Cluster headache in Greece: an observational clinical and demographic study of 302 patients

The Prevalence and Clinical Phenotypes of Cluster Headache in Relation with Latitude

PURPOSE OF REVIEW

Previous studies have indicated a possible link between the prevalence of cluster headache (CH) and sunlight exposure. However, this theory has yet to be tested systemically. In this article, we aim to examine how latitude affects the prevalence and phenotypes of CH.

RECENT FINDINGS

To our knowledge, there is by far no article describing the effect of latitude on disease phenotype; thus, we performed a literature review. We noted positive effects of latitude on 1-year prevalence, the proportion of chronic CH, and the proportion of miosis and/or ptosis. Latitude may affect the phenotypic presentations of cluster headache, probably partially mediated via temperature and sunlight variations. Still, other factors, such as environmental exposure to smoking and the genetic difference between the Eastern and Western populations, may participate in the pathogenesis and clinical manifestations of CH.

Profile of Chinese Cluster Headache Register Individual Study (CHRIS): Clinical characteristics, diagnosis and treatment status data of 816 patients in China

BACKGROUND

The clinical profile of cluster headache may differ among different regions of the world, warranting interest in the data obtained from the initial Chinese Cluster Headache Register Individual Study (CHRIS) for better understanding.

METHODS

We conducted a multicenter, prospective, longitudinal cohort study on cluster headache across all 31 provinces of China, aiming to gather clinical characteristics, treatment approaches, imaging, electrophysiological and biological samples.

RESULTS

In total 816 patients were enrolled with a male-to-female ratio of 4.33:1. The mean age at consultation was 34.98 ± 9.91 years, and 24.89 ± 9.77 years at onset. Only 2.33% were diagnosed with chronic cluster headache, and 6.99% had a family history of the condition. The most common bout was one to two times per year (45.96%), lasting two weeks to one month (44.00%), and occurring frequently in spring (76.23%) and winter (73.04%). Of these, 68.50% experienced one to two attacks per day, with the majority lasting one to two hours (45.59%). The most common time for attacks was between 9 am and 12 pm (75.86%), followed by 1 am and 3 am (43.48%). Lacrimation (78.80%) was the most predominant autonomic symptom reported. Furthermore, 39.22% of patients experienced a delay of 10 years or more in receiving a correct diagnosis. Only 35.67% and 24.26% of patients received common acute and preventive treatments, respectively.

CONCLUSION

Due to differences in ethnicity, genetics and lifestyle conditions, CHRIS has provided valuable baseline data from China. By establishing a dynamic cohort with comprehensive multidimensional data, it aims to advance the management system for cluster headache in China.

Epidemiology, burden and clinical spectrum of cluster headache: a global update

BACKGROUND

This narrative review aims to broaden our understanding of the epidemiology, burden and clinical spectrum of cluster headache based on updated findings with a global perspective.

METHODS

We conducted a literature search on the following topics: (a) epidemiology; (b) burden: quality of life, disability, economic burden, job-related burden and suicidality; and (c) clinical spectrum: male predominance and its changes, age, pre-cluster and pre-attack symptoms, aura, post-drome, attack characteristics (location, severity, duration and associated symptoms), bout characteristics (attack frequency, bout duration and bout frequency), circadian and seasonal rhythmicity and disease course.

RESULTS

New large-scale population-based reports have suggested a lower prevalence than previous estimations. The impact of cluster headache creates a significant burden in terms of the quality of life, disability, economic and job-related burdens and suicidality. Several studies have reported decreasing male-to-female ratios and a wide age range at disease onset. The non-headache phases of cluster headache, including pre-cluster, pre-attack and postictal symptoms, have recently been revisited. The latest data regarding attack characteristics, bout characteristics, and circadian and seasonal rhythmicity from different countries have shown variability among bouts, attacks, individuals and ethnicities. Studies on the disease course of cluster headache have shown typical characteristics of attacks or bouts that decrease with time.

CONCLUSIONS

Cluster headache may be more than a "trigeminal autonomic headache" because it involves complex central nervous system phenomena. The spectrum of attacks and bouts is wider than previously recognised. Cluster headache is a dynamic disorder that evolves or regresses over time.

Treatment pattern and response for cluster headache in Korea: A prospective multicenter observation study

BACKGROUND

Only limited data are available regarding the treatment status and response to cluster headache in an Asian population. Therefore, this study aimed to provide a real-world treatment pattern of cluster headache and the response rate of each treatment in an Asian population.

METHODS

Patients with cluster headache were recruited between September 2016 and January 2019 from 16 hospitals in Korea. At the baseline visit, we surveyed the patients about their previous experience of cluster headache treatment, and acute and/or preventive treatments were prescribed at the physician's discretion. Treatment response was prospectively evaluated using a structured case-report form at 2 ± 2 weeks after baseline visit and reassessed after three months.

RESULTS

Among 295 recruited patients, 262 experiencing active bouts were included. Only one-third of patients reported a previous experience of evidence-based treatment. At the baseline visit, oral triptans (73.4%), verapamil (68.3%), and systemic steroids (55.6%) were the three most common treatments prescribed by the investigators. Most treatments were given as combination. For acute treatment, oral triptans and oxygen were effective in 90.1% and 86.8% of the patients, respectively; for preventive treatment, evidence-based treatments, i.e. monotherapy or different combinations of verapamil, lithium, systemic steroids, and suboccipital steroid injection, helped 75.0% to 91.8% of patients.

CONCLUSION

Our data provide the first prospective analysis of treatment responses in an Asian population with cluster headache. The patients responded well to treatment despite the limited availability of treatment options, and this might be attributed at least in part by combination of medications. Most patients were previously undertreated, suggesting a need to raise awareness of cluster headache among primary physicians.

Clinical Profile of Chronic Cluster Headaches in a Regional Headache Center in Japan

Objective Little is known about the prevalence and characteristics of chronic cluster headache (CCH) in Japan. We therefore characterized the clinical profile of CCH in Japan by surveying patients with CCH who were registered at a Japanese regional headache center. We also reviewed the existing literature for the prevalence and clinical characteristics of CCH reported in various populations. Methods In this single-center retrospective study, we assessed consecutive patients with cluster headache (CH) who visited a regional tertiary headache center between February 2011 and July 2020. They were treated following the Clinical Practice Guideline for Chronic Headache 2013. We compared their demographic characteristics and clinical features according to the CCH onset pattern (primary vs. secondary). Results Of 420 patients with CH, 19 (4.2%) had CCH (9 primary and 10 secondary). The incidence of CCH in Japan is relatively low compared to that in Western countries but is comparable to that in other Asian countries. CCH showed a higher predominance of men than women. Compared to primary CCH, secondary CCH included a higher proportion of current smokers and older patients during clinic visits. Subcutaneous sumatriptan and oxygen inhalation were the most common abortive treatments, and oral prednisolone and verapamil were the most common preventive treatments. Home oxygen therapy was effective in six of seven patients. Only two patients with coexisting migraine received calcitonin gene-related peptide (CGRP)-targeted therapies. Conclusions CCH remains refractory to treatment. Improving treatment outcomes will require maximizing the use of currently available drugs and expanding the use of neuromodulation, nerve block, and CGRP-targeted therapies.

Using natural language processing to automatically classify written self-reported narratives by patients with migraine or cluster headache

Background

Headache medicine is largely based on detailed history taking by physicians analysing patients’ descriptions of headache. Natural language processing (NLP) structures and processes linguistic data into quantifiable units. In this study, we apply these digital techniques on self-reported narratives by patients with headache disorders to research the potential of analysing and automatically classifying human-generated text and information extraction in clinical contexts.

Methods

A prospective cross-sectional clinical trial collected self-reported narratives on headache disorders from participants with either migraine or cluster headache. NLP was applied for the analysis of lexical, semantic and thematic properties of the texts. Machine learning (ML) algorithms were applied to classify the descriptions of headache attacks from individual participants into their correct group (migraine versus cluster headache).

Results

One-hundred and twenty-one patients (81 participants with migraine and 40 participants with cluster headache) provided a self-reported narrative on their headache disorder. Lexical analysis of this text corpus resulted in several specific key words per diagnostic group (cluster headache: Dutch (nl): “oog” | English (en): “eye”, nl: “pijn” | en: “pain” and nl: “terug” | en: “back/to come back”; migraine: nl: “hoofdpijn” | en: “headache”, nl: “stress” | en: “stress” and nl: “misselijkheid” | en: “nausea”). Thematic and sentiment analysis of text revealed largely negative sentiment in texts by both patients with migraine and cluster headache. Logistic regression and support vector machine algorithms with different feature groups performed best for the classification of attack descriptions (with F1-scores for detecting cluster headache varying between 0.82 and 0.86) compared to naïve Bayes classifiers.

Conclusions

Differences in lexical choices between patients with migraine and cluster headache are detected with NLP and are congruent with domain expert knowledge of the disorders. Our research shows that ML algorithms have potential to classify patients’ self-reported narratives of migraine or cluster headache with good performance. NLP shows its capability to discern relevant linguistic aspects in narratives from patients with different headache disorders and demonstrates relevance in clinical information extraction. The potential benefits on the classification performance of larger datasets and neural NLP methods can be investigated in the future.

Trial registration

This study was registered with clinicaltrials.gov with ID NCT05377437.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01490-0.

Sex-related differences in cluster headache: A hospital-based study in Taiwan

OBJECTIVES

To compare the clinical profiles between male and female cluster headache patients from a large cohort.

METHODS

This hospital-based study enrolled patients diagnosed with cluster headache between 1997 to 2021. Participants completed structured questionnaires collecting information on demographics, clinical profiles, and quality of life. Treatment regimens and effectiveness were determined through medical chart review. All variables were compared between the sexes.

RESULTS

In total, 798 patients (M/F:659/139) were enrolled. The male-to-female ratio was 4.7:1 for the full study period, but it declined from 5.2:1 to 4.3:1 for patients enrolled before and after 2010, respectively. The frequencies of chronic cluster headache (M:1.2%, F:1.4%) and aura (M:0.3%, F:0.7%) were low but similar between the sexes. Most headache features showed no difference between men and women. Female patients had significantly longer attack duration, shorter inter-bout duration, higher frequencies for eyelid edema, nausea and vomiting and lower frequencies for conjunctival injection and pacing. Sex difference did not influence headache-associated disability, anxiety, or depression, but poor sleep quality was significantly more common in women. Among menstruating women, 22/122 (18.0%) reported worsening headaches during menses. The effectiveness of treatment was similar between the sexes.

CONCLUSIONS

Despite a decline of male-to-female ratio in the past two decades, most clinical profiles were similar between the sexes.

Guidelines of the International Headache Society for Controlled Clinical Trials in Cluster Headache

In 1995, a committee of the International Headache Society developed and published the first edition of the Guidelines for Controlled Trials of Drugs in Cluster Headache. These have not been revised. With the emergence of new medications, neuromodulation devices and trial designs, an updated version of the International Headache Society Guidelines for Controlled Clinical Trials in Cluster Headache is warranted. Given the scarcity of evidence-based data for cluster headache therapies, the update is largely consensus-based, but takes into account lessons learned from recent trials and demands by patients. It is intended to apply to both drug and neuromodulation treatments, with specific proposals for the latter when needed. The primary objective is to propose a template for designing high quality, state-of-the-art, controlled clinical trials of acute and preventive treatments in episodic and chronic cluster headache. The recommendations should not be regarded as dogma and alternative solutions to particular methodological problems should be explored in the future and scientifically validated.

Cluster Analysis Revealed Two Hidden Phenotypes of Cluster Headache

Objective

To investigate the possible subgroups of patients with Cluster Headache (CH) by using K-means cluster analysis.

Methods

A total of 209 individuals (mean (SD) age: 39.8 (11.3) years), diagnosed with CH by headache experts, participated in this cross-sectional multi-center study. All patients completed a semi-structured survey either face to face, preferably, or through phone interviews with a physician. The survey was composed of questions that addressed sociodemographic characteristics as well as detailed clinical features and treatment experiences.

Results

Cluster analysis revealed two subgroups. Cluster one patients (n = 81) had younger age at diagnosis (31.04 (9.68) vs. 35.05 (11.02) years; p = 0.009), a higher number of autonomic symptoms (3.28 (1.16) vs. 1.99(0.95); p < 0.001), and showed a better response to triptans (50.00% vs. 28.00; p < 0.001) during attacks, compared with the cluster two subgroup (n = 122). Cluster two patients had higher rates of current smoking (76.0 vs. 33.0%; p=0.002), higher rates of smoking at diagnosis (78.0 vs. 32.0%; p=0.006), higher rates of parental smoking/tobacco exposure during childhood (72.0 vs. 33.0%; p = 0.010), longer duration of attacks with (44.21 (34.44) min. vs. 34.51 (24.97) min; p=0.005) and without (97.50 (63.58) min. vs. (83.95 (49.07) min; p = 0.035) treatment and higher rates of emergency department visits in the last year (81.0 vs. 26.0%; p< 0.001).

Conclusions

Cluster one and cluster two patients had different phenotypic features, possibly indicating different underlying genetic mechanisms. The cluster 1 phenotype may suggest a genetic or biology-based etiology, whereas the cluster two phenotype may be related to epigenetic mechanisms. Toxic exposure to cigarettes, either personally or secondarily, seems to be an important factor in the cluster two subgroup, inducing drug resistance and longer attacks. We need more studies to elaborate the causal relationship and the missing links of neurobiological pathways of cigarette smoking regarding the identified distinct phenotypic classes of patients with CH.

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.

Diagnostic Delay and Its Predictors in Cluster Headache

Objective

Cluster headache (CH) is a rare, primary headache disorder, characterized of excruciating, strictly one-sided pain attacks and ipsilateral cranial autonomic symptoms. Given the debilitating nature of CH, delayed diagnosis can increase the disease burden. Thus, we aimed to investigate the diagnostic delay, its predictors, and clinical influence among patients with CH.

Methods

Data from a prospective multicenter CH registry over a 4-year period were analyzed. CH was diagnosed according to the International Classification of Headache Disorders (ICHD)-3 criteria, and diagnostic delay of CH was assessed as the time interval between the year of the first onset and the year of CH diagnosis. Patients were classified into three groups according to the tertiles of diagnostic delay (1st tertile, <1 year; 2nd tertile, 1–6 years; and 3rd tertile, ≥7 years).

Results

Overall, 445 patients were evaluated. The mean duration of diagnosis delay was 5.7 ± 6.7 years, (range, 0–36 years). Regarding the age of onset, majority of young patients (age <20 years) belonged to the third tertile (60%), whereas minority of old patients (>40 years) belonged to the third tertile (9.0%). For year of onset, the proportion of patients in the 3rd tertile was the highest for the groups before the publication year of the ICHD-2 (74.7%) and the lowest for the groups after the publication year of the ICHD-3 beta version (0.5%). Compared with the first CH, episodic CH [multivariable-adjusted odds ratio (aOR) = 5.91, 95% CI = 2.42–14.48], chronic CH (aOR = 8.87, 95% CI = 2.66–29.51), and probable CH (aOR = 4.12, 95% CI = 1.48–11.43) were associated with the tertiles of diagnostic delay. Age of onset (aOR = 0.97, 95% CI = 0.95–0.99) and PHQ-9 score (aOR = 0.96, 95% CI = 0.93–0.99) were inversely associated with the tertile of diagnostic delay. The prevalence of suicidal ideation was highest in the patients of the third tertile. The mean HIT-6 score increased significantly with the diagnostic delay (p = 0.041).

Conclusions

Patients with a younger onset of CH have a higher risk of diagnostic delay. Nevertheless, the rate of delayed diagnosis gradually improved over time and with the publication of the ICHD criteria, supporting the clinical significance of diagnostic clinical criteria and headache education to reduce the disease burden of CH.

History of cluster headache

Objective:

To summarise the history of cluster headache evolving concepts and growing insights.

Background:

Excruciating pain, activation of the parasympathetic nervous system, and circadian rhythmicity characterise cluster headache attacks.

Results:

We find the oldest descriptions of patients suffering from the disorder in case reports of the 17th and 18th centuries. Only in the 19th and early 20th centuries did physicians start hypothesizing its cause. Initially, many researchers suspected the origin of the pain in peripheral nerves or blood vessels. However, eventually, they understood that the cause of the disease lies in the brain. In 1998, Positron emission tomography studies revealed increased activity of the posterior hypothalamus, whose role remains incompletely understood. Only recently have researchers realised that being diseased implies more than dysfunction. Recent studies analysed the consequences of cluster headache for each patient. Many struggle to deal with the disorder even in the absence of pain.

Conclusion:

Physicians have been aware of this type of pain for at least 300 years. Only when researchers studied pathological anatomy and physiology did knowledge accrue. A more comprehensive picture of the disease severity emerged when they also considered its consequences.

Phenotype of Cluster Headache: Clinical Variability, Persisting Pain Between Attacks, and Comorbidities-An Observational Cohort Study in 825 Patients

INTRODUCTION

Cluster headaches can occur with considerable clinical variability. The inter- and intra-individual variability could contribute to the fact that the clinical headache phenotype is not captured by too strict diagnostic criteria, and that the diagnosis and the effective therapy are thereby delayed. The aim of the study was to analyze the severity and extent of the clinical symptoms of episodic and chronic cluster headaches with regard to their variability and to compare them with the requirements of the International Classification of Headache Disorders 3rd edition (ICHD-3) diagnostic criteria.

METHODS

The study was carried out as a cross-sectional analysis of 825 patients who had been diagnosed with cluster headaches by their physician. Using an online questionnaire, standardized questions on sociodemographic variables, clinical features of the cluster headache according to ICHD-3, and accompanying clinical symptoms were recorded.

RESULTS

The majority of patients with cluster headaches have clinical features that are mapped by the diagnostic criteria of ICHD-3. However, due to the variability of the symptoms, there is a significant proportion of clinical phenotypes that are not captured by the ICHD-3 criteria for cluster headaches. In addition, change in the side of the pain between the cluster episodes, pain location, as well as persisting pain between the attacks is not addressed in the ICHD-3 criteria. In the foreground of the comorbidities are psychological consequences in the form of depression, sleep disorders, and anxiety.

CONCLUSIONS

The variability of the phenotype of cluster headaches can preclude some patients from receiving an appropriate diagnosis and effective therapy if the diagnostic criteria applied are too strict. The occurrence of persisting pain between attacks should also be diagnostically evaluated due to its high prevalence and severity as well as psychological strain. When treating patients with cluster headaches, accompanying psychological illnesses should carefully be taken into account.

Cluster headache: a single tertiary center study

OBJECT

The characteristics of cluster headache (CH) patients in many countries and the diagnostic and therapeutic approach have been described in several publications, but so far no clinical data have been published from Turkey.

MATERIAL METHODS

This is a cross-sectional retrospective study that includes all patients who were diagnosed with CH and referred to our headache clinic, Dokuz Eylül University Faculty of Medicine, Neurology Department from 1991 to January 2018.

RESULTS

We included 114 patients (24 females and 90 males) in our study. The mean age at onset was 31.68 ± 12.72 (range 13-68). Eighty-six (78.18%) patients had episodic cluster headache (ECH) and 24 (21.82%) patients had chronic cluster headache (CCH). The age at onset was significantly higher in the patients with CCH than with ECH (p = 0.002). The most common location was orbitotemporal for both genders. The most common accompanying symptoms were lacrimation (80.73%). The male:female ratio in all patients was 3:7, 3.8:1 in those with CCH and 4:1 in those with ECH. Eighty-nine (87.25%) patients had prophylactic treatment and 60 of them received verapamil.

CONCLUSION

In our study, some clinical features of our patients were similar to those of Europe and America or the Asian countries and some of them not. There are regional differences in cluster headache patients. With more awareness of cluster headache and research from many countries, clinical differences can be revealed more objectively in the future.

A brief diagnostic screen for cluster headache: Creation and initial validation of the Erwin Test for Cluster Headache

OBJECTIVE

To use 1) newly generated data, 2) existing evidence, and 3) expert opinion to create and validate a new cluster headache screening tool.

METHODS

In phase 1 of the study, we performed a prospective study of an English translation of an Italian screen on 95 participants (45 with cluster headache, 17 with other trigeminal autonomic cephalalgias, 30 with migraine, and 3 with trigeminal neuralgia). In phase 2, we performed a systematic review in PubMed of all studies until September 2019 with diagnostic screening tools for cluster headache. In phase 3, a 6-person panel of cluster headache patients, research coordinators, and headache specialists analyzed the data from the first two phases to generate a new diagnostic screening tool. Finally, in phase 4 this new screen was validated on participants at a single headache center (all diagnoses) and through research recruitment (trigeminal autonomic cephalalgias only, as recruitment was essential but was otherwise low).

RESULTS

In total, this study included 319 unique participants including 109 cluster headache participants (95 total participants/45 cluster headache participants in phase 1, and 224 total participants/64 cluster headache participants in phase 4). It also found 123 articles on potential screening tools in our systematic review. In phase 1, analysis of the English translation of an Italian screen generated 7 questions with high sensitivity and specificity against migraine, trigeminal neuralgia, and other trigeminal autonomic cephalalgias, but had grammatical and other limitations as a general screening tool. In phase 2, the systematic review revealed nine studies that met inclusion criteria as diagnostic screening tools for cluster headache, including four where sensitivity and specificity were available for individual questions or small groups of questions. In phase 3, this data was reviewed by the expert panel to generate a brief (6-item), binary (yes/no), written screening test. In phase 4, a total of 224 participants completed the new 6-item screening test (81 migraine, 64 cluster headache, 21 other trigeminal autonomic cephalalgias, 35 secondary headaches, 7 neuralgias, 5 probable migraine, and 11 other headache disorders). Answers to the 6 items were combined in a decision tree algorithm and three items had a sensitivity of 84% (confidence interval or 95% confidence interval 73-92%), specificity of 89% (95% confidence interval 84-94%), positive predictive value of 76% (95% confidence interval 64-85%), and negative predictive value of 93% (95% confidence interval 88-97%) for the diagnosis of cluster headache. These three items focused on headache intensity, duration, and autonomic features.

CONCLUSION

The 3-item Erwin Test for Cluster Headache is a promising diagnostic screening tool for cluster headache.

Cluster headache in children and adolescents: a systematic review of case reports

AIM

To describe the clinical characteristics and therapeutic options available to paediatric patients with cluster headache.

METHOD

Based on a literature search of the medical databases PubMed, LILACS, and Web of Science and using selected descriptors, we carried out a systematic review of case reports on cluster headache in paediatric patients published from 1990 to 2020.

RESULTS

Fifty-one patients (29 males, 22 females) with a mean (SD) age of 9 years 7 months (3y 10mo; range 2-16y) were diagnosed with cluster headache. The mean (SD) diagnosis was made 27.8 months (26.2mo) after the onset of cluster headache. Pain occurred at night or on waking up (76.5%) and consisted of 1 to 3 attacks per day (62.7%) lasting 30 to 120 minutes (68.6%). Headaches were unilateral (90.2%), had a pulsatile character (64.7%), and severe intensity (100%). There were autonomic manifestations (90.2%) predominantly ipsilateral to pain, in this order: lacrimation; conjunctival injection; nasal congestion; ptosis; eyelid oedema; and rhinorrhoea. Sumatriptan and oxygen inhalation were the most effective treatments for acute manifestation. Prophylaxis, corticosteroids, verapamil, and gabapentin were the most effective drugs.

INTERPRETATION

Due to the small number of published studies, this review could not provide reliable data; however, it appears that cluster headache in children and adolescents is similar to adults, both in clinical characteristics and treatment. What this paper adds Cluster headache in children and adolescents is poorly studied. Cluster headache is uncommon before 10 years of age and diagnosis is difficult in the first few years of life. Treatment of cluster headache in children and adolescents is similar to that used in adults. The notion of the effectiveness of prophylactic treatment is based only on authors' experience.

Evidence That HFE H63D Variant Is a Potential Disease Modifier in Cluster Headache

Cluster headache (CH) is a primary headache disorder with a complex genetic background. Several studies indicate a potential link between iron homeostasis and the pathophysiology of primary headaches. The HFE gene encodes for a protein involved in iron metabolism, while genetic variants in HFE have been associated with hereditary hemochromatosis (HH), an iron overload disorder. The objective of the current study was to examine the association of the more common HFE H63D variant, with the susceptibility to develop CH and diverse clinical phenotypes in a population of Southeastern European Caucasian (SEC) origin. Genomic DNA samples from 128 CH patients and 294 neurologically healthy controls were genotyped for the HFE rs1799945 (H63D) variant. H63D genotypic and allelic frequency distribution did not differ significantly between patients and controls (p > 0.05). Subgroup analysis revealed a significantly more frequent occurrence of the variant G allele in chronic compared to episodic CH patients, indicative for a possible correlation of the HFE gene with the susceptibility for disease chronification. Although homozygosity for the less prevalent H63D variant G allele was minimal in the CH cohort, the results of the present study are in accordance with previous studies in CH and migraine patients, suggesting that HFE H63D variant modifies the disease clinical characteristics. Hence, despite the absence of a per se association with CH susceptibility in the current SEC cohort, variability in HFE gene may be potentially regarded as a disease modifier genetic factor in CH.

VDR Gene Polymorphisms and Cluster Headache Susceptibility: Case-Control Study in a Southeastern European Caucasian Population

Cluster headache (CH) is a severe primary headache disorder with a genetic component, as indicated by family and twin studies. Diurnal and seasonal rhythmicity are key features of the disease and might be related to vitamin D, as low vitamin D levels have been observed in patients with cluster headache. In addition, the vitamin D receptor (VDR) occurs in brain areas and particularly in the hypothalamus. The aim of the present case-control study was to investigate the association of cluster headache susceptibility and clinical phenotypes with the VDR gene polymorphisms FokI, BsmI and TaqI in a Southeastern European Caucasian population. DNA was extracted from 131 unrelated CH patients and 282 non-headache controls and genotyped using real-time PCR (melting curve analysis). Linkage disequilibrium (LD) analysis confirmed that BsmI and TaqI, both located in the 3'UTR of the VDR gene, are in strong LD. Genotype and allele frequency distribution analysis of the VDR FokI, BsmI, and TaqI polymorphisms showed no statistically significant difference between cases and controls, whereas haplotype analysis indicated that the TAC haplotype might be associated with decreased cluster headache susceptibility. Intra-patient analysis according to diverse clinical phenotypes showed an association of the BsmI GG and TaqI TT genotypes with more frequent occurrence of CH attacks in this cohort. Therefore, a possible association was observed between VDR gene polymorphisms BsmI and TaqI or a linked locus and susceptibility for cluster headache development and altered clinical phenotypes in the Southeastern European Caucasian study population. Further large-scale replication studies are needed to validate these findings.

Pediatric-onset trigeminal autonomic cephalalgias: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

There are five headache disorders composing the trigeminal autonomic cephalalgias (cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), and hemicrania continua). Little is known about these disorders in the pediatric population. The objectives of this study are to report the full age ranges of pediatric trigeminal autonomic cephalalgias and to determine if pediatric-onset trigeminal autonomic cephalalgias display similar signs and symptoms as adult onset.

METHODS

Search criteria in Medline Ovid, Embase, PsycINFO, and Cochrane Library were created by a librarian. The remainder of the steps were independently performed by two neurologists using PRISMA guidelines. Inclusion criteria for titles and abstracts were articles discussing cases of trigeminal autonomic cephalalgias with age of onset 18 or younger, as well as any epidemiological report on trigeminal autonomic cephalalgias (as age of onset data was often found in the results section but not in the title or abstract). Data extracted included age of onset, sex, and International Classification of Headache Disorders criteria for trigeminal autonomic cephalalgias (including pain location, duration, frequency, autonomic features, restlessness) and some migraine criteria (photophobia, phonophobia, and nausea). Studies that did not meet full criteria for trigeminal autonomic cephalalgias were examined separately as "atypical trigeminal autonomic cephalalgias"; secondary headaches were excluded from this category.

RESULTS

In all, 1788 studies were searched, 86 met inclusion criteria, and most (56) examined cluster headache. In cluster headache, onset occurred at every pediatric age (range 1-18 years) with a full range of associated features. Autonomic and restlessness features were less common in pediatric patients, while migrainous features (nausea, photophobia, and phonophobia) were found at similar rates. The sex ratio of pediatric-onset cluster headache (1.8, 79 male and 43 female) may be lower than that of adult-onset cluster headache. Data for other trigeminal autonomic cephalalgias, while more limited, displayed most of the full range of official criteria. The data for atypical trigeminal autonomic cephalalgias were also limited, but the most common deviations from the official criteria were abnormal frequencies and locations of attacks.

CONCLUSIONS

Trigeminal autonomic cephalalgias can start early in life and have similar features to adult-onset trigeminal autonomic cephalalgias. Specifically, pediatric-onset cluster headache patients display the full range of each criterion for cluster headache (except maximum frequency of six instead of eight attacks per day). However, cranial autonomic features and restlessness occur at a lower rate in pediatrics. Additional information is needed for the other trigeminal autonomic cephalalgias. As for expanding the ICHD-3 criteria for pediatric-onset trigeminal autonomic cephalalgias, we have only preliminary data from atypical cases, which suggests that the frequency and location of attacks sometimes extend beyond the official criteria.Trial Registration: This study was registered as a systematic review in PROSPERO (registration number CRD42020165256).

Insights into real-world treatment of cluster headache through a large Italian database: prevalence, prescription patterns, and costs

Objective: This study aimed at estimating the treated cluster headache (CH) prevalence and describing prescription patterns and direct costs paid by the Italian National-Health-System.Methods: Through the ReS database (healthcare administrative data collection of a large sample of the Italian population), adults in treatment for CH (acute therapy with sumatriptan/subcutaneous or oxygen, associated with preventive therapy with verapamil or lithium) were selected. A cross-sectional analysis described the prevalence of CH-treated subjects repeated annually in 2013-2017. A longitudinal analysis of patients selected in 2013-2015 and followed for 2 years provided the prescription patterns.Results: The annual prevalence of CH-treated patients increased from 6.4×100,000 adults in 2013 to 6.7 in 2017. In 2013-2015, 570 patients (80.7% M; mean age 46) treated for CH were found. In 50.4%, the identifying CH treatment was sumatriptan/subcutaneous+verapamil. During follow-up, >1/3 changed the preventive drug and interruption was the most frequent modification, although acute treatments were still prescribed. The mean annual cost/patient ranged from €2,956 to €2,267; pharmaceuticals expenditure represented the 56.4% and 57.3%, respectively.Conclusions: This study showed an important unmet need among CH patients, carrying a high economic burden that should be considered in the evaluation of the impact of incoming therapies (e.g. Calcitonin-Gene-Related-Peptide antibodies).

Cefaleia em Salvas em Crianças e Adolescentes: Uma revisão sistemática de relatos de casos

OBJETIVO

Descrever as características clínicas e as melhores opções terapêuticas para cefaleia em salvas na idade pediátrica. MÉTODO: Com base em pesquisa bibliográfica nas bases de dados médicos PubMed, LiLacs e WoS e usando descritores selecionados, analisamos todos os relatos de casos de cefaleia em salvas em idade pediátrica publicados de 1990 a 2020.

RESULTADOS

Cinquenta e um pacientes (29 meninos e 22 meninas) com idade média (DP) de 9 anos e 7 meses (3 anos e 10 meses), variando de 2 a 16 anos, foram diagnosticados com cefaleia em salvas. O diagnóstico médio (DP) foi feito 27,8 meses (26,2 meses) após o início da cefaleia em salvas. A dor ocorreu à noite ou ao despertar (76,5%), uma a três crises por dia (62,7%), com duração de 30-120 minutos (68,6%), localizada unilateralmente (90,2%), de caráter pulsátil (64,7%) e intensidade severa (100%). Houve manifestações autonômicas (90,2%), predominantemente ipsilaterais à dor, nesta ordem: lacrimejamento, injeção conjuntival, congestão nasal, ptose, edema palpebral e rinorreia. Sumatriptano e inalação de oxigênio foram os tratamentos agudos mais eficazes. Na profilaxia, corticosteroides, verapamil e gabapentina foram os medicamentos mais eficazes. INTERPRETAÇÃO: Devido ao pequeno número de estudos publicados, esta revisão não foi capaz de fornecer dados confiáveis, mas parece que a cefaleia em salvas em crianças e adolescentes é semelhante à do adulto, tanto nas características clínicas quanto no tratamento.

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.

Recently available and emerging therapeutic strategies for the acute and prophylactic management of cluster headache: a systematic review and expert opinion

Introduction: Although it causes a huge burden to sufferers, cluster headache (CH), remains an undertreated condition, partly due to the absence of established acute and prophylactic treatment options. New therapeutic approaches providing fast and safe relief from CH are needed. Areas covered: A systematic review was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendation on recently published (last 5 years) papers on CH treatment. The authors also collected preliminary results from ongoing trials on emerging therapeutic/preventive pharmacological and interventional approaches for CH. Studies and results are reviewed and discussed. Expert opinion: The complexity of CH pathophysiology prevents the definition of reliable acute and preventive treatments. In the real-world clinical setting, several treatments are combined to provide relief to patients and increase their quality of life. Drugs targeting neuropeptides or their receptors within the trigeminovascular network are of particular interest to prevent CH attacks. Calcitonin gene-related peptide (CGRP) blockade seems attractive and promising, but studies on anti-CGRP monoclonal antibodies indicated rather modest or even absence of a prophylactic effect. A deeper insight into CH pathophysiology, and combined approaches may lead the path to new, more effective, and personalized CH therapies.

Real-life treatment of cluster headache in a tertiary headache center - results from the Danish Cluster Headache Survey

BACKGROUND

Pharmacological treatment of cluster headache constitutes the core of clinical management, but evidence is sparse. We aimed to generate insight in the existing treatment and identify associations between clinical features and treatment response.

METHODS

Patients aged 18-65 diagnosed with cluster headache according to the ICHD-2 completed a questionnaire followed by a structured interview. Multiple logistic regression was used to identify associations.

RESULTS

The population consisted of 400 patients with an episodic: chronic ratio of 1.7:1. Episodic patients were more likely to respond to triptans (odds ratio = 1.77, confidence interval: 1.08-2.91, p = 0.023) and oxygen (odds ratio = 1.64, confidence interval: 1.05-2.57, p = 0.031) than chronic. Oxygen response was less likely if pain intensity was very severe (odds ratio = 0.53, confidence interval: 0.33-2.57, p = 0.006) and the risk of a poor response increased with disease duration (odds ratio = 0.79, confidence interval: 0.65-0.96, p = 0.016). Among current users of sumatriptan injection and oxygen, the proportion achieving 100% relief was higher with sumatriptan injection (p > 0.001) than with oxygen. No associations were identified regarding verapamil. Only 57% of current users of preventive medication responded at a 50% level.

CONCLUSION

Episodic cluster headache is more responsive to acute therapy than chronic. Further, sumatriptan injection was more effective than oxygen and the responder-rate was limited with verapamil. More effective acute and preventive therapies are needed for cluster headache patients.

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.

Development and Evaluation of a Screening Tool to Aid the Diagnosis of a Cluster Headache

Cluster headache (CH), a severe primary headache, is often misdiagnosed and mismanaged. The aim of this study was to develop and evaluate a screening tool to aid the diagnosis of CH. We developed a novel 12-item screening tool. This was comprised of four components: (1) images depicting headache pain; (2) pain descriptors; (3) key questions that could differentiate between CH and migraine; and (4) a visual analogue pain scale. The total possible questionnaire score ranged from 3-32. Patients with CH and migraines (control group) were recruited prospectively from a headache centre in the North of England, UK. Two-hundred and ninety-six patients were included in the study: 81 CH patients, 36 of which suffer with episodic CH and 45 with chronic CH; 215 migraine patients, 92 of which suffer with episodic migraine and 123 with chronic migraine. The mean questionnaire score was higher in CH patients versus migraine patients (28.4 versus 19.5). At a cut-off score of >25 out of 32, the screening tool had a sensitivity of 86.4% and a specificity of 92.0% in differentiating between CH and migraine. The screening tool could be a useful instrument to aid the diagnosis of a CH. The images depicting headache pain do not clearly discriminate between CH and migraine.

Analysis of HCRTR2, GNB3, and ADH4 Gene Polymorphisms in a Southeastern European Caucasian Cluster Headache Population

Studies point to an increased hereditary risk of cluster headache. HCRTR2 gene rs2653349 and ADH4 gene rs1800759 polymorphisms have been associated with cluster headache susceptibility. Also, GNB3 rs5443 polymorphism, associated with increased signal transduction via GPCRs, seems to influence triptan treatment response. DNA from 114 cluster headache patients and 570 non-related controls, representing a general Southeastern European Caucasian (SEC) population, was extracted from buccal swabs and genotyped using real-time PCR. Gene distribution for the rs2653349 was GG = 79.8%, GA = 18.4%, and AA = 1.8% for patients and GG = 79.1%, GA = 19.1%, and AA = 1.8% for controls. The frequency of the mutated A allele was 11.0% for patients and 11.3% for controls. The frequencies for rs5443 were CC = 44.7%, CT = 44.7%, and TT = 10.5% for patients and CC = 43.9%, CT = 42.6%, and TT = 13.5% for controls. The frequency of the mutated T allele was 32.9% for patients and 34.8% for controls. A 2.7-fold more frequent appearance of the mutated T allele was observed in patients with better triptan treatment response, although not statistically significant. For rs1800759, the frequencies were CC = 36.0%, CA = 43.0%, and AA = 21.0% for patients and CC = 34.0%, CA = 50.2%, and AA = 15.8% for controls. The frequency of the mutated A allele was 42.5% and 40.9% for patients and controls, respectively. The mutated T allele of GNB3 rs5443 polymorphism was more prevalent in patients with better triptan treatment response, indicating a possible trend of association between this polymorphism and triptan treatment response in SEC population. According to our observation, no association of HCRTR2 rs2653349 and ADH4 rs1800759 polymorphisms and cluster headache in SEC population could be documented.

The EUROLIGHT cluster headache project: Description of methods and the study population – An Internet-based cross-sectional study of people with cluster headache

Objective:

To present the methodology and to describe the sample of a large, Internet-based survey on the burden of cluster headache (CH).

Methods:

Participants filled out a questionnaire online. Inclusion criteria were a reported diagnosis of CH and a residency in a European country; exclusion criteria were refusal to give informed consent and to complete the questionnaire.

Results:

A total of 1514 participants completed the questionnaire. Of these, 66.2% were male and 31.2% reported suffering from chronic CH. The diagnosis was validated based upon the responses in 92.9% of the participants. Other diagnoses seemed more likely in 0.8%. Among the participants with self-reported chronic CH, the International Classification of Headache Disorders-3 beta criteria for chronicity were fulfilled by 90.8%.

Conclusions:

In this article, we discuss the applied methodology as well as the properties of the sample. The overall accuracy of the self-reported diagnoses was very good as judged by our questionnaire; women and chronic CH were slightly over-represented. We will present the results of more thorough analyses in future articles and believe that these data will provide deeper insights into the burden of CH and will help to give a voice to those who endure this painful disease.

Diagnostic delay of cluster headache: A cohort study from the Danish Cluster Headache Survey

Aim

To investigate the influence of clinical and demographic features on diagnostic delay in cluster headache patients, in order to discuss diagnostic pitfalls and raise disease awareness.

Methods

A large, well-characterized cohort of 400 validated cluster headache patients from the Danish Cluster Headache Survey, diagnosed according to ICHD-II, were investigated. ANOVA was applied to investigate differences in diagnostic delay between groups. Selected independent variables were assessed in relation to diagnostic delay using a gamma regression model.

Results

Diagnostic delay was significantly reduced for each decade of cluster headache onset from 1950–2010 ( p < 0.001). Onset after 1990 was associated with shorter diagnostic delay (OR = 0.28, p < 0.001), whereas attack duration > 180 minutes (OR = 1.62, p < 0.034), migraine-like features (OR = 1.30, p < 0.043) and nocturnal attacks (OR = 1.39, p < 0.021) were associated with prolonged diagnostic delay. Further, diagnostic delay decreased with age of onset (age < 20: 13.8 years, age 20–40: 5.4 years and age > 40: 2.1 years, p < 0.001).

Conclusion

Diagnostic delay was reduced for every decade investigated, whereas some atypical cluster headache features were associated with prolonged diagnostic delay. Better medical education and more disease awareness are needed to prevent misdiagnosis and prolonged diagnostic delay.

Systematic literature review on the delays in the diagnosis and misdiagnosis of cluster headache

INTRODUCTION

Patients with cluster headache (CH), the most common trigeminal autonomic cephalalgia, often face delayed diagnosis, misdiagnosis and mismanagement.

OBJECTIVES

To identify, appraise and synthesise clinical studies on the delays in diagnosis and misdiagnosis of CH in order to determine its causes and help the management of this condition.

METHODS

The systematic review was prepared, conducted and reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis. It was registered with International Prospective Register of Systematic Reviews. A systematic search of different electronic databases (Medline, EMBASE, PsycINFO, PubMed, CINAHL, BNI, HMIC, AMED, HBE and Cochrane Library) was carried out in May 2017. Reference lists of relevant articles were hand searched.

RESULTS

The search identified 201 unique studies. Fifteen studies met the inclusion criteria of which 13 case series studies and two survey studies. Nine studies assessed the delays in diagnosis and misdiagnosis of CH, five studies the delays in diagnosis and one study the misdiagnosis of CH. The studies included 4661 patients. Delays in diagnosis, misdiagnosis and mismanagement have been reported in many European countries, Japan and in the USA with well-developed health services. The patients with CH often visited many different clinicians, surgeons and dentists and received multiple diagnosis prior to being correctly diagnosed.

CONCLUSION

This systematic review shows that the delays in the diagnosis of CH are a widespread problem, the time to diagnosis still vary from country to country and both patients and physicians are responsible for the delays in diagnosis.

Childhood-Onset Cluster Headache: Observations From a Personal Case-Series and Review of the Literature

BACKGROUND/OBJECTIVES

Puberty seems to be a turning point in cluster headache (CH) onset. To verify its influence on CH phenotype, we focused on cases with onset ≤13 years. A review of the literature follows.

METHOD

We considered CH cases with age-of-onset ≤13 years evaluated at our center between 1975 and 2015; these cases were matched by sex to two consecutive patients with age-of-onset as close as possible (±2 years) to the median age-of-onset of the overall CH population.

RESULTS

Of the overall 808 cases (585 men and 223 women, M:F ratio = 2.6), 38 patients (20 men and 18 women, M:F ratio = 1.1) had pediatric onset (PO). The diagnostic delay was significantly higher among cases with PO (21.2 ± 12.4 years, P < .0001). In this group, females had more frequently a chronic course and a familiarity for CH. Men with PO had some significant distinctive features, including higher frequency and longer duration of headache attacks, and higher proportion of various cranial autonomic and migraine-like symptoms.

CONCLUSIONS

We confirmed that CH with childhood onset does not show a male predominance, which was actually inverted for chronic cases. Furthermore, males with PO seem to have a specific clinical phenotype.