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

Psychotropic Drugs Reemerging as Headache Medicines

Scientific and public attention on the therapeutic effects of psychedelics and other psychoactive compounds in headache disorders has recently grown. The use and reported therapeutic effects of such treatments have long been reported, though formal clinical trials are only recently taking place. When considering how these substances might be further studied and eventually applied, it is important to consider the specific headache disorder, the particular drug, and the mode of use. No singular protocol will be applicable across all headache disorders and drugs. In this leading article, the nuance required to consider the value of classic psychedelics, ketamine, and cannabinoids as headache medicines is presented.

Managing Cluster Headache in Patients with Medical, Psychiatric, and Surgical Comorbidities

PURPOSE OF REVIEW

What should a provider know about medications and other treatments in patients with cluster headache who have medical, psychiatric, and surgical comorbidities? What conversations should providers have with patients about living with and managing cluster headache?

RECENT FINDINGS

While the number of treatments used in cluster headache is relatively small, numerous considerations were identified related to managing patients with comorbidities. Many of these touch on cardiac, cardiovascular, and cerebrovascular health, but full histories are needed to guide safe and effective treatment. Both older and newer treatments may be contraindicated in certain patients with cluster headache or should be considered carefully. In addition to incorporating medical, psychiatric, and surgical histories in the management plan, collaboration with other providers may be beneficial. Providers should also inquire about patient practices and discuss participation in clinical trials that might be a good fit for the individual.

Oxygen as an abortive therapy in cluster headache: a narrative review and clinical practice aspects

Cluster headache (International Classification of Headache Disorders third edition, ICHD-3 3.1) is a primary headache disorder affecting around 0.12% of individuals. It is characterized by severe headache attacks causing significant negative impact on the lives of patients. While administration of 100% oxygen is considered to be the first-choice acute treatment, undertreatment also exists. Reasons for undertreatment may entail problems with the correct prescription of oxygen, reimbursement issues or the practical implementation of home oxygen therapy. The aim of this manuscript is to review the scientific evidence on oxygen therapy for cluster headache and provide a practical guidance for both physicians and patients to optimize its use in an acute setting. The current evidence of the administration of 100% oxygen as a safe and effective treatment for cluster headache is strong. Based on several clinical trials and surveys, the recommended flow rates range between 12 and 15 L/min via a non-rebreathing mask, for at least fifteen minutes. The frequency of cluster headache attacks and thus the need for acute treatment can be very high. Fortunately, the Belgian social security system provides a full and lifetime reimbursement of oxygen therapy for cluster headache if the diagnosis and the need for this therapy has been certified by a neurologist, neurosurgeon or neuropsychiatrist.

Open label experience of repeated OnabotulinumtoxinA injections towards the sphenopalatine ganglion in patients with chronic cluster headache and chronic migraine

BACKGROUND

A novel technique for injection of OnabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) has shown promise in refractory chronic migraine (CM) and chronic cluster headache (CCH). Open label safety and efficacy data are presented here.

METHODS

Patients with refractory CM or CCH who had received at least one injection and completed headache diaries were included. Efficacy was defined as ≥50% reduction in moderate-to-severe headache days for CM, or ≥50% reduction in attack frequency for CCH, at weeks five to eight.

RESULTS

Over 261 injections, there were 123 adverse events (AE), of which one was serious. Most (93%) AEs were mild and all were transient. The 50% response to one injection was 81% for CM and 69% for CCH. The response gradually reduced over subsequent months for CM but stayed between 55% and 67% for CCH. Repeated injections were beneficial.

CONCLUSIONS

Injections resulted in improvement for both groups and was maintained with repeated injections. Repeat injection after three months may be beneficial in CM. Adverse events were not uncommon, but universally transient, presumably as a result of the mechanism of action of BTA. Repeated BTA injection towards the SPG could be an effective treatment for refractory CM and CCH. Larger, randomised, placebo-controlled trials are required.

The profile of refractory chronic cluster headache

INTRODUCTION

Chronic cluster headache (CCH) is a relatively rare primary headache disorder whose management is often challenging. The prevalence of refractory CCH (rCCH) is unknown. Our aim is to describe the frequency of rCCH within a population of CCH, define the clinical profile of the refractory patients and the treatments they underwent.

METHODS

We conducted a cross-sectional study through a review of the medical records of CCH patients in six hospitals in Madrid, Spain. Data on epidemiological, clinical presentation, treatment and disease activity at the moment were collected. The European Headache Federation diagnostic criteria were used for rCCH definition. High disease activity was defined as having at least 3 severe attacks per week that impact quality of life despite treatment. Non-rCCH and rCCH groups were compared.

RESULTS

88 CCH patients were analyzed, 68.2% (60/88) met rCCH criteria at some point in their evolution. A longer diagnostic delay (4.6 ± 7.1 vs. 3.2 ± 3.7 years, p = 0.017) was observed in rCCH. All rCCH patients tried therapies without established evidence from randomized clinical trials. OnabotulinumtoxinA and galcanezumab were initiated in 77.3% (68/88) and 5.7% (5/88), but discontinued in 52.9% (36/68) and 60.0% (3/5), respectively. Occipital nerve stimulation (ONS) was implanted in 29.6% (26/88), with 50.0% (13/26) still active. Other treatment options are described and discussed. Despite treatment, 60.2% (53/88) still have high disease activity.

CONCLUSION

CCH is a disorder with poor prognosis, meeting refractoriness criteria in more than half. OnabotulinumtoxinA and ONS could be the effective in refractory patients.

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.

The location of pain in cluster headache: Data from the International Cluster Headache Questionnaire

OBJECTIVE

To identify the most common locations of cluster headache pain from an international, non-clinic-based survey of participants with cluster headache, and to compare these locations to other cluster headache features as well as to somatotopic maps of peripheral, brainstem, thalamic, and cortical areas.

BACKGROUND

Official criteria for cluster headache state pain in the orbital, supraorbital, and/or temporal areas, yet studies have noted pain extending beyond these locations, and the occipital nerve appears relevant, given the effectiveness of suboccipital corticosteroid injections and occipital nerve stimulation. Furthermore, cranial autonomic features vary between patients, and it is not clear if the trigeminovascular reflex is dermatome specific (e.g., do patients with maxillary or V2 division pain have more rhinorrhea?). Finally, functional imaging studies show early activation of the posterior hypothalamus in a cluster headache attack. However, the first somatosensory area to be sensitized is unclear; the first area can be hypothesized based on the complete map of pain locations.

METHODS

The International Cluster Headache Questionnaire was an internet-based cross-sectional survey that included a clickable pain map of the face. These data were compared to several other datasets: (1) a meta-analysis of 22 previous publications of pain location in cluster headache (consisting of 6074 patients); (2) four cephalic dermatome maps; (3) participants' survey responses for demographics, autonomic features, and effective medications; and (4) previously published somatotopic maps of the brainstem, thalamus, primary somatosensory cortex, and higher order somatosensory cortex.

RESULTS

One thousand five hundred eighty-nine participants completed the pain map portion of the survey, and the primary locations of pain across all respondents was the orbital, periorbital, and temporal areas with a secondary location in the lower occiput; these primary and secondary locations were consistent with our meta-analysis of 22 previous publications. Of the four cephalic dermatomes (V1, V2, V3, and a combination of C2-3), our study found that most respondents had pain in two or more dermatomes (range 85.7% to 88.7%, or 1361-1410 of 1589 respondents, across the four dermatome maps). Dermatomes did not correlate with their respective autonomic features or with medication effectiveness. The first area to be sensitized in the canonical somatosensory pathway is either a subcortical (brainstem or thalamus) or higher order somatosensory area (parietal ventral or secondary somatosensory cortices) because the primary somatosensory cortex (area 3b) and somatosensory area 1 have discontinuous face and occipital regions.

CONCLUSIONS

The primary pain locations in cluster headache are the orbital, supraorbital, and temporal areas, consistent with the official International Classification of Headache Disorders criteria. However, activation of the occiput in many participants suggests a role for the occipital nerve, and the pain locations suggest that somatosensory sensitization does not start in the primary somatosensory cortex.

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.

Pharmacogenomic study-A pilot study of the effect of pharmacogenomic phenotypes on the adequate dosing of verapamil for migraine prevention

OBJECTIVE

To investigate factors affecting the efficacy and tolerability of verapamil for migraine prevention using individual pharmacogenomic phenotypes.

BACKGROUND

Verapamil has a wide range of dosing in headache disorders without reliable tools to predict the optimal doses for an individual.

METHODS

This is a retrospective chart review examining adults with existing pharmacogenomic reports at Mayo Clinic who had used verapamil for migraine. Effects of six cytochrome P450 phenotypes on the doses of verapamil for migraine prevention were assessed.

RESULTS

Our final analysis included 33 migraine patients (82% with aura). The mean minimum effective and maximum tolerable doses of verapamil were 178.2(20-320) mg and 227.9(20-480) mg. A variety of CYP2C9, CYP2D6, and CYP3A5 phenotypes were found, without significant association with the verapamil doses after adjusting for age, sex, body mass index, and smoking status.

CONCLUSIONS

We demonstrated a wide range of effective and tolerable verapamil doses used for migraine in a cohort with various pharmacogenomic phenotypes.

Cluster Headache, SUNCT, and SUNA

OBJECTIVE

This article reviews the epidemiology, clinical features, differential diagnosis, pathophysiology, and management of three types of trigeminal autonomic cephalalgias: cluster headache (the most common), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA).

LATEST DEVELOPMENTS

The first-line treatments for trigeminal autonomic cephalalgias have not changed in recent years: cluster headache is managed with oxygen, triptans, and verapamil, and SUNCT and SUNA are managed with lamotrigine. However, new successful clinical trials of high-dose prednisone, high-dose galcanezumab, and occipital nerve stimulation provide additional options for patients with cluster headache. Furthermore, new genetic and imaging tests in patients with cluster headache hold promise for a better understanding of its pathophysiology.

ESSENTIAL POINTS

The trigeminal autonomic cephalalgias are a group of diseases that appear similar to each other and other headache disorders but have important differences. Proper diagnosis is crucial for proper treatment.

Commentary on 2022 guidelines on clinical trial design in cluster headache and further suggestions

BACKGROUND

New guidelines for cluster headache clinical trials were recently published. We welcome these new guidelines and raise additional considerations in trial methodologies.

MAIN BODY

We present non-inferiority trials to overcome ethical issues with placebo use, and additionally discuss issues with trial recruitment.

CONCLUSIONS

We highlight some possible issues and solutions to be considered with the recently published cluster headache trial guidelines.

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.

Cluster Headache: Diagnosis, Management, and Treatment in Pediatric Headache

Despite its rarity, cluster headache can affect children. Patients with cluster headaches often experience symptoms in their adolescence, but the time it takes for a correct diagnosis can be very long. Cluster headache can be mistaken for other pathologies, which can result in patients being diagnosed and treated incorrectly. CH therapy often represents a challenge in pediatric age as there are no studies dedicated to this age category and the therapy strategy is generally based on data from adult experience. The aim of this review is to provide a summary of the current literature on cluster headache in children and adolescents.

Efficacy of Oxygen Treatment Using Home Oxygen Concentrators for the Treatment of Cluster Headaches: A Randomized, Crossover, Multicenter Study

BACKGROUND AND PURPOSE

Oxygen treatment is the first-line acute treatment for cluster headaches (CHs), but this can be impeded by insurance coverage and oxygen-tank maintenance. Oxygen concentrators filter nitrogen from ambient air to produce oxygen-rich gas, and can therefore be an alternative to conventional oxygen therapy using a tank. We investigated the effectiveness and safety of using two home oxygen concentrators and compared them with using oral zolmitriptan for the acute treatment of CHs.

METHODS

Forty patients with episodic CHs in an active cluster period were enrolled in this randomized, crossover, multicenter study. Two attacks during the cluster period were treated using oxygen delivered by connecting two home oxygen concentrators, whereas the other two attacks were treated using oral zolmitriptan (5 mg) in a random sequence. The primary endpoint was substantial pain reduction (0 or 1 on a five-point rating scale from 0 to 4 points) at 15 min after treatment.

RESULTS

In total, 125 attacks among 32 patients were randomized and treated (63 attacks using oxygen and 62 using zolmitriptan) according to the study protocol. More attacks treated using oxygen reached the primary endpoint than did those treated using zolmitriptan (31.7% [20/63] vs. 12.9% [8/62], p=0.013). After 30 min, 57.1% of the patients who received oxygen and 38.7% who received zolmitriptan reported pain relief (p=0.082). All patients treated using oxygen reported an improvement in pain, and 61.3% preferred oxygen while only 9.7% preferred zolmitriptan. No adverse events occurred during the oxygen treatment.

CONCLUSIONS

Oxygen treatment administered using two home oxygen concentrators resulted in better pain relief than oral zolmitriptan in patients with episodic CHs. Our results suggest that home oxygen concentrators are capable of efficiently supplying oxygen in a similar manner to using an oxygen tank.

Effectiveness and safety profile of greater occipital nerve blockade in cluster headache: a systematic review

BACKGROUND

Greater occipital nerve (GON) blockade is a short-term preventive therapy for cluster headache (CH). We conducted a systematic review to evaluate the effectiveness and safety of GON blockade in patients with CH.

METHODS

On 23 October 2020, we searched MEDLINE, Embase, Embase Classic, PsycINFO, CINAHL, CENTRAL and Web of Science databases from their inception date. Studies included participants with a CH diagnosis who received corticosteroid and local anaesthetic suboccipital region injections. Outcomes were change in the frequency/severity/duration of attacks; proportion of participants responding to treatment, time to attack freedom from an attack, change in attack bout length and/or the presence of adverse effects after GON blockade. Risk of bias was assessed with the Cochrane Risk of Bias V.2.0 (RoB2)/Risk of Bias in Non-randomized Studies - of Interventions (ROBINS- I) tools and a specific tool for case reports/series.

RESULTS

Two RCTs, eight prospective and eight retrospective studies, and four case reports were included in the narrative synthesis. Every effectiveness study found a significant response in one or more of frequency/severity/duration of individual attacks or proportion of patients responding to treatment (47.8%-100.0%). There were five instances of potentially irreversible adverse effects. A higher injectate volume and use of concurrent prophylaxis may be associated with an increased likelihood of response. Methylprednisolone may have the best safety profile of available corticosteroids.

DISCUSSION

GON blockade is safe and effective for CH prevention. Higher injectate volumes may improve likelihood of response, and the likelihood of serious adverse events may be reduced by using methylprednisolone.

PROSPERO REGISTRATION NUMBER

CRD42020208435.

Health equity, care access and quality in headache - part 2

BACKGROUND

Headache disorders are a global public health concern affecting diverse populations. This review examines headache service organizations in low-, middle-, and high-income countries. It addresses global challenges in pharmacological headache treatment, with a focus on safety, tolerability, reproductive and child health, and outlines disparities in accessing innovative treatments worldwide.

MAIN BODY

Organized headache services are essential due to the wide prevalence and varying severity of headache disorders. The tiered headache service model is globally recognized, although its implementation varies based on financial and workforce considerations. Headache burden affects well-being, causing disability, economic challenges, and work limitations, irrespective of location or income. All nations still require improved diagnosis and treatment, and the majority of countries face obstacles including limited access, awareness, economic barriers, and inadequate health policies. Provided adequate internet availability, telemedicine could help improve health equity by expanding access to headache care, since it can offer patients access to services without lengthy waiting times or extensive travel and can provide healthcare unavailable in underserved areas due to staff shortages. Numerous health disparities restrict global access to many headache medications, especially impacting individuals historically excluded from randomized controlled trials, such as those with cardiovascular and cerebrovascular conditions, as well as pregnant women. Furthermore, despite advancements in researching migraine treatments for young patients, the options for treatment remain limited. Access to headache treatment relies on factors like medication availability, approval, financial coverage, and healthcare provider expertise. Inadequate public awareness leads to neglect by policymakers and undertreatment by patients and healthcare providers. Global access discrepancies are exacerbated by the introduction of novel disease-specific medications, particularly impacting Asian, African, and Latin American nations excluded from clinical trials. While North America and Europe experience broad availability of migraine treatments, the majority of countries worldwide lack access to these therapies.

CONCLUSIONS

Healthcare disparities, treatment access, and medication availability are concerning issues in headache medicine. Variations in national healthcare systems impact headache management, and costly innovative drugs are widening these gaps. Healthcare practitioners and experts should acknowledge these challenges and work towards minimizing access barriers for equitable global headache care in the future.

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.

Managing and Preventing Migraine in the Emergency Department: A Review

Migraine is a leading cause of disability worldwide, and acute migraine attacks are a common reason for patients to seek care in the emergency department (ED). There have been recent advancements in the care of patients with migraine, specifically emerging evidence for nerve blocks and new pharmacological classes of medications like gepants and ditans. This article serves as a comprehensive review of migraine in the ED, including diagnosis and management of acute complications of migraine (eg, status migrainosus, migrainous infarct, persistent aura without infarction, and aura-triggered seizure) and use of evidence-based migraine-specific treatments in the ED. It highlights the role of migraine preventive medications and provides a framework for emergency physicians to prescribe them to eligible patients. Finally, it evaluates the evidence for nerve blocks in the treatment of migraine and introduces the possible role of gepants and ditans in the care of patients with migraine in the ED.

Ten-Year Durability of Hypothalamic Deep Brain Stimulation in Treatment of Chronic Cluster Headaches: A Case Report and Literature Review

Chronic cluster headache (CCH) is a debilitating primary headache that causes excruciating pain without remission. Various medical and surgical treatments have been implemented over the years, yet many provide only short-term relief. Deep brain stimulation (DBS) is an emerging treatment alternative that has been shown to dramatically reduce the intensity and frequency of headache attacks. However, reports of greater than 10-year outcomes after DBS for CCH are scant. Here, we report the durability of DBS in the posterior inferior hypothalamus after 10 years on a patient with CCH. Our patient experienced an 82% decrease in the frequency of headaches after DBS, which was maintained for over 10 years. The side effects observed included depression, irritability, anxiety, and dizziness, which were alleviated by changing programming settings. In the context of current literature, DBS shows promise for long-term relief of cluster headaches when other treatments fail.

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.

Effects of Non-Invasive Neuromodulation of the Vagus Nerve for the Management of Cluster Headache: A Systematic Review

BACKGROUND

Cluster headache (CH) is a type of headache that has a global prevalence of 0.5-3/1000 people, provokes severe, strictly unilateral pain through the first branch of the trigeminal nerve, and is associated with observable autonomous responses. CH provokes intense pain and decreases quality of life.

OBJECTIVE

In this study, we aimed to carry out a systematic review of the effectiveness of non-invasive neuromodulation of the vagus nerve in patients with cluster headaches, which was registered on PROSPERO No. CRD42021265126.

METHODS

Six databases were used from their date of inception to February 2023 to obtain studies with the group intervention of non-invasive neuromodulation of the vagus nerve for cluster headache, with outcomes based on pain attacks, duration, and disabilities. Data on the subjects, group intervention, main outcomes, and results were collected by two authors.

RESULTS

The search provided 1003 articles, with three clinical trials being eligible for inclusion in the review. The methodological quality scores ranged from 6 to 8 points (mean: 7.3, SD: 0.8) out of a maximum of 10 points. The post-treatment results showed some positive effects using n-VNS as a treatment for cluster headache, more specifically regarding cervical neuromodulation of the vagus nerve.

CONCLUSIONS

The systematic review found moderate-to-high-quality evidence supporting that n-VNS and cervical n-VNS may have some positive effects at the end of the treatment being effective to relieve the frequency and intensity of cluster headaches. The poor quantity of studies available and the lack of homogeneity in the study protocols did not allow the pooling of data for a meta-analysis.

Management of cluster headache: Treatments and their mechanisms

BACKGROUND

The management of cluster headache is similar to that of other primary headache disorders and can be broadly divided into acute and preventive treatments. Acute treatments for cluster headache are primarily delivered via rapid, non-oral routes (such as inhalation, nasal, or subcutaneous) while preventives include a variety of unrelated treatments such as corticosteroids, verapamil, and galcanezumab. Neuromodulation is becoming an increasingly popular option, both non-invasively such as vagus nerve stimulation when medical treatment is contraindicated or side effects are intolerable, and invasively such as occipital nerve stimulation when medical treatment is ineffective. Clinically, this collection of treatment types provides a range of options for the informed clinician. Scientifically, this collection provides important insights into disease mechanisms.

METHODS

Two authors performed independent narrative reviews of the literature on guideline recommendations, clinical trials, real-world data, and mechanistic studies.

RESULTS

Cluster headache is treated with acute treatments, bridge treatments, and preventive treatments. Common first-line treatments include subcutaneous sumatriptan and high-flow oxygen as acute treatments, corticosteroids (oral or suboccipital injections) as bridge treatments, and verapamil as a preventive treatment. Some newer acute (non-invasive vagus nerve stimulation) and preventive (galcanezumab) treatments have excellent clinical trial data for episodic cluster headache, while other newer treatments (occipital nerve stimulation) have been specifically tested in treatment-refractory chronic cluster headache. Most treatments are suspected to act on the trigeminovascular system, the autonomic system, or the hypothalamus.

CONCLUSIONS

The first-line treatments have not changed in recent years, but new treatments have provided additional options for patients.

Obstetric and Gynecologic Disorders and the Nervous System

OBJECTIVE

This article discusses obstetric and gynecologic associations with common neurologic disorders.

LATEST DEVELOPMENTS

Neurologic complications of obstetric and gynecologic disorders can arise throughout the lifespan. Caution should be exercised when prescribing fingolimod and natalizumab to patients with multiple sclerosis who are of childbearing potential because of the risk of disease rebound when they are discontinued. OnabotulinumtoxinA is considered safe in pregnancy and lactation based on long-term observational data. Hypertensive disorders of pregnancy are associated with higher subsequent cerebrovascular risk, likely via multiple mechanisms.

ESSENTIAL POINTS

Neurologic disorders may present in a variety of obstetric and gynecologic contexts, with meaningful implications for recognition and treatment. These interactions must be considered when treating women with neurologic conditions.

Deep Brain Stimulation for Chronic Cluster Headaches: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic cluster headache (CCH) is a severe and debilitating sub-type of trigeminal autonomic cephalalgia that can be resistant to medical management and associated with significant impairment in quality of life. Studies of deep brain stimulation (DBS) for CCH have provided promising results but have not been assessed in a comprehensive systematic review/meta-analysis.

OBJECTIVE

The objective was to perform a systematic literature review and meta-analysis of patients with CCH treated with DBS to provide insight on safety and efficacy.

METHODS

A systematic review and meta-analysis were performed according to PRISMA 2020 guidelines. 16 studies were included in final analysis. A random-effects model was used to meta-analyze data.

RESULTS

Sixteen studies reported 108 cases for data extraction and analysis. DBS was feasible in >99% of cases and was performed either awake or asleep. Meta-analysis revealed that the mean difference in headache attack frequency and headache intensity after DBS were statistically significant (p < 0.0001). Utilization of microelectrode recording was associated with statistically significant improvement in headache intensity postoperatively (p = 0.006). The average overall follow-up period was 45.4 months and ranged from 1 to 144 months. Death occurred in <1%. The rate of major complications was 16.67%.

CONCLUSIONS

DBS for CCHs is a feasible surgical technique with a reasonable safety profile that can be successfully performed either awake or asleep. In carefully selected patients, approximately 70% of patients achieve excellent control of their headaches.

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.

Are psychedelics the answer to chronic pain: A review of current literature

AIMS

We aim to provide an evidence-based overview of the use of psychedelics in chronic pain, specifically LSD and psilocybin.

CONTENT

Chronic pain is a common and complex problem, with an unknown etiology. Psychedelics like lysergic acid diethylamide (LSD) and psilocybin, may play a role in the management of chronic pain. Through activation of the serotonin-2A (5-HT2A) receptor, several neurophysiological responses result in the disruption of functional connections in brain regions associated with chronic pain. Healthy reconnections can be made through neuroplastic effects, resulting in sustained pain relief. However, this process is not fully understood, and evidence of efficacy is limited and of low quality. In cancer and palliative related pain, the analgesic potential of psychedelics was established decades ago, and the current literature shows promising results on efficacy and safety in patients with cancer-related psychological distress. In other areas, patients suffering from severe headache disorders like migraine and cluster headache who have self-medicated with psychedelics report both acute and prophylactic efficacy of LSD and psilocybin. Randomized control trials are now being conducted to study the effects in cluster headache Furthermore, psychedelics have a generally favorable safety profile especially when compared to other analgesics like opioids. In addition, psychedelics do not have the addictive potential of opioids.

IMPLICATIONS

Given the current epidemic use of opioids, and that patients are in desperate need of an alternative treatment, it is important that further research is conducted on the efficacy of psychedelics in chronic pain conditions.

Systemic Steroids for Otolaryngology-Head and Neck Surgery Disorders: An Evidence-Based Primer for Clinicians

OBJECTIVE

To offer pragmatic, evidence-informed guidance on the use of systemic corticosteroids (SCS) for common otolaryngologic disorders.

DATA SOURCES

PubMed, Cochrane Library, and American Academy of Otolaryngology-Head and Neck Surgery Foundation clinical practice guidelines.

REVIEW METHODS

A comprehensive search of published literature through November 2021 was conducted on the efficacy of SCS, alone or in combination with other treatments, for managing disorders in otolaryngology and the subdisciplines. Clinical practice guidelines, systematic reviews, and randomized controlled trials, when available, were preferentially retrieved. Interventions and outcomes of SCS use were compiled to generate summary tables and narrative synthesis of findings.

CONCLUSIONS

Evidence on the effectiveness of SCS varies widely across otolaryngology disorders. High-level evidence supports SCS use for Bell's palsy, sinonasal polyposis, and lower airway disease. Conversely, evidence is weak or absent for upper respiratory tract infection, eustachian tube dysfunction, benign paroxysmal positional vertigo, adenotonsillar hypertrophy, or nonallergic rhinitis. Evidence is indeterminate for acute laryngitis, acute pharyngitis, acute sinusitis, angioedema, chronic rhinosinusitis without polyps, Ménière's disease, postviral olfactory loss, postoperative nerve paresis/paralysis, facial pain, and sudden sensorineural hearing loss.

IMPLICATIONS FOR PRACTICE

Clinicians should bring an evidence-informed lens to SCS prescribing to best counsel patients regarding the risks, anticipated benefits, and limited data on long-term effects. Alternate routes of corticosteroid administration-such as sprays, drops, inhalers, and intralesional injections-may be preferable for many disorders, particularly those that are self-limited or require a prolonged duration of therapy. Prudent use of SCS reduces the risk of medication-related adverse effects. Clinicians who are conversant with high-level evidence can achieve optimal outcomes and stewardship when prescribing SCS.

Diagnostic Yield of Neuroimaging for Headache in a Pediatric Emergency Department: A Single Tertiary Centre Experience

OBJECTIVES

This study aimed to examine headache neuroimaging findings among the pediatric population visiting the emergency department in Saudi Arabia.

METHODS

This was a cross-sectional retrospective study of pediatric patients who presented to the emergency department with a headache as their primary complaint. Data were extracted from the electronic medical files of the patients at King Abdullah Specialized Children Hospital (KASCH) between 2015 and 2020. The diagnosis of headache was confirmed using a computerized tomography (CT) scan or magnetic resonance imaging (MRI) upon the patients' presentation.

RESULTS

A total of 263 patients met the inclusion criteria, and their data were extracted. The CT scans were abnormal in 50% of the patients. The MRI showed abnormal findings for 26% of the patients. CT scans and MRI identified that abnormalities were predominantly among patients with the secondary type of headache. The most common abnormal findings on CT were sinusitis (16%), masses (7%), and hydrocephalus (7%). The most common abnormal findings on MRI were masses (8%), cysts (5%), and hydrocephalus (3%). Of all patients with headaches, 10% had a prior diagnosis of headache, and 12% had a family history of headache. A significantly higher percentage of patients with secondary headache were prescribed NSAID and required admission compared to patients with primary headache (p ≤ 0.05). There was no statistically significant differences in the proportion of patients diagnosed with primary and secondary headache in terms of their neurological examination and headache types (p = 0.43).

CONCLUSIONS

Neuroimaging is essential for diagnosing headaches in children. Headaches were associated with sinusitis in children. The secondary type was more likely to have abnormal CT and MRI results. Primary type headaches were more common in those with a family history. CT scans and MRIs are needed when a headache is accompanied by an abnormal clinical evaluation. Neuroimaging and mild CT usage may be explored if there are clinical abnormalities or family history.

Medication adherence in patients with cluster headache and migraine: an online survey

To examine factors for adherent and non-adherent behavior in patients with cluster headache and migraine. Adults with cluster headache or migraine were included in this anonymous online survey using a questionnaire accessed via homepages of headache support groups. Medication adherence in preventive treatment was measured with the Medication Adherence Report Scale (MARS-D). Factors for non-adherent behavior were examined (subjective socioeconomic status, psychological comorbidities, self-efficacy, coping, side effects, expectations of treatment, information on medical treatment, and trust in the physician/treatment concept). 200 participants (n = 58 with cluster headache, n = 142 with migraine) were included. The rate of medication adherence in preventive treatment was 32.8% for participants with cluster headache and 20.4% for migraine. The most common reasons for low adherence in participants with cluster headache were altering the prescribed medication dose (34%) or taking less than instructed (14%), which was mostly due to insufficient benefit from the medication or side effects. Positive expectations of medical treatment (p ≤ 0.05) correlated significantly with adherent behavior in cluster headache. Furthermore, the adherence-promoting factors coping and self-efficacy were more pronounced in patients with cluster headache than in those with migraine (p < 0.05). This study is the first to comprehensively investigate medication adherence and factors influencing adherent/non-adherent behavior in patients with cluster headache. Patients with cluster headache had similar adherence levels to patients with migraine, but had higher resources of adherence-promoting factors.

Symptoms and pathophysiology of cluster headache. Approach to combined occipital and supraorbital neurostimulation

Cluster headache (CH) is included under section 3 - Trigeminal autonomic cephalalgias (TAC) of the International Headache Society (IHS) classification. It is one of the most frequent, painful and disabling primary headaches. Acute and preventive pharmacological treatments are often poorly tolerated and of limited effectiveness. Due to improved understanding of the pathophysiology of CH, neuromodulation devices are now considered safe and effective options for preventive and acute treatment of CH. In this paper, we review the information available to date, and present the case of a patient with disabling cluster headache highly resistant to medical treatment who underwent implantation of a peripheral nerve neurostimulation system to stimulate the supraorbital nerves (SON) and greater occipital nerve (GON) in our Pain Unit. We also review the diagnostic criteria for CH, the state of the knowledge on the pathophysiology of CH, and the role played by neuromodulation in treating this condition.

Preventive treatment of refractory chronic cluster headache: systematic review and meta-analysis

BACKGROUND

Preventive treatment for refractory chronic cluster headache (rCCH) is challenging and many therapies have been tried.

OBJECTIVE

To study what could be considered the therapy of choice in rCCH through a systematic review and meta-analysis.

METHODS

This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was registered in PROSPERO (ID CRD42021290983). A systematic search was performed in MEDLINE, Embase, Cochrane, clinicaltrials.gov, and the WHO's-International-Clinical-Trials-Registry-Platform. Studies on the preventive treatment for rCCH as defined by the European Headache Federation consensus statement were included. A meta-analysis of the pooled response rate was conducted for the different therapies.

RESULTS

Of 336 results, 45 were eligible for inclusion. Most articles studied the effect of neuromodulation as a preventive treatment for rCCH. The most studied neuromodulation technique was occipital nerve stimulation (ONS), with a pooled response rate in the meta-analysis of 57.3% (95% CI 0.481-0.665). Deep brain stimulation (DBS) was the second most studied treatment with a pooled response rate of 77.0% (95% CI 0.594-0.957). DBS results were more heterogeneous than ONS, which could be related to the different stimulation targets in DBS studies, and reported more serious adverse events than in ONS studies. The remaining therapies (anti-CGRP pathway drugs, warfarin, ketamine-magnesium infusions, serial occipital nerve blocks, clomiphene, onabotulinum toxin A, ketogenic diet, sphenopalatine ganglion radiofrequency or stimulation, vagus nerve stimulation, percutaneous bioelectric current stimulation, upper cervical cord stimulation, and vidian neurectomy) present weaker results or have less quality of evidence.

CONCLUSIONS

The results of this systematic review and meta-analysis suggest that ONS could be the first therapeutic strategy for patients with rCCH based on the current evidence.

Continuous positive airway pressure in cluster headache: A randomized, placebo-controlled, triple-blind, crossover study

BACKGROUND

Oxygen inhalation aborts cluster headache attacks, and case reports show the effect of continuous positive airway pressure. The aim of this study was to investigate the prophylactic effect of continuous positive airway pressure in chronic cluster headache.

METHODS

This was a randomized placebo-controlled triple-blind crossover study using active and sham continuous positive airway pressure treatment for chronic cluster headache. Patients entered a one month's baseline period before randomly being assigned to two months' active continuous positive airway pressure treatment followed by a four weeks' washout period and two months' sham continuous positive airway pressure or vice versa. Primary outcome measure was number of cluster headache attacks/week.

RESULTS

Of the 30 included participants (12 males, median age 49.5 years, min-max 20-66 years), 25 completed both treatment/sham cycles (two discontinued, three lost to follow-up). The median number of cluster headache attacks per week was reduced from 8.25 (0.75-89.75) attacks to 6.25 (0-56.00) attacks for active continuous positive airway pressure and to 7.50 (0.50-43.75) attacks for sham continuous positive airway pressure, but there was no difference in active versus sham (p = 0.904). One patient had a serious adverse event during active treatment, none occurred during sham treatment.

CONCLUSIONS

Continuous positive airway pressure treatment did not reduce the number of cluster headache attacks compared to sham treatment in chronic cluster headache patients.

TRIAL REGISTRATION CLINICALTRIALS.GOV

NCT03397563.

Real-world experience with 240 mg of galcanezumab for the preventive treatment of cluster headache

Background

Galcanezumab of 300 mg monthly is the FDA approved preventive medication for cluster headache (CH) during the cluster period. Compared to the 120 mg galcanezumab syringe for the treatment of migraines, the 100 mg syringe for CH has globally not been as widely available. The aim of our study was to investigate the preventive efficacy and tolerability of two 120 mg galcanezumab doses for episodic CH in clinical practices.

Methods

We evaluated patients with CH who received at least 1 dose of 240 mg (2 prefilled syringe of 120 mg) of galcanezumab in the 3 university hospitals from February 2020 to September 2021. In the patients with episodic CH, the efficacy and safety data of galcanezumab were analyzed regarding to the presence of the conventional preventive therapy at the timing of therapy of galcanezumab. The data of other subtypes of CH were separately described.

Results

In 47 patients with episodic CH, galcanezumab was started median 18 days after the onset of current bout (range 1–62 days) and 4 patients (10.8%) received second dose of galcanezumab. The median time to the first occurrence of 100% reduction from baseline in CH attacks per week after galcanezumab therapy was 17 days (25% to 75% quartile range: 5.0 ~ 29.5) in all patients with episodic CH, 15.5 days (3.8 ~ 22.1) in 36 patients with galcanezumab therapy add-on conventional preventive therapy, 21.0 days (12.0 ~ 31.5) in 11 patients started galcanezumab as initial preventive therapy. Among 33 patients with headache diary, the proportion of patients with 50% or more reduction in weekly CH attacks at week 3 from baseline were 78.8%. There was no significant difference in the proportion of patients with a reduction of at least 50% in weekly frequency of CH attacks at week 3 between 24 patients received galcanezumab therapy add-on conventional preventive therapy and 9 patient who received initial galcanezumab therapy. (83.3%, vs 66.7%, p = 0.36). There were no significant differences in proportion of “very much better or “much better” between 36 patients received galcanezumab therapy add-on conventional preventive therapy and 11 patient who received initial GT (86.1%, vs 63.6%, p = 0.18).

Conclusion

One 240 mg dose of galcanezumab with/without conventional therapy for the prevention of CH is considered effective and safe in clinical practices, as seen in the clinical trial of galcanezumab.

Long-Term Follow-Up Safety and Effectiveness of CT-Guided Radiofrequency Thermocoagulation of Sphenopalatine Ganglion in Refractory Headache Treatment

OBJECTIVE

The purpose of this study was to evaluate the effectiveness and safety of computed tomography (CT)-guided radiofrequency thermocoagulation (RFTA) of the sphenopalatine ganglion (SPG) for patients with refractory headache.

METHODS

A total of 14 patients with refractory migraine and 10 patients with cluster headache (CH) who underwent CT-guided SPG RF between May 2019 and August 2021 at the Jiaxing First Hospital, located in Jiaxing City, Zhejiang Province, China, were included and analyzed in this retrospective cohort study. Pain score, sleep quality scores, and treatment effects were observed before operation as well as 1 day and 1, 3, 6, 12, and 24 months after surgery. Also, the incidence of facial numbness at different timepoints after operation was evaluated.

RESULTS

The frequency and duration of attacks decreased after treatment in patients with migraine, and the shortening of the cluster period and the prolongation of the remission period after treatment in patients with CH indicated that the treatment was effective. The numeric rating scale (NRS) ranged from 0 to 10, where 0 meant no pain and 10 meant the worst imaginable pain. The NRS of patients at 1 day and 1, 3, 6, 12, and 24 months after surgery was significantly lower than before operation (P < 0.05). The treatment of patients with migraine and CH was effective. The overall incidence of numbness in patients with migraine and the total incidence of numbness in patients with CH was recorded. The total incidence of numbness decreased gradually, but no significant difference was detected in the incidence of numbness between the two groups (P > 0.05). No serious adverse reactions, such as orthostatic hypertension, intracranial infection, and visual disturbance, occurred in the patients after operation.

CONCLUSION

CT-guided RFTA of the SPG significantly relieves headache symptoms in patients with refractory migraine and CH. It has the advantages of rapid onset, long duration, and a safe and reliable treatment process, making it worthy of clinical application.

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.

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.

Cluster headache: A review of clinical presentation, evaluation, and management

ABSTRACT

Cluster headache is a primary headache disorder that leads to attacks of excruciating unilateral head pain with ipsilateral cranial autonomic features. These attacks can cluster, with frequent occurrences for weeks or months at a time followed by a period of complete remission. The excruciating pain of these attacks often is accompanied by increased suicidality, delays in diagnosis, and unnecessary invasive interventions. This article reviews the clinical presentation, differential diagnosis, evaluation, and treatment of cluster headache.

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.

Comprehensive Management of Headache for the Otolaryngologist: A Summary

Otolaryngologists will frequently encounter patients with head and facial pain. The headache may be a primary disorder or a symptom of a secondary pathology. Understanding diagnostic criteria and the autonomic and otologic manifestations of primary headaches is imperative for accurate diagnosis and treatment. This article summarizes key points in the issue "Comprehensive Management of Headache for the Otolaryngologist" and can be used as a cursory reference.

Oxygen Therapy in Cluster Headache, Migraine, and Other Headache Disorders

Oxygen therapy (OT) can relieve head pain in certain primary headache disorders, including cluster headache (CH). The exact underlying mechanism is currently uncertain, but suggested mechanisms include inhibition of the trigeminoautonomic reflex, modulation of neurotransmitters, and cerebral vasoconstriction. OT is the standard for acute treatment of CH, but patients with CH often experience considerable difficulties accessing home OT due to problems with insurance coverage. Inhalation of 100% oxygen at 6–12 L/min for 15–30 min using a non-rebreather face mask is one of the most effective acute therapies for CH, but several trials have indicated the superiority of higher oxygen flow rates of up to 15 L/min and/or using a demand-valve oxygen mask that can produce very high flow rates. Two randomized controlled trials have demonstrated the efficacy of OT in migraine, but obtaining reliable evidence is considered difficult because of different inhalation protocols, varying outcome measures, and small samples. There are some reports on the efficacy of OT as an adjuvant therapy in hypnic headache, primary headache in the emergency department, and even postdural puncture headache. The goal of this review article is to expand the knowledge regarding the use of oxygen in the treatment of headache disorders.

Nummular and Side-locked Headaches for the Otolaryngologist

Side-locked headaches are a common symptom having a wide-ranging differential. Unchanging in laterality, these headaches can represent neuralgias, trigeminal autonomic cephalgias, ophthalmologic disorders, otolaryngologic and craniofacial disorders, vascular disorders, and malignancy. In rarer situations, they have presented secondary to neurosurgical or dermatologic considerations. Loss of cranial nerves and visual changes warrant additional evaluation.

Current practice for primary headache disorders and perspectives on peripheral nerve blocks among emergency physicians in Canada: A national survey

OBJECTIVE

This national postal survey aimed to examine Canadian emergency physicians' practice patterns with respect to drug treatment and perspectives on peripheral nerve blocks.

BACKGROUND

The treatment of primary headache disorders in the emergency department is variable.

METHODS

We surveyed 500 emergency physicians listed in the Canadian Medical Directory according to a modified Dillman's method: an initial invitation was followed by up to four reminders to nonresponders. Physicians were asked questions regarding their frequency of medication administration and perspectives toward peripheral nerve blocks.

RESULTS

Of 500 mailed surveys, 468 were delivered and 179 physicians responded (response rate = 38.2%). The majority of physicians were men (92/144, 63.9%); 80.6% (116/144) had been in practice for greater than or equal to 10 years with 50.7% (75/148) in a community or district general teaching hospital. Commonly used pharmacotherapies for primary headaches were intravenous dopamine receptor antagonists (69%), co-administration of ketorolac and a dopamine receptor antagonist (54.2%), intravenous fluid boluses (54%), nonsteroidal anti-inflammatory drugs (NSAIDs) alone (53.5%), and acetaminophen (51.4%). Only 80 of 144 physicians (55.6%) reported previous experience with peripheral nerve blocks (95% confidence interval [CI] = 48%-65%). The majority (68/80, 85.0%) agreed peripheral nerve blocks are safe and 55.1% (43/78) agreed they are effective. The vast majority (118/140, 84.3%) would consider peripheral nerve blocks as a first-line treatment option given sufficient evidence from a future trial (95% CI = 78%-90%).

CONCLUSION

NSAIDs alone, as well as dopamine receptor antagonists with or without ketorolac are commonly used for primary headache in Canadian emergency departments. A large proportion of physicians have never used a peripheral nerve block in their practice; among those who have experience with peripheral nerve blocks, the majority find them safe and effective. The majority of respondents would consider peripheral nerve blocks as a first-line treatment option given sufficient evidence from a future trial.

Challenges and complexities in designing cluster headache prevention clinical trials: A narrative review

Objective

To provide a review of challenges in clinical trials for the preventive treatment of cluster headache (CH) and highlight considerations for future studies.

Background

Current guidelines for preventive treatment of CH are largely based on off‐label therapies supported by a limited number of small randomized controlled trials. Guidelines for clinical trial design for CH treatments from the International Headache Society were last issued in 1995.

Methods/Results

Randomized controlled clinical trials were identified in the European and/or United States clinical trial registries with a search term of “cluster headache,” and manually reviewed. Cumulatively, there were 27 unique placebo‐controlled prevention trials for episodic and/or chronic CH, of which 12 were either ongoing, not yet recruiting, or the status was unknown. Of the remaining 15 trials, 5 were terminated early and 7 of the 10 completed trials enrolled fewer patients than planned or did not report the planned sample size. A systematic search of PubMed was also utilized to identify published manuscripts reporting results from placebo‐controlled preventive trials of CH. This search yielded 16 publications, of which 7 were registered. Through critical review of trial data and published manuscripts, challenges and complexities encountered in clinical trials for the preventive treatment of CH were identified. For example, the excruciating pain associated with CH demands a suitably limited baseline duration, rapid treatment efficacy onset, and poses a specific issue regarding duration of investigational treatment period and length of exposure to placebo. In episodic CH, spontaneous remission as part of natural history, and the unpredictability and irregularity of cluster periods across patients present additional key challenges.

Conclusions

Optimal CH trial design should balance sound methodology to demonstrate efficacy of a potential treatment with patient needs and the natural history of the disease, including unique outcome measures and endpoint timings for chronic versus episodic CH.

Recent advances in the diagnosis and management of cluster headache

Cluster headache, a primary headache disorder, consists of short (15-180 minutes), frequent (up to eight a day), unilateral attacks of facial pain with associated ipsilateral autonomic features and restlessness. The attacks are suspected to be one of the most painful human experiences, and the disorder is associated with a high rate of suicidal ideation. Proper diagnosis is key, as some of the most effective treatments, such as high flow oxygen gas, are rarely used in other headache disorders. Yet diagnostic delay is typically years for this disorder, as it is often confused with migraine and trigeminal neuralgia, and secondary causes may be overlooked. This review covers the clinical, pathophysiologic, and therapeutic features of cluster headache. Recent updates in diagnosis include the redefinition of chronic cluster headache (remission periods lasting less than three months instead of the previous one month), and recent advances in management include new treatments for episodic cluster headache (galcanezumab and non-invasive vagus nerve stimulation).