PDF: ta-VNS for acute stroke
(2022)Objective
To assess the long-term efficacy and safety of transcutaneous auricular vagus nerve stimulation (ta-VNS) combined with rehabilitation in patients with acute ischemic or hemorrhagic stroke.
Study Summary
• Patients received 4 weeks of rehabilitation paired with either active ta-VNS or sham stimulation and were followed for 1 year.
• The ta-VNS group showed significantly greater improvements in motor function, sensory function, emotional state, and quality of life compared to the control group.
• These benefits were apparent from 2 weeks post-treatment and were sustained for the entire 1-year follow-up. The treatment was safe and well-tolerated.
Intervention
4 weeks of conventional rehabilitation training preceded by either active or sham transcutaneous auricular vagus nerve stimulation (ta-VNS) in patients within 1 month of an ischemic or hemorrhagic stroke. Follow-up was for 1 year.
Study Design
Arms: Array
Outcome
• The ta-VNS group also had significantly better scores on measures of anxiety, depression, and quality of life.
• No major side effects were reported; the treatment was safe and did not cause adverse cardiovascular changes.
Bottom Line
In patients with acute ischemic or hemorrhagic stroke, non-invasive transcutaneous auricular vagus nerve stimulation (ta-VNS) combined with conventional rehabilitation training was safe and significantly improved the recovery of motor and sensory functions, as well as emotional responses, compared to sham stimulation with rehabilitation. These benefits were observed starting from 2 weeks and were sustained for up to 1 year.
Major Points
- This was a double-blind, randomized, sham-controlled trial involving 60 patients with acute stroke (both ischemic and hemorrhagic) within one month of symptom onset.
- Patients were randomized 1:1 to receive either active ta-VNS or sham ta-VNS, with both groups also receiving conventional rehabilitation training.
- The intervention consisted of 20-minute stimulation sessions five times per week for four weeks, immediately followed by a 30-minute rehabilitation session.
- The ta-VNS group showed significantly greater improvements compared to the control group across all primary functional outcomes (Fugl-Meyer Assessment for Upper and Lower Extremity, Sensory function, and Wolf Motor Function Test) at all follow-up time points from 2 weeks to 1 year.
- Patients in the ta-VNS group also reported significantly less anxiety and depression (HADS scale) and better quality of life (Stroke Impact Scale) compared to controls.
- The treatment was safe and well-tolerated, with no major side effects reported and no significant changes in cardiovascular vital signs.
Study Design
- Study Type
- Two-group, pragmatic, double-blinded, randomized controlled trial
- Randomization
- Yes
- Blinding
- Double-blind (participants, physical therapists, and researchers)
- Sample Size
- 60
- Follow-up
- 1 year
- Centers
- 1
- Countries
- China
Primary Outcome
Definition: The primary functional outcome was the improvement in motor and sensory functions, as evaluated by the Wolf Motor Function Test (WMFT) and Fugl-Meyer Assessment (FMA) scales at multiple time points up to 1 year.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| Showed significant improvement from baseline but was significantly lower than the ta-VNS group at all follow-up points. | Showed significantly greater improvement on FMA-Upper limb, FMA-Lower limb, FMA-Sensory, and WMFT scores compared to the control group at all follow-up points (2 weeks, 1, 3, 6, and 12 months). | - | <0.05 for all comparisons at all follow-up time points |
Limitations & Criticisms
- The study had a small sample size (60 patients).
- The lack of an active stimulation control group means that placebo effects cannot be entirely ruled out.
- The optimal parameters for electrical stimulation (timing, electrode placement, waveform) have not been identified and may have influenced the therapeutic effect.
Citation
Neural Regen Res 17(8):1809-1813.