Migraines are moderate to severe headaches that may last for hours, days or longer. They are often accompanied by nausea, photophobia, phonophobia and the perception of unpleasant odours. In some people, they may be accompanied by an aura, characterised by the focal neurological symptoms that usually precede or sometimes accompany the headache. The International Headache Society's international classification of headache disorders classifies migraine types.
The usual treatment options for migraines are medical therapies, to either stop or prevent attacks (see NICE's guideline on headaches in over 12s). For acute migraine attacks, these include analgesics, triptans and antiemetics. Treatments to stop or reduce the frequency of migraine attacks include beta blockers, calcium-channel blockers, tricyclic antidepressants, antiepileptics and calcitonin gene-related peptide inhibitors.
Invasive treatments are reserved for people with distressing symptoms that are refractory to medical therapy. These include nerve blocks, botulinum toxin (see NICE's technology appraisal guidance on botulinum toxin type A for the prevention of headaches in adults with chronic migraine), acupuncture, and interventional procedures (see NICE's interventional procedures guidance on occipital nerve stimulation, transcutaneous stimulation of the cervical branch of the vagus nerve and transcranial magnetic stimulation).
Transcutaneous electrical stimulation of the supraorbital nerve uses small electrical currents to stimulate the supraorbital nerves (branches of the ophthalmic nerve, the first division of the trigeminal nerve) through the skin overlying the nerves. It is also called external trigeminal nerve stimulation or eTNS. The aim is to relieve headache and, when used regularly, to reduce the severity and the frequency of migraine attacks.
People with migraine administer the therapy themselves using a small battery-operated device. For example, 1 device consists of a headband with a central button connected to a self-adhesive electrode patch. This is applied to the forehead above the eyebrows. When the device is activated, small electrical impulses stimulate the supraorbital nerves (branches of the ophthalmic nerve, the first division of the trigeminal nerve). The intensity of the electrical pulses increases periodically and can be self-adjusted. Stimulation is applied daily for about 1 to 2 hours during an acute migraine attack, and for 20 minutes for prevention between attacks.