial plasticity could target post-stroke motor speech disorders. Here, we outline the rationale for pairing VNS with traditional speech therapy to enhance recovery in the context of stroke of speech motor function. We also explore similar treatments that aim to enhance synaptic plasticity during speech therapy, and how VNS differs from these existing therapeutic strategies. Based on this evidence, we posit that VNS-paired speech therapy shows promise as a means of enhancing recovery after post-stroke motor speech disorders. Continued development is necessary to comprehensively establish and optimize this approach, which has the potential to increase quality of life for the many individuals suffering with these common impairments.

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