Noninvasive vagus nerve stimulation in the management of cluster headache: clinical evidence and practical experience

The efficacy of invasive vagal nerve stimulation as well as other invasive neuromodulatory approaches such as deep brain stimulation, occipital nerve stimulation, and ganglion sphenopalatine stimulation has been shown in the treatment of headache disorders in several studies in the past. However, these invasive treatment options were quite costly and often associated with perioperative and postoperative side effects, some severe. As such, they were predominantly restricted to chronic and therapy refractory patients. Transcutaneous vagal nerve stimulation now offers a new, noninvasive neuromodulatory treatment approach. Recently published studies showed encouraging results of noninvasive vagus nerve stimulation (nVNS), especially with respect to cluster headache, with high tolerability and a low rate of side effects; however, randomized controlled trials are needed to prove its efficacy. Further data also indicate therapeutic benefits regarding treatment of migraine and medication overuse headache. This review summarizes current knowledge and personal experiences of nVNS in the treatment of cluster headache.