Botulinum toxins for the prevention of migraine in adults

Risk factors affecting the therapeutic effect of onabotulinum toxin a on chronic migraine

BACKGROUND

OnabotulinumtoxinA demonstrates effectiveness in chronic migraine prevention but is hindered by variable patient responses. This study aims to identify modifiable and non-modifiable risk factors influencing the response to onabotulinumtoxinA.

METHODS

We conducted a retrospective cohort study at a tertiary hospital involving chronic migraine patients treated with onabotulinumtoxinA. Data on risk factors and patient perceptions were collected through medical records and questionnaires.

RESULTS

A total of 131 patients were included. At 12 months, a significant reduction in headache frequency was observed: from 26 episodes pre-treatment to 13 at 3 months, 12 at 6 months, 11 at 9 months, and 10 at 12 months. A third of patients stopped overusing medication after treatment. Univariate logistic regressions revealed that fibromyalgia was associated with a reduced likelihood of achieving ≥50% response to onabotulinumtoxinA (OR (odds ratio) = 0.213, p = 0.031), while secondary education was associated with an increased likelihood of response (OR = 4.400, p = 0.029). Adjusted logistic regression confirmed that fibromyalgia significantly reduced the likelihood of ≥50% response (aOR (adjusted odds ratio) = 0.064, p = 0.033).

CONCLUSIONS

This study confirms the real-world effectiveness of onabotulinumtoxinA in reducing headache frequency. Furthermore, patients with fibromyalgia may have a diminished likelihood of responding positively, underscoring the importance of personalized treatment strategies.

Efficacy of onabotulinumtoxinA treatment in episodic migraine

Background

OnabotulinumtoxinA (BoNT-A) is approved as a prophylactic treatment of chronic migraine (CM) only. We aimed to assess the efficacy and safety of BoNT-A in the treatment of episodic migraine (EM).

Methods

This is a prospective study included migraine patients, aged 18-65 years, and completed 1 year treatment with BoNT-A. Patients received 4 courses of BoNT-A treatment. Patient's headache was assessed by headache diary at baseline, and before every injection. Migraine Specific Quality of Life Questionnaire (MSQ) and work productivity were collected at baseline and in their last visit. Adverse events (AEs) were reported.

Results

The study recruited 210 patients. Between baseline and the final visit, there were a significant reduction in migraine days, analgesic consumption days, and headache severity (9.54 ± 1.70 versus 4.58 ± 2.77, p < 0.001), (8.47 ± 1.49 versus 2.98 ± 0.21, p < 0.001), (8.37 ± 0.72 versus 2.54 ± 0.18, p < 0.001), respectively. BoNT-A treatment reduced the mean number of missed hours from work and daily activities over a 7-day period (4.63 ± 2.39 versus 6.26 ± 2.04, p < 0.001); (2.24 ± 3.30 versus 3.94 ± 3. 45; p < 0.001). Treatment with BoNT-A significantly improved the MSQ scores at last visit versus baseline visit, MSQ Role Function-Restrictive (51.55 ± 29.12 vs. 26.89 ± 17.42; p < 0.001), MSQ Role Function-Preventive (56.07 ± 24.73 vs. 30.64 ± 15.25; p < 0.001), and for MSQ Emotional Function (76.47 ± 115.29 vs. 35.12 ± 20.83; p < 0.001). Fifty-four patients (14.4%) experienced mild and short-lasting AEs.

Conclusion

BoNT-A is an effective and well tolerated therapy in the prophylaxis of EM. It improved MSQ and WPAI.

Direct Comparison of Treatment Outcome Between the Botulinum Toxin and Calcitonin Gene-Related Peptide Monoclonal Antibody in Migraine Patients

Background

Migraine is a genetic disorder characterized by recurrent episodes of headache that are throbbing in nature. The objective of this study was to directly compare the efficacy and safety of anti-calcitonin gene-related peptide (anti-CGRP) and botulinum neurotoxin (BoNT) for the preventive treatment of chronic migraine.

Methods

This quasi-experimental comparative study was conducted on 80 "chronic migraine patients" at King Fahad University Hospital, Dammam, KSA. Chronic migraineurs were divided into two groups (40 patients/group) and were treated with the standard doses of BoNT (group I) and anti-CGRP (group II). All the patients filled out the migraine pain scale, migraine disability assessment score, headache impact test (HIT-6), and adverse drug event questionnaire before the start and at the end of 9 months of treatment.

Results

Most of the patients were females (76.3% vs. 23.8%) and were suffering from migraine for more than 24 months (66%). The mean age of the participants was 39.07 ± 10.01 years. Both BoNT and anti-CGRP groups showed a statistically significant decrease in mean HIT-6 and pain scores after 9 months of intervention. A direct comparison between the two treatment groups showed that the anti-CGRP drug caused a higher decrease in HIT-6 and pain scores as compared to the botulinum drug, but the difference was not statistically significant (P = 0.075 and 0.07, respectively). The most common adverse effect was "headache", reported by 45% and 40% of patients, followed by "pain at the site of injection" reported by 27.5% and 32.5% of BoNT and anti-CGRP groups, respectively. The two groups did not differ significantly in the frequency of adverse effects such as nausea, vomiting, visual problems, etc., except "joint stiffness". A significantly higher number of anti-CGRP patients experienced joint stiffness as compared to the BoNT group (17.5% vs. 0%, P = 0.006).

Conclusion

A direct comparison between the two treatments indicated that neither of the two interventions is statistically superior to the other in terms of efficacy and both are equally effective in the management of migraine. However, BoNT can be preferred over anti-CGRP because of its cost-effectiveness.

2023 U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline for the Management of Headache

DESCRIPTION

Headache medicine and therapeutics evidence have been rapidly expanding and evolving since the 2020 U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) clinical practice guideline (CPG) for the management of headache. Therefore, the CPG was revised in 2023, earlier than the standard 5-year cycle. This article reviews the 2023 CPG recommendations relevant to primary care clinicians for treatment and prevention of migraine and tension-type headache (TTH).

METHODS

Subject experts from the VA and the DoD developed 12 key questions, which guided a systematic search using predefined inclusion and exclusion criteria. After reviewing evidence from 5 databases published between 6 March 2019 and 16 August 2022, the work group considered the strength and quality of the evidence, patient preferences, and benefits versus harms on critical outcomes before making consensus recommendations.

RECOMMENDATIONS

The revised CPG includes 52 recommendations on evaluation, pharmacotherapy, invasive interventions, and nonpharmacologic interventions for selected primary and secondary headache disorders. In addition to triptans and aspirin-acetaminophen-caffeine, newer calcitonin gene-related peptide (CGRP) inhibitors (gepants) are options for treatment of acute migraine. Medications to prevent episodic migraine (EM) include angiotensin-receptor blockers, lisinopril, magnesium, topiramate, valproate, memantine, the newer CGRP monoclonal antibodies, and atogepant. AbobotulinumtoxinA can be used for prevention of chronic migraine but not EM. Gabapentin is not recommended for prevention of EM. Ibuprofen (400 mg) and acetaminophen (1000 mg) can be used for treatment of TTH, and amitriptyline for prevention of chronic TTH. Physical therapy or aerobic exercise can be used in management of TTH and migraines.

Adverse and serious adverse events incidence of pharmacological interventions for managing chronic and episodic migraine in adults: a systematic review

Background

Migraine is the second most common prevalent disorder worldwide and is a top cause of disability with a substantial economic burden. Many preventive migraine medications have notable side effects that affect different body organs.

Method

We systematically searched for published randomised controlled trials (RCTs) using terms for migraine/headache and preventive medications. Using eligibility criteria, two reviewers independently assessed the articles. Cochrane risk-of-bias tool was applied to assess the quality of the studies. Data were classified by system organ class (SOC).

Results

Thirty-two RCTs with 21 780 participants met the eligibility criteria for the incidence of adverse events (AEs). Additionally, 33 RCTs with 22 615 participants were included to synthesise the incidence of serious AEs (SAEs). The percentage of attributed AEs and SAEs to each SOC for 10 preventive drugs with different dosing regimens was calculated. Amitriptyline and topiramate had a higher incidence of nervous system disorders; Topiramate was also associated with a higher incidence of psychiatric disorders. All drugs showed a certain incidence of infections and infestations, with Onabotulinumtoxin A (BTA) having the lowest rate. BTA had a higher incidence of musculoskeletal disorders than the other drugs. Calcitonin gene-related peptide (CGRP) monoclonal antibodies (MAbs) such as fremanezumab and galcanezumab were linked to more general disorders and administration site conditions than other drugs.

Conclusion

Notably, the observed harm to SOCs varies among these preventive drugs. We suggest conducting head-to-head RCTs to evaluate the safety profile of oral medications, BTA, and CGRP MAbs in episodic and/or chronic migraine populations.

PROSPERO registration number

CRD42021265993.

Recent Developments in Engineering Non-Paralytic Botulinum Molecules for Therapeutic Applications

This review discusses the expanding application of botulinum neurotoxin in treating neurological conditions. The article specifically explores novel approaches to using non-paralytic botulinum molecules. These new molecules, such as BiTox or el-iBoNT, offer an alternative for patients who face limitations in using paralytic forms of botulinum neurotoxin due to concerns about muscle function loss. We highlight the research findings that confirm not only the effectiveness of these molecules but also their reduced paralytic effect. We also discuss a potential cause for the diminished paralytic action of these molecules, specifically changes in the spatial parameters of the new botulinum molecules. In summary, this article reviews the current research that enhances our understanding of the application of new botulinum neurotoxins in the context of common conditions and suggests new avenues for developing more efficient molecules.

Efficacy and Safety Analysis of Botox Application and Iatrogenic Botulism: Panacea or Peril?

Clostridium botulinum toxin-A (BoNT-A) creates temporary paralysis in the muscles by acting on the muscle-nerve junction. It is injected into the mimic muscles when a decrease in the movements of the mimic muscles is desired. Despite many favorable applications, the use of BoNT-A is not without drawbacks. Although there is no expected serious side effect on health in BoNT-A treatments, various problems can be encountered in patients treated for aesthetic purposes. Botulism is a rare but potentially life-threatening syndrome, which is caused by the toxin produced by the bacterium Clostridium botulinum, which acts on the nervous system, vegetative forms of C. botulinum can only survive in anaerobic conditions, while spore forms are common in nature and can withstand harsh conditions. Botulism can stem from bacterial spores which release toxin in the body; in the form of enteric botulism, and wound botulism. The cases that develop 'iatrogenic botulism' after such procedures are usually those receiving high-dose toxin for therapeutic purposes. The treatment of botulism mainly consists of anti-toxin therapy and, if necessary, intensive care to prevent organ failures, including respiratory support. This article aims to cover all these issues related to botulism and other adverse outcomes related to BoNT-A injection in light of the most recent literature.

The efficacy of various interventions as good strategies to reduce pain in botulinum neurotoxin A for wrinkles. A systematic review of the randomized controlled trials (RCTs)

Various topical interventions have been described to minimize botulinum neurotoxin-A (BoNT)-induced pain. The purpose of this study is to conduct a systematic review of relevant randomized controlled trials (RCTs) to compare the efficacy of pain relief methods during BoNT injection. PubMed, Scopus, and Web of Science were searched using "Botox," "Botulinum," or "BTX." We identified RCTs in which BoNT were injected to eliminate wrinkles. The pain score was the study outcome, and pain reduction method was compared with routine one. The meta-analysis was reported using the PRISMA checklist. The Higgins I(I2) statistical model assessed results heterogeneity. Two thousand one hundred and twenty-three articles were identified, thirteen articles eligible. Two hundred and sixty-two healthy volunteers were performed on these RCTs. Meta-analysis evaluated different methods to ease BoNT injection pain, and these methods significantly improved outcomes by 0.23% (95%CI, 0.11-0.46, p = .000). Subgroup analysis based on injection area showed no significant heterogeneity, but heterogeneity decreased when subgroup analysis based on other methods was done (Cochran's Q test = 115.52, p = .0001, I2 = 87.9%). This meta-analysis confirms the effectiveness of pain relief methods during BoNT injection. Evaluation of different methods showed their effectiveness, but finding the best method requires comparative studies, although the role of pH and EMLA has been proven.

Unmet Needs in the Acute Treatment of Migraine

Migraine represents the most common neurologic disorder, ranking second among the world's causes of disability [expressed as years lived with disability (YLDs)]. Patients often do not receive the best therapy because of safety issues, tolerance, and prescription accessibility. General practitioners are not always educated about the disease, and specialists are few and often difficult to reach. Therapies are limited and have many side effects that can impede the prescription. Prophylactic therapy is recommended in case of four or more headaches a month, eight or more headache days a month, debilitating headaches, and medication-overuse headaches. The available therapeutic options are in constant development. The classic one consists of non-specific drugs: β-blockers, tricyclics, antiepileptics, and botulinum toxin. Monoclonal antibodies targeting the calcitonin gene receptor (CGRP) peptide or its receptor are the only ones specifically designed to treat migraine. Their efficiency and convenient safety profile have been demonstrated in a number of trials versus both placebo and classic therapies. The treatment of acute migraine attack consists of medications designed to affect the painful symptoms. For over 30 years, the cornerstones of treatment in clinical practice have continued to be represented by triptans and non-steroidal anti-inflammatory drugs (NSAIDs), with the well-know related adverse effects. Opioids are used inappropriately and overprescribed. Polytherapy is strongly not recommended but is still a common practice because treatment is not optimized and thus not efficient. Great promise comes from gepants, also targeting CGRP, and ditans, 5-HT1F receptor agonists. They seem to outweigh the risk of medication overuse headache because of their efficacy and rapid onset and have no cardiovascular contraindications. Nonetheless, these points remain to be confirmed. Although therapies have been implemented in the last years, significant unmet treatment needs remain a reality in patients' lives. This commentary aims to identify the most important unmet needs in the acute treatment of migraine, analyzing the current status of available therapies and their limits. We also analyzed some of the prophylactic therapies available, especially focusing on anti-CGRP monoclonal antibodies, to better understand the importance of setting a therapeutic strategy that includes the two modes, both acute and prophylactic, to reach the best result. We hope that having an overview of the shortcomings will help to provide constructive ideas for improvement.

Dramatic Effect of Botox Injection in Disabling Chronic Migraine Secondary to Inoperable Cerebral Arteriovenous Malformation

Arteriovenous malformation is a developmental anomaly of the vascular system characterized by arteriovenous shunt through a collection of tortuous vessels without intervening capillary bed. Brain arteriovenous malformations (AVMs) may cause hemorrhagic stroke, epilepsy, and chronic headache. Migraine with aura was reported in up to 58% of females with AVM. A 23-year-old female presented with episodes of severe left-side headache for five months, throbbing in character with photophobia, phonophobia, and nausea. Brain MRI showed a large AVM in the left cerebellar hemisphere. She was diagnosed with grade six AVM, which is inoperable, and secondary migraine. Her migraine symptoms didn't respond to oral medications. However, it responded dramatically to Botox injections. Seven days after Botox injection, her headache disappeared, and her well-being improved. Three years post-diagnosis and treatment, she got married, then three months later became pregnant. During pregnancy, she followed up with neurology, obstetrics, and gynecology. She was delivered by cesarean section to minimize the risk of intracranial hemorrhage and delivered without complications. The female patient in this case with migraine secondary to inoperable brain AVM treated with Botox; she got married and delivered by C-section without complications. This case raises the following important lessons: large AVMs can present with migraine only, and Botox has a dramatic effect on the treatment and the ability to have a safe pregnancy and delivery in large AVM cases.

Combination of anti-CGRP/CGRP-R mAbs with onabotulinumtoxin A as a novel therapeutic approach for refractory chronic migraine: a retrospective study of real-world clinical evidence and a protocol for a double-blind, randomized clinical trial to establish the efficacy and safety

Chronic migraine is a disabling neurovascular disorder that ranks amongst the top causes of years lived with disability worldwide. The duration and the frequency of migraine affect cognitive and affective domains, inducing worsening of memory, executive functions, orientation and causing anxiety. Population-based studies report a worrying level of resistance to treatments. Therefore, this study aims: 1) to assess efficacy of monoclonal antibodies (mAbs) directed towards the calcitonin gene-related peptide (CGRP) or its receptor (CGRP-R) for chronic migraine resistant to current preventatives; 2) to design a clinical trial protocol to evaluate the efficacy and safety of combination therapy utilizing anti-CGRP/CGRP-R together with onabotulinumtoxin A in patients suffering from resistant chronic migraine; 3) to provide a molecular rationale for combination therapy. A controlled trial is warranted as pooled analysis of real-world data from our group highlighted that combined treatment provides ≥50% reduction vs. baseline (onabotulinumtoxin A) of monthly headache days (MHDs) in up to 58.8% of patients, but there has been only sparse application of this combined therapy to date. The mAbs chosen are: erenumab, because its combination effect with onabotulinumtoxin A improved symptoms in 65% of patients; eptinezumab, due to its faster action. The results highlight that early diagnosis of migraine improves therapeutic outcomes with mAbs alone, confirming their effectiveness and the need for an adequately powered clinical trial evaluating the safety and potential superior effectiveness of eptinezumab/erenumab and onabotulinumtoxin A together.

The comparative effectiveness of migraine preventive drugs: a systematic review and network meta-analysis

OBJECTIVE

While there are several trials that support the efficacy of various drugs for migraine prophylaxis against placebo, there is limited evidence addressing the comparative safety and efficacy of these drugs. We conducted a systematic review and network meta-analysis to facilitate comparison between drugs for migraine prophylaxis.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov from inception to August 13, 2022, for randomized trials of pharmacological treatments for migraine prophylaxis in adults. Reviewers worked independently and in duplicate to screen references, extract data, and assess risk of bias. We performed a frequentist random-effects network meta-analysis and rated the certainty (quality) of evidence as either high, moderate, low, or very low using the GRADE approach.

RESULTS

We identified 74 eligible trials, reporting on 32,990 patients. We found high certainty evidence that monoclonal antibodies acting on the calcitonin gene related peptide or its receptor (CGRP(r)mAbs), gepants, and topiramate increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo. We found moderate certainty evidence that beta-blockers, valproate, and amitriptyline increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, and low certainty evidence that gabapentin may not be different from placebo. We found high certainty evidence that, compared to placebo, valproate and amitriptyline lead to substantial adverse events leading to discontinuation, moderate certainty evidence that topiramate, beta-blockers, and gabapentin increase adverse events leading to discontinuation, and moderate to high certainty evidence that (CGRP(r)mAbs) and gepants do not increase adverse events.

CONCLUSIONS

(CGRP(r)mAbs) have the best safety and efficacy profile of all drugs for migraine prophylaxis, followed closely by gepants.

Pharmacological interventions for prophylaxis of vestibular migraine

BACKGROUND

Vestibular migraine is a form of migraine where one of the main features is recurrent attacks of vertigo. These episodes are often associated with other features of migraine, including headache and sensitivity to light or sound. These unpredictable and severe attacks of vertigo can lead to a considerable reduction in quality of life. The condition is estimated to affect just under 1% of the population, although many people remain undiagnosed. A number of pharmacological interventions have been used or proposed to be used as prophylaxis for this condition, to help reduce the frequency of the attacks. These are predominantly based on treatments that are in use for headache migraine, with the belief that the underlying pathophysiology of these conditions is similar.

OBJECTIVES

To assess the benefits and harms of pharmacological treatments used for prophylaxis of vestibular migraine.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 23 September 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in adults with definite or probable vestibular migraine comparing beta-blockers, calcium channel blockers, antiepileptics, antidepressants, diuretics, monoclonal antibodies against calcitonin gene-related peptide (or its receptor), botulinum toxin or hormonal modification with either placebo or no treatment. We excluded studies with a cross-over design, unless data from the first phase of the study could be identified.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vertigo (assessed as a dichotomous outcome - improved or not improved), 2) change in vertigo (assessed as a continuous outcome, with a score on a numerical scale) and 3) serious adverse events. Our secondary outcomes were: 4) disease-specific health-related quality of life, 5) improvement in headache, 6) improvement in other migrainous symptoms and 7) other adverse effects. We considered outcomes reported at three time points: < 3 months, 3 to < 6 months, > 6 to 12 months. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included three studies with a total of 209 participants. One evaluated beta-blockers and the other two evaluated calcium channel blockers. We did not identify any evidence for the remaining interventions of interest. Beta-blockers versus placebo One study (including 130 participants, 61% female) evaluated the use of 95 mg metoprolol once daily for six months, compared to placebo. The proportion of people who reported improvement in vertigo was not assessed in this study. Some data were reported on the frequency of vertigo attacks at six months and the occurrence of serious adverse effects. However, this is a single, small study and for all outcomes the certainty of evidence was low or very low. We are unable to draw meaningful conclusions from the numerical results. Calcium channel blockers versus no treatment Two studies, which included a total of 79 participants (72% female), assessed the use of 10 mg flunarizine once daily for three months, compared to no intervention. All of the evidence for this comparison was of very low certainty. Most of our outcomes were only reported by a single study, therefore we were unable to conduct any meta-analysis. Some data were reported on improvement in vertigo and change in vertigo, but no information was available regarding serious adverse events. We are unable to draw meaningful conclusions from the numerical results, as these data come from single, small studies and the certainty of the evidence was very low.

AUTHORS CONCLUSIONS

There is very limited evidence from placebo-controlled randomised trials regarding the efficacy and potential harms of pharmacological interventions for prophylaxis of vestibular migraine. We only identified evidence for two of our interventions of interest (beta-blockers and calcium channel blockers) and all evidence was of low or very low certainty. Further research is necessary to identify whether these treatments are effective at improving symptoms and whether there are any harms associated with their use.

Review of Interventional Therapies for Refractory Pediatric Migraine

This is a review of the latest and seminal evidence in pediatric migraine. It covers the etiology and pathophysiology known today, and then will review treatment options, efficacy and safety, quality of data and indications. Though migraine is usually regarded as an infliction in adults, it is not uncommon in the pediatric population and affects up to 8% of children. Children may experience migraine differently than adults, and present not only with headache but also frequent gastrointestinal symptoms. They are frequently shorter in duration than in adults. Traditional migraine treatment in adults is less effective in children. In this population, adjunct therapies - such as interventional techniques - should be considered when traditional treatment fails, including Botulinum Toxin A (BTA) injections, peripheral nerve and ganglion blocks. BTA injections are FDA approved for migraine prophylaxis in adults, but currently not in children; however, recent evidence shows efficacy and safety in pediatric migraine management. Nerve blocks stop nociceptive afferent fibers through injection of local anesthetics, and it may be associated with the local injection of corticosteroids. Although more common in adults, recent data suggests they are safe and effective in children and adolescents. Blocking the sphenopalatine ganglion can be achieved through nasal approach, and achieves a similar action by blocking the entire ganglion. Interventional techniques may provide a key component in the alleviation of this otherwise debilitating chronic migraine pain. Though most studies have been performed in adults, new studies provide encouraging results for treatment in children.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

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.

Management of chronic migraine

Chronic migraine is a neurologic disorder associated with considerable disability, lost productivity, and a profound economic burden worldwide. The past five years have seen a dramatic expansion in new treatments for this often challenging condition, among them calcitonin gene related peptide antagonists and neuromodulatory devices. This review outlines the epidemiology of and diagnostic criteria and risk factors for chronic migraine. It discusses evidence based drug and non-drug treatments, their advantages and disadvantages, and the principles of patient centered care for adults with chronic migraine, with attention to differential diagnosis and comorbidities, clinical reasoning, initiation and monitoring, cost, and availability. It discusses the international guidelines on drug treatment for chronic migraine and evaluates non-drug treatments including behavioral and complementary therapies and lifestyle modifications. Finally, it discusses the management of chronic migraine in special populations, including pediatrics, pregnancy, and older people, and considers future questions and emerging research in the field.

OnabotulinumtoxinA in chronic migraine: is the response dose dependent?

Background

OnabotulinumtoxinA has been widely used for control of chronic migraine. The aim of the current study was to evaluate the efficacy of different doses of the onabotulinumtoxinA therapy in patients with chronic migraine.

Methods

This is a retrospective paired comparison study on patients with chronic migraine who received at least 3 rounds of 150 units of onabotulinumtoxinA followed by at least 3 rounds of 200 units of onabotulinumtoxinA. The data from the patient-reported questionnaires about headache days, severe headache days and wearing off periods were reviewed.

Results

A total of 175 patients were included in this study. The headache days and severe headache days decreased from 13.62 ± 10.79 and 5.88 ± 6.73 to 11.02 ± 10.61and 4.01 ± 4.89 days, after increase in the onabotulinumtoxinA dose, respectively (P < 0.001 for both comparisons). The favorable effect of the 200 units compared to the 150 units of the onabotulinumtoxinA, was independent from the headache location and the duration of the onabotulinumtoxinA 150 units therapy; and persisted as patients continued to receive the higher dose of onabotulinumtoxinA. Increase in the onabotulinumtoxinA dose was also associated with a decreased wearing off period (P < 0.05).

Conclusion

We found that increase in the onabotulinumtoxinA is associated with fewer headache and severe headache days. Future randomized clinical trials are needed to confirm the dose-dependent response to onabotulinumtoxinA.

Evaluation of Recombinant Botulinum Neurotoxin Type A1 Efficacy in Peripheral Inflammatory Pain in Mice

Well-established efficacy of botulinum neurotoxin type A (BoNT/A) in aesthetic dermatology and neuromuscular hyperactivity disorders relies on canonical interruption of acetylcholine neurotransmission at the neuromuscular junction at the site of the injection. The mechanisms and the site of activity of BoNT/A in pain, on the other hand, remain elusive. Here, we explored analgesic activity of recombinant BoNT/A1 (rBoNT/A1; IPN10260) in a mouse model of inflammatory pain to investigate the potential role of peripheral sensory afferents in this activity. After confirming analgesic efficacy of rBoNT/A1 on CFA-induced mechanical hypersensitivity in C57Bl6J mice, we used GCaMP6s to perform in vivo calcium imaging in the ipsilateral dorsal root ganglion (DRG) neurons in rBoNT/A1 vs. vehicle-treated mice at baseline and following administration of a range of mechanical and thermal stimuli. Additionally, immunohisochemical studies were performed to detect cleaved SNAP25 in the skin, DRGs and the spinal cord. Injection of CFA resulted in reduced mechanical sensitivity threshold and increased calcium fluctuations in the DRG neurons. While rBoNT/A1 reduced mechanical hypersensitivity, calcium fluctuations in the DRG of rBoNT/A1- and vehicle-treated animals were similar. Cleaved SNAP25 was largely absent in the skin and the DRG but present in the lumbar spinal cord of rBoNT/A1-treated animals. Taken together, rBoNT/A1 ameliorates mechanical hypersensitivity related to inflammation, while the signal transmission from the peripheral sensory afferents to the DRG remained unchanged. This strengthens the possibility that spinal, rather than peripheral, mechanisms play a role in the mediation of analgesic efficacy of BoNT/A in inflammatory pain.

Pharmacological interventions for prophylaxis of vestibular migraine

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the benefits and harms of pharmacological treatments used for prophylaxis of vestibular migraine.

Sex Differences in Chronic Migraine: Focusing on Clinical Features, Pathophysiology, and Treatments

PURPOSE OF REVIEW

This review provides an update on sex differences in chronic migraine (CM), with a focus on clinical characteristics, pathophysiology, and treatments.

RECENT FINDINGS

Approximately 6.8-7.8% of all migraineurs have CM, with an estimated prevalence of 1.4-2.2% in the general population. The economic burden caused by CM, including medical costs and lost working ability, is threefold higher than that caused by episodic migraine (EM). Notably, the prevalence of migraine is affected by age and sex. Female migraineurs with CM experience higher levels of headache-related disability, including longer headache duration, higher frequency of attacks, and more severely impacted efficiency at work. Sex hormones, including estrogen, testosterone, and progesterone, contribute to the sexually dimorphic characteristics and prevalence of migraine in men and women. Recent neuroimaging studies have indicated that migraine may have a greater impact and cause greater dysfunction in the organization of resting-state functional networks in women. Accumulating evidence suggests that topiramate, Onabotulinumtoxin A and calcitonin gene-related peptide (CGRP) monoclonal antibodies are effective as the preventative treatments for CM. Recent evidence highlights a divergence in the characteristics of CM between male and female populations. The data comparing the treatment response for CM regarding sex are lacking.

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 cure: a patients' perspective

Objective To conduct a web-based survey concerning patient’s perspective in the migraine cure. Material and Methods A total of 1,102 patients fitting the International Classification of Headache Disorders (ICHD-3) migraine criteria, seeking medical care at the Brain Research Institute at Albert Einstein Hospital in Sao Paulo, Brazil, from January to December 2015, participated in the survey. The online-based survey was accessed via the institute’s website and consisted of demographic data, a description of migraine symptoms, diagnosis and treatment, and the patient’s opinion of migraine cure and which treatment they would consider taking. Results Migraine intensity was significantly higher in female participants than male participants. Chronic migraine tended to affect female participants more than male participants. There was a significant difference in the rate of migraine cure belief between patients with episodic and chronic migraine. Conclusion Some points that were important to migraineurs have been identified in this study. Ultimately, the findings of this study may facilitate the migraine treatment decision process, by providing a better understanding of patients’ perspectives and beliefs, thus creating a more friendly communication between migraineurs and care providers and hopefully, improving the quality of life of patients.

Botulinum toxin injection in the management of chronic migraine: the Saudi experience with a proposal for a new protocol

There are no data from Saudi Arabia about the use of botulinum toxin for migraine prevention. In this article, we aim to study the clinical profile, safety, and response to treatment with botulinum toxin injection for migraine patients. In addition, we aim to share our experience with the use of botulinum toxin modified injection protocol (5/20/100 protocol) in the management of migraine in Saudi patients. A retrospective single-center observational study was conducted at King Abdulaziz Medical City in Jeddah, Saudi Arabia. The protocol for botulinum toxin injection for migraine in our hospital consisted of injecting five muscles with a total of 20 injection sites consuming 100 units of Onabotulinumtoxin A (BOTOX^®, Allergan, Inc., Irvine, CA). A total of 30 patients were included in our study. The mean frequency of migraine days showed a significant reduction from baseline at 15.61 ± 10.92 days per month to 6.14 ± 6.16 days (9.47 days reduction) after botulinum toxin injection (39.3% reduction; paired t test = 5.177; p = 0.0001). The frequency of using abortive medications was reduced in 19 patients (63.3%). Only four patients (13.3%) achieved a headache-free status. Only three patients (10%) had adverse events from botulinum toxin injection. In conclusion, botulinum toxin is an effective, safe, and well-tolerated treatment option for the prevention of chronic migraine. Our protocol (5/20/100 protocol) may improve the safety and cost and reduce the incidence of adverse events. Patients who do not respond to our protocol may switch to the standard protocol after the failure of the first treatment session.

Selective Expression of a SNARE-Cleaving Protease in Peripheral Sensory Neurons Attenuates Pain-Related Gene Transcription and Neuropeptide Release

Chronic pain is a leading health and socioeconomic problem and an unmet need exists for long-lasting analgesics. SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) are required for neuropeptide release and noxious signal transducer surface trafficking, thus, selective expression of the SNARE-cleaving light-chain protease of botulinum neurotoxin A (LCA) in peripheral sensory neurons could alleviate chronic pain. However, a safety concern to this approach is the lack of a sensory neuronal promoter to prevent the expression of LCA in the central nervous system. Towards this, we exploit the unique characteristics of Pirt (phosphoinositide-interacting regulator of TRP), which is expressed in peripheral nociceptive neurons. For the first time, we identified a Pirt promoter element and cloned it into a lentiviral vector driving transgene expression selectively in peripheral sensory neurons. Pirt promoter driven-LCA expression yielded rapid and concentration-dependent cleavage of SNAP-25 in cultured sensory neurons. Moreover, the transcripts of pain-related genes (TAC1, tachykinin precursor 1; CALCB, calcitonin gene-related peptide 2; HTR3A, 5-hydroxytryptamine receptor 3A; NPY2R, neuropeptide Y receptor Y2; GPR52, G protein-coupled receptor 52; SCN9A, sodium voltage-gated channel alpha subunit 9; TRPV1 and TRPA1, transient receptor potential cation channel subfamily V member 1 and subfamily A member 1) in pro-inflammatory cytokines stimulated sensory neurons were downregulated by viral mediated expression of LCA. Furthermore, viral expression of LCA yielded long-lasting inhibition of pain mediator release. Thus, we show that the engineered Pirt-LCA virus may provide a novel means for long lasting pain relief.

Diagnosis and management of migraine in ten steps

Migraine is a disabling primary headache disorder that directly affects more than one billion people worldwide. Despite its widespread prevalence, migraine remains under-diagnosed and under-treated. To support clinical decision-making, we convened a European panel of experts to develop a ten-step approach to the diagnosis and management of migraine. Each step was established by expert consensus and supported by a review of current literature, and the Consensus Statement is endorsed by the European Headache Federation and the European Academy of Neurology. In this Consensus Statement, we introduce typical clinical features, diagnostic criteria and differential diagnoses of migraine. We then emphasize the value of patient centricity and patient education to ensure treatment adherence and satisfaction with care provision. Further, we outline best practices for acute and preventive treatment of migraine in various patient populations, including adults, children and adolescents, pregnant and breastfeeding women, and older people. In addition, we provide recommendations for evaluating treatment response and managing treatment failure. Lastly, we discuss the management of complications and comorbidities as well as the importance of planning long-term follow-up.

OnabotulinumtoxinA in Migraine: A Review of the Literature and Factors Associated with Efficacy

The efficacy of onabotulinumtoxinA (OnaB-A) as a preventative treatment for chronic migraine, emerging fortuitously from clinical observation is now supported by class one evidence and over two decades of real-world clinical data. There is still limited ability to predict a clinically meaningful response to OnaB-A for individual patients, however. This review summarises briefly the proposed mechanism of OnaB-A in chronic migraine, the literature of predictors of clinical response, and recent developments in the field.

Clinical and Neurophysiological Effects of Botulinum Neurotoxin Type A in Chronic Migraine

Chronic pain syndromes present a subversion of both functional and structural nociceptive networks. We used transcranial magnetic stimulation (TMS) to evaluate changes in cortical excitability and plasticity in patients with chronic migraine (CM) treated with botulinum neurotoxin type A (BoNT/A). We enrolled 11 patients with episodic migraine (EM) and 11 affected by CM. Baseline characteristics for both groups were recorded using single- and paired-pulse TMS protocols. The same TMS protocol was repeated in CM patients after four cycles of BoNT/A completed in one year. At baseline, compared with EM patients, patients with CM had a lower threshold in both hemispheres (right hemisphere: 46% ± 7.8 vs. 52% ± 4.28, p = 0.03; left hemisphere: 52% ± 4.28 vs. 53.54% ± 6.58, p = 0.02). In EM, paired-pulse stimulation elicited a physiologically shaped response, whereas in CM, physiological intracortical inhibition (ICI) between 1 and 3 ms intervals was absent at baseline. On the contrary, increasing intracortical facilitation (ICF) was observed for all interstimulus intervals (ISIs). In CM, cortical excitability was partially reduced after BoNT/A treatment, along with a significant decrease observed in MIDAS score (from 20.7 to 9.8; p = 0.008). The lower motor threshold in CM reflects a higher cortical hyperexcitability. The lack of physiological ICI in CM could indicate sensitisation of the trigeminovascular system. Although reduced, this type of response is still observable after treatment, despite a marked clinical improvement. Our study suggests a long-term alteration of cortical plasticity due to chronic pain.

Calcitonin Gene-Related Peptide Monoclonal Antibodies Versus Botulinum Neurotoxin a in the Preventive Treatment of Chronic Migraine: An Adjusted Indirect Treatment Comparison Meta-Analysis

Purpose: Calcitonin gene-related peptide monoclonal antibodies (CGRPmAbs) are new agents approved by the US Food and Drug Administration for preventive treatment of chronic migraine. Comparison between CGRPmAbs and previously approved Botulinum neurotoxin A (BoNT-A) will inform optimal preventive treatment of chronic migraine, but head-to-head trials are lacking. We therefore aimed to perform adjusted indirect comparison between CGRPmAbs and BoNT-A through a meta-analysis.

Methods: OVID MEDLINE, EMBASE and the Cochrane central register of controlled trials, clinical registries, and government websites were searched from inception to September 2019. Randomized controlled trials comparing CGRPmAbs or BoNT-A with placebo in the preventive treatment of chronic migraine were included. The primary outcomes were headache days and migraine days measured at week 12. Data were synthesized by using a frequentist approach; and the treatments were ranked by P-score.

Results: We included 10 trials (n = 4,678) after screening 1049 candidates. Six trials were with low risk of bias. Fremanezumab had an effect similar to BoNT-A in the reduction of headache days at week 12 (standard mean difference [SMD] 0.08, 95%CI -0.55 to -0.7). Galcanezumab reduced more migraine days than BoNT-A at week 12 (SMD, -0.94, 95%CI −1.24 to −0.63); fremanezumab showed similar findings (SMD, −0.55, 95%CI −0.85 to −0.24). Galcanezumab and fremanezumab had better effect in mitigating headache impact at week 12. CGRPmAbs and BoNT-A had similar adverse event rate.

Conclusion: CGRPmAbs and BoNT-A had similar effect in the preventive treatment of chronic migraine. BoNT-A might be preferentially selected owing to its cost-effectiveness profiles. Further studies with direct comparison of the two treatments are warranted.

Safety and tolerability of eptinezumab in patients with migraine: a pooled analysis of 5 clinical trials

BACKGROUND

The humanized anti-CGRP monoclonal antibody eptinezumab has been evaluated in five large-scale clinical trials conducted in patients with migraine. This integrated analysis was conducted to evaluate the comprehensive safety and tolerability of eptinezumab in patients with migraine across these studies.

METHODS

Data were pooled from four randomized, double-blind, placebo-controlled studies and the first year of one open-label study.

RESULTS

The pooled population comprised 2867 adults with migraine: eptinezumab, n = 2076 (4797 infusions); placebo, n = 791 (1675 infusions). A total of 1137/2076 (54.8%) patients who received eptinezumab and 414/791 (52.3%) patients who received placebo experienced ≥1 treatment-emergent adverse event (TEAE); rates were similar across eptinezumab dose groups (10-1000 mg). For most patients with TEAEs, the events were mild or moderate in severity and considered unrelated to study drug by the investigators. Thirty infusion-site AEs occurred in 27/2076 (1.3%) patients who received eptinezumab and 7 in 7/791 (0.9%) patients who received placebo. Infusion-site AEs led to infusion interruption in 19/2076 (0.9%) and 5/791 (0.6%) patients in the eptinezumab and placebo groups, respectively. Nasopharyngitis occurred in ≥2% of patients in the eptinezumab 300-mg group and with an incidence of at least 2 percentage points greater than in the placebo group; however, in most patients (eptinezumab, 139/140; placebo 40/41), its occurrence was considered not related to study treatment. Adverse events coded to hypersensitivity occurred for 23/2076 (1.1%) patients treated with eptinezumab and no patients in the placebo group. If additional TEAE terms that could indicate hypersensitivity are considered (e.g., urticaria, flushing/hot flush, rash, and pruritus), hypersensitivity reactions in the two pivotal placebo-controlled phase 3 studies occurred in ≥2% of patients in the eptinezumab 100-mg and 300-mg groups, and the incidence was at least 2 percentage points greater in either of these groups than in the placebo group. Most hypersensitivity reactions were not serious and resolved with standard medical treatment or observation without treatment, usually within 1 day.

CONCLUSIONS

In adults with migraine, the intravenous administration of eptinezumab every 12 weeks demonstrated a favorable safety and tolerability profile.

TRIAL REGISTRATION

ClinicalTrials.gov (Identifiers: NCT01772524 , NCT02275117 , NCT02559895 , NCT02974153 , NCT02985398 ).

An Update on Botulinum Toxin in Neurology

Botulinum neurotoxin (BoNT) is an effective treatment for many neurologic disorders. This article gives a comprehensive overview of the clinical applications of BoNT across the field of neurology.

Proposal of a clinical care pathway for quality and safe management of headache patients: a consensus study report

BACKGROUND

Headache is one of the most prevalent and disabling conditions. Its optimal management requires a coordinated and comprehensive response by health systems, but there is still a wide variability that compromises the quality and safety of the care process.

PURPOSE

To establish the basis for designing a care pathway for headache patients through identifying key subpathways in the care process and setting out quality and clinical safety standards that contribute to providing comprehensive, adequate and safe healthcare.

METHOD

A qualitative research study based on the consensus conference technique. Eleven professionals from the Spanish National Health System participated, seven of them with clinical experience in headache and four specialists in healthcare management and quality. First, identification of the key subpathways in the care process for headache, barriers/limitations for optimal quality of care, and quality and safety standards applied in each subpathway. Second, two consecutive consensus rounds were carried out to assess the content of the subpathway level descriptors, until the expert agreement was reached. Third, findings were assessed by 17 external healthcare professionals to determine their understanding, adequacy and usefulness.

RESULTS

Seven key subpathways were identified: (1) primary care, (2) emergency department, (3) neurology department, (4) specialised headache unit, (5) hospitalisation, (6) outpatients and (7) governance and management. Sixty-seventh barriers were identified, the most frequent being related to diagnostic errors (36,1%), resource deficiency (25%), treatment errors (19,4%), lack of health literacy (13,9%) and inadequate communications with care transitions (5,6%). Fifty-nine quality and 31 safety standards were defined. They were related to evaluation (23.3%), patient safety (21.1%), comprehensive care (12.2%), treatment (12.2%), clinical practice guidelines (7.8%), counselling (6.7%), training (4.4%) and patient satisfaction (3.3%).

CONCLUSIONS

This proposal incorporates a set of indicators and standards, which can be used to define a pathway for headache patients and determine the levels of quality.

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.

Diagnosis and treatment of migraine: Russian experts' recommendations

Migraine is one of the most common types of headache, which can lead to a significant decrease in quality of life. Researchers identify migraine with aura, migraine without aura, and chronic migraine that substantially reduces the ability of patients to work and is frequently concurrent with mental disorders and drug-induced headache. The complications of migraine include status migrainosus, persistent aura without infarction, migrainous infarction (stroke), and a migraine aura-induced seizure. The diagnosis of migraine is based on complaints, past medical history, objective examination data, and the diagnostic criteria as laid down in the International Classification of Headache Disorders, 3 rd edition. Add-on trials are recommended only in the presence of red flags, such as the symptoms warning about the secondary nature of headache. Migraine treatment is aimed at reducing the frequency and intensity of attacks and the amount of analgesics taken. It includes three main approaches: behavioral therapy, seizure relief therapy, and preventive therapy. Behavioral therapy focuses on lifestyle modification. Nonsteroidal anti-inflammatory drugs, simple and combined analgesics, triptans, and antiemetic drugs for severe nausea or vomiting are recommended for seizure relief. Preventive therapy which includes antidepressants, anticonvulsants, beta-blockers, angiotensin II receptor antagonists, botulinum toxin type A-hemagglutinin complex and monoclonal antibodies to calcitonin gene-related peptide or its receptors, is indicated for frequent or severe migraine attacks and for chronic migraine. Pharmacotherapy is recommended to be combined with non-drug methods that involves cognitive behavioral therapy; progressive muscle relaxation; mindfulness; biofeedback; post-isometric relaxation; acupuncture; therapeutic exercises; greater occipital nerve block; non-invasive high-frequency repetitive transcranial magnetic stimulation; external stimulation of first trigeminal branch; and electrical stimulation of the occipital nerves (neurostimulation).

Calcitonin gene-related peptide antagonists versus botulinum toxin A for the preventive treatment of chronic migraine protocol of a systematic review and network meta-analysis: A protocol for systematic review

BACKGROUND

Although calcitonin gene-related peptide antagonists and botulinum toxin A have been shown efficacy in preventing chronic migraine, there is no direct evidence for their comparative effectiveness. This review is to assess the comparative effectiveness and safety of calcitonin gene-related peptide antagonists and botulinum toxin A for chronic migraine using network meta-analysis.

METHODS

OVID MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials will be searched for relevant randomized controlled trials from their inception to December 2019 without language restriction. We will include trials testing the effectiveness of calcitonin gene-related peptide antagonists or botulinum toxin A in patients with chronic migraine. The outcomes are mean change from baseline in the number of headache days, the mean change from baseline in the number of migraine days, the mean change from baseline in headache hours, responder rate, and adverse events rate. The methodological quality of the included randomized controlled trials will be evaluated using Cochrane Collaboration's risk of bias tool. Standardized mean difference will be used to synthesize continuous variables and risk ratio will be used to synthesize categorical variables. Pairwise and network meta-analysis will be performed using a frequentist method in netmeta package (R 3.5.0, www.r-project.org).

RESULTS

Ethical approval and informed consent are not required for this systematic review. The results will be submitted to a peer-reviewed journal and conference abstracts for publication.

CONCLUSION

The result of the review will systematically provide suggestions for clinicians, patients, and policy makers in the treatment of chronic migraine.PROSPERO registration number: CRD42018089201.

Mechanisms of Botulinum Toxin Type A Action on Pain

Already a well-established treatment for different autonomic and movement disorders, the use of botulinum toxin type A (BoNT/A) in pain conditions is now continuously expanding. Currently, the only approved use of BoNT/A in relation to pain is the treatment of chronic migraines. However, controlled clinical studies show promising results in neuropathic and other chronic pain disorders. In comparison with other conventional and non-conventional analgesic drugs, the greatest advantages of BoNT/A use are its sustained effect after a single application and its safety. Its efficacy in certain therapy-resistant pain conditions is of special importance. Novel results in recent years has led to a better understanding of its actions, although further experimental and clinical research is warranted. Here, we summarize the effects contributing to these advantageous properties of BoNT/A in pain therapy, specific actions along the nociceptive pathway, consequences of its central activities, the molecular mechanisms of actions in neurons, and general pharmacokinetic parameters.

Cochrane systematic review and meta-analysis of botulinum toxin for the prevention of migraine

OBJECTIVES

To assess the effects of botulinum toxin for prevention of migraine in adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CENTRAL, MEDLINE, Embase and trial registries.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) of botulinum toxin compared with placebo, active treatment or clinically relevant different dose for adults with chronic or episodic migraine, with or without the additional diagnosis of medication overuse headache.

DATA EXTRACTION AND SYNTHESIS

Cochrane methods were used to review double-blind RCTs. Twelve week post-treatment time-point data was analysed.

RESULTS

Twenty-eight trials (n=4190) were included. Trial quality was mixed. Botulinum toxin treatment resulted in reduced frequency of -2.0 migraine days/month (95% CI -2.8 to -1.1, n=1384) in chronic migraineurs compared with placebo. An improvement was seen in migraine severity, measured on a numerical rating scale 0 to 10 with 10 being maximal pain, of -2.70 cm (95% CI -3.31 to -2.09, n=75) and -4.9 cm (95% CI -6.56 to -3.24, n=32) for chronic and episodic migraine respectively. Botulinum toxin had a relative risk of treatment related adverse events twice that of placebo, but a reduced risk compared with active comparators (relative risk 0.76, 95% CI 0.59 to 0.98) and a low withdrawal rate (3%). Although individual trials reported non-inferiority to oral treatments, insufficient data were available for meta-analysis of effectiveness outcomes.

CONCLUSIONS

In chronic migraine, botulinum toxin reduces migraine frequency by 2 days/month and has a favourable safety profile. Inclusion of medication overuse headache does not preclude its effectiveness. Evidence to support or refute efficacy in episodic migraine was not identified.

Acute withdrawal and botulinum toxin A in chronic migraine with medication overuse: a double-blind randomized controlled trial

Botulinum toxin A (BTA) is widely used as treatment of chronic migraine. Efficacy in studies, however, was only modest and likely influenced by unblinding due to BTA-induced removal of forehead wrinkles. Moreover, most study participants were overusing acute headache medications and might have benefitted from withdrawal. We assessed in a double blind, placebo-controlled, randomized clinical trial whether add-on therapy with BTA enhances efficacy of acute withdrawal. Participants were enrolled between December 2012 and February 2015, with follow-up to January 2016, in a single academic hospital in the Netherlands. A total of 179 participants, male and female, aged 18-65, diagnosed with chronic migraine and overuse of acute headache medication were included. All participants were instructed to withdraw acutely from all medication for a 12-week period, in an outpatient setting. In addition, they were randomly assigned (1:1) to 31 injections with BTA (155 units) or placebo (saline); to prevent unblinding, placebo-treated participants received low doses of BTA (17.5 units in total) in the forehead, along with saline injections outside the forehead region. Primary endpoint was percentage change in monthly headache days from baseline to the last 4 weeks of double-blind treatment (Weeks 9-12). Among 179 randomized patients, 90 received BTA and 89 received placebo, and 175 (98%) completed the double-blind phase. All 179 patients were included in the intention-to-treat analyses. BTA did not reduce monthly headache days versus placebo (-26.9% versus -20.5%; difference -6.4%; 95% confidence interval: -15.2 to 2.4; P = 0.15). Absolute changes in migraine days at 12 weeks for BTA versus placebo were -6.2 versus -7.0 (difference: 0.8; 95% confidence interval: -1.0 to 2.7; P = 0.38). Other secondary endpoints, including measures for disability and quality of life, did also not differ. Withdrawal was well tolerated and blinding was successful. Thus, in patients with chronic migraine and medication overuse, BTA does not afford any additional benefit over acute withdrawal alone. Acute withdrawal should be tried first before initiating more expensive treatment with BTA.

An open-label prospective study of the real-life use of onabotulinumtoxinA for the treatment of chronic migraine: the REPOSE study

BACKGROUND

The PREEMPT Studies established onabotulinumtoxinA as preventive treatment for adults with chronic migraine (CM). The purpose of the REal-life use of botulinum toxin for the symptomatic treatment of adults with chronic migraine, measuring healthcare resource utilisation, and Patient-reported OutcomeS observed in practice (REPOSE) Study was to observe real-life, long-term (24-month) use of onabotulinumtoxinA in adults with CM and report on the utilisation, effectiveness, safety, and tolerability.

METHODS

The REPOSE Study was a European, open-label, multicentre, prospective, noninterventional study. Patients received onabotulinumtoxinA approximately every 12 weeks according to their physician's usual practice, guided by the summary of product characteristics (SPC). Patients were observed for 24 months after initiating onabotulinumtoxinA treatment. Outcome measures were collected at baseline and all administration visits and included onabotulinumtoxinA injection practices, headache-day frequency, Migraine-Specific Quality-of-Life Questionnaire (MSQ), EuroQol 5-Dimension Questionnaire (EQ-5D), and adverse drug reactions (ADRs) to evaluate safety/tolerability.

RESULTS

Of 641 patients enrolled, 633 received ≥1 dose of onabotulinumtoxinA for a total of 3499 treatment sessions. At baseline, mean (SD) age was 45.4 (11.7) years; patients were predominantly women (85.3%). Injection practices closely followed the SPC in mean dosage (155.1 U) and injection sites per session (31.4), with the exception of a prolongation of the recommended 12-week dosing interval, with 79.1% of patients receiving ≥1 treatment session that was > 13 weeks after the previous treatment session. Headache-day frequency was reduced from a baseline mean (SD) of 20.6 (5.4) to 7.4 (6.6) days at administration visit 8 (P < 0.001). Each MSQ domain (restrictive, preventive, and emotional) was significantly reduced from baseline through each administration visit (P < 0.001). The median EQ-5D total and health state scores were significantly improved from baseline through each administration visit (P < 0.001). Overall, 18.3% of patients reported an ADR; most were mild to moderate intensity, with only 1.3% of patients reporting a serious ADR. Eyelid ptosis (5.4%), neck pain (2.8%), and musculoskeletal stiffness (2.7%) were the most frequently reported.

CONCLUSIONS

Long-term, real-world preventive treatment of CM with onabotulinumtoxinA showed effectiveness with a sustained reduction in headache-day frequency and significant improvement in quality-of-life measures. ADRs were mild to moderate, with no new safety concerns identified.

TRIAL REGISTRATION

Trial registration number: NCT01686581. Name of registry: ClinicalTrials.gov. URL of registry: https://clinicaltrials.gov/ct2/show/NCT01686581 . Date of retrospective registration: September 18, 2012. Date of enrolment of first patient: July 23, 2012.

Radiofrequency Ablation for Treating Headache

PURPOSE OF REVIEW

Examining the efficacy of radiofrequency ablation in treating headache conditions.

RECENT FINDINGS

The efficacy of radiofrequency ablation in treating headache conditions is not well studied. Chronic headache conditions can be difficult to treat with little consensus on management of headaches associated with pericranial neuralgias. In this retrospective study, we found that radiofrequency ablation is an effective and safe treatment for resistant headache conditions. This study is important as it describes a novel treatment for chronic headache which can benefit a large number of patients.

Advances in the understanding of headache in idiopathic intracranial hypertension

PURPOSE OF REVIEW

To review the most relevant developments in the understanding of headache in idiopathic intracranial hypertension (IIH).

RECENT FINDINGS

The phenotype of the typical IIH headache is diverging from the historical thinking of a raised intracranial pressure headache, with the majority being classified as having migraine. A larger proportion of those with IIH have a past medical history of migraine, compared with the general population, highlighting the importance of re-examining those who have a change or escalation in their headache. The mechanisms underlying headache in IIH are not understood. Additionally, factors which confer a poor headache prognosis are not established. It is clear, however, that headache has a detrimental effect on all aspects of the patient's quality of life and is currently ranked highly as a research priority by IIH patients to better understand the pathophysiology of headache in IIH and identification of potential headache specific therapeutic agents.

SUMMARY

Headache remains the predominate morbidity in the majority of those with IIH. Headache management is an unmet need in IIH and future studies are required to investigate the probable complex mechanisms, as well as effective management.

European headache federation guideline on idiopathic intracranial hypertension

Background

Idiopathic Intracranial Hypertension (IIH) is characterized by an elevation of intracranial pressure (ICP no identifiable cause. The aetiology remains largely unknown, however observations made in a number of recent clinical studies are increasing the understanding of the disease and now provide the basis for evidence-based treatment strategies.

Methods

The Embase, CDSR, CENTRAL, DARE and MEDLINE databases were searched up to 1st June 2018. We analyzed randomized controlled trials and systematic reviews that investigate IIH.

Results

Diagnostic uncertainty, headache morbidity and visual loss are among the highest concerns of clinicians and patients in this disease area. Research in this field is infrequent due to the rarity of the disease and the lack of understanding of the underlying pathology.

Conclusions

This European Headache Federation consensus paper provides evidence-based recommendations and practical advice on the investigation and management of IIH.

Electronic supplementary material

The online version of this article (10.1186/s10194-018-0919-2) contains supplementary material, which is available to authorized users.