Transcutaneous stimulation of the cervical branch of the vagus nerve for cluster headache and migraine

In a randomised controlled trial of 97 patients with cluster headache treated by standard care plus transcutaneous vagus nerve stimulation (tVNS; n=48) or standard care alone (n=49), the mean number of cluster headache attacks per week decreased by 5.9 attacks in the standard care plus tVNS group and by 2.1 attacks in the standard care alone group at 4‑week follow‑up (p value between groups=0.02). Baseline measurements were not reported. During the extension phase of the study, patients from both groups received adjunctive tVNS for 4 additional weeks. In this period, the mean number of cluster headache attacks per week decreased from 9.6 to 7.6 in patients who were initially in the standard care plus tVNS group (n=30; p<0.001) and from 15.7 to 12.4 in patients initially in the standard care alone group (n=41; p<0.001).

In a case series of 19 patients with cluster headache, complete resolution of pain was achieved in 47% of cluster headache attacks within a mean of 11 minutes of starting neurostimulation.

In the randomised controlled trial of 97 patients with cluster headache treated by standard care plus tVNS or standard care alone, the mean number of times subcutaneous sumatriptan was used decreased from 7.2 to 2.8 in the standard care plus tVNS group (n=32; p=0.007) and increased from 6.8 to 7.5 in the standard care alone group (n=42; not significant), during the last 2 weeks of the 4‑week follow‑up period. In the same study, the mean number of times inhaled oxygen was used decreased from 17.3 to 6.5 in the standard care plus tVNS group (n=32; p=0.02) and from 12.6 to 10.8 in the standard care alone group (n=42; not significant) during the last 2 weeks of the 4‑week follow‑up period.

In the randomised controlled trial of 97 patients with cluster headache treated by standard care plus tVNS or standard care alone, mean EQ‑5D scores (ranging from 0 to 100 with higher scores indicating better quality of life) increased from baseline by 9.20 and 0.27 points respectively at 4‑week follow‑up (p=0.039). During the extension phase of the study, patients from both groups received adjunctive tVNS for 4 additional weeks. In this period, mean EQ‑5D scores increased from baseline by 10.79 points in patients who were initially in the standard care plus tVNS group and by 4.36 points in patients initially in the standard care alone group (p value not reported).

In a case series of 50 patients with high‑frequency episodic migraine or chronic migraine, pain relief (defined as more than a 50% improvement in visual analogue scale scores for pain) was reported in 38% (50 of 131) of attacks, 1 hour after neurostimulation. Complete resolution of pain was reported in 18% (23 of 131) of attacks, 1 hour after neurostimulation. Pain relief and complete resolution of pain were reported in 51% (67 of 131) and 23% (30 of 131) of attacks respectively, 2 hours after neurostimulation.

In a case series of 30 patients with migraine, relief of nausea was reported in 38% (11 of 29) of attacks accompanied by nausea. In the same study, relief of photophobia was reported in 30% (16 of 53) of attacks accompanied by photophobia. Relief of phonophobia was reported in 52% (17 of 33) of attacks accompanied by phonophobia.

In the case series of 50 patients with high‑frequency episodic migraine or chronic migraine, complete recovery from functional disability was reported in 35% (46 of 131) of attacks 2 hours after neurostimulation.

In the case series of 50 patients with high‑frequency episodic migraine or chronic migraine, rescue medication was needed in 53% (70 of 131) of attacks 2 hours after neurostimulation.

Specialist advisers listed key efficacy outcomes as complete resolution of pain, reduction in the frequency, duration and severity of headache episodes, use of rescue medication, and improvements in quality of life.