Pharmacotherapy for Cluster Headache

Ketamine as Treatment for Cluster Headache: A Systematic Review of Literature and a Case Series

INTRODUCTION

Cluster headache is a severe and debilitating neurological condition characterized by intense, excruciating pain with a significant impact on patients' wellbeing. Although different treatment options are available, many patients continue to experience inadequate relief. Therefore, experimental strategies are increasingly studied. One of the more promising approaches is the use of ketamine. We present the currently available evidence and our own data.

METHODS

In this mixed-methods paper, we first summarize the available evidence of ketamine for treatment of cluster headache based on a systematic review of literature in MEDLINE, EMBASE and the Cochrane library of systematic reviews. As the level of evidence is quite limited, we report our own cohort study with ten patients treated with ketamine infusions for cluster headache. They were followed up to investigate the patients' experience of treatment success and quality of life.

RESULTS

The search and review of literature identified four reports with a total of 68 patients. All were uncontrolled case series. The current literature suggests that ketamine might decrease cluster headache. However, as the applied regimes and reported outcomes are highly heterogeneous, further analysis was futile. Our own data show high patient satisfaction with ketamine treatment.

CONCLUSION

Despite the limited evidence, ketamine might be considered a potential therapeutic approach for cluster headache. Therefore, further research including randomized controlled trials should be encouraged.

Orexins and primary headaches: an overview of the neurobiology and clinical impact

INTRODUCTION

Primary headaches, including migraines and cluster headaches, are highly prevalent disorders that significantly impact quality of life. Several factors suggest a key role for the hypothalamus, including neuroimaging studies, attack periodicity, and the presence of altered homeostatic regulation. The orexins are two neuropeptides synthesized almost exclusively in the lateral hypothalamus with widespread projections across the central nervous system. They are involved in an array of functions including homeostatic regulation and nociception, suggesting a potential role in primary headaches.

AREAS COVERED

This review summarizes current knowledge of the neurobiology of orexins, their involvement in sleep-wake regulation, nociception, and functions relevant to the associated symptomology of headache disorders. Preclinical reports of the antinociceptive effects of orexin-A in preclinical models are discussed, as well as clinical evidence for the potential involvement of the orexinergic system in headache.

EXPERT OPINION

Several lines of evidence support the targeted modulation of orexinergic signaling in primary headaches. Critically, orexins A and B, acting differentially via the orexin 1 and 2 receptors, respectively, demonstrate differential effects on trigeminal pain processing, indicating why dual-receptor antagonists failed to show clinical efficacy. The authors propose that orexin 1 receptor agonists or positive allosteric modulators should be the focus of future research.

Research hotspots and frontiers of cluster headaches: a bibliometric analysis

Background

Extensive research on cluster headaches (CHs) has been conducted worldwide; however, there is currently no bibliometric research on CHs. Therefore, this study aimed to analyze the current research hotspots and frontiers of CHs over the past decade.

Methods

Raw data on CHs was obtained from the Web of Science Core Collection database from 2014 to 2023. CiteSpace V6.2 R7 (64 bit) and Microsoft Excel were used to assess the annual publication volume, authors, countries, and references. VOSviewer 1.6.19 software was used to assess the institutions, cited authors, and keywords, and co-occurrence and clustering functions were applied to draw a visual knowledge map.

Results

In the past decade, the overall annual publication volume of articles related to CHs has increased year by year, showing promising development prospects. The total 1909 articles contained six types of literature, among which the proportion of original research articles was the highest (1,270 articles, 66.53%), published in 201 journals. Cephalalgia (439 articles, 23.00%) had the highest publication volume, and the Lancet was the journal with the highest impact factor (IF = 168.9). Furthermore, the United States of America was the country with the most published papers (584 articles, 30.60%), University of London was the research institution with the most published papers (142 articles, 7.44%), and Goodsby, Peter J was found to be the most prolific author (38 articles, 1.99%).

Conclusion

This study may provide some direction for subsequent researcher on CHs. The hotspots and frontiers of future research on CHs are suggested as follows: in basic medicine, more attention should be paid to pathophysiology, especially on increasing research on the pathogenesis mediated by CGRP; in clinical medicine, more attention should be paid to the design of evidence-based medicine methodology, especially the strict design, including double-blind, questionnaire, and follow-up, in randomized controlled trials, using high-quality articles for meta-analyses, and recommending high-level evidence; therapeutic techniques need to be further explored, suggesting the implementation of transcranial magnetic stimulation of the cortex, and stimulation of the sphinopalatine ganglia and occipital nerve to achieve peripheral neuromodulation. Furthermore, chronic migraine and insomnia are inextricably linked to CHs.

Genetic and Phenotypic Profiling of Triptan Users in a Swedish Cluster Headache Cohort

Up to 25% of individuals who live with cluster headache (CH), an extremely painful primary headache disorder, do not adequately respond to the first-line treatment, triptans. Studies have indicated that genetic variants can play a role in treatment response. Likewise, differences in clinical characteristics can give clues to mechanisms underlying triptan non-response. Our aim was to investigate five genetic variants previously implicated in triptan response and their relation to triptan usage in our Swedish CH cohort and to investigate potential distinctions in clinical characteristics. 545 CH patients were screened for the genetic variants rs1024905, rs6724624, rs4795541, rs5443, and rs2651899 with a case control design based on triptan usage. Analysis of clinical characteristics was based on self-reported questionnaire data from 893 patients. One genetic variant, rs1024905, was significantly associated with triptan non-usage in CH (Pc = 0.010). In addition, multi-allele effector analysis showed that individuals with a higher number of effector variants were less likely to use triptans (P = 0.007). Analysis of clinical characteristics showed that triptan users were more likely to have alcohol as a trigger (57.4% vs 43.4%, P = 0.002), have autonomic symptoms (95.1% vs 88.1%, P = 0.002), and be current smokers (27.0% vs 21.9%, P = 0.033) compared to non-users. These results support the hypothesis that genetic variants can play a role in triptan usage in CH and that patients with a typical CH phenotype are more likely to use triptans.

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.

CCH attack frequency reduction after psilocybin correlates with hypothalamic functional connectivity

OBJECTIVE

To evaluate the feasibility and prophylactic effect of psilocybin as well as its effects on hypothalamic functional connectivity (FC) in patients with chronic cluster headache (CCH).

BACKGROUND

CCH is an excruciating and difficult-to-treat disorder with incompletely understood pathophysiology, although hypothalamic dysfunction has been implicated. Psilocybin may have beneficial prophylactic effects, but clinical evidence is limited.

METHODS

In this small open-label clinical trial, 10 patients with CCH were included and maintained headache diaries for 10 weeks. Patients received three doses of peroral psilocybin (0.14 mg/kg) on the first day of weeks five, six, and seven. The first 4 weeks served as baseline and the last 4 weeks as follow-up. Hypothalamic FC was determined using functional magnetic resonance imaging the day before the first psilocybin dose and 1 week after the last dose.

RESULTS

The treatment was well tolerated. Attack frequency was reduced by mean (standard deviation) 31% (31) from baseline to follow-up (pFWER  = 0.008). One patient experienced 21 weeks of complete remission. Changes in hypothalamic-diencephalic FC correlated negatively with a percent change in attack frequency (pFWER  = 0.03, R = -0.81), implicating this neural pathway in treatment response.

CONCLUSION

Our results indicate that psilocybin may have prophylactic potential and implicates the hypothalamus in possible treatment response. Further clinical studies are warranted.

Preventive therapy with galcanezumab for two consecutive cluster bouts in patients with episodic cluster headache: an observational multicenter study

BACKGROUND

Cluster headache is a severe and disabling primary headache disorder. Galcanezumab is a monoclonal antibody against calcitonin gene-related peptide and a preventive therapy for episodic cluster headache. However, the approval and insurance coverage for episodic cluster headache differ in each country. Additionally, the consistency of efficacy of galcanezumab therapy has not yet been evaluated. This study aimed to assess the efficacy and safety of 240 mg of galcanezumab therapy for consecutive cluster bouts in patients with episodic cluster headache.

METHODS

The study enrolled patients with episodic cluster headache who received two courses of galcanezumab therapy at three university hospitals in Republic of Korea between February 2020 and April 2022. The efficacy and safety of galcanezumab were analyzed by comparing daily headache frequency, the number of headache days, and headache intensity and adverse effects during the one-week period before and the third week after galcanezumab injection for each episode of cluster bouts. Paired t-test was used for comparing repeated data from different episodes of cluster bout.

RESULTS

Sixteen patients were enrolled in this study. Fourteen patients received galcanezumab therapy for two consecutive cluster bouts. Galcanezumab was administered 24 days and 11 days after the first and second cluster bouts, respectively. The proportion of patients with 50% or more reduction in frequency of daily headache at week 3 from baseline was 86% and 64% during the first and second episodes, respectively. The proportion of patients who received transitional therapy before galcanezumab therapy was higher in the first episode of cluster bout than that in the second episode of cluster bout. No serious adverse reactions or significant differences in adverse effects between cluster bouts were noticed. Two patients received a second galcanezumab therapy during the pre-cluster period, and their cluster periods ended without typical cluster headache attacks 10-60 days after galcanezumab therapy.

CONCLUSIONS

This exploratory analysis suggests that galcanezumab may be effective as a preventive therapy in subsequent cluster bouts. Patients with episodic cluster headaches who underwent galcanezumab therapy tended to receive a second round of treatment in the early stages of their next cluster bout without transitional therapy.

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.

A Rare Case of Cluster Headache Occurring Exclusively During Sleep Without Autonomic Symptoms and Agitation: A Case Report and Literature Review

As a primary headache disorder, cluster headache (CH) is a severe unilateral headache that recurs at certain times of the year, such as during season changes. It is characterized by autonomic symptoms, such as ipsilateral lacrimal and nasal discharge, as well as an inability to stay still during headache attacks. We report a rare case of CH in a 67-year-old male who presented with a severe right-sided headache lasting 30 minutes to one hour and occurring only during sleep. The headache resolved within five minutes after the subcutaneous injection of sumatriptan and was not accompanied by any autonomic symptoms or clear agitation.

CT-Guided Thermocoagulation of the Pterygopalatine Ganglion for Refractory Trigeminal Autonomic Cephalalgia

INTRODUCTION

Trigeminal autonomic cephalalgia (TAC) is a type of one-sided cerebral painful headache, with attacks regularly accompanied by autonomic responses, such as tearing, runny nose, panic, nausea and vomiting on the affected side. Currently, the most common treatment strategies are drugs, nerve grafts and surgery. Clinical understanding of TACs is limited. Here, we report the case of thermocoagulation treatment of the pterygopalatine ganglion in an uncommon TAC under local anesthesia.

CASE PRESENTATION

A rare case of TAC was treated with computed tomography (CT)-guided thermocoagulation within the pterygopalatine ganglion. Pain and autonomic signs were relieved immediately after surgery, with the patent retaining only slight numbness on the left side of the face. This numbness completely resolved at 6 months of follow-up and there was no recurrence.

DISCUSSION

Trigeminal autonomic cephalalgia seriously affects the patient's quality of life, but clinical understanding is limited. In the case reported here, we performed CT-guided thermocoagulation of the pterygopalatine ganglion at 90 °C for 180 s for treatment of a trigeminal autonomic headache. To our knowledge, this is the first report of using thermocoagulation at 90 °C to treat the pterygopalatine ganglion. We found that this strategy results in fewer side effects and is a more cost-effective treatment for such patients than other options.

CONCLUSION

Computed tomography-guided thermocoagulation of the pterygopalatine ganglion at 90 °C for 180 s for treatment of trigeminal autonomic headache is a safe and economical treatment option.

Self-Reported Efficacy of Treatments in Cluster Headache: a Systematic Review of Survey Studies

PURPOSE OF REVIEW

The use and efficacy of various substances in the treatment of CH have been studied in several retrospective surveys. The aim of the study is to systematically review published survey studies to evaluate the reported efficacies of both established and unconventional substances in abortive and prophylactic treatment of both episodic and chronic CH, specifically assessing the consistency of the results.

RECENT FINDINGS

No systematic review have been conducted of these studies previously. A systematic literature search with a set of search terms was conducted on PubMed. Retrospective surveys that quantified the self-reported efficacy of two or more CH treatments, published in English during 2000-2020, were included. Several key characteristics and results of the studies were extracted. A total of 994 articles were identified of which 9 were found to be eligible based on the selection criteria. In total, 5419 respondents were included. Oxygen and subcutaneous triptan injections were most reported as effective abortive treatments, while psilocybin and lysergic acid diethylamide were most commonly reported as effective prophylactic treatments. The reported efficacy of most substances was consistent across different studies, and there were marked differences in the reported efficacies of different substances. The reported order of efficacy is generally in agreement with clinical studies. The findings suggest that retrospective surveys can be used to obtain supporting information on the effects of various substances used in the treatment of CH and to form hypotheses about novel treatment methods. The consistently reported efficacy of psilocybin and LSD in prophylactic treatment indicates need for clinical studies.

Warfarin in the treatment of refractory chronic cluster headache: a case report and review in therapeutic options

Cluster headache is the most common of trigeminal autonomic cephalalgia, with variable prevalence. It can be episodic or chronic, with few remission and high therapeutic failure. The case refers to a 55-year-old female patient, hypertensive and diabetic, with a history of migraine without aura with pain management. In 2014, the patient began to present a new headache pattern, with a diagnosis of Chronic Cluster Headache. Pain management to nasal sumatriptan as an acute treatment. For the prophylactic treatment, she presented therapeutic failure to several medications, with pain management with the use of warfarin. Associated with valproic acid to control migraine. There are few cases described in the literature about the use of warfarin, and its mechanism is still unclear. Warfarin was a key drug, with more than a 50% reduction in attack control. There is a need for more clinical trials randomly that support it. Cluster headache has peculiar clinical diagnosis, being increasingly well recognized and diagnosed. Knowledge and institution of treatment can significantly improve the quality of life of patients, helping to recover the functionality of patients affected by treatment failure.

Comparative Impact of Pharmacological Therapies on Cluster Headache Management: A Systematic Review and Network Meta-Analysis

It is important to find effective and safe pharmacological options for managing cluster headache (CH) because there is limited evidence from studies supporting the general efficacy and safety of pharmacological therapies. This systematic review and network meta-analysis (NMA) analyzed published randomized controlled trials (RCTs) to evaluate the efficacy and safety of pharmacological treatments in patients with CH. The PubMed and Embase databases were searched to identify RCTs that evaluated the efficacy and safety of pharmacological treatments for CH. Efficacy outcomes included frequency and duration of attacks, pain-free rate, and the use of rescue agents. Safety outcomes were evaluated based on the number of patients who experienced adverse events. A total of 23 studies were included in the analysis. The frequency of attacks was reduced (mean difference (MD) = −1.05, 95% confidence interval (CI) = −1.62 to −0.47; p = 0.0004), and the pain-free rate was increased (odds ratio (OR) = 3.89, 95% CI = 2.76−5.48; p < 0.00001) in the pharmacological treatment group, with a lower frequency of rescue agent use than the placebo group. Preventive, acute, and triptan or non-triptan therapies did not show significant differences in efficacy (p > 0.05). In the NMA, different results were shown among the interventions; for example, zolmitriptan 5 mg was more effective than zolmitriptan 10 mg in the pain-free outcome (OR = 0.40, 95% CI = 0.19−0.82; p < 0.05). Pharmacological treatment was shown to be more effective than placebo to manage CH with differences among types of therapies and individual interventions, and it was consistently shown to be associated with the development of adverse events. Thus, individualized therapy approaches should be applied to treat CH in real-world practice.

Pharmacogenetics in Primary Headache Disorders

Primary headache disorders, such as migraine, tension-type headache (TTH), and cluster headache, belong to the most common neurological disorders affecting a high percentage of people worldwide. Headache induces a high burden for the affected individuals on the personal level, with a strong impact on life quality, daily life management, and causes immense costs for the healthcare systems. Although a relatively broad spectrum of different pharmacological classes for the treatment of headache disorders are available, treatment effectiveness is often limited by high variances in therapy responses. Genetic variants can influence the individual treatment success by influencing pharmacokinetics or pharmacodynamics of the therapeutic as investigated in the research field of pharmacogenetics. This review summarizes the current knowledge on important primary headache disorders, including migraine, TTH, and cluster headache. We also summarize current acute and preventive treatment options for the three headache disorders based on drug classes and compounds taking important therapy guidelines into consideration. Importantly, the work summarizes and discusses the role of genetic polymorphisms regarding their impact on metabolism safety and the effect of therapeutics that are used to treat migraine, cluster headache, and TTH exploring drug classes such as nonsteroidal anti-inflammatory drugs, triptans, antidepressants, anticonvulsants, calcium channel blockers, drugs with effect on the renin-angiotensin system, and novel headache therapeutics such as ditans, anti-calcitonin-gene-related peptide antibodies, and gepants. Genetic variants in important phase I-, II-, and III-associated genes such as cytochrome P450 genes, UGT genes, and different transporter genes are scrutinized as well as variants in genes important for pharmacodynamics and several functions outside the pharmacokinetic and pharmacodynamic spectrum. Finally, the article evaluates the potential and limitations of pharmacogenetic approaches for individual therapy adjustments in headache disorders.

Tolerability and safety of galcanezumab in patients with chronic cluster headache with up to 15 months of galcanezumab treatment

Objective

The objective of the study was to assess the tolerability and safety of galcanezumab in patients with chronic cluster headache (CH) with up to 15 months of treatment.

Background

Chronic CH is a highly debilitating disease with a substantial and unmet medical need.

Methods

Patients were randomized to receive placebo or galcanezumab (300 mg) monthly for 12 weeks, followed by an optional 52‐week open‐label extension and 16‐week posttreatment follow‐up (washout). This is a secondary analysis and long‐term follow‐up of a previously conducted clinical trial. The safety analysis included patients who received galcanezumab at any time during the study. Outcomes included adverse events (AEs), discontinuations, laboratory values, vital signs, electrocardiograms (ECGs), and suicidality ratings.

Results

A total of 233 patients received at least one galcanezumab dose. The mean exposure was 341 days. Galcanezumab‐treated patients were mostly male (n = 169/233; 72.5%) with a mean age of 44.9 (±10.9) years. Treatment‐emergent adverse events (TEAEs) were reported by 185 patients (n = 185/233; 79.4%), 23 patients (n = 23/233; 9.9%) reported serious adverse events (SAEs), and 18 patients (n = 18/233; 7.7%) discontinued due to AEs. The SAE CH was reported by three patients. The most common TEAEs (>10%) were nasopharyngitis (n = 41/233; 17.6%) and injection site pain (n = 33/233; 14.2%). 27.5% of patients (n = 64/233) had TEAEs related to injection sites. Likely hypersensitivity events, including injection site rash, injection site urticaria, and injection site hypersensitivity were reported (n = 14/233; 6.0%). There were past histories of suicidal ideation (n = 55/237; 23.2%) and suicidal behavior (n = 9/236; 3.8%). During the study, 15 patients (n = 15/230; 6.5%), seven with previous history, reported suicidal ideation. One patient had a nonfatal suicide attempt during the open‐label extension and an aborted attempt during the washout. There were no new safety findings compared with the placebo‐controlled treatment period in laboratory values, vital signs, or ECGs.

Conclusions

Galcanezumab 300 mg monthly had a favorable tolerability and safety profile in patients with chronic CH with up to 15 months of treatment.

Cluster Headache: Clinical Characteristics and Opportunities to Enhance Quality of Life

PURPOSE OF REVIEW

Cluster headache is a highly disabling primary headache disorder characterized by severe pain and autonomic features. We present the existing body of literature on psychological factors associated with cluster headache and recommendations to address gaps in current clinical care with regards to psychological treatments for cluster headache.

RECENT FINDINGS

People with cluster headache often endorse depressive symptoms, are more likely than the general population to report suicidal ideation and behaviors, and experience significantly decreased quality of life. Psychological treatments such as Acceptance and Commitment Therapy may be particularly valuable for patients with cluster headache given that they are transdiagnostic in nature and can therefore simultaneously address the disease burden and common psychiatric comorbidities that present. Greater understanding of the debilitating nature of cluster headache and behavioral interventions that seek to reduce the burden of the disease and improve the quality of life of people with cluster headache is paramount.

Gene polymorphism association studies in cluster headache: A field synopsis and systematic meta-analyses

BACKGROUND

A plethora of studies have attempted to identify genetic determinants of disease susceptibility and treatment response of patients with cluster headache (CH), but results are often conflicting, and no comprehensive overview with a quantitative summary of the evidence in this field is available.

METHODS

A systematic search of relevant publications was performed without any language restrictions on PubMed, Web of Knowledge, Cochrane Library, and OpenGrey, up to December 2020. A standardized data extraction form was used to collect relevant data from each included study. Meta-analyses were conducted for gene polymorphisms investigated in at least two studies and the Bayesian false discovery probability (BFDP) test was applied to the pooled odds ratios (ORs) to assess the credibility of the observed associations.

RESULTS

Among the 27 articles identified by the systematic review, 17 studies evaluating 12 single nucleotide polymorphisms (SNPs) were included in the quantitative data analysis. The pooled results showed no significant association with CH risk of 10 SNPs, including five SNPs of HCRTR2 (rs2653349, rs2653342, rs3122156, rs10498801, and rs3800539), two SNPs of ADH4 (rs1800759 and rs1126671), CLOCK rs1801260, and two SNPs (rs1006417 and ADCYAP1R1 rs12668955) previously identified by a genome-wide association study (GWAS). Conversely, the pooled results revealed the association of the HCRTR2 rs9357855 A allele with a higher risk of CH (A vs. G, OR: 1.33, 95% CI: 1.04-1.72, p = 0.026), and of GNB3 rs5443 with a higher response rate of patients with CH to triptan drugs (CT+TT vs. CC, OR: 1.96, 95% CI: 1.04-3.72, p = 0.038). However, assuming a prior probability of 0.001, the respective BFDP values being higher than 0.8 (BFDP_rs9357855  = 0.998; BFDP_rs5443  = 0.998) revealed lack of noteworthy results.

CONCLUSIONS

Well-designed GWASs and large replication studies are still needed to identify reliable genetic variants of disease susceptibility and treatment response of patients with CH.

Genetic Susceptibility Loci in Genomewide Association Study of Cluster Headache

Objective

Identifying common genetic variants that confer genetic risk for cluster headache.

Methods

We conducted a case–control study in the Dutch Leiden University Cluster headache neuro‐Analysis program (LUCA) study population (n = 840) and unselected controls from the Netherlands Epidemiology of Obesity Study (NEO; n = 1,457). Replication was performed in a Norwegian sample of 144 cases from the Trondheim Cluster headache sample and 1,800 controls from the Nord‐Trøndelag Health Survey (HUNT). Gene set and tissue enrichment analyses, blood cell‐derived RNA‐sequencing of genes around the risk loci and linkage disequilibrium score regression were part of the downstream analyses.

Results

An association was found with cluster headache for 4 independent loci (r² < 0.1) with genomewide significance (p < 5 × 10⁻⁸), rs11579212 (odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.33–1.72 near RP11‐815 M8.1), rs6541998 (OR = 1.53, 95% CI = 1.37–1.74 near MERTK), rs10184573 (OR = 1.43, 95% CI = 1.26–1.61 near AC093590.1), and rs2499799 (OR = 0.62, 95% CI = 0.54–0.73 near UFL1/FHL5), collectively explaining 7.2% of the variance of cluster headache. SNPs rs11579212, rs10184573, and rs976357, as proxy SNP for rs2499799 (r² = 1.0), replicated in the Norwegian sample (p < 0.05). Gene‐based mapping yielded ASZ1 as possible fifth locus. RNA‐sequencing indicated differential expression of POLR1B and TMEM87B in cluster headache patients.

Interpretation

This genomewide association study (GWAS) identified and replicated genetic risk loci for cluster headache with effect sizes larger than those typically seen in complex genetic disorders. ANN NEUROL 2021;90:203–216

Diagnosis and Management of Headaches in the Emergency Department (ED) in Adults and Children

Background

Headache accounts for a significant number of cases presenting to the Emergency Department (ED) and has a high societal cost, contributed by recurrent ED and clinic visits, and unnecessary diagnostic tests.

Objective

This review article covers the important clinical tools needed to evaluate headaches in both adults and children in the ED.

Methods

Medline/PubMed was searched using the keywords "Emergency department", "headache", "adult", "pediatric", "clinical assessment", "diagnosis" and "treatment", in the title or abstract. The search covers the period from 1 January 1990 to 31 December 2019.

Results

The articles selected were based on their relevancy to the objective of this review article. Additional relevant publications were identified from article references lists.

Conclusion

The emergency physician plays a key role in differentiating between primary and secondary headaches. Within the limited ED resources, appropriate diagnostic testing should be used to identify the life-threatening headaches. This will ensure patients are given the appropriate evidence-based pharmacological therapy and holistic management.

Pain localization in cluster headache patients: Onset, peak, and radiation

OBJECTIVE AND AIM

To describe differences in pain locations for onset, peak, and radiation aspects of cluster headache (CH) attacks.

METHODS AND MATERIALS

Data were collected for 23 months using a cross-sectional online survey composed of 117 questions on pain location, demographics, and clinical features. 5260 datapoints on 44 pain locations from 631 respondents were analyzed.

RESULTS

During the onset and peak of attacks, pain is concentrated periorbitally. Pain locations outside the periorbital region were reported more frequently for radiation than for onset and peak of attacks. Dorsal (occipital, neck, shoulder) pain was reported more frequently in connection with onset and radiation than during peak: onset (13%) versus peak (6%), p < 0.001, and radiation (22%) versus peak (6%), p < 0.001. There was no significant difference in dorsal pain frequencies for onset (13%) vs. radiation (22%), p = 0.552. Furthermore, the frequency with which individual pain locations were reported differed significantly for onset, peak, and radiation in CH.

CONCLUSIONS

Analysis of the pain location data shows specific frequencies and distributions of pain location for three aspects of CH attacks. The frequency with which individual pain points were reported differed significantly for onset, peak, and radiation. In general, dorsal pain points were reported more frequently for onset and radiation than for peak pain. Pain locations beyond the eye (extraorbital points) were more frequently reported in connection with radiating pain. Our findings could serve as a basis for future research, correlating CH pain patterns with the outcome of treatment approaches.

Acute Topiramate Toxicity in a Five-Year-Old Child

Topiramate (TOPAMAX®) is an anti-epileptic drug for which acute toxicity is infrequently reported. We present the case report of a five-year-old, otherwise healthy boy who presented to the emergency department (ED) for symptoms of acute encephalopathy. He was lethargic, having slurred speech, hallucinating, intermittently agitated, and had multiple episodes of urinating on himself. Computed tomography (CT) of the head, lumbar puncture, electroencephalography, and magnetic resonance imaging (MRI) were all normal. The urine drug screen was also negative. Two days after admission, a saliva toxicology screen was significant for a topiramate level of 3487.8 ng/ml, which he was not taking and which his mother admitted taking for weight loss. The patient was observed for two days, over which time his symptoms completely resolved, and he was back to baseline. The following is the take-away for physicians: Careful history-taking should bedone to identify potential drug exposures in children presenting with acute encephalopathy. Especially, given the emerging off-label use of drugs, like in this case, topiramate, which was used by the mother for weight loss. We postulated a possible idiosyncratic reaction vs true drug toxicity, which correlates with findings in a previous case reportout of Boston Children's Hospital by Taub et al.; and in this case, serum level was about one-third the reported level in this case report^. The patient presented with comparable symptoms and time to recovery.

Primaries non-migraine headaches treatment: a review

In the "headache world," great attention has always been paid to migraine patients, especially for the research and development of new therapies. For the other forms of primary headaches, especially those of Chapters 2 and 3 of the classification, there are however therapies that, even if not specific, can give significant results. Tension-type headache recognizes in NSAIDs the most effective drugs to treat acute attack, while prevention is based on the use of tricyclic antidepressants and muscle relaxants. For TACs, the discussion is more complex: first of all, there are two forms of primary headache that respond absolutely to indomethacin. For these, the main problem is how to manage the possible side effects arising from prolonged treatments and possibly what to use as an alternative. For cluster headaches and short-lasting unilateral neuralgiform headache attacks, we have drugs with good efficacy as regards medical therapy, such as verapamil or lamotrigine, but in recent years, neuromodulation techniques, both surgical and non-invasive, have also been affirming themselves, which represent a more possibility for forms of headache that are often very disabling and resistant to common analgesics.

Usage of antiepileptic drugs in different diseases in Germany - A retrospective study

AIM

The goal of this study was to analyze and quantify the usage of antiepileptic drugs (AEDs) in different diseases and settings in Germany.

METHODS

This retrospective study, based on data from the Disease Analyzer database (IQVIA), included patients from 550 general practices (GP) and 73 neurological practices. Patients who had received at least one prescription for AED from one of these practices between January 2009 and December 2011 (time period 1, n = 39,434) or between January 2016 and December 2018 (time period 2, n = 49,128) were analyzed.

RESULTS

In patients who received AED prescriptions from neurologists, epilepsy (43%) was the most common diagnosis and did not change over time. The proportion of pain diagnoses slightly decreased from 35% in the period from 2009 to 2011 to 34% in the period from 2016 to 2018, while psychiatric disorders increased from 13% to 15%. In GPs, 58% of patients received their AED prescriptions for pain disorders, followed by epilepsy (29%) in the period from 2009 to 2011. The proportion of pain patients slightly increased to 60%, while that of patients with epilepsy slightly decreased to 27%.

CONCLUSIONS

The main indications for which AEDs are prescribed vary with the type of medical practice. The different indications for different AEDs changed between the two time periods, which is in line with the state of the research.

Chronic Cluster Headache Update and East-West Comparisons: Focusing on Clinical Features, Pathophysiology, and Management

PURPOSE OF REVIEW

This review provides an update on chronic cluster headache (CH) focusing on clinical features, pathophysiology, and management as well as comparisons between Eastern and Western populations.

RECENT FINDINGS

Chronic CH in Eastern populations was relatively rare, compared to that in Western populations. Lacrimation and/or conjunctival injection is the most frequently reported cranial autonomic symptom, and visual aura is predominant in chronic CH patients. Neuroimaging evidence in both ethnic groups suggests that CH pathophysiology involves the hypothalamus and pain-modulatory areas, with dynamic alternations between CH episodes. Recent evidence indicates that midbrain dopaminergic systems may participate in CH chronicity. Noteworthy advances have emerged in neuromodulatory therapies for chronic CH, but treatment with calcitonin gene-related peptide (CGRP) monoclonal antibodies has been unsuccessful. Recent evidence shows divergence of chronic CH between Eastern and Western populations. Neuromodulatory therapies but not CGRP inhibition is effective in this intractable patient group.

Erenumab for chronic cluster headache: A case report

The preventive treatment for cluster headache is often limited by a lack of efficacy or side effects. Calcitonin gene-related peptide (CGRP) has been implicated in the pathophysiology of cluster headache. Galcanezumab, a monoclonal antibody against calcitonin gene-related peptide (CGRP), significantly reduced the frequency of episodic cluster headache attacks. We report the case of a 38-year-old woman with chronic refractory cluster headache and comorbid migraine who received erenumab in 4 repeated doses of 70 mg subcutaneously over 25 weeks. Attack frequency decreased from three attacks per day to several attacks per week. Erenumab seemed to be highly effective in the prevention of cluster headache attacks in this patient. We suggest that randomized control trials should be performed.

Effect of calcitonin gene-related peptide (-receptor) antibodies in chronic cluster headache: Results from a retrospective case series support individual treatment attempts

Objective

To assess the efficacy of monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor in chronic cluster headache (CCH) treatment under real world conditions.

Background

Calcitonin gene-related peptide has an important pathophysiological role in cluster headache. Although the randomised controlled trial with the calcitonin gene-related peptide antibody galcanezumab was negative, chronic cluster headache patients with insufficient response to other preventive treatments have been receiving individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies.

Methods

Data from 22 chronic cluster headache patients who received at least one dose of a calcitonin gene-related peptide(-receptor) antibody and recorded attack frequency in a headache diary were retrospectively collected at eight headache centres.

Results

The number of previous preventive therapies was 6.5 ± 2.4 (mean ± standard deviation, range: 2–11). The average number of attacks per week was 23.3 ± 16.4 at baseline and significantly decreased by −9.2 ± 9.7 in the first month of treatment with a calcitonin gene-related peptide(-receptor) antibody (p < 0.001). Fifty-five percent of the patients were 50% responders and 36% were 75% responders with respect to attack frequency. Significant reduction of attack frequency started at week 1 (−6.8 ± 2.8 attacks, p < 0.01). Results were corroborated by significant decreases in weekly uses of acute headache medication (−9.8 ± 7.6, p < 0.001) and pain intensity during attacks (−1.2 ± 2.0, numerical rating scale (NRS) [0–10], p < 0.01) in the first month. In months 2 (n = 14) and 3 (n = 10), reduction of attack frequency from baseline was −8.0 ± 8.4 (p = 0.004) and −9.1 ± 10.0 (p = 0.024), respectively.

Conclusion

Under real-world conditions, individual treatment with calcitonin gene-related peptide(-receptor) antibodies was effective in 55% of our chronic cluster headache patients. This finding supports individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies in chronic cluster headache patients insufficiently responding to other therapies.

Galcanezumab for the prevention of cluster headache

INTRODUCTION

Cluster headache (CH) is among the worst painful conditions. The available therapies are scarce and not specific, leaving many patients unsatisfied because of poor efficacy and/or tolerability. Patients not responding to common treatments are offered semi-invasive and invasive procedures with uncertain results. Based on the current understanding of CH pathophysiology, new possible therapeutic approaches come from drugs interfering with Calcitonin Gene Related Peptide (CGRP).

AREAS COVERED

After summarizing the evidence for CGRP involvement in CH pathophysiology, we review the published literature (PubMed) and information (clinicaltrials.gov, EudraCT, EMA and FDA websites) regarding a novel anti-CGRP monoclonal antibody, Galcanezumab, its pharmacological properties, development, and evidence for the treatment of CH. Publications regarding other indications (migraine) are considered for completeness and safety/tolerability profile.

EXPERT OPINION

In one randomized clinical trial, Galcanezumab has proven to be effective and safe as a preventive treatment in episodic CH, with a favorable tolerability profile offering a potential new option in the therapeutic arsenal. Inefficacy of galcanezumab in chronic CH as well as the inefficacy of another monoclonal antibody against CGRP (fremanezumab) in both episodic and chronic CH question the scalability of the drug in CH management. Further, studies comparing galcanezumab to the current standard treatments are highly desirable.

Iontophoretic skin delivery systems: Success and failures

Iontophoretic transdermal delivery uses a small electric current to push charged molecules into the skin under an electrode of same polarity and offers an attractive option to facilitate the delivery of macromolecules or hydrophilic molecules and to improve patient compliance. This technique has been used in physical therapy clinics for several decades, though the science was not always there to support claims of clinical effectiveness. Recently, this modality of treatment has undergone more systematic and rigorous investigations to withstand the scrutiny of regulatory authorities. In recent years various drugs have gained FDA approval for iontophoretic patches. This technique is gaining recognition due to better compliance rates, non-invasive drug delivery leading to fewer side effects, and sustained release of the drug. Furthermore, programmed delivery and bolus delivery systems have helped with customizing the drug dosage and frequency of dosage based on the patient's need.