Study protocol of Prednisone in episodic Cluster Headache (PredCH): a randomized, double-blind, placebo-controlled parallel group trial to evaluate the efficacy and safety of oral prednisone as an add-on therapy in the prophylactic treatment of episodic cluster headache with verapamil

Immunological findings in patients with migraine and other primary headaches: a narrative review

Experimental findings suggest an involvement of neuroinflammatory mechanisms in the pathophysiology of migraine. Specifically, preclinical models of migraine have emphasized the role of neuroinflammation following the activation of the trigeminal pathway at several peripheral and central sites including dural vessels, the trigeminal ganglion, and the trigeminal nucleus caudalis. The evidence of an induction of inflammatory events in migraine pathophysiological mechanisms has prompted researchers to investigate the human leukocyte antigen (HLA) phenotypes as well as cytokine genetic polymorphisms in order to verify their potential relationship with migraine risk and severity. Furthermore, the role of neuroinflammation in migraine seems to be supported by evidence of an increase in pro-inflammatory cytokines, both ictally and interictally, together with the prevalence of Th1 lymphocytes and a reduction in regulatory lymphocyte subsets in peripheral blood of migraineurs. Cytokine profiles of cluster headache (CH) patients and those of tension-type headache patients further suggest an immunological dysregulation in the pathophysiology of these primary headaches, although evidence is weaker than for migraine. The present review summarizes available findings to date from genetic and biomarker studies that have explored the role of inflammation in primary headaches.

Impact of Galcanezumab on Total Pain Burden: A Post Hoc Analysis of a Phase 3, Randomized, Double-Blind, Placebo-Controlled Study in Patients with Episodic Cluster Headache

Purpose

In a phase 3 study, galcanezumab significantly reduced the frequency of episodic cluster headache attacks across weeks 1–3 (primary endpoint) compared with placebo. However, multiple pain dimensions may contribute to the total burden of episodic cluster headache pain. This post hoc analysis assessed the impact of galcanezumab on the total pain burden of episodic cluster headache using a composite measure.

Patients and Methods

Patients with episodic cluster headache were randomized 1:1 to galcanezumab 300 mg or placebo once monthly for 8 weeks. Mean weekly total pain burden was calculated (daily cluster headache attack frequency × average duration × average pain severity summed over 7 days) using data collected in an electronic patient-reported outcomes diary. Change from baseline in weekly total pain burden across weeks 1–3 was compared between galcanezumab and placebo. To explore construct validity, mean weekly total pain burden scores were stratified by Patient Global Impression of Improvement (PGI-I) responses at the week 4 clinic visit.

Results

The reduction from baseline in mean weekly total pain burden was significantly greater with galcanezumab (N=49) than with placebo (N=57): the least squares mean difference was −11.18 severity-weighted hours (p=0.035). Median weekly total pain burden decreased as PGI-I ratings improved, from 33.6 to 5.0 severity-weighted hours for patients who felt “very much worse” and “very much better,” respectively.

Conclusion

Galcanezumab significantly reduced mean weekly total pain burden compared with placebo in patients with episodic cluster headache. The composite pain measure demonstrated construct validity. Total pain burden may provide a holistic measure of the pain of episodic cluster headache.

Clinical Trials

ClinicalTrials.gov, NCT02397473.

Cluster headache pathophysiology - insights from current and emerging treatments

Cluster headache is a debilitating primary headache disorder that affects approximately 0.1% of the population worldwide. Cluster headache attacks involve severe unilateral pain in the trigeminal distribution together with ipsilateral cranial autonomic features and a sense of agitation. Acute treatments are available and are effective in just over half of the patients. Until recently, preventive medications were borrowed from non-headache indications, so management of cluster headache is challenging. However, as our understanding of cluster headache pathophysiology has evolved on the basis of key bench and neuroimaging studies, crucial neuropeptides and brain structures have been identified as emerging treatment targets. In this Review, we provide an overview of what is known about the pathophysiology of cluster headache and discuss the existing treatment options and their mechanisms of action. Existing acute treatments include triptans and high-flow oxygen, interim treatment options include corticosteroids in oral form or for greater occipital nerve block, and preventive treatments include verapamil, lithium, melatonin and topiramate. We also consider emerging treatment options, including calcitonin gene-related peptide antibodies, non-invasive vagus nerve stimulation, sphenopalatine ganglion stimulation and somatostatin receptor agonists, discuss how evidence from trials of these emerging treatments provides insights into the pathophysiology of cluster headache and highlight areas for future research.

[Cluster headaches-proven and novel approaches : A critical evaluation of treatment studies]

Trigeminal autonomic cephalalgias are characterized by unilateral headaches accompanied by cranial autonomic symptoms and a sense of restlessness. Clinical trials have been conducted on acute therapy and prophylaxis of cluster headache in recent years. Since the other trigeminal autonomic cephalalgias are rare, it is virtually impossible to conduct controlled clinical trials for their investigation. Recent trials provide data on the efficacy of prednisolone, galcanezumab, fremanzeumab and noninvasive vagal nerve stimulation. Methodological difficulties arise in terms of patient recruitment for clinical trials, clinical endpoints and potential differences in the pathophysiology of episodic and chronic cluster headache.

Treatment of Cluster Headache: The American Headache Society Evidence-Based Guidelines

BACKGROUND

Cluster headache (CH), the most common trigeminal autonomic cephalalgia, is an extremely debilitating primary headache disorder that is often not optimally treated. New evidence-based treatment guidelines for CH will assist clinicians with identifying and choosing among current treatment options.

OBJECTIVES

In this systematic review we appraise the available evidence for the acute and prophylactic treatment of CH, and provide an update of the 2010 American Academy of Neurology (AAN) endorsed systematic review.

METHODS

Medline, PubMed, and EMBASE databases were searched for double-blind, randomized controlled trials that investigated treatments of CH in adults. Exclusion and inclusion criteria were identical to those utilized in the 2010 AAN systematic review.

RESULTS AND RECOMMENDATIONS

For acute treatment, sumatriptan subcutaneous, zolmitriptan nasal spray, and high flow oxygen remain the treatments with a Level A recommendation. Since the 2010 review, a study of sphenopalatine ganglion stimulation was added to the current guideline and has been administered a Level B recommendation for acute treatment. For prophylactic therapy, previously there were no treatments that were administered a Level A recommendation. For the current guidelines, suboccipital steroid injections have emerged as the only treatment to receive a Level A recommendation with the addition of a second Class I study. Other newly evaluated treatments since the 2010 guidelines have been given a Level B recommendation (negative study: deep brain stimulation), a Level C recommendation (positive study: warfarin; negative studies: cimetidine/chlorpheniramine, candesartan), or a Level U recommendation (frovatriptan).

CONCLUSIONS

This AHS guideline can be utilized for understanding which therapies have superiority to placebo or sham treatment in the management of CH. In clinical practice, these recommendations should be considered in concert with other variables including safety, side effects, patient preferences, clinician experience, cost, and the invasiveness of the intervention. Given the lack of Class I evidence and Level A recommendations, particularly for a number of commonly used preventive therapies, further studies are warranted to demonstrate safety and efficacy for established and emerging therapies.

Effects of non-invasive vagus nerve stimulation on attack frequency over time and expanded response rates in patients with chronic cluster headache: a post hoc analysis of the randomised, controlled PREVA study

BACKGROUND

In the PREVention and Acute treatment of chronic cluster headache (PREVA) study, attack frequency reductions from baseline were significantly more pronounced with non-invasive vagus nerve stimulation plus standard of care (nVNS + SoC) than with SoC alone. Given the intensely painful and frequent nature of chronic cluster headache attacks, additional patient-centric outcomes, including the time to and level of therapeutic response, were evaluated in a post hoc analysis of the PREVA study.

FINDINGS

After a 2-week baseline phase, 97 patients with chronic cluster headache entered a 4-week randomised phase to receive nVNS + SoC (n = 48) or SoC alone (n = 49). All 92 patients who continued into a 4-week extension phase received nVNS + SoC. Compared with SoC alone, nVNS + SoC led to a significantly lower mean weekly attack frequency by week 2 of the randomised phase; the attack frequency remained significantly lower in the nVNS + SoC group through week 3 of the extension phase (P < 0.02). Attack frequencies in the nVNS + SoC group were significantly lower at all study time points than they were at baseline (P < 0.05). Response rates were significantly greater with nVNS + SoC than with SoC alone when response was defined as attack frequency reductions of ≥25%, ≥50%, and ≥75% from baseline (≥25% and ≥50%, P < 0.001; ≥75%, P = 0.009). The 100% response rate was 8% with nVNS + SoC and 0% with SoC alone.

CONCLUSIONS

Prophylactic nVNS led to rapid, significant, and sustained reductions in chronic cluster headache attack frequency within 2 weeks after its addition to SoC and was associated with significantly higher ≥25%, ≥50%, and ≥75% response rates than SoC alone. The rapid decrease in weekly attack frequency justifies a 4-week trial period to identify responders to nVNS, with a high degree of confidence, among patients with chronic cluster headache.

Cost-effectiveness analysis of non-invasive vagus nerve stimulation for the treatment of chronic cluster headache

Background

Cluster headache (CH) is a debilitating condition that is generally associated with substantial health care costs. Few therapies are approved for abortive or prophylactic treatment. Results from the prospective, randomised, open-label PREVA study suggested that adjunctive treatment with a novel non-invasive vagus nerve stimulation (nVNS) device led to decreased attack frequency and abortive medication use in patients with chronic CH (cCH). Herein, we evaluate whether nVNS is cost-effective compared with the current standard of care (SoC) for cCH.

Methods

A pharmacoeconomic model from the German statutory health insurance perspective was developed to estimate the 1-year cost-effectiveness of nVNS + SoC (versus SoC alone) using data from PREVA. Short-term treatment response data were taken from the clinical trial; longer-term response was modelled under scenarios of response maintenance, constant rate of response loss, and diminishing rate of response loss. Health-related quality of life was estimated by modelling EQ-5D™ data from PREVA; benefits were defined as quality-adjusted life-years (QALY). Abortive medication use data from PREVA, along with costs for the nVNS device and abortive therapies (i.e. intranasal zolmitriptan, subcutaneous sumatriptan, and inhaled oxygen), were used to assess health care costs in the German setting.

Results

The analysis resulted in mean expected yearly costs of €7096.69 for nVNS + SoC and €7511.35 for SoC alone and mean QALY of 0.607 for nVNS + SoC and 0.522 for SoC alone, suggesting that nVNS generates greater health benefits for lower overall cost. Abortive medication costs were 23 % lower with nVNS + SoC than with SoC alone. In the alternative scenarios (i.e. constant rate of response loss and diminishing rate of response loss), nVNS + SoC was more effective and cost saving than SoC alone.

Conclusions

In all scenarios modelled from a German perspective, nVNS was cost-effective compared with current SoC, which suggests that adjunctive nVNS therapy provides economic benefits in the treatment of cCH. Notably, the current analysis included only costs associated with abortive treatments. Treatment with nVNS will likely promote further economic benefit when other potential sources of cost savings (e.g. reduced frequency of clinic visits) are considered.

Trial registration

Clinicaltrials.gov identifier NCT01701245, 03OCT2012.

Evidence-based treatments for cluster headache

Cluster headache (CH), one of the most painful syndromes known to man, is managed with acute and preventive medications. The brief duration and severity of the attacks command the use of rapid-acting pain relievers. Inhalation of oxygen and subcutaneous sumatriptan are the two most effective acute therapeutic options for sufferers of CH. Several preventive medications are available, the most effective of which is verapamil. However, most of these agents are not backed by strong clinical evidence. In some patients, these options can be ineffective, especially in those who develop chronic CH. Surgical procedures for the chronic refractory form of the disorder should then be contemplated, the most promising of which is hypothalamic deep brain stimulation. We hereby review the pathogenesis of CH and the evidence behind the treatment options for this debilitating condition.

Pharmacotherapy options for cluster headache

INTRODUCTION

Cluster headache (CH) is a primary headache disorder and the most common trigeminal autonomic cephalalgia. Patients suffer from very severe unilateral headache attacks accompanied by ipsilateral trigeminal autonomic symptoms. Previous studies described a high burden of disease due to its impact on social life as well as an increased suicide ideation rate. The mean time to diagnosis in western industrialized countries is estimated at 4 years.

AREAS COVERED

Many treatment options for CH exist, but due to the rarity of the disease, controlled randomized clinical studies remain difficult to perform. This review summarizes the current knowledge about the treatment of CH including internationally accepted treatment guidelines, and an additional MEDLINE search (1 February 2015).

EXPERT OPINION

International treatment recommendations and official guidelines give reassurance about specific pharmacotherapy options for CH, but only few of these are backed by sufficient scientific evidence. The limited therapeutic efficacy in some patients leads to the use of alternative, complementary, but also illicit drugs to better cope with the disease. Many single cases, case series and uncontrolled studies were performed with different substances in an attempt to find a better way to treat or prevent the excruciatingly painful attacks associated with CH. Large-scale, randomized controlled clinical trials are desperately needed in order to further increase the quality of patient care for this outstanding but terrifying disease.