Cluster headache

Cluster headache is an attack of severe pain localised to the unilateral orbital, supra-orbital, and/or temporal areas that lasts from 15 minutes to 3 hours. It occurs from once every other day to 8 times per day.

Attacks occur at the same time period for several weeks (the cluster period); accompanied by ipsilateral autonomic signs. Most patients are restless or agitated during attacks compared to people with migraine who often report motion sensitivity during attacks.

Pathophysiology is thought to result from hypothalamic activation with secondary trigeminal and autonomic activation. Cluster period attacks can be precipitated by alcohol, volatile smells, warm temperatures, and sleep.

Diagnosis is based on International Headache Society International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria.

Medications for acute treatment should be used in combination with prophylactic medications.

Greater occipital nerve blockade often provides relief until preventative medications take effect. Neurostimulation techniques have provided dramatic response in patients with chronic cluster headaches that are refractory to medical treatments. Invasive neurostimulation techniques employed in cluster headache include occipital nerve stimulation and posterior hypothalamic region deep brain stimulation. Emerging techniques include non-invasive vagal nerve stimulation and invasive sphenopalatine ganglion stimulation.

Cluster headache is considered one of the most painful conditions known. The clinical picture consists of unilateral headache attacks lasting 15 to 180 minutes, associated with autonomic symptoms secondary to parasympathetic hyperactivity and sympathetic hypo-activity. Some patients will develop chronic cluster headache and experience daily attacks without periods of remission. Pain is often localised to the unilateral orbital, supra-orbital, and/or temporal areas and can occur from once every other day to 8 times per day.

During an attack the pain is strictly unilateral, although some patients report the pain shifting sides between or during bouts but not during the attack itself. Both cluster bouts and attacks during a cluster period can show cyclical periodicity occurring at the same time of year or the same time of day. Autonomic features accompanying pain include ptosis, conjunctival injection, lacrimation, rhinorrhoea, nasal stuffiness, eyelid and facial swelling, aural fullness, facial sweating, and redness. Most patients become very restless or agitated during an acute attack, unlike people with migraine who often report motion sensitivity during attacks.

Approximately 90% of patients have episodic cluster headache, which consists of at least two cluster periods of attacks lasting from 7 days to 1 year when untreated (cluster periods usually last from 2 weeks to 3 months), separated by remission periods lasting at least 3 months.[1]Bahra A, May A, Goadsby PJ. Cluster headache: a prospective clinical study with diagnostic implications. Neurology. 2002 Feb 12;58(3):354-61. http://www.ncbi.nlm.nih.gov/pubmed/11839832?tool=bestpractice.com

The chronic form of cluster headache is seen in approximately 10% of patients and consists of attacks that occur for 1 year or longer without remission, or with remission periods lasting less than 3 months.[1]Bahra A, May A, Goadsby PJ. Cluster headache: a prospective clinical study with diagnostic implications. Neurology. 2002 Feb 12;58(3):354-61. http://www.ncbi.nlm.nih.gov/pubmed/11839832?tool=bestpractice.com [2]Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018 Jan;38(1):1-211. https://journals.sagepub.com/doi/10.1177/0333102417738202 http://www.ncbi.nlm.nih.gov/pubmed/29368949?tool=bestpractice.com The condition may be chronic from onset or may evolve over time from the episodic form.