Table 1.
Characteristics of the included studies.
| Author | Migraine type | Intervention | Intervention time | Groups (n) | Mean age | F (Intervention)/ F (Control) |
|---|---|---|---|---|---|---|
| Silberstein et al. (20) | Chronic migraine | n-cVNS | 2 months | Intervention (n = 30) | 39.2 years | 26/27 |
| Sham (n = 29) | ||||||
| Grazzi et al. (19) | Episodic migraine | n-cVNS | 4 weeks | Intervention (n = 120) | 39.2 years | 95/91 |
| Sham (n = 123) | ||||||
| Diener et al. (18) | Episodic migraine | n-cVNS | 12 weeks | Intervention (n = 165) | 42.4 years | 142/138 |
| Sham (n = 167) | ||||||
| Najib et al. (21) | Migraine | n-cVNS | 12 weeks | Intervention (n = 56) | 42.5 years | 49/44 |
| Sham (n = 57) | ||||||
| Straube et al. (9) | Chronic migraine | n-aVNS | 12 weeks | Intervention (n = 17) | 41.5 years | 13/19 |
| Control group (n = 22) | ||||||
| Zhang et al. (22) | Migraine | n-aVNS | 4 weeks | Intervention (n = 33) | 30.4 years | 23/23 |
| Sham (n = 26) |
n-cVNS, non-invasive cervical vagus nerve stimulation; n-aVNS, non-invasive auricular vagus nerve stimulation; F, female.