Table 1.
Comparison of the two pilot VNS studies (Dawson et al., 2016; Kimberley et al., 2018).
| Dawson et al., 2016 | Kimberley et al., 2018 | |
|---|---|---|
| Number of sites | 2 United Kingdom | 4 United States and United Kingdom |
| Study design | Randomized, single-blind (Assessor) | Randomized, blinded (Assessor, Therapist, Participant), sham-controlled, cross-over |
| Number of participants | 20 (VNS: n = 9; Control: n = 11) | 17 (VNS: n = 8; Control: n = 9) |
| VNS implantation | Only VNS group implanted | Both VNS and Control group implanted |
| Long-term home therapy | No | Yes |
| Inclusion criteria | ARAT (Action Research Arm Test) | FMA-UE (Fugl-Meyer Assessment – Upper Extremity) |
| Outcome measure end-points | End of in-clinic (6 weeks) assessment followed by a 30-day assessment | End of in-clinic (6 weeks) assessment followed by 30-day and 3-month assessment |
| Imaging (Structural MRI) | Yes | Yes |
| Safety | (One) Transient vocal cord palsy and dysphagia after implant, (Five) minor events including nausea, metallic taste in the mouth. No serious adverse device effects. | (Three) Serious adverse events related to implantation surgery including wound infection, shortness of breath with dysphagia and hoarseness. No serious adverse device effects. |
| Efficacy (FMA change from baseline at 6 weeks) | 9.6 vs. 3 (between group difference = 6.5 points, CI: 0.4 to 12.6, p = 0.038). ∗Response rate: 66% vs. 36.4% | 7.6 vs. 5.3 (between group difference = 2.3 points, CI: -1.8 to 6.4, p = 0.2). ∗Response rate: 75% vs. 33%. At 3 months, post-therapy, 9.5 vs. 3.8 (between group difference = 5.7 points, CI: -1.4 to 11.5, p = 0.055). ∗Response rate: 88% vs. 33% (p = 0.03). |
∗FMA change ≥6 points.