Beyond chronic migraine: a systematic review and expert opinion on the off-label use of botulinum neurotoxin type-A in other primary headache disorders

Effects of OnabotulinumtoxinA on Allodynia and Interictal Burden of Patients with Chronic Migraine

BACKGROUND

We primarily aimed to ascertain whether treatment with OnabotulinumtoxinA (BoNTA) might influence the extent of the interictal burden and cutaneous allodynia in patients with chronic migraine (CM).

METHODS

Seventy CM patients, who received three consecutive cycles of BoNTA, were studied. The interictal burden was assessed with the Migraine Interictal Burden Scale (MIBS-4), while cutaneous allodynia was examined with the Allodynia Symptom Checklist (ASC-12) together with PI-NRS VAS to obtain hair brushing scores, and then these were compared from baseline (T0) to the last efficacy evaluation follow-up (T1). Efficacy outcomes, mostly mean headache days (MHD) and "Headache Impact Test" scores, were also assessed between T0 and T1.

RESULTS

BONTA improved the interictal burden, with a decrease in MIBS-4 scoring by an average of -7 at T1, compared to baseline (p < 0.001). The percentage of patients with a moderate/severe interictal burden was substantially decreased. Likewise, BoNTA reduced the extent of cutaneous allodynia, with a significant reduction in both the ASC-12 (1 vs. 6; p < 0.001) and PI-NRS VAS (1 vs. 5; p < 0.001) to hair brushing median scores at T1, compared to baseline. Reduced MHD rates were significantly associated with a smaller interictal burden at T1. The efficacy of BoNTA, with a significant reduction in MHD and HIT-6 scores at T1 compared to T0, was re-confirmed.

CONCLUSIONS

BoNTA resulted in a statistically significant reduction in the interictal burden and also improved cutaneous allodynia. The reduction in ictal burden was associated with the down-scaling of the interictal burden. Hence, BoNTA improved the full spectrum of migraine impairment by diminishing the clinical expression of central sensitization.

Single OnabotulinumtoxinA Session Add-On to Carbamazepine or Oxcarbazepine in Treatment-Refractory Trigeminal Neuralgia: A Case Series with 24-Week Follow Up

We sought to assess the efficacy of combining onabotulinumtoxinA (BoNTA) as add-on therapy to carbamazepine or oxcarbazepine in treatment-refractory patients with trigeminal neuralgia (TGN) who failed to respond (less than 30% response rate) to adequate monotherapy. We conducted a retrospective study on 15 patients with a definite diagnosis of TGN, according to the established criteria, and underwent BoNTA as part of their treatment plan. A single BoNTA session was administered subcutaneously, according to patients' perceived zone of pain, at different dosages ranging from 30 to 200 units (mean ± standard deviation: 87.3 ± 39.2). All patients (15/15; 100%) reported large reductions in the severity of their TGN-related neuropathic pain. The mean pain score on the VAS scale significantly decreased from 9.3 ± 1.1 to 3.7 ± 1.2 at 2 weeks after injecting BoNTA (p < 0.001) and remained stable at 4 and 24 weeks post-injection. Regarding the impact of BoNTA on patients' health-related quality of life, there were significant improvements in both the physical and mental health domains (p < 0.05) of SF-36 tool. BoNTA may be a safe and effective treatment option for patients with refractory TGN when added on to carbamazepine or oxcarbazepine. The use of a single BoNTA session for TGN treatment may be an alternative to surgical interventions and as add-on treatment to oral medications, providing patients with a minimally invasive, effective, safe and well-tolerated option.

Epicranial headache part 1: Primary stabbing headache

BACKGROUND/OBJECTIVE

Primary stabbing headache is a common but under-recognized primary headache disorder. The objectives of this review were to provide practical information for better understanding and identification of the disease, suggest an algorithm for differential diagnosis, and provide an insight into the pathophysiology of primary stabbing headache hypothesized from its clinical course.

METHODS

This narrative review of primary stabbing headache is based on a literature search and the authors' clinical reasoning.

RESULT

The phenotype of each stab is typically abrupt, ultrashort-lasting (<3 s), focal or multifocal, paroxysms of pain occurring sporadically or in clusters. The diagnosis of primary stabbing headache is clinical; fixed or migrating stabs without background pain or sensory abnormalities and the absence of features suggestive of other disorders (e.g., cranial autonomic symptoms or signs) can aid in the diagnosis of primary stabbing headache. The clinical patterns include monophasic, intermittent, and chronic primary stabbing headache, of which the first two are considered typical. The pathophysiology of primary stabbing headache has not yet been elucidated. In this review, we postulated the mechanism of stabbing headache, based on the pain phenotype and clinical course, and provide a clinical algorithm for the differential diagnosis of primary stabbing headache.

CONCLUSION

Knowledge about the typical manifestations and clinical patterns of primary stabbing headache will aid in the proper diagnosis and differential diagnosis. Treatment should be tailored by considering the clinical patterns. Further research is needed to elucidate the pathophysiological mechanisms and optimal treatment of primary stabbing headache.

Results of a Web-Based Survey on 2105 Greek Migraine Patients-Second Part: Efficacy of Acute and Prophylactic Migraine Treatments and Corresponding Patients' Reported Satisfaction

Background and Objectives: The Greek Society of Migraine and Headache Patients conducted, in 2020, its second online survey, titled "Migraine in Greece-2020", after publication of the first similar online survey conducted in 2018. To compare the current findings with the corresponding data obtained in 2018, we herein release the second part of results obtained from the 2020 survey on the efficacy of preventive and symptomatic anti-migraine medications and the patients' reported satisfaction with these treatments. Materials and Methods: We surveyed 2105 migraine patients from all over Greece with the use of a 151-questions specific migraine-focused questionnaire in Greek language, which was distributed through the online research software "SurveyMonkey". Results: Triptans were mostly used with efficacy for the symptomatic relief of migraine attacks. About 2 of 3 surveyed patients had received various prophylactic oral medications and the majority of them discontinued these prophylactic medications as a result of inefficacy/safety issues. BoNTA was reported to be effective only when administration was commenced by a trained neurologist/headache specialist, while our current findings are generally comparable to those obtained in our 2018 pre-COVID-19 survey and the pandemic has not imposed any significant attitudes on migraine therapies and corresponding patients' satisfaction. Conclusion: Although a market change is anticipated with the evolving widespread use of anti-CGRPs monoclonal antibodies or gepants in the symptomatic and prophylactic treatment of migraine, it is of great interest to review published results of larger longitudinal population-based studies to further ascertain the satisfaction of patients to migraine therapies.

OnabotulinumtoxinA Add-On to Monoclonal Anti-CGRP Antibodies in Treatment-Refractory Chronic Migraine

We sought to assess the effectiveness of combining dual therapy with onabotulinumtoxinA (BTX) add-on to anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (anti-CGRP MAbs) in treatment-refractory patients with chronic migraine (CM). We retrospectively reviewed the medical files of 19 treatment-refractory patients with CM who had failed to two oral migraine preventatives, at least three consecutive BTX cycles (less than 30% response rate), at least three consecutive sessions with either fremanezumab or erenumab (less than 30% response rate), and were eventually switched to dual therapy with BTX add-on to any of the already-given anti-CGRP MAbs. We then assessed from baseline to each monotherapy or dual intervention predefined efficacy follow-up the changes in the following efficacy outcomes: (i) monthly headache days (MHD), (ii) monthly days with moderate/severe peak headache intensity, and (iii) monthly days with intake of any acute headache medication. Response (50% reduction in MHD) rates, safety, and tolerability were also determined. In the majority of cases (n = 14), dual targeting proved effective and was associated with clinically meaningful improvement in all efficacy variables; 50% response rates (also disability and QOL outcomes) coupled with favorable safety/tolerability. Our results advocate in favor of the view that dual therapy is effective and should be considered in difficult-to-treat CM patients who have failed all available monotherapies.

How Does Botulinum Toxin Inhibit Itch?

Two decades after reports of the anti-pruritic effects of botulinum neurotoxins (BoNTs), there is still no approved product for the anti-itch indication of BoNTs, and most clinical case reports still focus on the off-label use of BoNTs for various itchy conditions. Few randomized clinical trials have been conducted with controversial results, and the beneficial effects of BoNTs against itch are mainly based on case studies and case series. These studies are valuable in presenting the potential application of BoNTs in chronic pruritic conditions, but due to the nature of these studies, they are categorized as providing lower levels of evidence or lower grades of recommendation. To obtain approval for the anti-pruritic indication of BoNTs, higher levels of evidence are required, which can be achieved through conducting large-scale and well-designed studies with proper control groups and established careful and reliable primary and secondary outcomes. In addition to clinical evidence, presenting the mechanism-based antipruritic action of BoNTs can potentially strengthen, accelerate, and facilitate the current efforts towards further investments in accelerating the field towards the potential approval of BoNTs for itchy conditions. This review, therefore, aimed to provide the state-of-the-art mechanisms underlying the anti-itch effect of BoNTs from basic studies that resemble various clinical conditions with itch as a hallmark. Evidence of the neuronal, glial, and immune modulatory actions of BoNTs in reducing the transmission of itch are presented, and future potential directions are outlined.

A systematic review with expert opinion on the role of gepants for the preventive and abortive treatment of migraine

INTRODUCTION

Gepants are small molecules targeting the calcitonin gene-related peptide (CGRP) that have been recently introduced and are under additional clinical development as preventive and abortive treatment options for migraine.

AREAS COVERED

After providing a narrative overview of current preventive and acute treatment options for migraine and summarizing the pathophysiology of migraine attack and the role of CGRP, we performed a systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, on trials on gepants in preventive and acute treatment of migraine. Studies and results were reviewed and discussed, and expert opinion was presented. We also collected data on relevant ongoing trials.

EXPERT OPINION

Whether direct targeting CGRP pathways within the central nervous system or indirectly modulating them from the peripheral nervous system is more effective and safer in migraine remains still unclear. The available data on the efficacy and safety of gepants suggest they may represent an abortive, and to some extent, preventive treatment option for migraine, in patients who do not respond or have adverse effects to first/second line treatments or at high risk for medication overuse headache; thus opening new therapeutic horizons.

Assessing the Significance of the Circadian Time of Administration on the Effectiveness and Tolerability of OnabotulinumtoxinA for Chronic Migraine Prophylaxis

We aimed to provide insights on the role of the circadian time of administration in influencing the efficacy and tolerability/safety profile of OnabotulinumtoxinA (BoNTA) for chronic migraine (CM) prophylaxis. Methods: We retrospectively reviewed the medical files of BoNTA-naïve patients with CM who completed three consecutive cycles of treatment, according to the standard PREEMPT paradigm. Participants were classified to those scheduled to be treated in the morning hours from 8:00 to 12:00 (AM) or afternoon hours from 13:00 to 18:00 (PM). We then assessed and compared between groups the changes from baseline (T0—trimester before BoNTA’s first administration) to the period after its third administration (T3) in the following efficacy outcomes: (i) mean number of headache days/month, (ii) mean number of days/month with peak headache intensity of >4/10, (iii) mean number of days/month with consumption of any abortive treatment. Safety−tolerability was also compared between groups. Results: A total of 50 AM and 50 PM-treated patients were evaluated. The within-group analysis in both groups showed a significant decrease in all efficacy variables between T0 and T3. However, the between-group comparisons of all BoNTA-related efficacy outcomes at T3 vs. T0 documented comparable improvements between AM vs. PM-treated patients. Safety/tolerability was also similar between groups. Conclusions: We were not able to identify significant differences between patients treated in the AM vs. PM, so as to demonstrate that the circadian time of administration should be considered before initiating BoNTA in CM patients.

Botox (OnabotulinumtoxinA) for Treatment of Migraine Symptoms: A Systematic Review

Background. Migraine is one of the most common types of headache, and it is the second most common cause of neurological disorders, with an annual prevalence of about 15% of the population. This study aimed to evaluate the effect of BoNT-A on the duration and intensity of migraine attacks. In addition, we investigated the effective injection sites. Methods. According to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, we searched online databases, including Web of Science, PubMed, EMBASE, Scopus, Cochrane Library, ProQuest, ClinicalTrials.gov, and Google Scholar from 2011 to 2021. Results. A total of 24 articles were included in the study. The use of BoNT-A in individuals suffering from chronic migraine (CM) decreases the frequency of migraine attacks per month, pain intensity, medication use, emergency visits, and migraine-related disabilities. The BoNT-A was well tolerated and leads to improved performance and better quality of life (QoL). Overall, treatment with BoNT-A in adults with CM is beneficial. In addition, the use of BoNT-A in individuals with vestibular migraine (VM) reduces the frequency of migraines and brings about the improvement of disability status caused by migraine headaches. Meanwhile, the use of BoNT-A reduces the frequency of migraine attacks per month among individuals with chronic refractory migraine (CRM). Conclusions. The use of BoNT-A is a low-cost option for the treatment of various kinds of migraines, including chronic, episodic, unilateral, and vestibular types. BoNT-A can reduce the frequency of migraine attacks per month and diminish the severity of pain.