An Evidence-Based Review of Fremanezumab for the Treatment of Migraine

Genistein mitigates nitroglycerine-induced migraine: modulation of nitric oxide-mediated vasodilation and oxidative stress

Migraine is a widespread brain condition described by frequent, recurrent episodes of incapacitating, moderate-to-severe headaches with throbbing pain that are usually one-sided. It is the 2nd most debilitating state lived with disability in terms of years, with a prevalence rate of 15-20%. Significant drops in estrogen levels have been associated with triggering acute migraine attacks in certain cases. Phytoestrogens are plant-derived compounds that resemble estrogen in structure, enabling them to imitate estrogen's functions in the body by attaching to estrogen receptors. Thus, the study was aimed to explore the protective effect of genistein against migraine. Moreover, the role of nitric oxide was also studied in the observed effect of genistein. Nitric oxide (NO) is implicated in migraine pathophysiology due to its role in promoting cerebral vasodilation and modulation of pain perception. Exploring L-NAME, a nitric oxide synthase inhibitor in migraine research helps scientists better understand the role of NO in migraine. Nitroglycerine treatment significantly increased the facial-unilateral head pain and spontaneous pain, as evidenced by the increased number of head scratching and groomings. Nitroglycerine treatment also induced anxiogenic behavior in mice. A significant reduction in the number of entries in the light phase and open arm, respectively. Biochemical analysis indicated a significant increase in inflammatory and oxidative stress in the nitroglycerin group. A significant increase and decrease in brain TBARS and GSH were observed with nitroglycerine treatment, respectively. Moreover, nitroglycerine treatment has uplifted the serum TNF-α level. Genistein (20 mg/kg) significantly mitigated the facial-unilateral head pain, spontaneous pain, photophobia, and anxiety-like behavior induced by nitroglycerine. Biochemical analysis showed that genistein (20 mg/kg) significantly abrogated the nitroglycerine-induced lipid peroxidation and increased serum TNF-α level. Genistein treatment also upregulated the brain GSH level and downregulated the serum TNF-α level. The L-NAME-mediated alleviation of the protective effect of genistein might be attributed to the vasodilatory effect of L-NAME. Conclusively, it can be suggested that genistein might provide relief from migraine pain by inhibiting nitric oxide-mediated vasodilation and oxidative stress.

Prevalence and burden of migraine in the United States: A systematic review

BACKGROUND

This study reviewed migraine prevalence and disability gathered through epidemiologic survey studies in the United States conducted over the past three decades. We summarized these studies and evaluated changing patterns of disease prevalence and disability.

METHODS

We conducted a systematic review of US studies addressing the prevalence, disability, and/or burden of migraine, including both episodic migraine (EM) and chronic migraine (CM). A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was used in conjunction with the PubMed search engine. Eligible studies were published before February 2022, were conducted in the United States, included representative samples, and used a case definition of migraine based on the International Classification of Headache Disorders (ICHD). The primary measure of disease burden was the Migraine Disability Assessment Scale (MIDAS). The MIDAS measures days lost due to migraine over 3 months in three domains and defines groups with moderate (Grade III) or severe disability (Grade IV) using cut-scores.

RESULTS

Of the 1609 identified records, 26 publications from 11 US population-based studies met eligibility criteria. The prevalence of migraine in the population has remained relatively consistent for the past 30 years: ranging from 11.7% to 14.7% overall, 17.1% to 19.2% in women, and 5.6% to 7.2% in men in the studies reviewed. CM prevalence is 0.91% (1.3% among women and 0.5% of men) in adults and 0.8% in adolescents. The proportion of people with migraine and moderate-to-severe MIDAS disability (Grades III-IV), has trended upward across studies from 22.0% in 2005 to 39.0% in 2012, to 43.2% in 2016, and 42.4% in 2018. A consistently higher proportion of women were assigned MIDAS Grades III/IV relative to men.

CONCLUSION

The prevalence of migraine in the United States has remained stable over the past three decades while migraine-related disability has increased. The disability trend could reflect changes in reporting, study methodology, social and societal changes, or changes in exacerbating or remediating factors that make migraine more disabling, among other hypotheses. These issues merit further investigation.

Migraine and Its Treatment from the Medicinal Chemistry Perspective

Migraine is a disease of neurovascular origin that affects the quality of life of more than one billion people and ranks sixth among the most common diseases in the world. Migraine is characterized by a moderate or severe recurrent and throbbing headache, accompanied by nausea, vomiting, and photo-phonophobia. It usually starts in adolescence and is twice as common in women as in men. It is classified as with or without aura and has chronic or acute treatment types according to the frequency of occurrence. In acute treatment, analgesics that relieve pain in the fastest way are preferred, while there are different options in chronic treatment. While non-specific methods were used in the treatment of migraine until the 1950s, triptans, ditans, and CGRP-receptor-dependent therapies (monoclonal antibodies and gepants) started to be used in the clinic more recently. In this Review, we focus on the synthesis, side effects, and pharmacological and pharmacokinetic properties of FDA-approved drugs used in acute and preventive-specific treatment of migraine.

Efficacy and Safety of Anti-calcitonin Gene-Related Peptide (CGRP) Monoclonal Antibodies in Preventing Migraines: A Systematic Review

The neuropeptide calcitonin gene-related peptide (CGRP) is an essential pathophysiological treatment for migraines. A unique class of medications called CGRP monoclonal antibodies target CGRP and its receptor and have demonstrated promising benefits in the treatment and prevention of migraines. This study sought to identify and assess the quality of existing systematic reviews about the effectiveness of CGRP antibodies for preventing migraines, as well as systematically review and synthesize the evidence on these topics. This included the four Food and Drug Administration (FDA)-approved medications erenumab, galcanezumab, fremanezumab, and eptinezumab. The effectiveness and safety of these monoclonal antibodies in preventing migraines should also be examined in light of patient characteristics, and any gaps in the body of knowledge should be noted in order to suggest new lines of investigation. Data gathering included a thorough search of internet databases (PubMed, Cochrane Library, Web of Science, and Scopus) for relevant research released between 2018 and 2023. The findings imply that CGRP monoclonal antibodies are efficient and secure for preventing migraines and may be considered a first-line alternative for treating migraines and drug misuse. The results further imply that combination treatment with CGRP antibodies and onabotulinumtoxinA may enhance the prevention of migraine in adults. With suggestions for more studies to find and address these variables, the significance of genetic and epigenetic factors in the progression of pediatric patients' acute postoperative pain to chronic postsurgical pain is underlined. All four anti-CGRP monoclonal antibodies, erenumab, fremanezumab, galcanezumab, and eptinezumab, were shown to be safe and effective for the prevention of migraine when the research additionally looked at their individual effectiveness and safety. Additionally, the study discovered considerable variances in effectiveness amongst various groups. However, further investigation is required to establish the best time and dosage and the effect of patient characteristics on the effectiveness and safety of these medications.

Review of Tolerability of Fremanezumab for Episodic and Chronic Migraine

Calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) were the first class of medication specifically developed for the prevention of migraine. Fremanezumab is one of four CGRP mAbs currently available and is approved by the US Food and Drug Administration (FDA) for the preventative treatment of episodic and chronic migraines. This narrative review summarizes the history of fremanezumab development, the trials that led to its approval, and the later studies published evaluating its tolerability and efficacy. Evidence of fremanezumab for clinically significant efficacy and tolerability in patients with chronic migraine is especially important when considering the high level of disability, lower quality of life scores, and higher levels of health-care utilization associated with this condition. Multiple clinical trials demonstrated superiority of fremanezumab over placebo in terms of efficacy while demonstrating good tolerability. Treatment-related adverse reactions did not differ significantly compared to placebo and dropout rates were minimal. The most commonly observed treatment-related adverse reaction was mild-to-moderate injection site reaction, described as erythema, pain, induration, or swelling at the injection site.

Eptinezumab-jjmr, a humanized monoclonal specific to Calcitonin Gene Related Peptide, for the preventive treatment of migraine in adults

Purpose of Review

Migraines are prevalent and cause significant morbidity, decline in quality of life and healthcare costs universally. Treatment options are varied, but efficacy is limited. This review centers on Eptinezumab-jjmr, a humanized monoclonal specific to CGRP for the prevention of migraines in adults. Herein presented are the science and mechanism of action, indication and clinical evidence for use.

Recent Findings

Migraines are severe, recurrent headaches, which are either episodic or chronic in nature. The pain is severe, often accompanied by co-morbid symptoms, such as photophobia, phonophobia, nausea and emesis, and is limiting in nature. It is a prevalent disorder that causes significant, worldwide disability, morbidity, suffering, and costs.

The pathophysiology of migraines is actively studied, though recent research points to an initiating event causing migraine generation, that is then propagated by other brain regions, a significant one being the trigeminocervical complex. This is driven by biochemical transmitters, chiefly CGRP. This discovery led to the development of CGRP-targeting drugs, including gepants (small molecular antagonists) and anti-CGRP antibodies, such as Eptinezumab-jjmr.

Traditional therapy includes preventative and abortive treatment; however, adherence with preventative treatment has been historically poor, and certain types of abortive therapy carry risks and side effects that preclude them from a large patient population. Moreover, traditional therapy often falls short in migraine therapy. CGRP antagonist, including Eptinezumab, aims to cover the gaps in migraine therapy. We present here evidence to support the safe and effective use of Eptinezumab for the prevention of migraines.

Summary

Migraines are a prevalent primary headache disorder causing significant morbidity worldwide. Traditional abortive and preventative treatments fall short for many patients. Eptinezumab is part of new generation of CGRP-targeting medications and has shown significant evidence to support its use for the prevention of migraines. Further research is required to properly compare eptinezumab with existing pharmacotherapy and update guidelines on the appropriate combinations of therapies that are not available and the correct patient selection for each.

Rimegepant for the treatment of migraine

Migraine is a common form of primary headache, affecting up to 1 in every 6 Americans. The pathophysiology is an intricate interplay of genetic factors and environmental influence and is still being elucidated in ongoing studies. The trigeminovascular system is now known to have a significant role in the initiation of migraines, including the release of pain mediators such as CGRP and substance P. Traditional treatment of migraine is usually divided into acute and preventive treatment. Acute therapy includes non-specific therapy, such as NSAIDs and other analgesics, which may provide relief in mild to moderate migraines. 5-HT1 agonists may provide relief in severe migraine, but are not universally effective and carry a significant side-effect profile with frequent redosing requirement. Prophylactic therapy may reduce the occurrence of acute migraine attacks in selected patients, but does not completely eliminate it. More recently, CGRP antagonism has been studied and shown to be effective in both abortion and prevention of migraine. Novel medications, targeting CGRP, divide into CGRP antibodies and receptor antagonists (gepants). Rimegepant, a second-generation gepant, has shown efficacy in several clinical trials in treating acute migraine. Ongoing trials are also evaluating its role in migraine prophylaxis, and results are promising. It is also generally safer for use than existing options, does not appear to increase the chance of developing chronic migraines, and carries a very tolerable side effects profile. It is a part of a growing arsenal in migraine treatment, and may present the silver bullet for treatment of this disease.

Monoclonal Antibodies Generation: Updates and Protocols on Hybridoma Technology

Since its inception in 1975, the hybridoma technology revolutionized science and medicine, facilitating discoveries in almost any field from the laboratory to the clinic. Many technological advancements have been developed since then, to create these "magical bullets." Phage and yeast display libraries expressing the variable heavy and light domains of antibodies, single B-cell cloning from immunized animals of different species including humans or in silico approaches, all have rendered a myriad of newly developed antibodies or improved design of existing ones. However, still the majority of these antibodies or their recombinant versions are from hybridoma origin, a preferred methodology that trespass species barriers, due to the preservation of the natural functions of immune cells in producing the humoral response: antigen specific immunoglobulins. Remarkably, this methodology can be reproduced in small laboratories without the need of sophisticate equipment. In this chapter, we will describe the most recent methods utilized by our Monoclonal Antibodies Core Facility at the University of Texas-M.D. Anderson Cancer Center. During the last 10 years, the methods, techniques, and expertise implemented in our core had generated more than 350 antibodies for various applications.

Pharmacogenetics in Primary Headache Disorders

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

Migraine pharmacology and brain ischemia

Introduction: The aim of this review article was to analyze in details the mechanism of drugs’ effects in the treatment and prevention of a migraine attack, as well as to discuss the hypotheses of migraine pathogenesis.

Migraine attack treatment agents: The main agents for migraine attack treatment have an anti-nociceptive activity.

Agents for migraine preventive treatment: β-blocker propranolol also has anti-serotonin and analgesic activities, and most drugs used for the prophylactic treatment of migraine have a vasodilating activity.

Vascular hypothesis of migraine pathogenesis: Despite numerous studies that have expanded our understanding of migraine pathogenesis, the importance of the vascular component in the pathogenesis of this disease has not questioned yet.

Neurogenic hypotheses of cortical spreading depression: It is necessary to take into account the points of this hypothesis in the context of the pathophysiology of migraine.

Neurochemical serotonin hypotheses of migraine pathogenesis: Serotonin plays an important role in the pathogenesis of migraine.

Trigemino-vascular hypotheses of migraine pathogenesis: The trigemino-vascular hypothesis claims to solve the problem of migraine pain.

Migraine and ischemic brain damage: Migraine is a risk factor for ischemic stroke and cognitive disorders.

Search for the new anti-ischemic anti-migraine preparations: A methodology for the search for new anti-ischemic anti-serotonin drugs for the treatment of migraine is proposed.

Conclusion: Belonging of a drug to one or another pharmacological group does not always correspond to its therapeutic effect on the pathogenetic processes of migraine. Migraine with its variety of forms cannot fit only one of the proposed hypotheses on the pathogenesis of this disease.

Graphical abstract:

The Association Between Blood Pressure and Headache in Postmenopausal Women: A Prospective Hospital-Based Study

Background

Headache is the most frequent condition for outpatient patients because of neurological problems, but little is known about predisposing and enabling factors for headache patients.

Aim

To investigate the association between blood pressure (BP) and headache in postmenopausal women.

Methods

The postmenopausal women who were admitted to our hospital from January 2015 to December 2019 were screening according to the criteria. Their systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP) were assessed and the information of age, body mass index, smoking status, caffeine consumption, cholesterol levels, and daily alcohol use were collected. Multiple logistic regression model was established to evaluate the association between BP and headache.

Results

A total of 1571 postmenopausal women were included in the analysis, including 953 headache-free population and 618 headache participants during the studied periods. We found that increasing SBP and PP were associated with the lower occurrence of migraine, tension-type headache (TTH), probable migraine, and unclassified headache (P < 0.05). However, there was a negative association between DBP levels and the new occurrence of overall headache, but we did not find any relations of DBP with any subtypes of headache.

Conclusion

There were negative associations of SBP and PP with new occurrence of headache, especially migraine and TTH, but there is no relationship between DBP and the subsequent development of headache.

Pharmacokinetics, Pharmacodynamics and Drug-Drug Interactions of New Anti-Migraine Drugs-Lasmiditan, Gepants, and Calcitonin-Gene-Related Peptide (CGRP) Receptor Monoclonal Antibodies

In the last few years, there have been significant advances in migraine management and prevention. Lasmiditan, ubrogepant, rimegepant and monoclonal antibodies (erenumab, fremanezumab, galcanezumab, and eptinezumab) are new drugs that were launched on the US pharmaceutical market; some of them also in Europe. This publication reviews the available worldwide references on the safety of these anti-migraine drugs with a focus on the possible drug–drug (DDI) or drug–food interactions. As is known, bioavailability of a drug and, hence, its pharmacological efficacy depend on its pharmacokinetics and pharmacodynamics, which may be altered by drug interactions. This paper discusses the interactions of gepants and lasmiditan with, i.a., serotonergic drugs, CYP3A4 inhibitors, and inducers or breast cancer resistant protein (BCRP) and P-glycoprotein (P-gp) inhibitors. In the case of monoclonal antibodies, the issue of pharmacodynamic interactions related to the modulation of the immune system functions was addressed. It also focuses on the effect of monoclonal antibodies on expression of class Fc gamma receptors (FcγR).

Lasmiditan for the Treatment of Migraines With or Without Aura in Adults

Migraines are a common form of primary headache, affecting women more than men (17.4% and 5.7% of US population, respectively, a total of 12%) that carry significant morbidity and disability, as well as a hefty healthcare price tag. They are most prevalent in women of reproductive ages and are estimated to be the 6th disease in order of causing global burden. They are estimated to cause 45.1 million years lived with disability, or 2.9% of global years lost to disability. Migraine treatment divides into acute, abortive treatment for relief of an ongoing migraine attack, and prophylactic therapy to reduce the occurrence of migraines, specifically for patients suffering from chronic and frequent episodic migraines. Traditional abortive treatment usually begins with NSAID and non-specific analgesics that are effective in curbing mild to moderate attacks. 5HT1-agonists, such as triptans, are often used for second-line and for severe attacks. Triptans are generally better tolerated in the longterm than NSAIDs and other analgesics, though they carry a significant side-effect profile and are contraindicated in large parts of the population. Prophylactic therapy is usually reserved for patients with frequent recurrence owing to medication side effects and overall poor adherence to the medication schedule. Importantly, medication overuse may actually lead to the development of chronic migraines from previously episodic attacks. Recent research has shed more light on the pathophysiology of migraine and the role of CGRP in the trigeminovascular system. Recent pharmacological advances were made in developing more specific drugs based on this knowledge, including CGRP neutralizing antibodies, receptor antagonists, and the development of ditans. These novel drugs are highly specific to peripheral and central 5-HT1F receptors and effective in the treatment of acute migraine attacks. Binding these receptors reduces the production of CGRP and Glutamate, two important ligands in the nociceptive stimulus involved with the generation and propagation of migraines. Several large clinical studies showed Lasmiditan to be effective in the treatment of acute migraine attacks. Importantly, due to its receptor specificity, it lacks the vasoconstriction that is associated with triptans and is thus safer is larger parts of the population, specifically in patients with cardiac and vascular disease. Though more research is required, specifically with aftermarket surveillance to elucidate rare potential side effects, Lasmiditan is a targeted anti-migraine drug that is both safe and effective, and carries an overall superior therapeutic profile to its predecessors. It joins the array of medications that target CGRP signaling, such as gepants and CGRP-antibodies, to establish a new line of care for this common disabling condition.

Lasmiditan for Acute Treatment of Migraine in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

The US Food and Drug Administration has approved orally administered 100-mg and 200-mg doses of lasmiditan for the acute treatment of migraine, with or without aura. Having a unique mechanism of action, lasmiditan is the first and only Food and Drug Administration-approved serotonin 5-HT_1F receptor agonist.

OBJECTIVE

The objective of this study was to systematically evaluate the efficacy and safety of lasmiditan for the acute treatment of migraine in adult patients.

METHODS

We systematically searched PUBMED, EMBASE, and Cochrane Library databases. Any relevant articles published before 3 March, 2020 were collected. Inclusion criteria were: (1) randomized clinical trials; (2) enrolled adult participants diagnosed with migraine; (3) compared lasmiditan at 100 mg or 200 mg with placebo; (4) enrolled more than 100 participants; and (5) provided any available data for predefined primary or secondary outcomes.

RESULTS

Three high-quality, multi-centered randomized clinical trials with 4506 patients in total were included. We found that the use of lasmiditan was related to a significantly increased rate of pain freedom at 2 h post-dose with 31.60% patients achieving freedom of pain in the lasmiditan group compared with 17.55% patients in the placebo group (relative risk [RR] 1.80 [95% confidence interval (CI) 1.34-2.42]), with no significant heterogeneity. In addition, lasmiditan is reported to significantly increase the rate of absence of the most bothersome symptoms at 2 h compared with the placebo group with no significant heterogeneity (lasmiditan, 42.82%; placebo, 30.38%; RR 1.44 [95% CI 1.03-2.01], I² = 0%). With regard to the safety endpoints, compared with the placebo group, participants in the lasmiditan group had a higher rate of fatigue, paresthesia, and somnolence (fatigue: lasmiditan, 1.94%; placebo, 0.24%; RR 7.96 [95% CI 0.4-158.86]; paresthesia: lasmiditan, 6.91%; placebo, 1.56%; RR 4.46 [95% CI 1.54-12.93], somnolence: lasmiditan, 5.9%; placebo, 2.15%; RR 2.76 [95% CI, 1.49-5.11]) with low heterogeneity. A subgroup analysis demonstrated that without safety differences, participants who received the 200-mg dose had a higher percentage of freedom of pain at 2 h and sustained pain relief at 2-24 h compared with the 100-mg dose (freedom of pain at 2 h: lasmiditan, 34.53%; placebo, 28.67%; RR 1.2 [95% CI 1.04-1.38]; lasmiditan, 20.62%; placebo, 16.33%; RR 1.26 [95% CI 1.19-1.34]), with low heterogeneity for both outcomes (I² = 0%).

CONCLUSIONS

In this meta-analysis, the use of lasmiditan as an acute treatment for episodic migraine in adults led to a greater percentage of freedom of pain and the absence of the most bothersome symptoms at 2 h post-dose. Lasmiditan 200 mg had superior efficacy to 100-mg dose without a significantly increased risk for adverse events.

Hejie Zhitong prescription promotes sleep and inhibits nociceptive transmission-associated neurotransmitter activity in a rodent migraine model

BACKGROUND

Migraine is painful disease in which neurotransmitters related to pain transmission play an important role. Hejie Zhitong prescription (HJZT) has been used in the clinic as an effective prescription for the treatment of migraine for many years. Our team aimed to further explore its antimigraine mechanism based on previous research results and to explore the inhibitory effect of HJZT on the transmission of pain related to nitroglycerine (NTG)-induced migraine as well as the synergistic effect of HJZT with pentobarbital sodium on promoting sleep.

METHODS

Sixty mice were randomly assigned to groups and received the corresponding interventions. Sleep latency and sleep time were recorded to calculate the incidence of sleep. Forty-eight Wistar rats were randomly assigned and administered an intervention corresponding to their group. Calcitonin gene-related peptide (CGRP), serotonin (5-HT), substance P (SP), and cholecystokinin (CCK) levels were measured using ELISAs. Levels of the cannabinoid receptor type 1 (CB1R) and cyclooxygenase-2 (COX-2) protein were assessed using immunohistochemistry. The expression of the CGRP and CCK mRNAs in the midbrain and trigeminal ganglion (TG) were measured using real-time quantitative PCR.

RESULTS

HJZT promoted the occurrence of sleep in mice. HJZT downregulated COX-2 expression in the midbrain and TG of rats but upregulated the expression of the CB1R, and decreased the plasma level of the CGRP protein and expression of its mRNA in the midbrain and TG. It also downregulated the expression of the CCK mRNA in the midbrain and TG. The high-dose HJZT treatment increased plasma 5-HT levels, but did not induce changes in the plasma levels of the SP or CCK protein.

CONCLUSIONS

HJZT exerts a synergistic effect with pentobarbital sodium on promoting sleep. As for anti-migraine, HJZT can inhibits the expression of nociceptive transmission-associated neurotransmitters, including 5-HT, CGRP and CCK, which may be related to its upregulation of CB1R and downregulation of COX-2.

Addressing chronic persistent headaches after MTBI as a neuropathic pain state

An increasing number of patients with chronic persistent post-traumatic headache (PPTH) after mild traumatic brain injury (MTBI) are being referred to headache or pain specialists as conventional treatment options for primary headache disorders have not been able to adequately alleviate their debilitating headache symptoms. Evolving clinical and mechanistic evidences support the notation that chronic persistent MTBI related headaches (MTBI-HA) carry the hallmark characteristics of neuropathic pain. Thus, in addition to conventional treatment options applicable to non-traumatic primary headache disorders, other available treatment modalities for neuropathic pain should be considered. In this comprehensive review article, the author reveals the prevalence of MTBI-HA and its clinical manifestation, discusses existing clinical and mechanistic evidence supporting the classification of chronic persistent MTBI-HA as a neuropathic pain state, and explores current available treatment options and future directions of therapeutic research related to MTBI-HA.