The revised International Headache Society (IHS) criteria for cluster headache are: attacks of severe or very severe, strictly unilateral pain, which is orbital, supraorbital, or temporal pain, lasting 15 to 180 minutes, and occurring from once every other day to eight times daily (
for full details).
The attacks are associated with at least one of the following cranial autonomic features, all of which are ipsilateral: conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead and facial sweating, miosis, ptosis, and eyelid oedema. The revised IHS criteria allow the diagnosis of cluster headache to be made in the absence of ipsilateral cranial autonomic features, provided the person reports a sense of restlessness or agitation. Attacks usually occur in series (cluster periods) lasting for weeks or months, separated by remission periods usually lasting months or years. However, about 10% to 15% of people have chronic symptoms without remissions. Cluster headache is further subclassified according to the duration of the bout. Episodic cluster headache is diagnosed when cluster headache attacks occur in periods lasting 7 days to 1 year, separated by remissions lasting 1 month or longer. Chronic cluster headache is diagnosed when cluster headache attacks occur for more than 1 year without remission, or with remissions lasting less than 1 month. The term cluster headache is now widely accepted, although historically the condition has been known by several different names, including: migrainous neuralgia, Horton's headache, histaminic cephalalgia, sphenopalatine neuralgia, Sluder's neuralgia, petrosal neuralgia, red migraine, erythroprosopalgia of Bing, ciliary neuralgia, erythromelalgia of the head, Vidian neuralgia, hemicrania angioparalytica, hemicrania periodic neuralgiforms, syndrome of hemicephalic vasodilation of sympathetic origin, and autonomic faciocephalalgia.
Table 1 The International Classification of Headache Disorders II (ICHD-II) diagnostic criteria for cluster headache.
Cluster headache is rare, but the exact prevalence remains a matter of debate because of the remarkable variation of the estimated prevalence — between 56 and 401 per 100,000 population — in the various studies.
Recent studies suggest that the prevalence of cluster headache is likely to be at least one person per 500.
Cluster headache is more prevalent in men. The gender ratio in the various case series varies between 2.5:1 and 7.2:1.
There is a small increased familial risk of cluster headache, suggesting a genetic role in causation.
People with cluster headache may over indulge in non-essential consumption habits
intake of alcohol,
and consumption of coffee.
There is an increased incidence of previous head trauma in cluster headache, ranging between 5% and 37%, although there is often a long interval between the head trauma and the onset of the headaches.
Onset of symptoms most commonly occurs between the second and fourth decades of life,
although cluster headache has been reported in all age groups. Although there is a paucity of literature on the long-term prognosis of cluster headache, the available evidence suggests that it is a lifelong disorder in most people. In one study, episodic cluster headache (ECH) evolved into chronic cluster headache (CCH) in about 10% of people, whereas CCH transformed into ECH in one third of people.
Furthermore, a substantial proportion of people with cluster headache can expect to develop longer remission periods with increasing age.
To reduce frequency, severity, and duration of headache once attacks have begun (abortive treatment) and to prevent attacks (preventive treatment), with minimal adverse effects from treatment; to improve quality of life.
Headache relief (measured by headache frequency, headache severity, and headache duration).
Clinical Evidence search and appraisal June 2009. The following databases were used to identify studies for this systematic review: Medline 1966 to June 2009, Embase 1980 to June 2009, and The Cochrane Database of Systematic Reviews, Issue 2, 2009 (1966 to date of issue). An additional search within The Cochrane Library was carried out for the Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA). We also searched for retractions of studies included in the review. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the contributor for additional assessment, using predetermined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews of RCTs and RCTs in any language, at least single blinded, and containing any number of individuals of whom more than 60% were followed up. There was no minimum length of follow-up required to include studies. We excluded all studies described as "open", "open label", or not blinded, unless blinding was impossible. We included systematic reviews of RCTs and RCTs where harms of an included intervention were studied applying the same study design criteria for inclusion as we did for benefits. In addition, we did an observational harms search for specific harms as highlighted by the contributor, peer reviewer, and editor. We searched for observational studies assessing cerebrovascular adverse effects of triptans, cardiovascular adverse effects of verapamil, and visceral fibrosis/scleroderma as an adverse effect of methysergide. In addition, we use a regular surveillance protocol to capture harms alerts from organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the reviews as required. To aid readability of the numerical data in our reviews, we round many percentages to the nearest whole number. Readers should be aware of this when relating percentages to summary statistics such as relative risks (RRs) and odds ratios (ORs). We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (). The categorisation of the quality of the evidence (high, moderate, low, or very low) reflects the quality of evidence available for our chosen outcomes in our defined populations of interest. These categorisations are not necessarily a reflection of the overall methodological quality of any individual study, because the Clinical Evidence population and outcome of choice may represent only a small subset of the total outcomes reported, and population included, in any individual trial. For further details of how we perform the GRADE evaluation and the scoring system we use, please see our website (www.clinicalevidence.com).
GRADE Evaluation of interventions for Cluster headache.