The Role of Melatonin in the Treatment of Primary Headache Disorders

Complementary and Integrative Medicine for the Treatment of Trigeminal Neuralgia and Trigeminal Autonomic Cephalalgia

PURPOSE OF REVIEW

Trigeminal neuralgia (TN) and trigeminal autonomic cephalalgias (TACs) are both painful diseases which directly impact the branches of the trigeminal nerve, which supply the face. Patients who have experienced adverse effects, have not responded to mainstream treatments, or have a personal preference for nonmedication options, often turn to complementary and integrative medicine (CIM). The aim of this review is to discuss the efficacy and safety of CIM therapies available for the treatment of TN and TACs.

RECENT FINDINGS

Not only are there limited therapeutic options for TN and TAC patients, but also is there a proportion of patients who are intolerant to standard medical treatments. Recent findings have illustrated that 86% of patients with headache disorders utilize CIM modalities in combination with mainstream medical therapy. CIM modalities can be helpful for these diseases and have primarily been studied in combination with standard medical therapy. There is limited evidence for CIM and behavioral therapies in managing these conditions, and more research is needed to confirm which therapies are safe and effective.

Melatonin in hemicrania continua and paroxysmal hemicrania

BACKGROUND

Hemicrania continua (HC) and paroxysmal hemicrania (PH) belong to a group of primary headache disorders called trigeminal autonomic cephalalgias. One of the diagnostic criteria for both HC and PH is the absolute response to the therapeutic dose of indomethacin. However, indomethacin is discontinued in many patients as a result of intolerance to its side effects. Melatonin, a pineal hormone, which shares similar chemical structure to indomethacin, has been reported to have some efficacy for HC in previous case reports and series. To our knowledge, there is no literature regarding the use of melatonin in PH. We aimed to describe the clinical use of melatonin in the preventive management of HC and PH.

METHODS

Patient level data were extracted as an audit from routinely collected clinical records in consecutive patients seen in outpatient neurology clinic at King's College Hospital, London, UK, from September 2014 to April 2023. Our cohort of patients were identified through a search using the keywords: hemicrania continua, paroxysmal hemicrania, melatonin and indomethacin. Descriptive statistics including absolute and relative frequencies, mean ± SD, median and interquartile range (IQR) were used.

RESULTS

Fifty-six HC patients were included with a mean ± SD age of 52 ± 16 years; 43 of 56 (77%) patients were female. Melatonin was taken by 23 (41%) patients. Of these 23 patients, 19 (83%) stopped indomethacin because of different side effects. The doses of melatonin used ranged from 0.5 mg to 21 mg, with a median dose of 10 mg (IQR = 6-13 mg). Fourteen (61%) patients reported positive relief for headache, whereas the remaining nine (39%) patients reported no headache preventive effect. None of the patients reported that they were completely pain free. Two patients continued indomethacin and melatonin concurrently for better symptom relief. Eight patients continued melatonin as the single preventive treatment. Side effects from melatonin were rare. Twenty-two PH patients were included with mean ± SD age of 50 ± 17 years; 17 of 22 (77%) patients were female. Melatonin was given to six (27%) patients. The median dose of melatonin used was 8 mg (IQR = 6-10 mg). Three (50%) patients responded to melatonin treatment. One of them used melatonin as adjunctive treatment with indomethacin.

CONCLUSIONS

Melatonin showed some efficacy in the treatment of HC and PH with a well-tolerated side effect profile. It does not have the same absolute responsiveness as indomethacin, at the doses used, although it does offer a well-tolerated option that can have significant ameliorating effects in a substantial cohort of patients.

Ternary Dry Powder Agglomerate Inhalation Formulation of Melatonin With Air Jet Mixing to Improve In Vitro And In Vivo Performance

An improved agglomerate formulation with melatonin and fine lactose for dry powder inhalation using Turbuhaler® was developed. Co-grinding lactose with 1 % magnesium stearate prior to air jet mixing served as a key factor to improve the in vitro aerosolization and in vivo efficacy. Elevated mixing pressure facilitated the dispersion and homogenization of the cohesive mixture for even distribution of agglomerate size after spheroidization and subsequent higher emitted dose with lower variation. Magnesium stearate was employed as a tertiary component to adjust the interparticle force for better aerosolization. At optimized mixing pressure, co-grinding lactose with magnesium stearate before jet mixing displayed further improvement of fine particle fraction to 71.6 ± 3.1 %. The superior fine particle deposition efficiency contributed to rapid onset of action and a high bioavailability of 67.0 % after intratracheal administration to rats. Overall, an inhalable melatonin dry powder formulation exhibiting good aerosol property and lung deposition with clinical translation potential was developed.

Sleep Disorders and Chronic Pain Syndromes in the Pediatric Population

Sleep problems are widespread in children and adolescents suffering from chronic pain disorders. Sleep loss intensifies the experience of pain and is detrimental to the budding self-efficacy of a young individual with limitless horizons. Addressing sleep disorders may prevent the chronification of pain and prevent adverse health outcomes, such as functional impairment, psychiatric comorbidities and overall poor quality of life. This review will explore the cyclical nature between sleep, pain and mood, as well as the functional impact of this relationship on children and adolescents. There will be a discussion about sleep assessment and diagnostic testing, followed by a description of sleep disturbances found in specific pain conditions, ranging from headache, musculoskeletal/abdominal pain, to rheumatologic disorders. Finally, there will be a brief review of pharmacologic and behavioral interventions designed to improve sleep quality, and when possible, to alleviate pain.

Patients with cluster headache show signs of insomnia and sleep related stress: results from an actigraphy and self-assessed sleep study

BACKGROUND

Cluster headache (CH) is a primary headache disorder which is characterized by circadian timing of headache attacks, usually at nighttime, in around two thirds of patients. Patients with CH often report sleep difficulties, though it is unknown whether this is a cause or a consequence of nightly headache attacks.

OBJECTIVE

In this case-control study we have assessed sleep quality in study participants with CH in cluster bout respectively in remission, compared to a control group of neurologically healthy individuals to investigate the potential connection between sleep and CH.

METHODS

Fifty study participants with CH and 42 controls were recruited for sleep assessment. Sleep was recorded using MotionWatch 8 actigraphs (CamNTech) for a period of two weeks. Study participants were instructed to wear the unit during rest and sleep and to fill out a sleep diary daily through the two-weeks period.

RESULTS

Results from actigraphy recordings and sleep diaries suggested that patients with CH spend longer time in bed than controls (CH 8.1 hours vs. Controls 7.7 hours, p=0.03), but do not sleep more than controls (CH 6.7 hours vs. controls 6.5 hours, p=0.3). In addition, CH patients reported increased sleep latency (p=0.003), particularly during, but not restricted to, cluster bouts. Study participants with CH further reported higher levels of stress at bedtime (p=0.01), and they felt less well rested than controls (p=0.001).

CONCLUSION

Our analysis suggests that sleep is negatively affected in CH both in cluster bout and in remission, manifesting in symptoms consistent with insomnia such as prolonged sleep latency and increased time in bed.

Pediatric hypnic headache: a systematic review

Introduction

Hypnic headache (HH) is a primary headache, and it is considered a rare condition in children. The underlying mechanisms of HH are not yet fully understood. This systematic review aims to provide a comprehensive description of the clinical features of all published cases of pediatric HH. It will also discuss the differences in headache features between children and adults, the increased diagnostic sensitivity of the new diagnostic criteria (ICHD-3), potential pathophysiological hypotheses explaining the higher incidence in adults, differential diagnoses, and therapeutic options for children.

Methods

A systematic search was conducted to identify and analyze articles reporting cases of HH in patients under the age of 18. The search was performed in major medical databases including Cochrane Library, EBSCO, Embase, Medline, PubMed, Science Direct, Scopus, and Web of Science. The search covered the period from 1988 to April 2023. Relevant studies were screened for eligibility, and data extraction was performed using a standardized approach.

Results

Seven children with HH were included in the analysis. The mean age of onset for headache attacks was 10 ± 4.3 years (range 3-15 years). The average time from the start of headaches to diagnosis was 15.8 ± 25.0 months (range 1-60 months). Headache features in children differed from those observed in adult HH patients. Children experienced throbbing/pulsating pain, while adults reported dull/pressure-like pain. Children also had lower frequency and shorter duration of attacks compared to adults. The use of ICHD-3 criteria appeared to be more sensitive and inclusive for diagnosing HH in children compared to the previous ICHD-2 criteria. The association of headache attacks with sleep suggests that HH may be a primary disorder with a chronobiological origin. Hypothalamic dysfunction and melatonin dysregulation, which are more prevalent in older individuals, could potentially explain the higher incidence of HH in adults. Other primary headaches and secondary causes should be ruled out. Melatonin prophylactic therapy may be considered for pediatric patients.

Discussion

Further evaluation of the clinical features of HH in children is needed. The development of specific diagnostic criteria for pediatric cases could improve diagnostic rates and enhance the management of children with HH.

Hypnic Headache - What do we know in 2022?

BACKGROUND

Hypnic Headache, also known as "alarm clock headache", is a rare primary headache disorder. It is characterized by frequently recurring headache attacks, which only develop during sleep, especially nighttime sleep.

OBJECTIVE

This article gives a narrative review on the current knowledge about Hypnic Headache with a focus on secondary Hypnic Headache.

METHODS

Based on literature research, using Pubmed and Google Scholar, latest case reports, studies, and systematic reviews about Hypnic Headache were analyzed and summarized focusing on therapeutic options and causes of secondary Hypnic Headache.

CONCLUSION

Hypnic Headache mainly occurs in elderly patients. However, younger patients and children may also suffer from Hypnic Headache. Many different causes of secondary Hypnic Headache are described in the literature and ought to be ruled out before diagnosing primary Hypnic Headache. The pathophysiology of primary Hypnic Headache remains unclear, but a dysfunction of the hypothalamus seems to play a key role.

Pyroptosis and Intervertebral Disc Degeneration: Mechanistic Insights and Therapeutic Implications

Low back pain (LBP) is a common problem worldwide, resulting in great patient suffering and great challenges for the social health system. Intervertebral disc (IVD) degeneration (IVDD) is widely acknowledged as one of the key causes of LBP. Accumulating evidence suggests that aberrant pyroptosis of IVD cells is involved in the pathogenesis of IVDD progression, however, the comprehensive roles of pyroptosis in IVDD have not been fully established, leaving attempts to treat IVDD with anti-pyroptosis approaches questionable. In this review, we summarize the characteristics of pyroptosis and emphasize the effects of IVD cell pyroptosis on the pathological progression of IVDD, including secretion of cytokines, nucleus pulposus cell apoptosis and autophagy, accelerated extracellular matrix degradation, annulus fibrosus rupture, cartilage endplate calcification, vascularization, sensory and sympathetic fiber neoinnervation, and infiltrating lymphatic vessels. Finally, we discuss several interventions used to treat IVDD by targeting pyroptosis. This review provides novel insights into the crucial role of IVD cell pyroptosis in IVDD pathogenesis, and could be informative for developing novel therapeutic approaches for IVDD and LBP.

Is Melatonin the “Next Vitamin D”?: A Review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements

Melatonin has become a popular dietary supplement, most known as a chronobiotic, and for establishing healthy sleep. Research over the last decade into cancer, Alzheimer’s disease, multiple sclerosis, fertility, PCOS, and many other conditions, combined with the COVID-19 pandemic, has led to greater awareness of melatonin because of its ability to act as a potent antioxidant, immune-active agent, and mitochondrial regulator. There are distinct similarities between melatonin and vitamin D in the depth and breadth of their impact on health. Both act as hormones, affect multiple systems through their immune-modulating, anti-inflammatory functions, are found in the skin, and are responsive to sunlight and darkness. In fact, there may be similarities between the widespread concern about vitamin D deficiency as a “sunlight deficiency” and reduced melatonin secretion as a result of “darkness deficiency” from overexposure to artificial blue light. The trend toward greater use of melatonin supplements has resulted in concern about its safety, especially higher doses, long-term use, and application in certain populations (e.g., children). This review aims to evaluate the recent data on melatonin’s mechanisms, its clinical uses beyond sleep, safety concerns, and a thorough summary of therapeutic considerations concerning dietary supplementation, including the different formats available (animal, synthetic, and phytomelatonin), dosing, timing, contraindications, and nutrient combinations.

Desynchronosis: Types, Main Mechanisms, Role in the Pathogenesis of Epilepsy and Other Diseases: A Literature Review

Circadian information is stored in mammalian tissues by an autonomous network of transcriptional feedback loops that have evolved to optimally regulate tissue-specific functions. Currently, stable circadian rhythms of the expression of clock genes (Bmal1/Per2/Cry1, etc.), hormones, and metabolic genes (Glut4/leptin, etc.) have been demonstrated. Desynchronoses are disorders of the body’s biorhythms, where the direction and degree of shift of various indicators of the oscillatory process are disturbed. Desynchronosis can be caused by natural conditions or man-made causes. The disruption of circadian rhythms is a risk factor for the appearance of physiological and behavioral disorders and the development of diseases, including epilepsy, and metabolic and oncological diseases. Evidence suggests that seizure activity in the epilepsy phenotype is associated with circadian dysfunction. Interactions between epilepsy and circadian rhythms may be mediated through melatonin, sleep–wake cycles, and clock genes. The correction of circadian dysfunction can lead to a decrease in seizure activity and vice versa. Currently, attempts are being made to pharmacologically correct desynchronosis and related psycho-emotional disorders, as well as combined somatic pathology. On the other hand, the normalization of the light regimen, the regulation of sleep–wake times, and phototherapy as additions to standard treatment can speed up the recovery of patients with various diseases.

Headache in the Pediatric Population: Focus on Migraine

Pediatric headache is a common condition with significant impact on quality of life and ability to function in academic, social, and extracurricular activities. Most pediatric patients seen in primary care and neurology clinics with headache have primary headache disorders. Diagnosis is largely based on clinical history. Imaging is rarely needed in the absence of red flag features. Careful diagnosis is important to guide appropriate treatment. Treatment focuses on a biopsychosocial model integrating lifestyle, pharmacologic and nonpharmacologic treatment modalities. As few therapies are approved in the pediatric population, treatments are often used off-label based on evidence extrapolated from adult studies. Outcomes vary over time but are generally favorable when headache disorders are diagnosed promptly and managed in a multidisciplinary setting.

Headache and rhinitis: pattern search on Google Trends for 17 years

OBJECTIVE

Headache and rhinitis are highly prevalent and comorbid. The objective of the present study is to analyze the correlation of headache and rhinitis, in addition to the temporal pattern of these diseases in 17 years, using the Google Trends platform.

METHODS

Google Trends was searched from January 2004 to June 2021, using the entry: ["rinite" (rhinitis) + "dor de cabeça" (headache)" + "Alzheimer" + "enxaqueca" (migraine)]. Migraine, primary headache, and Alzheimer's, with no clear relation with headache, were used as controls. After the descriptive analysis by dispersion diagrams, Pearson's test and a simple regression model were performed. Subsequently, this study analyzed the seasonality of the volume of research on rhinitis and headache.

RESULTS

A strong correlation between rhinitis and headache (0.86) was found in the time interval analyzed. In addition, a seasonality was identified in the volume of searches for the term rhinitis with increased volume in the fall and peaks in the month of May, with a decrease in the spring and early summer. Moreover, an increase of searches on headache was observed, suggesting worse burden of this pathology.

CONCLUSION

Headaches and rhinitis were correlated in 17 years of research on the Google Trends platform. Circannual variation of both conditions was observed. Additional studies with digital research may be useful to better understand the epidemiology and comorbidities of headache.

Episodic Migraine and Older Adults

PURPOSE OF REVIEW

Migraine is and continues to be a significant medical issue in older adults. Migraine can have different characteristics in older adults and specific diagnostic and treatment considerations need to be applied when managing headache and migraine in this population, which is increasing in both size and diversity. Contrary to widely held beliefs, migraine may not improve in older women following menopause and can have new onset in older age. The purpose of this review is to give an update on the diagnosis and treatment of episodic migraine in older adults.

RECENT FINDINGS

As the population ages, migraine in older adults will become a more significant public health issue. Migraine in older adults can present with different clinical symptoms than in a younger population and is primarily a diagnosis of exclusion in older adults. Migraine treatment considerations for older adults should include comorbidities and medication interactions. Recent findings suggest there are medications that should be avoided when treating seniors with migraine. The purpose of this review is to give an update on the most important aspects regarding the diagnosis and treatment of headache and migraine in older adults. In addition, recommendations will be made concerning medications that need careful consideration when prescribing to seniors.

Pediatric Headache in Primary Care and Emergency Departments: Consensus with RAND/UCLA Method

Headache is the most frequent neurological symptom in childhood and the main reason for admission to pediatric emergency departments. The aim of this consensus document is to define a shared clinical pathway between primary care pediatricians (PCP) and hospitals for the management of children presenting with headache. For the purposes of the study, a group of hospital pediatricians and a group of PCP from the Emilia Romagna’s health districts were selected to achieve consensus using the RAND/UCLA appropriateness method. Thirty-nine clinical scenarios were developed: for each scenario, participants were asked to rank the appropriateness of each option from 1 to 9. Agreement was reached if ≥75% of participants ranked within the same range of appropriateness. The answers, results, and discussion helped to define the appropriateness of procedures with a low level of evidence regarding different steps of the diagnostic-therapeutic process: primary care evaluation, emergency department evaluation, hospital admission, acute therapy, prophylaxis, and follow-up. The RAND proved to be a valid method to value appropriateness of procedures and define a diagnostic-therapeutic pathway suitable to the local reality in the management of pediatric headache. From our results, some useful recommendations were developed for optimizing the healthcare professionals’ network among primary care services and hospitals.

Headache and Sleep Disturbances in the Pediatric Population

The relationship between sleep disturbances and headaches in the pediatric population is bidirectional. Common underlying molecular mechanisms of sleep and headaches have been speculated to explain the clinical connection. We will summarize various sleep disturbances and their known relationships to headache, focusing on the pediatric population. Careful recognition and assessment of sleep disturbances in patients with headache is critical and may help guide treatment. First line therapies for sleep disturbances consist of behavioral approaches, though surgical and pharmacologic strategies are utilized in particular circumstances.

Nightmares in Migraine: A Focused Review

Nightmares usually occur during the sleep phase of rapid eye movement (REM) and are associated with some physical symptoms, including sweating, shortness of breath, and lower limb movements. Emotions of fear, anger, shame, and sadness may also accompany nightmares. These symptoms can occur during dreaming, upon awakening, or later when the dream experience is recollected. Nightmares may sporadically occur for everyone, but nightmare disorders are associated with features of impaired mental and physical health and require professional medical treatment. The occurrence of nightmares with several disorders has been reported in the literature, but in migraines it has only been investigated in a small number of studies. Considering the existing relationship between sleep disorders and migraine, the occurrence of nightmares in migraine can negatively affect this association and elevate the risk of depression and anxiety. This, in turn, further reduces the quality of life of affected individuals. Hence, expanding the knowledge on the link between nightmares and migraine, promoting an acceptable quantity and quality of sleep through pharmacological and nonpharmacological interventions in the management of nightmares in migraine, and further scientific investigation of the biopsychosocial mechanisms underlying the link, will be highly valuable for optimal care. This focused review, therefore, gives a brief overview of the current understanding of nightmares in migraine to highlight the open questions and value of further research. The ultimate goal is to contribute to timely recognition and sufficient action to offer beneficial outcomes for affected patients.

Sleep Disorders in Pediatric Migraine: A Questionnaire-Based Study

There is a high comorbidity between migraine and sleep disorders (SD), with a mutual dependence between sleep and headache. This study aimed to analyze the relationship between headache features (migraine frequency and severity, migraine equivalents, use and efficacy of treatments) and sleep in pediatric migraine. Parents of children and adolescents with migraine completed the Children’s Sleep Habits Questionnaire (CSHQ) and the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) and answered questions about headache characteristics. The presence of SD was defined according to CSHQ score. SD were detected in 72.9% of 140 subjects, but only 5.0% already received a diagnosis. Patients with SD presented statistically significant higher headache frequency (p = 0.031) and higher prevalence of migraine equivalents (p = 0.007). A higher CSHQ total score was associated with higher frequency of severe attacks (p = 0.012) and lower acute drug efficacy (p = 0.003). Significant positive correlations of sleep onset delay, sleep duration and nightwakings subscales with migraine frequency emerged. Our findings indicate that SD are highly prevalent in pediatric migraine and frequently associated with a higher headache severity and lower response to acute therapy, but often remain underdiagnosed. Improving sleep quality could help to reduce migraine intensity and disability and vice versa.

Headache in Children and Adolescents

PURPOSE OF REVIEW

This article reviews the approach to a child or adolescent with headache, the criteria for common diagnoses, and the evidence base for treatments.

RECENT FINDINGS

The guidelines for acute and preventive treatment of migraine were updated in 2019. These guidelines summarize the available evidence and outline the questions that should be addressed in future research. The US Food and Drug Administration (FDA) approval of several new classes of drugs and devices to treat adult migraine in the past few years has resulted in ongoing or planned pediatric trials.

SUMMARY

Headache is a common symptom in children, and it is important to take a detailed history and perform a thorough physical examination to make the diagnosis. Nearly 1 in 10 children experience recurrent headaches due to migraine, which cause significant impairment in school performance and quality of life. The acute and preventive treatments that are currently available will help at least two-thirds of children with migraine, and several trials of new therapies offer hope for the future.

Cluster Headache and Other Trigeminal Autonomic Cephalalgias

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Use of Nutraceutical Ingredient Combinations in the Management of Tension-Type Headaches with or without Sleep Disorders

Headache is the most common pain complaint in the pediatric population, with tension type headache (TTH) having a prevalence of 10–15% in children. Up to 70% of pediatric patients with chronic headache also experience sleep disruption, with a likely bidirectional relationship between headache and poor sleep. Treatment options include specific pharmacological approaches as well as non-pharmacological alternatives; nutraceuticals have the advantage of a relative lack of side effects. Exogenous melatonin has been shown to be useful and safe in improving sleep-wake cycles and quality of sleep in children, helping to regulate the circadian rhythm, with a secondary positive impact on headache. Supplementation with other nutraceutical ingredients, such as tryptophan, magnesium, and B vitamins, can have significant additional effects in children with primary headache, with or without sleep disorders. Tryptophan may reduce night awakenings and improve the efficiency of sleep. Primary headache has been related to low amounts of magnesium in serum, and integration with magnesium appears to be effective in reducing headache attacks without adverse effects. There are different observational reports and uncontrolled studies suggesting a possible synergistic effect for these nutraceuticals, but there is now a need for high-quality randomized controlled trials in order to confirm these positive preliminary findings.

Nutraceuticals and Behavioral Therapy for Headache

PURPOSE OF REVIEW

Headache affects and disables at least 1 billion people worldwide. Patients and providers seek new therapies to relieve headache without the side effects and financial burden of current treatments. This narrative review highlights recent treatment advances in integrative headache medicine: nutraceuticals and behavioral therapies.

RECENT FINDINGS

Growing use of complementary and alternative medicine (CAM) therapies for headache (riboflavin, coenzyme Q10, magnesium, vitamin D, melatonin) alongside mainstream treatments is increasing with improving evidence of quality, safety, and tolerability. Increasing interest in medical cannabis is tempered by lack of evidence regarding safety and efficacy. Behavioral therapies including cognitive behavioral therapy (CBT), biofeedback, mindfulness-based stress reduction (MBSR), and acceptance and commitment therapy (ACT) improve patient resiliency and self-efficacy outcomes and reduce disability. The body of evidence for nutraceutical and behavioral CAM interventions for headache continues to grow and improve in quality. Providers and patients should educate themselves regarding CAM therapies as part of integrative headache management. Future studies should examine combinatorial trials of CAM therapies against current standards of headache care.

Cluster headache pathophysiology - insights from current and emerging treatments

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

Hypnic Headache Responds to Topiramate: A Case Report and a Review of Mechanisms of Action of Therapeutic Agents

Hypnic headaches are unique as they are exclusively nocturnal, occurring in rapid-eye movement (REM) and non-REM sleep. Their nocturnal nature suggests a role for cyclic mechanisms involving the hypothalamus despite conflicting imaging results for the role of the posterior hypothalamus. Nevertheless, pharmacological therapeutics acting as highly effective agents, such as caffeine and melatonin, can modulate the sleep-wake cycle. In addition, indole agents such as indomethacin that are anti-nociceptive and affect cerebral blood flow also prove to be efficacious. Gabanoids and topiramate also have reported efficacy. We report the case of a topiramate-responsive hypnic headache patient and outline in detail the potential mechanisms of topiramate and the other therapeutic agents and adumbrate on the neuronal networks of migraine, the trigeminal autonomic cephalgias and suggest a potential neural circuit for hypnic headaches. 

An Overview and Therapeutic Promise of Nutraceuticals against Sports-Related Brain Injury

Sports-related traumatic brain injury (TBI) is one of the common neurological maladies experienced by athletes. Earlier the term 'punch drunk syndrome' was used in the case TBI of boxers and now this term is replaced by chronic traumatic encephalopathy (CTE). Sports-related brain injury can either be short term or long term. A common instance of brain injury encompasses subdural hematoma, concussion, cognitive dysfunction, amnesia, headache, vision issue, axonopathy, or even death if remain undiagnosed or untreated. Further, chronic TBI may lead to pathogenesis of neuroinflammation and neurodegeneration via tauopathy, formation of neurofibrillary tangles, and damage to the blood-brain barrier, microglial, and astrocyte activation. Thus, altered pathological, neurochemical, and neurometabolic attributes lead to the modulation of multiple signaling pathways and cause neurological dysfunction. Available pharmaceutical interventions are based on one drug one target hypothesis and thereby unable to cover altered multiple signaling pathways. However, in recent time's pharmacological intervention of nutrients and nutraceuticals have been explored as they exert a multifactorial mode of action and maintain over homeostasis of the body. There are various reports available showing the positive therapeutic effect of nutraceuticals in sport-related brain injury. Therefore, in the current article we have discussed the pathology, neurological consequence, sequelae, and perpetuation of sports-related brain injury. Further, we have discussed various nutraceutical supplements as well as available animal models to explore the neuroprotective effect/ upshots of these nutraceuticals in sports-related brain injury.

Recent Advances in the Management of Cluster Headache

Purpose of review

Among the spectrum of pain conditions, cluster headache represents one of the most severe. Targeted therapies for cluster headache are evolving thus improving the available therapeutic armamentarium. A better understanding of the currently available therapies, as well as new and emerging options, may aide physicians to manage affected sufferers better by evolving treatment guidance.

Recent findings

While classic first-line medications are useful in some patients with cluster headache, they are often accompanied by significant side effects that limit their use. Recently, novel treatments with better tolerability and decreased medication interactions have proven to be effective. A remarkable example of this is the blockage of the calcitonin gene-related peptide pathway with monoclonal antibodies, which may be a key element in the future treatment of cluster headache. The sphenopalatine ganglion and vagus nerve perform a critical role in the regulation of pain and the trigeminal autonomic reflex. Neuromodulation therapies targeting these structures have shown excellent tolerability and few significant adverse events, constituting a promising form of treatment. Finally, several potential therapeutic targets are examined in this review, such as small molecule CGRP receptor antagonists, known as gepants, and serotonin receptor 5-HT1F receptor agonists: ditans.

Summary

In summary, a deepening of the understanding of cluster headache mechanisms in recent years has driven the evolution of sophisticated therapeutic approaches that could allow a new era in the treatment of this difficult condition.

Myasthenia gravis exacerbation after melatonin administration: case series from a tertiary referral centre

Background

Myasthenia gravis is an autoimmune disease mediated by antibodies against proteins associated with the postsynaptic membrane of the neuromuscular junction. Several drugs may trigger an exacerbation of the disease. Melatonin supplements are widely used for the treatment of insomnia as they are well tolerated with few side effects. The role of melatonin in the immune system and its effects in autoimmune disorders remain uncertain.

Case presentation

We identified three patients in our referral centre from 2014 to 2019 who presented a worsening within days or weeks of starting melatonin. Two of them stopped the treatment without clinical improvement in the next week. Increasing dose of corticosteroids did not lead to clinical improvement in the next month and one of the patients was finally administered intravenous immunoglobulins.

Conclusion

Melatonin may trigger exacerbations of myasthenia gravis, probably due to an upregulation of the adaptive immune system and an interaction with the corticosteroids and other immunosuppressant treatments. We consider that melatonin should be administered with caution in these patients.

Safety and Efficacy of Melatonin in Chronic Tension-Type Headache: A Post-Marketing Real-World Surveillance Program

INTRODUCTION

Tension-type headache (TTH) is the most prevalent primary headache. Every year, about 2-3% of patients with TTH progress to chronic TTH with daily or near-daily headache, warranting preventive treatment. The treatment of chronic TTH is complex and very often associated with significant tolerability issues. To date, melatonin has been studied in only a few small uncontrolled trials. The aim of this surveillance program was to evaluate the efficacy of melatonin (Melaxen^®) in patients with TTH and disruption of circadian rhythms in real-world practice.

METHODS

Sixty-one patients with chronic TTH were enrolled. After the 30-day baseline period, patients took 3 mg of melatonin at bedtime for 30 days with a follow-up period of another 30 days. VAS pain intensity assessments, Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D), HIT-6 and Levin sleep quality scores were obtained at the baseline visit, at month 1, and month 2.

RESULTS

A significant decrease in the number of headache days per month, VAS pain intensity, HAM-A, HAM-D and HIT-6 scores, and an improvement in sleep quality were observed throughout the study. No treatment-emergent adverse events were reported.

CONCLUSIONS

Melatonin is an effective and safe alternative for the treatment of chronic TTH.

Meta-analysis of melatonin levels in cluster headache-Review of clinical implications

Cluster headache (CH) has been associated with circadian disturbances. The present systematic review examined available evidence for the utilization of melatonin (MT) in CH prophylaxis. First, case-control studies assessing nocturnal MT or its urine-expelled metabolite 6-sulfatoxymelatonin (aMT6s) in CH individuals and healthy controls (HC) were reviewed and meta-analyzed. Secondly, the results from randomized controlled trials (RCTs) and non-randomized studies evaluating MT's use in the prevention of CH were discussed. Literature search included MEDLINE, EMBASE, CENTRAL, PsycINFO, trial registries, Google Scholar, and OpenGrey. Bouts and remissions were assessed separately. Ten case-control studies (adult participants) were retrieved. Seven evaluated serum MT; meta-analysis involved only three of them (due to deficient reporting, n: bout = 31, remission = 38, HC = 31). Results were compatible with lower nocturnal serum MT levels during bouts [bout-HC; FE-MD = -29.89 pg/mL, 95% CI = (-46.00, -13.78), remission-HC; FE-MD = -2.40 pg/mL, 95% CI = (-16.57, 21.38), bout-remission; RE-MD = -32.10 pg/mL, 95% CI = (-56.78, -7.42)]. Nocturnal urinary melatonin was appraised in two studies, but reporting issues impeded the capitalization of the results. Nocturnal urine aMT6s was evaluated by two studies (n: bout = 29, remission = 22, HC = 20), and pooled results were indicative of lower aMT6s concentration in CH individuals during both active and inactive periods [bout-HC; FE-MD = -9.63 μg/nocturnal urine collection, 95% CI = (-14.40, -4.85), remission-HC; FE-MD = -9.12 μg/nocturnal urine collection, 95% CI = (-14.63,-3.62), bout-remission; FE-MD = -0.58 μg/nocturnal urine collection, 95% CI = (-4.58, 3.42)]. Regarding CH prophylaxis, one RCT and two non-randomized trials were retrieved, involving a total of 41 adult CH individuals (11-episodic, 31-chronic) and rendering the deduction of any conclusions precarious. Overall, available data for the role use of MT in CH are insufficient and inconclusive. Complementary studies evaluating endogenous MT concentrations and MT administration to patients with CH are warranted.

Melatonin (MEL) and its use in neurological diseases and insomnia: Recommendations of the French Medical and Research Sleep Society (SFRMS)

The French Medicine and Research Sleep Society had organized a consensus conference about sleep/wake circadian rhythms and their disorders. During this conference a subgroup of 11 sleep doctors/researchers looked specifically at the use of MEL in different pathologies. This article gives a summary of the main results of MEL therapy in some neurological diseases and insomnia approved by this consensus group. Exogenous MEL, which crosses the blood-brain barrier, has been used as a treatment in its two available forms: an immediate release form that principally shows a chronobiotic action and a long release form that mimics the physiological MEL secretion rhythm and is used to replace reduced physiological secretion. MEL secretion decreases frequently with age, mostly in elderly insomniacs and dementia patients. Results of level A studies show that MEL therapy, used as an add-on treatment, has beneficial effects in mild cognitive impairment (MCI) and Alzheimer patients with sleep disorders in improving sleep quality and in regulating the sleep/wake rhythm. MEL has to be prescribed as early as possible and for a long period, at a dose of 2 to 5 or 10 mg. It may have a beneficial effect on cognitive function in MCI but shows no effect in moderate to severe Alzheimer's disease. It should be emphasized that there are no serious side effects with MEL treatment. In these diseases, light therapy used 12 hours before melatonin treatment has a positive synergic effect. In REM sleep behavior disorder, immediate release MEL should be prescribed first as its side effect profile is much better than clonazepam shortly before bedtime. MEL has a good efficacy on clinical symptoms and PSG REM sleep without atonia episodes and is well tolerated. In Parkinson disease with sleep disorders and without REM sleep behavior disorder, MEL seems to improve subjective sleep quality but no conclusions can be drawn. There is insufficient scientific proof for using MEL as a prophylactic treatment in primary headache, migraine and cluster headache. In epileptic patients, MEL can be safely used to regulate the sleep/wake rhythm and to improve insomnia but more randomized controlled studies are necessary. In primary or no-comorbid insomnia, only a 2 mg dose of slow release MEL, 1 to 2 hours before bedtime, over a period of 3 to 12 weeks, is recommended. It decreases sleep onset latency, improves quality of sleep, morning alertness and quality of life without serious side effects and without withdrawal symptoms.

The association between melatonin and episodic migraine: A pilot network meta-analysis of randomized controlled trials to compare the prophylactic effects with exogenous melatonin supplementation and pharmacotherapy

Although exogenous melatonin supplementation has been suggested to be effective for episodic migraine prophylaxis, there is no conclusive evidence comparing the efficacy of exogenous melatonin supplementation to the other FDA-approved pharmacotherapy for episodic migraine prophylaxis. The aim of the current network meta-analysis (NMA) was to compare the efficacy of exogenous melatonin supplementation in patients with episodic migraine. The randomized placebo-controlled trials or randomized controlled trials (RCTs) incorporating a placebo in the study designs were included in our analyses. All of the NMA procedures were conducted under the frequentist model. The primary outcome was changes in frequency of migraine days and response rate after migraine prophylaxis with melatonin supplementation or pharmacological interventions. We included 25 RCTs in total with 4499 patients (mean age = 36.0 years, mean female proportion = 78.9%). The NMA demonstrated that migraine prophylaxis with oral melatonin 3 mg/d (immediate-release) at bedtime was associated with the greatest improvement in migraine frequency [mean difference = -1.71 days, 95% confidence interval (CI): -3.27 to -0.14 days compared to placebo] and the second highest response rate (odds ratio = 4.19, 95% CI = 1.46 to 12.00 compared to placebo). Furthermore, oral melatonin 3 mg (immediate-release) at bedtime was the most preferred pharmacological intervention among all of the investigated interventions when improvements in migraine frequency, response rate, dropout rate, and rates of any adverse events were taken into account. This pilot NMA suggests the potential prophylactic role of exogenous melatonin supplementation in patients with episodic migraine.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Migraine pathways and the identification of novel therapeutic targets

Introduction: Migraine is a chronic neurovascular disorder characterized by recurrent headache attacks associated with neurological and autonomic symptoms. The pathophysiological mechanisms of the disease are extremely complex, involving hypothalamic and trigeminovascular activation, cortical spreading depression, release of pro-inflammatory peptides, peripheral and central sensitization. The underlying cellular and molecular mechanisms have been scarcely investigated. Recently, genetic studies have suggested that different metabolic pathways could be involved in the pathogenesis of migraine.Areas covered: This review focuses on cellular and molecular mechanisms involved in migraine, suggesting a role for circadian clocks, ion channels, synaptic plasticity, vascular factors, ion metal homeostasis, and impaired glucose metabolism in the pathogenesis of the disease. Accordingly, the article proposes new therapeutic targets that may be of particular relevance for disease prevention.Expert opinion: Several complex molecular mechanisms are involved in setting the genetic threshold for migraine and the pathogenesis of headache attacks. Most promising new therapeutic targets are the modulation of hypothalamic activity and ion channels involved in pain transmission. Further studies in animals and humans are necessary to enhance the elucidation of the molecular mechanisms of migraine and open new avenues for disease prevention.

Managing cluster headache

Cluster headache is a neurological disorder that presents with unilateral severe headache associated with ipsilateral cranial autonomic symptoms. Cluster headache attacks often occur more than once a day, and typically manifesting in bouts. It has a point prevalence of 1 in 1000 and is the most common trigeminal autonomic cephalalgia. This article aims to guide general neurologists to an accurate diagnosis and practical management options for cluster headache patients.

Pediatric Migraine: An Update

This article outlines key features of diagnosis and treatment of migraine in children and adolescents. It emphasizes techniques that can be used by clinicians to optimize history taking in this population, as well as recognition of episodic conditions that may be associated with migraine and present in childhood. Acute treatment strategies include use of over-the-counter analgesics and triptan medications that have been approved by the US Food and Drug Administration for use in children and adolescents. Preventive treatment approach includes lifestyle modifications, behavioral strategies, and consideration of preventive medications with the lowest side effect profiles.

Current understanding of pineal gland structure and function in headache

PURPOSE

The pineal gland plays an important role in biological rhythms, circadian and circannual variations, which are key aspects in several headache disorders.

OVERVIEW

Melatonin, the main pineal secreting hormone, has been extensively studied in primary and secondary headache disorders. Altered melatonin secretion occurs in many headache syndromes. Experimental data show pineal gland and melatonin both interfere in headache animal models, decreasing trigeminal activation. Melatonin has been shown to regulate CGRP and control its release.

DISCUSSION

Melatonin has been used successfully as a treatment for migraine, cluster headaches and other headaches. There is a rationale for including the pineal gland as a relevant brain structure in the mechanisms of headache pathophysiology, and melatonin as a treatment option in primary headache.

Pediatric and Adolescent Headache

PURPOSE OF REVIEW

This article provides the practicing neurologist with a comprehensive, evidence-based approach to the diagnosis and management of headache in children and adolescents, with a focus on migraine.

RECENT FINDINGS

Four triptans are now labeled by the US Food and Drug Administration (FDA) for acute migraine treatment in adolescents, and rizatriptan is labeled for use in children age 6 and older. For preventive migraine treatment, the Childhood and Adolescent Migraine Prevention trial demonstrated that approximately 60% of children and adolescents with migraine will improve with a three-pronged treatment approach that includes: (1) lifestyle management counseling (on sleep, exercise, hydration, caffeine, and avoidance of meal skipping); (2) optimally dosed acute therapy, specifically nonsteroidal anti-inflammatory drugs and triptans; and (3) a preventive treatment that has some evidence for efficacy. For the remaining 40% of children and adolescents, and for those who would not have qualified for the Childhood and Adolescent Migraine Prevention trial because of having continuous headache or medication-overuse headache, the clinician's judgment remains the best guide to preventive therapy selection.

SUMMARY

Randomized placebo-controlled trials have been conducted to guide first-line acute and preventive migraine treatments in children and adolescents. Future research is needed to guide treatment for those with more refractory migraine, as well as for children and adolescents who have other primary headache disorders.

Emerging Novel Pharmacological Non-opioid Therapies in Headache Management: a Comprehensive Review

PURPOSE OF REVIEW

Chronic headache is a significant worldwide problem despite advances in treatment options. Chronic headaches can have significant a detrimental impact on the activities of daily living.

RECENT FINDINGS

Patients who do not obtain relief from chronic head and neck pain from conservative treatments are commonly being managed with interventional treatments. These interventional treatment options include botulinum toxin A, injections, local occipital nerve anesthetic and corticosteroid infiltration, occipital nerve subcutaneous stimulation and occipital nerve pulsed radiofrequency (PRF), sphenopalatine ganglion block, and radiofrequency techniques. Recently, evidence has emerged to support non-opioid-based drug and interventional approaches. Overall, more research is necessary to clarify the safety and efficacy of interventional treatments and to better understand the pathogenesis of chronic headache pain.

Integrative Management of Pediatric Primary Headaches

Pediatric primary headache disorders are best treated using a comprehensive and integrative approach, due to the complex interactions between psychosocial and biological processes. Although more quality research is needed for treatment approaches to pediatric headaches, current practice management includes both pharmaceutical and nonpharmaceutical management. This article describes the integrative treatments used in a large regional pediatric headache program. Lifestyle approaches, nutraceuticals and dietary supplements, acupuncture, transcutaneous neurostimulation, relaxation, clinical hypnosis, biofeedback, and psychological services are discussed in detail for clinicians who may consider applying to their practice. [Pediatr Ann. 2019;48(6):e231-e235.].

Chronic tension-type headache and coping strategies in adolescents: A qualitative interview study

OBJECTIVE

Headache is the most common cause of chronic pain in children and adolescents and may influence on several of the life's arenas such as high absence from school and inability to maintain leisure time activities. Adolescents with chronic headache also report co-morbidities such as anxiety, depression, insomnia, and reduced quality of life. This study aimed to explore which strategies adolescents use to cope with chronic tension-type headache in everyday life.

METHODS

A qualitative design with semistructured individual interviews was used. A strategic sample of 17 adolescents aged 14-19 with tension-type headache participated in the study. The interviews were audiotaped and transcribed verbatim. Transcripts were analysed using systematic text condensation.

RESULTS

To deal with the headache in everyday life, the adolescence expressed that it is important to have a good structure during the day, especially regarding regular meals and enough sleep. Sufficient rest and relaxation were also highlighted as crucial. Some of the adolescence had tried different therapies to help ease the pain but with varying effect. All of the adolescents had used or were using pain relievers, but they were ambivalent to the benefits. Low-intensity physical activity was perceived as beneficial and gave increased overall well-being. Such activity also gave release and distraction from the headache.

CONCLUSION

The adolescents used both problem-focused active strategies and emotion-focused passive strategies to deal with their headache in daily life. Through exploration and awareness of the types of behaviour that worked and did not work, they had arrived at strategies that helped them cope with their headache and its consequences.

Emerging relevance of circadian rhythms in headaches and neuropathic pain

Circadian rhythms of physiology are the keys to health and fitness, as dysregulation, by genetic mutations or environmental factors, increases disease risk and aggravates progression. Molecular and physiological studies have shed important light on an intrinsic clock that drives circadian rhythms and serves essential roles in metabolic homoeostasis, organ physiology and brain functions. One exciting new area in circadian research is pain, including headache and neuropathic pain for which new mechanistic insights have recently emerged. For example, cluster headache is an intermittent pain disorder with an exceedingly precise circadian timing, and preliminary evidence is emerging linking several circadian components (eg, Clock and Nr1d1) with the disease. In this review, we first discuss the broad metabolic and physiological relevance of the circadian timing system. We then provide a detailed review of the circadian relevance in pain disease and physiology, including cluster headache, migraine, hypnic headache and neuropathic pain. Finally, we describe potential therapeutic implications, including existing pain medicines and novel clock-modulating compounds. The physiological basis for the circadian rhythms in pain is an exciting new area of research with profound basic and translational impact.

Prophylaxis with melatonin for primary stabbing headache in pediatrics: a case report

INTRODUCTION

Primary stabbing headache (or "ice pick headache") is an alteration characterized by brief jabs (short stabs of pain, lasting ~3 seconds), which appear spontaneously, irregularly, and affecting unilaterally or bilaterally. Indomethacin has traditionally been used as the main therapeutic option. However, this drug is ineffective in a considerable percentage of patients and can generate multiple adverse effects that occur at therapeutic doses.

CLINICAL CASE

A 7-year-old male patient with primary stabbing headache of mild to moderate intensity, lasting 3 to 4 seconds, without relevant history, with normal neurodevelopment, neurological examination and neuroimaging; no triggers were identified. It was started therapeutic trial with Coenzyme Q10; however, no improvement in the symptoms was identified.

TREATMENT AND OUTCOMES

A therapeutic management was carried out with Melatonin, which led to complete remission of the symptoms; without adverse effects in the posterior follow-up months.

CLINICAL AND SCIENTIFIC RELEVANCE

There is little information regarding effective and safe treatments for primary stabbing headache in children. The present case identifies Melatonin as an innovative, effective and safe therapeutic alternative in the treatment of primary stabbing headache in children. This is a significant advance in the understanding of primary stabbing headache in the pediatric population.

CONCLUSION

Melatonin may be an effective and safe therapeutic option for the treatment of primary stabbing headache in pediatric patients. It is necessary to deepen its research, in order to establish its use in a clinical practice guide.

Melatonin for preventing primary headache: A systematic review

BACKGROUND

The aim of this study was to assess the effectiveness and safety of melatonin for primary headache.

METHODS

This systematic review following the Cochrane Handbook for Systematic Reviews of Interventions recommendations and PRISMA Statement.

RESULTS

Four randomized controlled trials were included (351 participants). According to the GRADE approach the quality of evidence was very low. The use of melatonin for migraine showed that (i) reduced the number of days with pain and the analgesic consumption when compared with placebo, (ii) no benefits on headache intensity, number of headache days and analgesics consumption when compared with amitriptyline, (iii) reduced the number of analgesic consumption, the attack frequency and the headache intensity when associated with propranolol plus nortriptyline vs placebo plus propranolol plus nortriptyline, and (iv) no difference for any of the interest outcomes when associated with propranolol plus nortriptyline vs sodium valproate plus propranolol plus nortriptyline. The use of melatonin for cluster headache when compared with placebo showed a reduction in the daily number of analgesic consumption and no difference in the number of daily attacks. Adverse events were poorly reported by all of the studies.

CONCLUSION

This review found that so far there are few clinical trials, with poor methodological quality about melatonin for primary headaches. The available evidence is not sufficient to support the use of melatonin in clinical practice for this population. Further research is still necessary for assess its effects (benefits and harms) for primary headaches patients. Number of Protocol registration in PROSPERO database: CRD42017067105 (available at https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017067105) .