Health Care Utilization and Direct Costs Among Patients Diagnosed with Cluster Headache in U.S. Health Care Claims Data

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.

Patient-identified burden and unmet needs in patients with cluster headache: An evidence-based qualitative literature review

Objectives:

To qualitatively identify evidence-based literature related to the daily burden and unmet treatment and psychosocial needs of patients with cluster headache (CH).

Methods:

A literature search was conducted through October 20, 2020 across MEDLINE, EMBASE, CINAHL, and PsychInfo databases exploring quality of life (QoL) and disease burden in adults with CH. The search was restricted to full-text reports in peer-reviewed journals. Methodologic quality was assessed using the Critical Skills Appraisal Program.

Results:

From 11 identified publications, QoL was reduced in persons living with CH, with significant psychological, social, and socio-economic burdens, and work-related disability. The CH disease trajectory is complex, with patients experiencing the impact of their disease across multiple domains beyond the biological manifestation of the disease including stigma, employment limitations, and suicidal ideation, and with a lack of effective treatment from the patient perspective.

Discussion:

These findings strengthen comprehension of the CH patient experience, enabling a deeper understanding of the patients’ perspective and experience of their disease andunmet needs, providing a basis for future research into this debilitating condition. Minor limitations of this study include data extraction and study selection biases.

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.

No Association Between G1246A Polymorphism in HCRTR2 Gene and Risk of Cluster Headache: Evidence From an Updated Meta-Analysis of Observational Studies

Background: The hypocretin receptor 2 (HCRTR2) gene may play a pathological role in cluster headache (CH). However, the conclusions of published reports on the relationship between the G1246A polymorphism (rs2653349) in the HCRTR2 gene and risk of CH remain controversial. This purpose of this article is to comprehensively study the current evidence and assess the association between G1246A polymorphism (rs2653349) in the HCRTR2 gene and risk of CH.

Materials and Methods: Four electronic databases—ISI Web of Science, CNKI, PubMed, and EMBASE—were comprehensively searched on August 2020 to find and pinpoint all observational articles related to this study. The association between G1246A polymorphism in the HCRTR2 gene and risk of CH under five different genetic models was evaluated based on the summary odds ratio and corresponding 95 confidence interval (95% CI). Methodological quality was assessed based on the Newcastle–Ottawa Scale (NOS). To assist the analysis, RevMan 5.3 software was used to perform subgroup and sensitivity analyses. Egger's and Begg's tests were then conducted to evaluate and assess publication bias. Finally, a meta-regression was carried out by residual (restricted) maximum likelihood (REML).

Results: Eight observation studies containing 3,161 healthy controls and 1,964 patients with CH were identified and to be used for the meta-analysis. With methodological quality NOS assessment, the incorporated studies showed an average score of 6.4 stars. The pooled data didn't support the association between G1246A polymorphism in the HCRTR2 gene and CH vulnerability in the overall population (OR: 0.85, 95% CI 0.69, 1.03; p = 0.10). Subgroup analysis by ethnicity showed no significant association between G1246A and CH in either Caucasians (OR: 0.89, 95% CI 0.77, 1.01; p = 0.08) or Asians (OR: 1.65, 95% CI 0.80, 3.41; p = 0.18). The robustness of the conclusion was tested and confirmed with the leave-one-out sensitivity analysis. Meta-regression analysis showed that chronological order of publication appeared to be significantly associated with the heterogeneity (t = 2.47, p = 0.039; residual I² = 0%, adjusted R² = 100%).

Conclusion: Our present study showed that the G1246A polymorphism in the HCRTR2 gene did not appear to be an accomplice and associated with CH predisposition among either the Asian or Caucasian population.

Reducing Episodic Cluster Headaches: Focus on Galcanezumab

The involvement of calcitonin gene-related peptide in migraine and cluster headache has led to the recent development of new therapies. Galcanezumab, a novel monoclonal antibody targeting the calcitonin gene-related peptide, is approved for the migraine prevention and has recently been tested for the prevention of cluster headache. Two clinical trials have been conducted to investigate the efficacy and safety of galcanezumab in episodic cluster headache and chronic cluster headache. While efficacy endpoints were not met in the chronic subtype, galcanezumab reduced the weekly frequency of attacks in patients with episodic cluster headaches. In both studies, the antibody was well tolerated. This review summarizes and critically reviews the available data regarding the rationale behind targeting the calcitonin gene-related peptide with galcanezumab for the prevention of cluster headache.

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.