Clinical intra- and interfamilial variability of cluster headache

From basic mechanisms to therapeutic perspectives in cluster headache

PURPOSE OF REVIEW

The pathophysiological understanding of cluster headache has evolved significantly over the past years. Although it is now well known that the trigeminovascular system, the parasympathetic system and the hypothalamus play important roles in its pathomechanism, we increasingly understand the functional role several neurotransmitters and hormones play in the communication between these structures.

RECENT FINDINGS

This work will give an overview of the current understanding of the role of calcitonin gene-related peptide, vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide, melatonin and orexins in cluster headache. On the basis of recent evidence, this study will also review the relevance of the monoclonal calcitonin gene-related peptide antibody galcanezumab as well as the sleep-regulating hormone melatonin in the treatment of cluster headache.

SUMMARY

Herein, we aim to review the basic mechanisms implicated in the pathophysiology of cluster headache and how the increased mechanistic understanding may lead to the discovery of novel therapeutic targets.

Challenges and complexities in designing cluster headache prevention clinical trials: A narrative review

Objective

To provide a review of challenges in clinical trials for the preventive treatment of cluster headache (CH) and highlight considerations for future studies.

Background

Current guidelines for preventive treatment of CH are largely based on off‐label therapies supported by a limited number of small randomized controlled trials. Guidelines for clinical trial design for CH treatments from the International Headache Society were last issued in 1995.

Methods/Results

Randomized controlled clinical trials were identified in the European and/or United States clinical trial registries with a search term of “cluster headache,” and manually reviewed. Cumulatively, there were 27 unique placebo‐controlled prevention trials for episodic and/or chronic CH, of which 12 were either ongoing, not yet recruiting, or the status was unknown. Of the remaining 15 trials, 5 were terminated early and 7 of the 10 completed trials enrolled fewer patients than planned or did not report the planned sample size. A systematic search of PubMed was also utilized to identify published manuscripts reporting results from placebo‐controlled preventive trials of CH. This search yielded 16 publications, of which 7 were registered. Through critical review of trial data and published manuscripts, challenges and complexities encountered in clinical trials for the preventive treatment of CH were identified. For example, the excruciating pain associated with CH demands a suitably limited baseline duration, rapid treatment efficacy onset, and poses a specific issue regarding duration of investigational treatment period and length of exposure to placebo. In episodic CH, spontaneous remission as part of natural history, and the unpredictability and irregularity of cluster periods across patients present additional key challenges.

Conclusions

Optimal CH trial design should balance sound methodology to demonstrate efficacy of a potential treatment with patient needs and the natural history of the disease, including unique outcome measures and endpoint timings for chronic versus episodic CH.

The clinical characteristics of familial cluster headache

Background

A positive family history predisposes to the development of cluster headache. The distinct characteristics of familial cluster headache have yet to be confirmed, however, evidence suggests a younger age of onset and higher proportion of females in this subgroup.

Objectives

To assess the rate and mode of inheritance of familial cluster headache in a tertiary referral centre for headache. To describe the clinical features of familial cluster headache.

Methods

A retrospective study conducted between 2007 and 2017. Cluster headache was confirmed in probands and affected relatives. Differences in demographics, clinical characteristics, and response-to-treatment in familial cluster headache were delineated through multivariate analysis using a control cohort of 597 patients with sporadic cluster headache.

Results

Familial cluster headache was confirmed in 48 (7.44%) patients and predominantly reflected an autosomal dominant mode of inheritance with reduced penetrance. Familial cases were more likely to report nasal blockage (OR 4.06, 95% CI; 2.600–6.494, p < 0.001) during an attack and a higher rate of concurrent short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (OR 3.76, 95% CI; 1.572–9.953, p = 0.004).

Conclusion

These findings add to evidence suggesting a genetic component to cluster headache. Here, we demonstrated prominent nasal blockage, and a higher occurrence of concomitant short-lasting unilateral neuralgiform headache with conjunctival injection and tearing in this subgroup, further delineating the phenotype.

Family History of Cluster Headache: A Systematic Review

Importance

Genetic and environmental factors are thought to contribute to cluster headache, and cluster headache can affect multiple members of a family. A thorough understanding of its inheritance is critical to understanding the pathogenesis of this debilitating disease.

Objective

To systematically review family history rates and inheritance patterns of cluster headache.

Evidence Review

A systematic review was performed in PubMed, Embase, and Cochrane Library. Search criteria were created by a librarian. Articles published between 1985 and 2016, after the publication date of a large review in 1985, were analyzed independently by 2 neurologists to identify family history rates and pedigrees. Pedigrees were analyzed by a genetic counselor.

Findings

A total of 1995 studies were found (1988 through the search criteria and 7 through other means). Forty articles met inclusion criteria: 22 large cohort studies, 1 twin-based study, and 17 case reports or small case series. Across the 22 large cohort studies, the positive family history rate of cluster headache varied between 0% and 22%, with a median of 8.2%. The largest 5 studies, of 1134, 785, 693, 609, and 500 probands each, had a positive family history in 18.0% (numerator not provided), 5.1% (40 of 785 cases), 10.0% (numerator not provided), 2.0% (12 of 609 cases), and 11.2% (56 of 500 cases), respectively. No meta-analysis was performed, given differences in methodologies. Separately, 1 twin-based study examined 37 twin pairs and reported a concordance rate of 5.4% (2 pairs). Finally, 67 pedigrees were identified. Most pedigrees (46 of 67 [69%]) were consistent with an autosomal dominant pattern, but 19 of 67 (28%) were consistent with an autosomal recessive inheritance pattern; 10 pedigrees of probable or atypical cluster headache were identified, and all were consistent with an autosomal dominant inheritance pattern. The sex ratio for cluster headache in identified pedigrees was 1.39 (103:74) in affected men and boys compared with affected women and girls, which is lower than that of the general cluster headache population.

Conclusions and Relevance

Cluster headache is an inherited disorder in a subset of families and is associated with multiple hereditary patterns. There is an unexpectedly high preponderance of women and girls with familial cluster headache; genetic subanalyses limited to female participants are necessary to further explore this observation, because these data are otherwise masked by the higher numbers of male participants with cluster headache. Overall, this systematic review supports the notion that familial cluster headache is likely the result of multiple susceptibility genes as well as environmental factors.

Prevalence of familial cluster headache: a systematic review and meta-analysis

INTRODUCTION

The population rate of familial cluster headache (CH) has been reported to be as high as 20% however this varies considerably across studies. To obtain a true estimate of family history in CH, we conducted a systematic review and meta-analysis of previously published data.

METHODS

Our systematic review involved a search of electronic databases (Medline, EMBASE, PubMed, CINAHL) to identify and appraise studies of interest utilising the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. To further ameliorate the accuracy of our analysis we included an additional unpublished cohort of CH patients recruited at a tertiary referral centre for headache, who underwent detailed family history with diagnostic verification in relatives. Data was extracted and meta-analysis conducted to provide a true estimation of family history.

RESULTS

In total, we identified 7 studies which fulfilled our inclusion criteria. The estimated true prevalence of CH patients with a positive family history was 6.27% (95% CI:4.65-8.40%) with an overall I² of 73%. Fitted models for gender subgroups showed higher estimates 9.26% (95% CI: 6.29-13.43%) in females. However the I² for the female model was 58.42% and significant (p = 0.047).

CONCLUSION

Our findings estimate a rate of family history in CH to be approximately 6.27% (95% CI: 4.65-8.40%). While estimates were larger for female probands, we demonstrated high heterogeneity in this subgroup. These findings further support a genetic role in the aetiology of CH.

Familial periodicity in a multigenerational family of cluster headache: A case report

I describe an unusual phenotypic phenomenon in two members of a multigenerational family of cluster headache (CH) with anticipation features. The index case, a 44-year-old woman, and her sister, a 40-year-old woman, have a CH phenotype with atypical features as the burning of the nose. Besides identically circadian and circannual features, they present distinct chronobiological features with the onset of the episodic pain attack every third day between them. I propose to entitle this clinical feature “familial periodicity” because of the remarkable phenotypic correlation and probably a similar genotype in the two sisters. Pathophysiologically, this phenomenon may be the result of the dysfunction of the suprachiasmatic nucleus of the hypothalamus on a genetic basis. This is the first case of familial periodicity, which allows extending the clinical spectrum of CH.

Younger Age of Migraine Onset in Children Than Their Parents: A Retrospective Cohort Study

Migraine is known to run in families and has long been considered a strongly heritable disorder. We sought to investigate the age of onset of migraine between successive generations. Our retrospective cohort included 102 children with migraine who were referred to a pediatric headache clinic and their affected parent(s). Age at migraine onset was significantly lower in the children with a history of maternal or paternal migraine than in their mothers or fathers ( P < .001). In conclusion, data on parental history of migraine showed that children with migraine were significantly younger at first appearance of the disease than their affected parents.

Diagnosis, pathophysiology, and management of cluster headache

Cluster headache is a trigeminal autonomic cephalalgia characterised by extremely painful, strictly unilateral, short-lasting headache attacks accompanied by ipsilateral autonomic symptoms or the sense of restlessness and agitation, or both. The severity of the disorder has major effects on the patient's quality of life and, in some cases, might lead to suicidal ideation. Cluster headache is now thought to involve a synchronised abnormal activity in the hypothalamus, the trigeminovascular system, and the autonomic nervous system. The hypothalamus appears to play a fundamental role in the generation of a permissive state that allows the initiation of an episode, whereas the attacks are likely to require the involvement of the peripheral nervous system. Triptans are the most effective drugs to treat an acute cluster headache attack. Monoclonal antibodies against calcitonin gene-related peptide, a crucial neurotransmitter of the trigeminal system, are under investigation for the preventive treatment of cluster headache. These studies will increase our understanding of the disorder and perhaps reveal other therapeutic targets.

Familial Cluster Headache. Is Atypical Cluster Headache in Family Members Part of the Clinical Spectrum?

Familial cluster headache (CH) was analysed in 21 Swedish families. Diagnosis was made according to The International Classification of Headache Disorders 2004. We identified 55 affected, of whom 42 had episodic or chronic CH, one had probable CH and 12 had atypical symptoms. The atypical cases did not fulfil the diagnostic criteria for CH, but had clinical symptoms with more resemblance to CH than to migraine or other trigeminal autonomic cephalgia syndromes. The overall male : female ratio was 1.8 : 1. The overall mean age at onset was significantly lower in the second/third generation than in the first generation (mean age at onset 22 vs. 31 years, SD ± 7 vs. 13 years; P < 0.01). This may be anticipation or selection bias, since individuals with late age at onset from the second/third generation may not yet have symptoms. The prevalence of migraine was 24% (13/55), i.e. similar to the prevalence in the general population. The high incidence of atypical CH cases in the Swedish families with other members affected with CH may suggest that the spectrum of CH is broader than previously thought. We suggest that atypical CH in CH families may represent an expanded spectrum of the disease with a common aetiology, i.e. a common genetic background.

Familial cluster headache in an Italian case series

To investigate the familial occurrence of cluster headache (CH) in a series of Italian patients, we focused on possible differences in the mean age of onset between familial and non-familial CH cases. We considered all consecutive patients referred to the Parma Headache Centre between 1975 and 2013 affected by CH; we subsequently reviewed these cases applying the ICHD3-beta criteria (785 probands, 569 men and 216 women). We identified those cases who reported at least a first-degree relative with a diagnosis of CH, which was confirmed by the clinical documentation they provided. Each one of the "familial cases" was matched by sex and age (±2 years) at the first visit to three consecutive CH patients who did not report any first-degree relative affected by CH. A positive family history of CH was found in 40 probands (5.1 %), 28 men (4.9 %), and 12 women (5.6 %). The male:female ratio was 2.3:1 among the 40 CH familial cases, while it was 2.7:1 among all the CH non-familial cases (745 patients). The mean age of onset was significantly (p < 0.01) lower in women with familial CH (28.5 years, SD 17.7 years, range 10-63 years) than in women with non-familial CH (46.7 years, SD 13.7 years, range 11-74 years); we did not find a significant age difference among men (the mean age of onset for the familial cases was 29.6 years, SD 13.6 years, range 6-63 years; while for the non-familial cases, it was 29.3 years, SD 13.2 years, range 13-59 years). Our study suggests that genetic factors may play a role in the female gender causing an earlier age of onset and a lower male-to-female sex ratio in familial cases.

Pathophysiology of trigeminal autonomic cephalalgias

Cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) are primary headaches recently classified together as trigeminal autonomic cephalalgias (TACs). The causes of these headaches have long been debated, with "peripheral" hypotheses in opposition to "central" hypotheses. The available information indicates that the pain originates from within the brain in cluster headache. The hypothalamic activation observed during TAC attacks by use of functional neuroimaging, and the success of hypothalamic stimulation as a treatment, confirm that the posterior hypothalamus is crucial in the pathophysiology of these headaches. The posterior hypothalamus is now known to modulate craniofacial pain, and hypothalamic activation occurs in other pain disorders, suggesting that this brain area is likely to have a more complex role in the pathophysiology of TACs than that of a mere trigger. Hypothalamic activation might play a part in terminating rather than triggering attacks, and might also give rise to a central permissive state, allowing attacks to take place.

Cluster headache: pathogenesis, diagnosis, and management

Cluster headache is a stereotyped primary pain syndrome characterised by strictly unilateral severe pain, localised in or around the eye and accompanied by ipsilateral autonomic features. The syndrome is characterised by the circadian rhythmicity of the short-lived attacks, and the regular recurrence of headache bouts, which are interspersed by periods of complete remission in most individuals. Headaches often start about 1-2 h after falling asleep or in the early morning, and show seasonal variation, suggesting that the hypothalamus has a role in the illness. Consequently, the vascular theory has been superseded by recognition that neurovascular factors are more important. The increased familial risk suggests that cluster headache has a genetic component in some families. Neuroimaging has broadened our pathophysiological view and has led to successful treatment by deep brain stimulation of the hypothalamus. Although most patients can be treated effectively, some do not respond to therapy. Fortunately, time to diagnosis of cluster headache has improved. This is probably the result of a better understanding of the pathophysiology in combination with efficient treatment strategies, leading to a broader acceptance of the syndrome by doctors.

Epidemiology and genetics of cluster headache

Cluster headache, the most severe primary headache, is characterised by unilateral pain, ipsilateral autonomic features, and, in many cases, restlessness. Recent epidemiological studies indicate that the prevalence of cluster headache is about one person per 500. Genetic epidemiological surveys indicate that first-degree relatives are five to 18 times-and second-degree relatives, one to three times-more likely to have cluster headache than the general population. Inheritance is likely to be autosomal dominant with low penetrance in some families, although there may also be autosomal recessive or multifactorial inheritance in others. To date, no molecular genetic clues have been identified for cluster headache. Identification of genes for cluster headache is likely to be difficult because most families reported have few affected members and genetic heterogeneity is likely. Future focus should be on ion channel genes and clock genes. This review summarises the epidemiology and genetics of cluster headache.

Cluster headache sine headache: two new cases in one family

We report two cases of cluster headache sine headache occurring in a family of cluster headache sufferers. A 54-year-old female, suffered for 15 years from short-lasting, right-sided attacks of eye reddening, lacrimation, rhinorrea, palpebral oedema and miosis, seven to eight times per day, in periods of 20-30 days. She did not experience headache, either with or without these phenomena. Her son suffers from periorbital, short-lasting, right-sided painful attacks accompanied by eye reddening, lacrimation, rhinorrea and nasal stiffnesss, occurring in periods of 30-35 days. Soon after the end of the current cluster period he still had daily attacks lasting 10-15 min, with the oculo-nasal autonomic phenomena only. The occurrence of cluster headache sine headache and cluster headache in the same family strongly suggests that the first condition is related to the cluster headache syndrome. Cluster headache sine headache should be considered as a subtype of the cluster headache syndrome.

Genetic epidemiology of migraine and cluster headache

Migraine. The present genetic epidemiological survey of migraine was based on semi-structured interviews by a physician. The operational diagnostic criteria of the International Headache Society were used. Three thousand males and 1,000 females aged 40 were drawn from the Danish National Central Person Registry. They received a questionnaire by post regarding migraine and the response rate was 87%. People with self-reported migraine and a random sample reporting no migraine were invited to a headache interview and physical and neurological examination. Those not reacting to the invitation were interviewed by telephone. The participation of the interview was 87%. Kappa was 0.77 validating self-reported migraine against a clinical interview by a physician. Non-responders did not differ from responders regarding migraine. The lifetime prevalence of MO and MA was 9.3% and 6.3% in males and 20.1% and 9.6% in females. People with MA were included as probands in the family study. An equivalent number of probands with MO and probands who had never had migraine were random samples of the people with MO) and those who had never had migraine, respectively. First-degree relatives and spouses were interviewed blindly by a physician. The 378 probands had 1,109 first-degree relatives and 229 spouses. Compared with the general population, the first-degree relatives of probands with MO had a 1.9-fold increased risk of MO and a 1.4-fold increased risk of MA, after standardization for sex and age. The first-degree relatives of probands with MA had a 3.8-fold increased risk of MA and no increased risk of MO. The first-degree relatives of probands who had never had migraine had no increased risk of either MO or MA. Spouses to pro-bands with MC) had a 1.5-fold increased risk of MO, while spouses to probands with MA had no increased risk of MA. The familial patterns indicate that MO and MA are distinct entities. The familial occurrence suggests that MO is caused by a combination of genetic and environmental factors, while MA is determined mainly or exclusively by genetic factors. The complex segregation analysis supports the importance of genetic factors and suggests multifactorial inheritance without generational difference in both MO and MA, but genetic heterogeneity cannot be excluded.

Genetics of migraine

Although family studies and twin studies are not sufficiently reliable to establish this theory with certainty, migraine likely is influenced by hereditary susceptibility. The association of migraine with a large number of hereditary diseases opens the possibility to choose candidate chromosomes for linkage studies. A rare subtype of migraine, familial hemiplegic migraine, is linked to chromosome 19p and at least one other locus. The chromosome 19p also seems to be involved in "normal" migraine, although conflicting results have been reported.

Cluster headache is an autosomal dominantly inherited disorder in some families: a complex segregation analysis

We investigated the mode of inheritance of cluster headache in 370 families. The probands were from a neurological clinic in Jutland and two departments of neurology in Copenhagen County, Denmark. The criteria of the International Headache Society were used. The patterns of segregation of cluster headache were assessed by complex segregation analysis performed with the computer program POINTER. Of the 370 probands with cluster headache, 25 had 36 relatives with cluster headache. The segregation analysis suggests that cluster headache has an autosomal dominant gene (p < 0.10) with a penetrance of 0.30-0.34 in males and 0.17-0.21 in females. The gene is present in 3 to 4% of males and 7 to 10% of females with cluster headache. An autosomal dominant gene has a role in cluster headache in some families.