The Efficacy of Botulinum Toxin in Pediatric Chronic Migraine: A Literature Review

The safety and efficacy of onabotulinumtoxinA injections for children and adolescents with chronic migraine: A systematic review and meta-analysis

OBJECTIVE

To qualitatively and quantitatively summarize the evidence for the use of onabotulinumtoxinA injections in children and adolescents with migraine.

BACKGROUND

There are limited evidence-based treatment options for youth with migraine, especially youth with chronic migraine (CM). OnabotulinumtoxinA injections are an established evidence-based treatment for adults with CM. While several studies have assessed their safety and efficacy among adolescents with CM, there are no published systematic reviews summarizing the pediatric evidence.

METHODS

We carried out a systematic review, reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis, aiming to identify studies that included five or more children and adolescents aged ≤18 years with a diagnosis of migraine, who were treated with ≥50 units (U) of onabotulinumtoxinA and had outcomes assessed ≥4 weeks after one or more injection cycle. Both observational studies and randomized controlled trials (RCTs) were eligible for inclusion. Two investigators independently carried out the first (titles and abstracts) and second (full text) screening stages, as well as data extraction and quality appraisal. The American Academy of Neurology risk of bias grading scheme was used to assess study risk of bias. Studies with adequate data were pooled using random effects meta-analyses, and Hedge's g standardized mean differences with 95% confidence intervals (CIs) were generated to estimate the effect sizes of the continuous outcomes included. Studies lacking data required for meta-analysis were summarized qualitatively.

RESULTS

We screened 634 studies and included 14 studies comprising 491 participants, of whom 489 had CM. Two studies were RCTs, 12 were observational uncontrolled studies, and all but one study included only youth with CM. Five Class IV observational uncontrolled studies were amenable to pooling in meta-analyses. After a mean of 2-2.6 injection cycles, headache frequency was shown to decrease significantly after treatment with onabotulinumtoxinA (Hedge's g = 0.97, 95% CI 0.58-1.35; p < 0.0001), as did severity (Hedge's g = 1.24, 95% CI 0.55-1.94; p = 0.0005), with both estimates having a large effect size magnitude. A Class I parallel-group RCT of one injection series (155 U, 74 U, or placebo), powered to detect a change in 4 headache days per month, did not find outcome differences between the active and placebo treatment arms. A Class IV crossover RCT showed superiority of active (155 U) versus placebo injections. The remaining Class IV observational studies that were excluded from the meta-analyses all showed improved outcomes with onabotulinumtoxinA injections over time. No serious adverse events related to treatment occurred.

CONCLUSION

OnabotulinumtoxinA injections have established safety for use in children and adolescents with CM and are likely effective in reducing headache frequency and severity over time. However, in the absence of an adequately powered parallel-group RCT assessing the efficacy of multiple injection cycles, it remains unclear if this intervention is superior to placebo.

Beyond the Guidelines: A Narrative Review of Treatments on the Horizon for Migraine in Children and Adolescents

Migraine is common in children and adolescents and can cause significant disability. There are relatively limited evidence-based treatment options available, especially when compared with treatment of migraine in adults. The Pediatric Research Equity Act requires the study of a new drug or biologic in pediatric populations. As such it is mandatory that the newest migraine treatment options available for adults be evaluated in children and adolescents. It will take years before results from clinical trials in pediatric patients become available. In the meantime, there is eagerness among clinicians to seek out the existing evidence that may help provide clarity on utilization of the newer migraine therapies in children and adolescents because many of the currently available, guideline-recommended treatments do not provide benefit for all patients. In this narrative review, the literature regarding onabotulinumtoxinA, neuromodulatory devices, calcitonin gene-related peptide (CGRP) monoclonal antibodies, 5-hydroxytryptamine (1F) agonists (i.e., ditans), and CGRP small-molecule receptor antagonists (i.e., gepants) for the treatment of migraine in children and adolescents will be summarized.

Advances in the Acute and Preventive Treatment of Pediatric Migraine

PURPOSE OF REVIEW

Headaches are common in children and adolescents. Treatments for debilitating migraine are often not FDA approved or lack evidence of efficacy for children. This narrative review looks at the evidence for acute and preventative pharmacologic and non-pharmacologic treatment of pediatric migraine, as well as reviewing any recent or ongoing clinical trials.

RECENT FINDINGS

Studies have been published on pharmacological treatments for headache, as well as non-pharmacological treatments. Recent findings in pediatric migraine using onabotulinumtoxinA, calcitonin gene related peptide antagonists, interventional procedures, and devices are reviewed. Pharmacologic as well as non-pharmacologic approaches for the prevention and treatment of migraine show safety and efficacy data that is promising. These treatments should be incorporated in a multi-modal approach to the management of pediatric migraine. Continued studies, prospective and randomized, are needed to further assess these newer treatments for migraine in the pediatric setting.

What is new in migraine management in children and young people?

For this narrative review, we found recent publications on the use and effectiveness of old therapies including nutraceuticals, such as riboflavin, vitamin D, magnesium, melatonin and talking therapies. Recent large trials of established conventional pharmaceuticals such as propranolol, pizotifen, topiramate and amitriptyline for childhood migraine have failed, but the use of a quasi-placebo in future trials could help. We reviewed the evidence for angiotensin antagonists including candesartan in adults, but found a lack of evidence for their use in children. There have been new developments in pharmaceuticals recently, including a more selective 5-HT1F agonist, lasmiditan, an effective acute treatment with no vasoconstrictor activity in adults, currently being tested in children. Also, a number of new calcitonin gene-related peptide (CGRP) antibodies and antagonists, with proven efficacy in acute treatment and/or prevention of migraine in adults, are undergoing trials in children. Peripheral nerve blocks and botulinum toxin are gaining popularity in adult practice, but we really need more good quality evidence for their effectiveness in children. Finally, electroceuticals, that is, therapeutic electric devices, are now marketed for acute and or preventative treatment, including an external trigeminal nerve stimulator (e-TNS), a non-invasive vagal nerve stimulator (nVNS), a single-pulse transcranial magnetic stimulator (sTMS) and a remote electrical neuromodulation device (REN). At the moment, evidence for their effectiveness in children is still lacking. So, there has been much progress, but mostly for adults. We are in urgent need of more migraine trials in children.

Is Botox Right for Me: When to Assess the Efficacy of the Botox Injection for Chronic Migraine in Pediatric Population

Botulinum toxin type A (BoNT-A) has shown to be a safe and effective treatment for children with chronic migraines. Our study was to assess the efficacy of the Onabotulinum toxin type A at different intervals after initiation of therapy. We conducted a retrospective and prospective analysis of 34 patients at a children's hospital where children received four rounds of the BoNT-A therapy for the treatment of chronic migraine. Among the 34 patients, 25 patients (age range: 13-21 years), who responded to the BoNT-A therapy, were included in the analysis. Patients received standard 31 injection, 155 unit's protocol. Patients were assessed every 3 months after their initial injection. Reasons for discontinuation of therapy were analyzed. After the first two BoNT-A sessions, significant improvement was observed with a decrease in headache frequency and intensity (p < 0.001). There was further reduction in headache frequency and intensity with the fourth round of BoNT-A therapy, with comparative analysis between the second and fourth round showing a p-value of <0.001. In terms of reduction of emergency room visits and hospitalization, a significant improvement was seen after the third round of BoNT-A therapy (p < 0.01). A significant decrease in the number of abortive and preventive medications was seen after the second round of BoNT-A therapy (p < 0.001). The efficacy of BoNT-A treatment in decreasing headache frequency, intensity, and the number of abortive and preventive medications can be assessed effectively after two treatment sessions. This trend continued to be observed with additional third and fourth sessions.

Outpatient Approach to Resistant and Refractory Migraine in Children and Adolescents: a Narrative Review

PURPOSE OF REVIEW

Migraine is one of the top reasons for consulting a pediatric neurologist. Although the majority of children and adolescents who receive evidence-based first-line interventions for migraine will improve substantially, a subset of patients develop resistant or refractory migraine.

RECENT FINDINGS

In this review, we summarize the level of evidence for a variety of acute and preventive treatment options to consider in children and adolescents with resistant or refractory migraine. We describe the level of evidence for interventional procedures (onabotulinumtoxinA injections, greater occipital and other nerve blocks), neuromodulation (single-pulse transcranial magnetic stimulation, external trigeminal nerve stimulation, remote electrical neuromodulation, and non-invasive vagal nerve stimulation), calcitonin gene-related peptide (CGRP) pathway antagonists (anti-CGRP monoclonal antibodies and gepants), psychological therapies, and manual therapies (acupuncture, craniosacral therapy, massage and physical therapy, and spinal manipulation).

Generalized Anxiety Disorder: A Predictor for Poor Responsiveness to Botulinum Toxin Type A Therapy for Pediatric Migraine

BACKGROUND

To assess the efficacy, safety, and predictors for poor responsiveness of botulinum toxin type A (BoNT-A) for chronic migraine in the adolescent and young adult population.

METHODS

A retrospective analysis of 56 patients who received BoNT-A for chronic migraine with an age range from 13 to 21 years was performed. Of 56 patients, 34 were enrolled in the study based on the inclusion criterion. Patients who received three dosages of BoNT-A were assessed at nine months from the first injection. Variables including age, body mass index, headache intensity, frequency, character, and side effects were assessed. The patients were divided into two groups based on response to BoNT-A therapy, responders and nonresponders.

RESULTS

Overall among the 34 patients enrolled in the study, the average headache frequency decreased from 18.6 of 28 to 9.9 of 28 days, P value, <0.001 from baseline. There was significant decrease in the average headache intensity, 8.1 to 4.3. Of 34 patients, 25 (73%) patients responded to treatment with decrease in headache frequency by ≥ 50% from the baseline. Among the nonresponder patients, a significant number of patients (six of nine, 67%) had generalized anxiety disorder with Generalized Anxiety Disorder-7 score greater than 15 versus the responder group (six of 25, 24%, P value 0.040).

CONCLUSIONS

BoNT-A remains a safe and effective therapy for adolescent and young adult patients with chronic migraines at nine months of follow-up. Generalized anxiety disorder with Generalized Anxiety Disorder-7 score greater than 15 can be a major predictor of poor response to this therapy.

Approach to Pediatric Intractable Migraine

PURPOSE OF REVIEW

Intractable migraine in children and adolescents is a significant cause of disability and decreased quality of life (QoL) in this population. Challenges include lack of unifying definition for intractable migraine, and limited data on best-practice management in this age group, with most current treatment pathways extrapolated from adult studies or expert consensus.

RECENT FINDINGS

A comprehensive approach in the evaluation and management of intractable migraine in this age group encompasses excluding secondary causes of headache; making an accurate diagnosis; identifying and appropriately managing modifiable risk factors; and initiating appropriate pharmacologic therapy to reduce disability, improve health-related quality of life, reduce risk of progression, and develop adaptive pain coping strategies. Several strategies for management of pediatric intractable migraine including use of acute medications, bridge therapy in outpatient setting, emerging therapies for preventive therapy, and a stepwise combination therapy for management of pediatric intractable migraine in emergency and inpatient setting are presented based on available clinical data, safety/tolerability, availability, cost-effectiveness, and expert consensus. This descriptive review of the available literature focuses on approach to therapy for acute intractable migraine in a pediatric population including outpatient, emergency department (ED), and inpatient management.