In 2016, NICE issued two separate sets of guidance recommending the use of devices. The first was for transcutaneous stimulation of the cervical branch of the vagus nerve for cluster headache and migraine, in relation to the gammaCore device made by electroCore.14,15 This involves holding the device against the neck over the carotid artery to stimulate the vagus nerve with a small electric current for two minutes.14

While the evidence on efficacy was “limited in quantity and quality”, the procedure can be used within the NHS “with special arrangements for clinical governance, consent and audit or research.” NHS trust clinical governance leads need to be informed, and patients need to “understand the uncertainty about the procedure's efficacy” and be provided with clear written information, said NICE.14

It added that the evidence was better for cluster headache than for migraine, and that there were no major safety concerns.