2 Indications and current treatments
2.1 Cluster headaches are characterised by episodes of unilateral periorbital pain, conjunctival injection, lacrimation and rhinorrhoea. Attacks can last from a few minutes to several hours and can occur many times a day, for several days, weeks, months or years. Migraines are severe headaches that may last for hours, days or longer, often accompanied by nausea, photophobia, phonophobia and the perception of unpleasant odours. In some people migraines 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.
2.2 The usual treatment option for patients with cluster headache or migraine is medical therapy, either to stop or prevent attacks. Treatments for acute cluster headache attacks include oxygen inhalation and medications such as triptans. Corticosteroids and verapamil may be used to prevent or reduce the frequency of cluster headaches. Treatments for acute migraine attacks include analgesics, triptans and anti‑emetics (as recommended in NICE's guideline on headaches in over 12s). Beta‑blockers, tricyclic antidepressants and antiepileptics (topiramate, sodium valproate) may be used to prevent or reduce the frequency of migraine attacks.
2.3 Invasive treatments are reserved for patients with distressing symptoms that are refractory to medical treatments. For patients with chronic cluster headache, these include deep brain stimulation to modulate central processing of pain signals. For patients with chronic migraine, these include treatments such as 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 or nerve stimulation.