Cluster headache diagnostic delay and its predictors: a systematic review with a meta-analysis

BACKGROUND

Despite its characteristic clinical expression, cluster headache (CH) often remains unrecognized in clinical practice, with patients suffering from CH having to wait a long time before receiving a correct diagnosis and benefit from appropriate treatment.

METHODS

This work is a systematic review of data accessible through PubMed and published up to December 2024, focusing on the delay in CH diagnosis and its predictors. A meta-analysis was performed to estimate the mean CH diagnostic delay using the inverse of variance as the weight. A qualitative analysis was performed to identify predictors of this delay.

RESULTS

Among the 108 studies identified, 22 and 11 were selected for the qualitative analysis and meta-analysis respectively. These selected studies included a total of 8654 subjects (range 23-1604). This whole population was composed of 6383 men, 2180 women and 91 subjects with sex not specified. CH form was indicated for 7177 subjects with 5808, 1182 and 187 with episodic CH, chronic CH and undetermined form respectively. Meta-analysis estimated the overall CH diagnostic delay at 10,43 years (95% CI [9.09; 11.77]) with a reduction in the CH diagnostic delay over time since the sixties and the continuation of such a reduction every decade since 2000. Qualitative analyses identified several predictors of this diagnostic delay. Autonomic symptoms were associated with a decrease in the delay of diagnosis, whereas lower age of CH onset, alternating attack side and nocturnal headaches were associated with an increase in the delay of diagnosis.

CONCLUSION

This systematic review including meta-analysis confirms an important unmet need in terms of CH diagnosis. Further work is needed to identify more precisely the predictors of this delay for better management of patients suffering from CH. TRIAL REGISTRATION: The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 01/10/2025 (registration number: CRD42025630779).

Headache Phenotype and the Psychosocial Burden of Cluster Headaches: An Analysis of Patients Prior to Hospitalization

INTRODUCTION

The specific headache phenotype, accompanying symptoms and psychological impact that lead to admission of patients with cluster headache are not yet known. The aim of this study was therefore to analyze the characteristics of patients who were admitted to a tertiary headache center in 2018, 2019 and 2020 due to cluster headache.

METHODS

A total of 207 patients with cluster headache were examined, who were admitted to the Kiel Headache Center, a tertiary headache center in Germany, in the years 2018, 2019, and 2020. A retrospective cohort study was conducted to analyze the phenotype and psychosocial impact of cluster headaches in a standardized manner. The data were collected based on information from the standardized Kiel Headache Questionnaire, the Migraine Disability Assessment (MIDAS) questionnaire, and the World Health Organization (WHO) Disability Assessment Schedule (WHODAS 2.0).

RESULTS

Most of the patients had a chronic course of disease over many years, and 71.5% had had the disease for more than 5 years. Cluster headache attacks occurred in 98.6% of the patients, with strong to very strong pain intensity, and more than 78% of the patients experienced three or more attacks per day. Nighttime occurrence led to severe sleep disturbances with exhaustion, a lack of energy, and an inability to work. In 31.4% of the patients, persistent pain in the area also contributed to the inability to work. A total of 94.7% of the patients had a MIDAS score of grade 4. The analysis of the WHODAS 2.0 score revealed that 92.7% of the patients with cluster headaches experienced severe limitations in their health and functionality. These individuals were particularly severely affected by the accompanying psychological symptoms and the psychosocial impact of cluster headaches. The highly stressful complications of cluster headaches were particularly evident in the high frequency of suicidal ideation in more than 40% of the patients examined. Severe illness affected almost all areas of professional, social, and family life and caused a very high level of suffering.

CONCLUSIONS

The results revealed a pronounced, severe symptom complex in patients with cluster headaches that went far beyond the purely diagnostic criteria. The psychosocial impact of cluster headaches should be given close attention in the care of these patients.

Consistency between headache diagnoses and ICHD-3 criteria across different levels of care

BACKGROUND

Diagnosing headache disorders poses significant challenges, particularly in primary and secondary levels of care (PSLC), potentially leading to misdiagnosis and underdiagnosis. This study evaluates diagnostic agreement for migraine, tension-type headache (TTH), and cluster headache (CH) between PSLC and tertiary care (TLC) and assesses adherence to the International Classification of Headache Disorders 3rd edition (ICHD-3) guidelines.

METHODS

A retrospective, cross-sectional analysis was conducted at Charité - Universitätsmedizin Berlin's tertiary headache center. The patients' self-reported diagnoses from the PSLC were compared with those in TLC and with ICHD-3 criteria. Cohen's kappa (κ) and R² were used to assess diagnostic agreement.

RESULTS

Among 1,468 patients (43.4 ± 14.4 years; 74.5% women), 69.5% reported a diagnosis in PSLC, and 99.5% were diagnosed at their first TLC visit. Overall agreement between PSLC and TLC was 80% (κ = 0.55; R²=30%). Agreement between the PSLC and ICHD-3 was 77% for migraine, 82% for TTH, and 96% for CH (κ = 0.65; R²=41%). TLC diagnoses aligned with ICHD-3 in over 90%.

CONCLUSION

Our findings indicate a significant degree of diagnostic agreement across different levels of care according to the ICHD-3 guidelines. However, there remains insufficient reliability in clinical diagnostics, highlighting the need for continued efforts to improve the early recognition and diagnostic accuracy and consistency of primary headaches to optimize patient care and treatment outcomes in Germany.

Healthcare resource use and costs associated with the misdiagnosis of migraine

OBJECTIVE

To compare healthcare resource utilization and healthcare costs in patients with migraine with or without a history of misdiagnosis.

BACKGROUND

Despite the high prevalence of migraine, migraine is commonly misdiagnosed. The healthcare resource use and cost burden of a misdiagnosis is unknown.

METHODS

This retrospective cohort study identified adults with an incident migraine diagnosis from the Merative™ Marketscan® Commercial and Medicare Supplemental Databases between June 2018 and 2019. Patients with a diagnosis of commonly considered misdiagnoses (headache, sinusitis, or cervical pain) before their migraine diagnosis were classified as the "misdiagnosed cohort." Patients in the misdiagnosed cohort were potentially misdiagnosed, then eventually received a correct diagnosis. Patients without a history of commonly considered misdiagnoses prior to their migraine diagnosis were classified as the "correctly diagnosed cohort." Healthcare resource utilization and healthcare costs were assessed in the period before migraine diagnosis and compared between the cohorts. Outcomes were reported as per patient per month and compared with incidence rate ratios.

RESULTS

A total of 29,147 patients comprised the correctly diagnosed cohort and 3841 patients comprised the misdiagnosed cohort and met the inclusion criteria. Patients in the misdiagnosed cohort had statistically significantly higher rates of inpatient admissions (0.02 vs. 0.01, incidence rate ratio [IRR] 1.61, 95% confidence interval [CI] 1.47-1.74), emergency department visits (0.10 vs. 0.05; IRR 1.89, 95% CI 1.79-1.99), neurologist visits (0.12 vs. 0.02; IRR 5.95, 95% CI 5.40-6.57), non-neurologist outpatient visits (2.64 vs. 1.58; IRR 1.67, 95% CI 1.62-1.72) and prescription fills (2.82 vs. 1.84; IRR 1.53, 95% CI 1.48-1.58) compared to correctly diagnosed patients. Misdiagnosed patients had statistically significantly higher rates of healthcare cost accrual for inpatient admissions ($1362 vs. $518; IRR 2.62, 95% CI 2.50-2.75), emergency department visits ($222 vs. $98; IRR 2.27, 95% CI 2.18-2.36), neurologist visits ($42 vs. $9; IRR 4.39, 95% CI 4.00-4.79), non-neurologist outpatient visits ($1327 vs. $641; IRR 2.07, 95% CI 1.91-2.24), and prescription fills ($305 vs. $215; IRR 1.41, 95% CI 1.18-1.70) compared to correctly diagnosed patients.

CONCLUSION

Patients with migraine who have a history of misdiagnoses have higher rates of healthcare resource utilization and cost accrual versus those without such history.

Time and headache: Insights into timing processes in primary headache disorders for diagnosis, underlying pathophysiology and treatment implications

BACKGROUND

Time in headache disorders is crucial for diagnosis and gives insight into headache pathophysiology.

OBJECTIVE

To summarize published studies which describe timing processes in both attack presentation (onset, duration) and disease characterization (age of onset, evolution over time) in primary headache disorders and link to pathophysiology.

METHODS

A comprehensive search was conducted through Ovid MEDLINE(R) and PubMed, focusing on English-language articles from 1946 to 2023 to write the review. The International Classification of Headache Disorders, 3rd edition provided the framework for the review of primary headache disorders (migraine, tension-type headache and cluster headache).

RESULTS

Attack presentation: Migraine attacks exhibit significant circadian and infradian rhythms, influenced by hormonal levels, light sensitivity, and hypothalamic activation. Tension-type headache lacks clear chronobiological patterns, with limited understanding of its underlying mechanisms. Cluster headache displays a distinct circannual pattern, with attacks often occurring at night and relevant involvement of the hypothalamus. Disease characterization: Age of onset exhibits the earliest peak in migraine; frequency and typical features of primary headache disorders decrease over time.

CONCLUSION

This comprehensive analysis of time patterns in primary headache disorders underscores their role in phenotyping, understanding and treating primary headache disorders, offering promising avenues for advancing and tailoring headache management.

Recent advances in diagnosing, managing, and understanding the pathophysiology of cluster headache

Cluster headache, characterised by attacks of severe, recurrent, unilateral headache and ipsilateral cranial autonomic symptoms, remains a primary headache with an elusive pathophysiology. Recent advances have introduced effective treatments and broadened understanding of the clinical features of cluster headache. These features are similar in patients globally, but regional differences in prevalence and burden exist. International collaborations have led to identification of eight genetic loci associated with cluster headache. The pathophysiological mechanisms are still not fully understood but recent studies show that targeting the trigeminal autonomic reflex by neurostimulation, or targeting the neuropeptide calcitonin gene-related peptide (CGRP), might lessen the attack burden. The US Food and Drug Administration has approved galcanezumab, a monoclonal antibody targeting CGRP, as the first specific preventive treatment for episodic cluster headache. However, a preventive effect was not replicated in chronic cluster headache, and the European Medicines Agency did not approve galcanezumab, restricting its availability in Europe. Owing to the low prevalence of cluster headache, continued collaboration through multicentre clinical trials and data sharing will be imperative for further breakthroughs in understanding and management.

Cluster headache: an update on clinical features, epidemiology, pathophysiology, diagnosis, and treatment

Cluster headache (CH) is one of the worst primary headaches that remain underdiagnosed and inappropriately treated. There are recent advances in the understanding of this disease and available treatments. This paper aims to review CH's recent clinical and pathophysiological findings, diagnosis, and treatment. We performed a narrative literature review on the socio-demographics, clinical presentations, pathophysiological findings, and diagnosis and treatment of CH. CH affects 0.1% of the population with an incidence of 2.07-9.8/100,00 person-years-habitants, a mean prevalence of 53/100,000 inhabitants (3-150/100,000 inhabitants). The male-to-female ratio remains inconclusive, as the ratio of 4.3:1 has recently been modified to 1.3-2.6, possibly due to previous misdiagnosis in women. Episodic presentation is the most frequent (80%). It is a polygenetic and multifactorial entity that involves dysfunction of the trigeminovascular system, the trigeminal autonomic reflex, and the hypothalamic networks. An MRI of the brain is mandatory to exclude secondary etiologies. There are effective and safe pharmacological treatments oxygen, sphenopalatine, and great occipital nerve block, with the heterogeneity of clinical trial designs for patients with CH divided into acute, transitional, or bridge treatment (prednisone) and preventive interventions. In conclusion, CH remains underdiagnosed, mainly due to a lack of awareness within the medical community, frequently causing a long delay in reaching a final diagnosis. Recent advances in understanding the principal risk factors and underlying pathophysiology exist. There are new therapeutic possibilities that are effective for CH. Indeed, a better understanding of this challenging pathology will continue to be a subject of research, study, and discoveries in its diagnostic and therapeutic approach.

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.

The World Health Organization Intersectoral Global Action Plan on Epilepsy and Other Neurological Disorders and the headache revolution: from headache burden to a global action plan for headache disorders

The World Health Organization (WHO) Intersectoral Global Action Plan on Epilepsy and Other Neurological Disorders was developed by WHO to address the worldwide challenges and gaps in provision of care and services for people with epilepsy and other neurological disorders and to ensure a comprehensive, coordinated response across sectors to the burden of neurologic diseases and to promote brain health across life-course. Headache disorders constitute the second most burdensome of all neurological diseases after stroke, but the first if young and midlife adults are taken into account. Despite the availability of a range of treatments, disability associated with headache disorders, and with migraine, remains very high. In addition, there are inequalities between high-income and low and middle income countries in access to medical care. In line with several brain health initiatives following the WHOiGAP resolution, herein we tailor the main pillars of the action plan to headache disorders: (1) raising policy prioritization and strengthen governance; (2) providing effective, timely and responsive diagnosis, treatment and care; (3) implementing strategies for promotion and prevention; (4) fostering research and innovation and strengthen information systems. Specific targets for future policy actions are proposed. The Global Action Plan triggered a revolution in neurology, not only by increasing public awareness of brain disorders and brain health but also by boosting the number of neurologists in training, raising research funding and making neurology a public health priority for policy makers. Reducing the burden of headache disorders will not only improve the quality of life and wellbeing of people with headache but also reduce the burden of neurological disorders increasing global brain health and, thus, global population health.

Clinical characteristics and treatment patterns of patients with episodic cluster headache: results from the United States, United Kingdom and Germany

OBJECTIVE

To describe clinical characteristics and regional treatment patterns of episodic cluster headache (CH).

METHODS

A point-in-time survey of physicians and their patients with CH was conducted in the United States, United Kingdom and Germany in 2017.

RESULTS

Overall, 1012 patients with episodic CH were analyzed. Demographic and clinical findings were generally consistent across regions. Most patients were men (66.6%) and the mean age was 40.9 years. The greatest proportion of patients (38.3%) had ≤1 attack per day. The mean number of attacks per day (APD) was 2.4 and mean number of cluster periods per year was 2.6; the mean cluster period duration was 30.8 days. Most patients (69.3%) did not report a specific or predicable time when cluster periods occurred. Acute treatment was prescribed for 47.6% of patients, 10.3% of patients received preventive treatment, and 37.9% of patients received combined acute and preventive treatment; 4.2% of patients were not receiving treatment. Frequently prescribed acute treatments were sumatriptan, oxygen, and zolmitriptan; oxygen use varied considerably across countries and was prescribed least often in the United States. Frequently prescribed preventive treatments were verapamil, topiramate, and lithium. Lack of efficacy and tolerability were the most common reasons for discontinuing preventive treatment.

CONCLUSIONS

We observed high use of acute treatments, but only half of patients used preventive treatments despite experiencing several cluster periods per year with multiple cluster APD. Further studies about the need for and benefits of preventive treatment for episodic CH are warranted.

European Academy of Neurology guidelines on the treatment of cluster headache

BACKGROUND AND PURPOSE

Cluster headache is a relatively rare, disabling primary headache disorder with a major impact on patients' quality of life. This work presents evidence-based recommendations for the treatment of cluster headache derived from a systematic review of the literature and consensus among a panel of experts.

METHODS

The databases PubMed (Medline), Science Citation Index, and Cochrane Library were screened for studies on the efficacy of interventions (last access July 2022). The findings in these studies were evaluated according to the recommendations of the European Academy of Neurology, and the level of evidence was established using GRADE (Grading of Recommendations Assessment, Development, and Evaluation).

RECOMMENDATIONS

For the acute treatment of cluster headache attacks, there is a strong recommendation for oxygen (100%) with a flow of at least 12 L/min over 15 min and 6 mg subcutaneous sumatriptan. Prophylaxis of cluster headache attacks with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy and tolerability) is recommended. Corticosteroids are efficacious in cluster headache. To reach an effect, the use of at least 100 mg prednisone (or equivalent corticosteroid) given orally or at up to 500 mg iv per day over 5 days is recommended. Lithium, topiramate, and galcanezumab (only for episodic cluster headache) are recommended as alternative treatments. Noninvasive vagus nerve stimulation is efficacious in episodic but not chronic cluster headache. Greater occipital nerve block is recommended, but electrical stimulation of the greater occipital nerve is not recommended due to the side effect profile.

Current treatment options for cluster headache: limitations and the unmet need for better and specific treatments-a consensus article

AIM

Treatment for cluster headache is currently based on a trial-and-error approach. The available preventive treatment is unspecific and based on few and small studies not adhering to modern standards. Therefore, the authors collaborated to discuss acute and preventive treatment in cluster headache, addressing the unmet need of safe and tolerable preventive medication from the perspectives of people with cluster headache and society, headache specialist and cardiologist.

FINDINGS

The impact of cluster headache on personal life is substantial. Mean annual direct and indirect costs of cluster headache are more than 11,000 Euros per patient. For acute treatment, the main problems are treatment response, availability, costs and, for triptans, contraindications and the maximum use allowed. Intermediate treatment with steroids and greater occipital nerve blocks are effective but cannot be used continuously. Preventive treatment is sparsely studied and overall limited by relatively low efficacy and side effects. Neurostimulation is a relevant option for treatment-refractory chronic patients. From a cardiologist's perspective use of verapamil and triptans may be worrisome and regular follow-up is essential when using verapamil and lithium.

CONCLUSION

We find that there is a great and unmet need to pursue novel and targeted preventive modalities to suppress the horrific pain attacks for people with cluster headache.

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.

Therapy for Psychiatric Comorbidities in Patients with Episodic Cluster Headache: A Prospective Multicenter Study

PURPOSE

To explore changes of depression, anxiety and sleep disturbance in patients with episodic cluster headache inside and outside the attack period and assess the therapy to improve the treatment.

PATIENTS AND METHODS

We prospectively recruited 396 patients from 11 specialized headache outpatients and analyzed their headache characteristics, Hospital Anxiety Depression Scale scores, Pittsburgh sleep quality index scores, and the usage of psychiatric medications during as well as 1 month after the attack period.

RESULTS

A total of 220 patients completed the follow-up, 52.73% of whom had anxiety, 47.27% had depression and 49.09% had sleep disturbance inside the attack period. At follow-up, the percentage of these patients significantly decreased to 16.36%, 21.82% and 14.55% in the remission period, respectively (p < 0.05). Antidepressants and mood stabilizers were prescribed to 58.18% of the patients. However, both of the changes of Hospital Anxiety Depression Scale scores after the end of the attack period for anxiety (3.52±2.91 vs 3.32±3.09, p =0.61) and depression (3.41±3.33 vs 2.90±3.58, P =0.28) were comparable in patients with and without taking these medications. Nocturnal onset of headache was positively correlated with Pittsburgh score (OR=8.71), anxiety (OR=2.33) and depression scores (OR=3.56) (p < 0.05).

CONCLUSION

Depression, anxiety and sleep disturbance were significantly alleviated after the attack period. However, psychiatric medications showed limited effect on depression and anxiety. Additionally, the nocturnal attack may cause anxiety and depression in episodic cluster headache.

Cluster headache - The worst possible pain on YouTube

In clinical practice, patients with cluster headache often ask questions or mention information that they have seen or heard on the Internet. Because YouTube (www.youtube.com) is the second most visited Web site worldwide and offers a plethora of video content, we found it timely to ascertain the quality of information on cluster headache that is freely available on YouTube. We conducted an inquiry on YouTube on January 24, 2022, with the search term "cluster headache." Eligible YouTube videos included those with ≥10,000 views and content related to cluster headache. We assessed the quality and reliability of the videos with the Global Quality Scale and DISCERN, respectively. The search strategy identified 644 videos of which 134 were eligible for inclusion. The sources of the included videos were categorized as "healthcare professional/institution" (n = 45), "personal experience" (n = 52), and "other" (n = 37). According to the Global Quality Scale, 70 (52%) were low quality, 34 (25%) were of moderate quality, and 30 (22%) were of high quality. According to DISCERN, 104 (78%) were of low reliability, 28 (21%) were of moderate reliability, and 2 (1%) were of high reliability. The quality and reliability of cluster headache-related information on YouTube has room for improvement, even the content provided by healthcare providers. These findings should incentivize stakeholders, for example, government services, professional societies, healthcare providers, to provide accessible and better information on cluster headache.

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.

Recent Advances and Updates in Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgias (TACs) are discrete primary headache disorders, characterized by severe unilateral head pain, typically trigeminal distribution, with ipsilateral cranial autonomic symptoms. The conditions within this group are hemicrania continua, cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache with autonomic symptoms. Several advances have been made in understanding the pathogenesis and evolving treatment options in TACs. This review will outline the advances and updates in each TAC.

Treatment experiences and clinical characteristics in migraine and tension-type headache patients before the first visit to a tertiary headache center

OBJECTIVES

To investigate previous treatment and clinical characteristics in migraine and tension-type headache patients at their first visit to a tertiary headache center.

METHODS

This was a cross-sectional study using data obtained from electronic questionnaires and medical charts. Migraine and tension-type headache patients were investigated at their first visit to the Danish Headache Center.

RESULTS

Out of 382 patients the main diagnoses of primary headaches were: 36% with episodic migraine, 43% with chronic migraine, 3% with episodic tension-type headache and 17% with chronic tension-type headache. The majority had attempted non-pharmacological treatment options such as physiotherapy (episodic migraine: 53%, chronic migraine: 68%, episodic tension-type headache: 50%, chronic tension-type headache: 65%) and acupuncture: (episodic migraine: 45%, chronic migraine: 62%, episodic tension-type headache: 17%, chronic tension-type headache: 51%). The majority of migraine patients had tried no more than one triptan (episodic migraine: 71%, chronic migraine: 66%). In total, 35% of episodic migraine and 19% of chronic migraine patients as well as 50% of episodic tension-type headache and 41% of chronic tension-type headache patients had never tried preventive medication. The headache under-response to treatment (HURT) questionnaire score was higher in chronic migraine (score 15) and chronic tension-type headache (score 16) patients than the episodic forms (P < 0.004).

CONCLUSIONS

Headache patients had attempted several non-pharmacological treatments prior to their first visit at a tertiary headache center in Denmark. The limited use of acute and preventive treatment before the first visit demonstrates a need for better treatment at the primary and secondary care level.

The economic and personal burden of cluster headache: a controlled cross-sectional study

Background

Cluster headache is a less-prevalent primary headache disorder but is overrepresented with regards to use of health care and social services. More insight into the socioeconomic impact is required.

Methods

We investigated both the personal and societal disease burden and cost in 400 patients with well-classified cluster headache according to the ICHD-criteria and 200 sex- and age matched controls. All participants completed a cross sectional questionnaire and semi-structured interview.

Results

Patients with chronic cluster headache constituted 146 out of 400 (37%). Overall, restriction in personal and/or professional life was reported by 94% of patients during attack periods. Even in remission, nine times as many episodic patients rated their health as poor/very poor compared to controls (9% vs 1%, p = 0.002). For chronic patients, the odds of rating health as good/very good were ten times lower compared to controls (OR:10.10, 95%CI:5.29–18.79. p < 0.001) and three times lower compared to episodic patients in remission (OR:3.22, 95%CI:1.90–5.47, p < 0.001). Additionally, chronic cluster headache patients were 5 times more likely to receive disability pension compared to episodic (OR:5.0, 95%CI:2.3–10.9, p < 0.001). The mean direct annual costs amounted to 9,158€ and 2,763€ for chronic and episodic patients, respectively (p < 0.001). We identified a substantial loss of productivity due to absence from work resulting in a higher indirect cost of 11,809 €/year/patient in the chronic population and 3,558 €/year/patient in the episodic population. Presenteeism could not be quantified but productivity was reduced in patients by 65% in periods with attacks compared to controls.

Conclusion

Cluster headache has a major negative impact on personal life, self-perceived health, and societal cost. Patients with the chronic variant are vastly more burdened. Patients with the episodic form were still markedly affected during the remission period. This study highlights the need for more effective therapy to lighten the burden on patients and society.

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.

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.

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 epidemiology including pediatric onset, sex, and ICHD criteria: Results from the International Cluster Headache Questionnaire

OBJECTIVE

To validate the diagnoses and to investigate epidemiological data from an international, non-clinic-based, and large (n = 1604) survey of participants with cluster headache.

BACKGROUND

There are several limitations in current epidemiological data in cluster headache including a lack of large non-clinic-based studies. There is also limited information on several aspects of cluster headache, such as pediatric incidence.

METHODS

The International Cluster Headache Questionnaire was an internet-based survey that included questions on cluster headache demographics, criteria from the International Classification of Headache Disorders (ICHD), and medications.

RESULTS

A total of 3251 subjects participated in the survey, and 1604 respondents met ICHD criteria for cluster headache. For validation, we interviewed a random sample of 5% (81/1604) of participants and confirmed the diagnosis of cluster headache in 97.5% (79/81). Pediatric onset was found in 27.5% (341/1583) of participants, and only 15.2% (52/341) of participants with pediatric onset were diagnosed before the age of 18. Men were more likely to have episodic cluster headache between ages 10 and 50, but the sex ratio was approximately equal for other ages. An overwhelming majority of respondents had at least one autonomic feature (99.0%, 1588/1604) and had restlessness (96.6%, 1550/1604), but many also had prototypical migrainous features including photophobia or phonophobia (50.1%, 804/1604), pain aggravated by physical activity (31.4%, 503/1604), or nausea and vomiting (27.5%, 441/1604). Interestingly, the first-line medications for acute treatment (oxygen) and preventive treatment (calcium channel blockers) were perceived as significantly less effective in chronic cluster headache (3.2 ± 1.1 and 2.1 ± 1.0 respectively on a 5-point ordinal scale) compared with episodic cluster headache (3.5 ± 1.0 and 2.4 ± 1.1, respectively, p < 0.001 for both comparisons).

CONCLUSIONS

Cluster headache often occurs in the pediatric population, although they are typically not diagnosed until adulthood. The onset of cluster headache is the inverse of that in migraine; in migraine women are more likely to have migraine between ages 10 and 50 but the sex ratio is approximately equal otherwise. Prototypical migrainous features are not useful in differentiating cluster headache from migraine. Participant data from a large international study also suggest that chronic cluster headache is not only less responsive to newer treatments (like noninvasive vagus nerve stimulation and galcanezumab), but to traditional first-line treatments as well.

Clinical symptoms of androgen deficiency in men with migraine or cluster headache: a cross-sectional cohort study

Background

To compare symptoms of clinical androgen deficiency between men with migraine, men with cluster headache and non-headache male controls.

Methods

We performed a cross-sectional study using two validated questionnaires to assess symptoms of androgen deficiency in males with migraine, cluster headache, and non-headache controls. Primary outcome was the mean difference in androgen deficiency scores. Generalized linear models were used adjusting for age, BMI, smoking and lifetime depression. As secondary outcome we assessed the percentage of patients reporting to score below average on four sexual symptoms (beard growth, morning erections, libido and sexual potency) as these items were previously shown to more specifically differentiate androgen deficiency symptoms from (comorbid) anxiety and depression.

Results

The questionnaires were completed by n = 534/853 (63%) men with migraine, n = 437/694 (63%) men with cluster headache and n = 152/209 (73%) controls. Responders were older compared to non-responders and more likely to suffer from lifetime depression.

Patients reported more severe symptoms of clinical androgen deficiency compared with controls, with higher AMS scores (Aging Males Symptoms; mean difference ± SE: migraine 5.44 ± 0.90, p <  0.001; cluster headache 5.62 ± 0.99, p <  0.001) and lower qADAM scores (quantitative Androgen Deficiency in the Aging Male; migraine: − 3.16 ± 0.50, p <  0.001; cluster headache: − 5.25 ± 0.56, p <  0.001). Additionally, both patient groups more often reported to suffer from any of the specific sexual symptoms compared to controls (18.4% migraine, 20.6% cluster headache, 7.2% controls, p = 0.001).

Conclusion

Men with migraine and cluster headache more often suffer from symptoms consistent with clinical androgen deficiency than males without a primary headache disorder.

Enlarging the spectrum of cluster headache: Extracranial autonomic involvement revealed by voice analysis

Background

People with cluster headache (CH) are frequently burdened by misdiagnosis or diagnostic delay. The peculiar somatic and behavioral changes characterizing patients with CH are not useful to improve diagnostic accuracy. In our clinical experience, we noticed a typical voice quality with low and croaking tone in patients with CH.

In this cross‐sectional study, we evaluated, by digital voice analysis, whether it is possible to identify typical voice quality characterizing patients with CH compared with healthy controls (HCs). Furthermore, to investigate whether putative differences in voice characteristics could be underpinned by constitutional aspects or pathological processes of vocal cords, subjects underwent a videolaryngostroboscopy. Smoking habits and alcohol consumption were specifically investigated.

Methods

After conducting digital recording of the voices from both patients with CH and HCs in a soundproof insulated cabin in the laboratory of the Audiology Department, a set of voice parameters was analyzed. We included the measures of fundamental frequency, calculations of jitter and shimmer, and noise‐to‐harmonics ratios as well as quantities related to the spectral tilt (i.e., H1–H2, H1–A1, H1–A2, and H1–A3) in 20 patients with CH and in 13 HCs. A videolaryngostroboscopy was performed in all subjects.

Results

Patients with CH, explored during the cluster bout period, showed significantly lower second harmonic (H1–H2) values compared with HCs (−6.9 ± 7.6 vs. 2.1 ± 6.7, p = 0.002), usually characterizing the so‐called creaky voice. By using a laryngoscopy investigation, a significantly higher prevalence of mild to moderate vocal cord edema and laryngopharyngeal reflux signs were found in patients with CH (100% of patients with CH vs. 15% of HC, p < 0.001).

Conclusion

Creaky phonation is a “physiological mode of laryngeal operation” usually underpinned by shortened and thickened vocal folds. Creaky voice phonation can be due to a vocal fold's reduced capability to become slack or flaccid secondary to vocal cord edema underpinned by laryngopharyngeal reflux affecting the phonatory mechanisms in patients with CH. The laryngopharyngeal reflux may represent a dysautonomic sign related to the increased parasympathetic tone during in‐bout period, reinforcing the hypothesis of an extracranial autonomic dysfunction as part of CH clinical picture.

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).

Cluster Headache and Other Trigeminal Autonomic Cephalalgias

PURPOSE OF REVIEW

The trigeminal autonomic cephalalgias (TACs) are relatively rare, but they represent a distinct set of syndromes that are important to recognize. Despite their unique features, TACs often go undiagnosed or misdiagnosed for several years, leading to unnecessary pain and suffering. A significant proportion of TAC presentations may have secondary causes.

RECENT FINDINGS

The underlying pathophysiology of TACs is likely rooted in hypothalamic dysfunction and derangements in the interplay of circuitry involving trigeminovascular, trigeminocervical, trigeminoautonomic, circadian, and nociceptive systems. Recent therapeutic advancements include a better understanding of how to use older therapies more effectively and the identification of new approaches.

SUMMARY

TAC syndromes are rare but important to recognize because of their debilitating nature and greater likelihood for having potentially serious underlying causes. Although treatment options have remained somewhat limited, scientific inquiry is continually advancing our understanding of these syndromes and how best to manage them.

Clinical Features of Cluster Headache: A Hospital-Based Study in Taiwan

Most previous studies on cluster headache (CH) focus on Western populations. This study aimed to investigate the clinical characteristics of CH in a neurology outpatient population in Taiwan. A cross-sectional survey was conducted from July 2015 to June 2019 in a medical college affiliated with a tertiary care hospital (Tri-Service General Hospital) in Taiwan. All consecutive patients reporting headache as their chief complaint were asked to participate in a face-to-face interview with a qualified headache specialist and to complete a detailed self-administered questionnaire. The diagnosis of CH was made according to the Third edition of the International Classification of Headache Disorders. The subjects comprised 80 consecutive new CH patients (13 women and 67 men; ratio, 1:5). The mean age at presentation was 36.0 ± 10.8 years (range, 16-64 years), mean age at onset was 27.2 ± 12.1 years (range, 5-65 years), and mean time lag before diagnosis was 9.3 ± 10.5 years (range, 0-46.4 years). Of the total CH patients, 25.3% reported feelings of restlessness during headache episodes. A seasonal predilection was reported by 18% of the CH patients. The use of tobacco was the most common (44/80 patients). Chronic CH was only observed in 5% of the patients and only one patient (1.3%) reported both a positive family history for CH and aura. Features of CH in Taiwanese patients differed from that of Caucasian patients; a lower prevalence of chronic CH, positive family history of CH, and occurrence of aura may be less common in the former than in the latter.

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.