Cluster headache
Cluster headache is a neurological disorder characterized by recurrent severe headaches on one side of the head, typically around the eye(s).[1] There is often accompanying eye watering, nasal congestion, or swelling around the eye on the affected side.[1] These symptoms typically last 15 minutes to 3 hours.[2] Attacks often occur in clusters which typically last for weeks or months and occasionally more than a year.[2]
The cause is unknown,[2] but is most likely related to dysfunction of the posterior hypothalamus.[6] Risk factors include a history of exposure to tobacco smoke and a family history of the condition.[2] Exposures which may trigger attacks include alcohol, nitroglycerin, and histamine.[2] They are a primary headache disorder of the trigeminal autonomic cephalalgias type.[2] Diagnosis is based on symptoms.[2]
Recommended management includes lifestyle adaptations such as avoiding potential triggers.[2] Treatments for acute attacks include oxygen or a fast-acting triptan.[2][4] Measures recommended to decrease the frequency of attacks include steroid injections, galcanezumab, civamide, verapamil, or oral glucocorticoids such as prednisone.[6][4][7] Nerve stimulation or surgery may occasionally be used if other measures are not effective.[2][6]
The condition affects about 0.1% of the general population at some point in their life and 0.05% in any given year.[5] The condition usually first occurs between 20 and 40 years of age.[2] Men are affected about four times more often than women.[5] Cluster headaches are named for the occurrence of groups of headache attacks (clusters).[1] They have also been referred to as "suicide headaches".[2]
Epidemiology[edit]
Cluster headache affects about 0.1% of the general population at some point in their life.[5] Males are affected about four times more often than females.[5] The condition usually starts between the ages of 20 and 50 years, although it can occur at any age.[1] About one in five of adults reports the onset of cluster headache between 10 and 19 years.[67]
Society and culture[edit]
Robert Shapiro, a professor of neurology, says that while cluster headaches are about as common as multiple sclerosis with a similar disability level, as of 2013, the US National Institutes of Health had spent $1.872 billion on research into multiple sclerosis in one decade, but less than $2 million on cluster headache research in 25 years.[74]
Research directions[edit]
Some case reports suggest that ingesting tryptamines such as LSD, psilocybin (as found in hallucinogenic mushrooms), or DMT can abort attacks and interrupt cluster headache cycles.[75][76] The hallucinogen DMT has a chemical structure that is similar to the triptan sumatriptan, indicating a possible shared mechanism in preventing or stopping migraine and TACs.[51] In a 2006 survey of 53 individuals, 18 of 19 psilocybin users reported extended remission periods. The survey was not a blinded or a controlled study, and was "limited by recall and selection bias".[75] The safety and efficacy of psilocybin is currently being studied in cluster headache, with the extension phase of one randomized controlled trial demonstrating reduced cluster attack burden after a 3-dose pulse of psilocybin.[77][78][79]
Fremanezumab, a humanized monoclonal antibody directed against calcitonin gene-related peptides alpha and beta, was in phase 3 clinical trials for cluster headaches, but the studies were stopped early due to a futility analysis demonstrating that a successful outcome was unlikely.[80][81]