Botulinum toxin type A (BOTOX) for treatment of migraine headaches: an open-label study

Insights from 25 years of onabotulinumtoxinA in migraine - mechanisms and management

OnabotulinumtoxinA (BTX-A) was first linked to beneficial effects in migraine 25 years ago and was approved by the FDA for preventive treatment of chronic migraine in 2010. The treatment has since had a major impact on the well-being of people with chronic migraine. The clinical development programme for BTX-A and research since its approval have provided insights into the neuromodulatory sensory effect of BTX-A, how it can control chronic migraine despite its peripheral action, and the underlying biology of migraine as a disease. In this Review, we consider the impact that BTX-A has had on the management of chronic migraine and on the research field. We discuss the insights provided by clinical research, encompassing the clinical trials and subsequent real-world evidence, and the mechanistic insights provided by preclinical and translational research. We also provide an overview of future directions of research in the field BTX-A in migraine and the clinical translation of this research.

Voltage-gated Calcium Channels as Potential Therapeutic Targets in Migraine

Migraine is a complex and highly incapacitating neurological disorder that affects around 15% of the general population with greater incidence in women, often at the most productive age of life. Migraine physiopathology is still not fully understood, but it involves multiple mediators and events in the trigeminovascular system and the central nervous system. The identification of calcitonin gene-related peptide as a key mediator in migraine physiopathology has led to the development of effective and highly selective antimigraine therapies. However, this treatment is neither accessible nor effective for all migraine sufferers. Thus, a better understanding of migraine mechanisms and the identification of potential targets are still clearly warranted. Voltage-gated calcium channels (VGCCs) are widely distributed in the trigeminovascular system, and there is accumulating evidence of their contribution to the mechanisms associated with headache pain. Several drugs used in migraine abortive or prophylactic treatment target VGCCs, which probably contributes to their analgesic effect. This review aims to summarize the current evidence of VGGC contribution to migraine physiopathology and to discuss how current pharmacological options for migraine treatment interfere with VGGC function. PERSPECTIVE: Calcitonin gene-related peptide (CGRP) represents a major migraine mediator, but few studies have investigated the relationship between CGRP and VGCCs. CGRP release is calcium channel-dependent and VGGCs are key players in familial migraine. Further studies are needed to determine whether VGCCs are suitable molecular targets for treating migraine.

Onabotulinumtoxina in the Prevention of Migraine in Pediatric Population: A Systematic Review

Migraine is a leading cause of disability worldwide, yet it remains underrecognized and undertreated, especially in the pediatric and adolescent population. Chronic migraine occurs approximately in 1% of children and adolescents requiring preventive treatment. Topiramate is the only FDA-approved preventative treatment for children older than 12 years of age, but there is conflicting evidence regarding its efficacy. OnabotulinumtoxinA is a known and approved treatment for the management of chronic migraine in people older than 18 years. Several studies examine its role in the pediatric population with positive results; however, the clear-cut benefit is still unclear. OnabotulinumtoxinA seems not only to improve disability scores (PedMIDAS) but also to improve the quality, characteristics, and frequency of migraines in the said population. This systematic review aims to summarize the evidence on the efficacy, dosing, administration, long-term outcomes, and safety of onabotulinumtoxinA in pediatric and adolescent migraine. Eighteen studies met the eligibility criteria and were included in this review. The mean monthly migraine days (MMDs), decreased from of 21.2 days per month to 10.7 after treatment. The reported treatment-related adverse effects were mild and primarily injection site related and ranged from 0% to 47.0%. Thus, this review provides compelling evidence suggesting that OnabotulinumtoxinA may represent a safe and effective preventive treatment option for pediatric migraine.

Synergism of Anti-CGRP Monoclonal Antibodies and OnabotulinumtoxinA in the Treatment of Chronic Migraine: A Real-World Retrospective Chart Review

BACKGROUND

Many patients with chronic migraine do not achieve clinically meaningful improvement in their headache frequency with monotherapy. The burden associated with chronic migraine calls for a multifaceted treatment approach targeting multiple aspects of migraine pathophysiology.

OBJECTIVE

The aim of this study was to evaluate the effect of concurrent anti-calcitonin gene-related peptide (CGRP) monoclonal antibody (mAb) and onabotulinumtoxinA (onabot) treatment on median monthly migraine days (MMD) in patients with chronic migraine, through a retrospective study.

METHODS

The electronic medical records of Cleveland Clinic patients either concurrently (dual therapy) or consecutively (monotherapy) treated with anti-CGRP mAbs and onabot between June 2018 and November 2021 were extracted. Only adult patients (≥ 18 years of age) were included in this study. MMDs for 194 concurrently treated (86.6% female and a median [interquartile range] age of 51 [41-61] years) and 229 consecutively treated (88.2% female and median age of 47 [IQR 39-57] years) patients were examined at baseline, after first therapy of either anti-CGRP mAb or onabot, and following dual therapy for 3 consecutive months. The reduction of MMDs for each treatment group were compared. The same approach was utilized to compare consecutive monotherapy at separate times (n = 229) and dual-therapy groups.

RESULTS

The initial treatment of the dual-therapy group reduced the median (IQR) MMDs from 30 (30-30) to 15 (12-30) [p < 0.0001]. After initiation of dual therapy, the median MMDs was further decreased from 15 (12-30) to 8 (3-22) [p < 0.0001]. A majority [132/194 (68.0%)] of the dual-therapy patients reported a ≥ 50% reduction in MMD and 90/194 (46.4%) reported a ≥ 75% reduction. For the consecutive monotherapy group, median MMDs changed from a baseline of 30 (25-30) to 15 (8-25) from onabot monotherapy and decreased from 25 (15-30) to 12 (4-25) after anti-CGRP mAb monotherapy. Almost half (113/229 [49.3%] from onabot, and 104/229 [45.4%] from anti-CGRP mAb) of these patients achieved a ≥ 50% reduction in MMDs and a minority (38/229 [16.6%] from onabot, and 45/229 [19.7%] from anti-CGRP mAb) achieved a reduction of ≥ 75%. Additionally, dual therapy showed significant improvement in MMDs compared with monotherapy of either treatment (p < 0.0001).

CONCLUSION

Dual therapy of anti-CGRP mAbs and onabot may be more efficacious than monotherapy, possibly due to their synergistic mechanisms of action.

Underrepresented and Underserved Populations in Neurological Research

Underserved and underrepresented populations have historically been excluded from neurological research. This lack of representation has implications for translation of research findings into clinical practice given the impact of social determinants of health on neurological disease risk, progression, and outcomes. Lack of inclusion in research is driven by individual-, investigator-, and study-level barriers as well as larger systemic injustices (e.g., structural racism, discriminatory practices). Although strategies to increase inclusion of underserved and underrepresented populations have been put forth, numerous questions remain about the most effective methodology. In this article, we highlight inclusivity patterns and gaps among the most common neurological conditions and propose best practices informed by our own experiences in engagement of local community organizations and collaboration efforts to increase underserved and underrepresented population participation in neurological research.

The Use of Botulinum Toxin Type A in Medically Refractory Pediatric Patients With Chronic Daily Headaches and Its Impact on the Quality of Life

Background: Chronic migraine in children has been a challenging condition to treat, prompting the investigation of alternative therapies. This retrospective single-center chart review aimed to evaluate the efficacy and safety of Botox injections for managing chronic migraine in children. Methods: The study included children with chronic daily headaches and chronic migraine who were medically refractory to previous treatments at OSF Healthcare/Illinois Neurological Institute, Peoria, between 2015 and 2021. Botox injections were administered quarterly following a specific protocol. Data were obtained from electronic medical records by manual review. Results: Twenty-four patients met the inclusion criteria (median age 15.4 years, 87% female). Comorbidities included depression (41.6%) and sleep disturbances (33.2%). Prior to Botox treatment, patients had been tried on a median number of 5 (interquartile range [IQR] 4, 7) medications. Botox injections resulted in a significant reduction in headache frequency, with a mean difference (6 months vs pretreatment) in the Headache Impact Test (HIT 3) scores of -19.6 (95% CI -24.8, -14.3), P < .001, and mean difference in the Migraine Disability Assessment (MIDAS) scores of -50.8 (95% CI -62.6, -39.0, P < .001). Subjective improvements included mood enhancement (13/24, 54.2%) and improved concentration (12/24, 50%). Treatment-related side effects were reported by 5/24 (20%) of patients and were mostly mild to moderate. Conclusions: Botox injections offer a promising therapeutic option for managing chronic migraine in children who have not responded to traditional medications. Future controlled trials and long-term follow-up studies are needed to further evaluate Botox treatment's benefits and adverse effects in children with chronic migraine.

Botox (onabotulinumtoxinA) mechanism of action

Studies in the 1920s found that botulinum neurotoxin type A (BoNT/A) inhibited the activity of motor and parasympathetic nerve endings, confirmed several decades later to be due to decreased acetylcholine release. The 1970s were marked by studies of cellular mechanisms aided by use of neutralizing antibodies as pharmacologic tools: BoNT/A disappeared from accessibility to neutralizing antibodies within minutes, although it took several hours for onset of muscle weakness. The multi-step mechanism was experimentally confirmed and is now recognized to consist broadly of binding to nerve terminals, internalization, and lysis or cleavage of a protein (SNAP-25: synaptosomal associated protein-25 kDa) that is part of the SNARE (Soluble NSF Attachment protein REceptor) complex needed for synaptic vesicle docking and fusion. Clinical use of the BoNT/A product onabotulinumtoxinA was based on its ability to reduce muscle contractions via inhibition of acetylcholine from motor terminals. Sensory mechanisms of onabotulinumtoxinA have now been identified, supporting its successful treatment of chronic migraine and urgency in overactive bladder. Exploration into migraine mechanisms led to anatomical studies documenting pain fibers that send axons through sutures of the skull to outside the head-a potential route by which extracranial injections could affect intracranial processes. Several clinical studies have also identified benefits of onabotulinumtoxinA in major depression, which have been attributed to central responses induced by feedback from facial muscle and skin movement. Overall, the history of BoNT/A is distinguished by basic science studies that stimulated clinical use and, conversely, clinical observations that spurred basic research into novel mechanisms of action.

Treatment of chronic migraine with Botox (onabotulinumtoxinA): Development, insights, and impact

Chronic migraine (CM) is a neurological disease characterized by frequent migraine attacks that prevent affected individuals from performing daily activities of living, significantly diminish quality of life, and increase familial burden. Before onabotulinumtoxinA was approved for CM, there were few treatment options for these seriously disabled patients and none had regulatory approval. The terminology and recognition of CM evolved in parallel with the onabotulinumtoxinA clinical development program. Because there were no globally accepted classification criteria for CM when onabotulinumtoxinA was in development, the patient populations for the trials conducted by Allergan were determined by the Allergan migraine team in collaboration with headache scientists and clinicians. These trials and collaborations ultimately led to improvements in CM classifications. In 2010, onabotulinumtoxinA became the first medication and first biologic approved specifically to prevent headaches in patients with CM. Approval was based on 2 similarly designed phase 3, double-blind, randomized, placebo-controlled, multicenter clinical studies. Both studies showed significantly greater improvements in mean change from baseline in headache-day frequency in patients with CM receiving onabotulinumtoxinA compared with those receiving placebo. The safety and effectiveness of onabotulinumtoxinA have been established globally in >5000 patients with CM with or without medication overuse treated in clinical and observational studies. Benefits also include improvements in quality of life, fewer psychiatric comorbidities, and reduced healthcare resource utilization. Across studies, onabotulinumtoxinA was well tolerated; adverse events tended to be mild or moderate in severity and to decline over subsequent treatment cycles.

Injection technique of the upper face with onabotulinumtoxinA in chronic migraine

BACKGROUND

The objective is to review the technique of onabotulinumtoxinA injection treatment in the glabellar and frontal regions using the PREEMPT (Phase III REsearch Evaluating Migraine Prophylaxis Therapy) paradigm, with review of the aesthetic issues related to the procedure. OnabotulinumtoxinA is an effective medication for the prevention of chronic migraine. The PREEMPT injection paradigm has been validated in randomized clinical trials and real-world settings. This treatment includes injections in the forehead and glabella area. In addition, for aesthetic uses, glabella onabotulinumtoxinA injections are done in similar muscles specifically the procerus, corrugator supercilii, and frontalis muscles. Often patients who have been injected with onabotulinumtoxinA for chronic migraine have concerns about their appearance and will ask if they can see an aesthetic injector to improve this. This is a difficult issue as onabotulinumtoxinA should be injected with an interval of 10-12 weeks to avoid development of antibodies against onabotulinumtoxinA, so all injections (migraine and aesthetic) should ideally be done close together; however, if an aesthetic injection is done on the same day as a PREEMPT injection, the effect of the PREEMPT injection will not yet be visible as it takes time for onabotulinumtoxinA effects to be seen. Thus, there is a risk of a potential overdose in a particular area if aesthetic injections are done without input from the PREEMPT injector.

METHODS

This is a narrative review supported by photographic documentation showing the technique of onabotulinumtoxinA injection of the upper face, considering anatomical differences between patients, and combining the needs in neurology and aesthetic medicine fields.

RESULTS

Practitioners treating chronic migraine often modify some of the principles of the PREEMPT paradigm. Many practitioners are unsure about injections in the glabellar and frontal areas. The authors present a technique for using the PREEMPT protocol and adapting this to the individual patient's anatomy to prevent an unsightly appearance or ptosis. In addition, sites are provided where an aesthetic injector could inject to improve the patient's appearance without overlapping with the PREEMPT injection sites.

CONCLUSION

Adherence to the PREEMPT injection protocol provides an evidence-based approach to achieving clinical benefit for patients with chronic migraine. Aesthetic elements of the treatment of the glabella and forehead require additional attention. The authors provide practical considerations and recommendations regarding this.

The pluripotential evolution and journey of Botox (onabotulinumtoxinA)

Clinical use of onabotulinumtoxinA evolved based on strategic, hypothesis-driven applications, as well as serendipitous observations by physicians and patients. The success of onabotulinumtoxinA in blepharospasm and strabismus led to its study in other head and neck dystonias, followed by limb dystonia, tremor, and spasticity. The aesthetic use of onabotulinumtoxinA followed initial reports from patients of improved facial lines after injections for facial dystonias and hemifacial spasm. Although patients with dystonias and spasticity regularly reported that their local pain improved after injections, onabotulinumtoxinA was not systematically explored for chronic migraine until patients began reporting headache improvements following aesthetic injections. Clinicians began assessing onabotulinumtoxinA for facial sweating and hyperhidrosis based on its inhibition of acetylcholine from sympathetic cholinergic nerves. Yet another line of research grew out of injections for laryngeal dystonia, whereby clinicians began to explore other sphincters in the gastrointestinal tract and eventually to treatment of pelvic sphincters; many of these sphincters are innervated by autonomic nerves. Additional investigations in other autonomically mediated conditions were conducted, including overactive bladder and neurogenic detrusor overactivity, achalasia, obesity, and postoperative atrial fibrillation. The study of onabotulinumtoxinA for depression also grew out of the cosmetic experience and the observation that relaxing facial muscle contractions associated with negative emotions may improve mood. For approved indications, the safety profile of onabotulinumtoxinA has been demonstrated in the formal development programs and post-marketing reports. Over time, evidence has accumulated suggesting clinical manifestations of systemic effects, albeit uncommon, particularly with high doses and in vulnerable populations. Although onabotulinumtoxinA is approved for approximately 26 indications across multiple local regions, there are 15 primary indication uses that have been approved in most regions, including the United States, Europe, South America, and Asia. This review describes many uses for which AbbVie has not sought and/or received regulatory approval and are mentioned for historical context only.

Three men in a boat: The comparison of the combination therapy of botulinum toxin and greater occipital nerve block with bupivacaine, with botulinum toxin monotherapy in the management of chronic migraine

OBJECTIVE

This study compared the impact of the combination therapy of onabotulinum toxin A and greater occipital nerve block (GoNT-A) with onabotulinum toxin A monotherapy (BoNT-A) based on its efficacy and safety in relation to the quality of life of adult chronic migraine (CM) patients.

BACKGROUND

Prophylactic treatment of CM is still difficult and complex. Combination treatments do not have an evidence base yet.

METHODS

This retrospective study included 85 patients. For greater occipital nerve block (GONB), 4 ml of the solution prepared using 1 ml of 0.5% bupivacaine and 3 ml of saline on both sides were bilaterally applied to 30 patients. For BoNT-A treatment, a total of 155 units of onabotulinum toxin A (BOTOX®) was intramuscularly injected into 31 specific points around the head and neck in 27 patients. Both protocols were similarly applied to 28 patients for GoNT-A treatment. MIDAS and HIT-6 scores were evaluated to measure patients' quality of life three months after the treatment.

RESULTS

When MIDAS and HIT-6 score groups were statistically compared, both GONB and GoNT-A applications showed a statistically significant reduction compared to the BoNT-A application (p < 0.05). The decrease in the MIDAS and HIT-6 scores of GONB and GoNT-A applications did not show a statistical difference (p > 0.05).

CONCLUSION

The combination of BoNT-A and GONB was superior to BoNT-A applied as monotherapy. Alternately, no significant difference was found between GONB therapy and combination therapy in all data. Combination treatments were well tolerated.

Real Life Data on OnabotulinumtoxinA for Treatment of Chronic Migraine in Pediatric Age

BACKGROUND

The use of OnabotulinumtoxinA (OBT-A) for the treatment of chronic migraine (CM) in adults represents a therapy with the greatest efficacy and safety data. However, we have little evidence on the use of OBT-A in children or adolescents. The present study aims to describe the experience with OBT-A in the treatment of CM in adolescents in an Italian third-level headache center.

METHODS

The analysis included all patients under the age of 18 treated with OBT-A for CM at the Bambino Gesù Children's Hospital. All patients received OBT-A following the PREEMPT protocol. Subjects were classified as good responders if a greater than 50% reduction in the monthly frequency of attacks was observed, partial responders if the reduction was between 30 and 50%, and non-responders if it was <30%.

RESULTS

The treated population consisted of 37 females and 9 males with a mean age of 14.7 years. Before starting OBT-A, 58.7% of the subjects had attempted prophylactic therapy with other drugs. From OBT-A initiation to the last clinical observation, the mean duration of follow-up was 17.6 ± 13.7 SD (range: 1-48) months. The number of OBT-A injections were 3.4 ± 3 SD. Sixty eight percent of the subjects responded to treatment within the first three administrations of OBT-A. Proceeding with the number of administrations, a progressive improvement in frequency was further observed.

CONCLUSIONS

The use of OBT-A in pediatric age can have benefits in terms of reduction in the frequency and intensity of headache episodes. Furthermore, treatment with OBT-A has an excellent safety profile. These data support the use of OBT-A in the treatment of childhood migraine.

Preliminary Findings of the Efficacy of Botulinum Toxin in Temporomandibular Disorders: Uncontrolled Pilot Study

Temporomandibular disorders are a common pathology affecting up to 70% of the population, with a maximum incidence in young patients. We used a sample of twenty patients recruited in the Maxillofacial Surgery Service of the University Hospital of Salamanca (Spain), who met the inclusion criteria, with unilateral painful symptomatology of more than three months' duration. All patients were randomly treated by intramuscular and intra-articular injections of botulinum toxin (100 U) in eight predetermined points. Pain symptomatology was assessed by the visual analog scale (VAS) at the different locations, together with joint symptomatology, at baseline and six weeks after treatment. Adverse effects were also evaluated. In 85% of the patients, pain upon oral opening improved and 90% showed improvement in pain upon mastication. A total of 75% of the patients reported improvement in joint clicking/noise. Headaches improved or disappeared in 70% of the patients treated. Despite the limitations of the study and the preliminary results, intramuscular and intra-articular infiltrations with botulinum toxin were effective in the treatment of symptoms associated with temporomandibular disorders (TMDs), with minimal adverse effects.

Assessment of the relative effectiveness of erenumab compared with onabotulinumtoxinA for the prevention of chronic migraine

OBJECTIVE

To assess the available clinical and economic evidence of erenumab vs onabotulinumtoxinA for chronic migraine (CM) and present de-novo indirect treatment comparisons (ITCs) based on available clinical trial data.

METHODS

We conducted ITCs based on results from the pivotal 295 trial (NCT02066415) of erenumab vs placebo and published aggregate data from the PREEMPT 1 (NCT00156910) and PREEMPT 2 (NCT00168428) trials of onabotulinumtoxinA vs placebo. ITCs were conducted for CM patients with and without prior administration of onabotulinumtoxinA and among CM patients with ≥3 prior preventive treatment failures. Efficacy was assessed based on responder rates of ≥50% reductions in monthly headache days (MHDs) and monthly migraine days (MMDs) as well as change from baseline in both MHDs and MMDs.

RESULTS

Among patients with CM, 140 mg erenumab was associated with a reduction of 1.2 MHD (p = .092) and a reduction of 1.0 MMD (p = .174) compared to onabotulinumtoxinA at Week 12. Among onabotulinumtoxinA-naïve patients, erenumab was associated with a reduction of 1.8 MHD (p = .026) and 1.4 MMD (p = .080) at Week 12. Among patients that had received ≥3 prior preventive treatments, the odds ratios comparing erenumab vs onabotulinumtoxinA were 1.7 for ≥50% responder rates based on reductions in MHD (p = .155) and 1.7 for ≥50% responder rates based on reductions in MMD (p = .140).

CONCLUSION

These findings suggest directional benefits (although not reaching the threshold of statistical significance) associated with erenumab vs onabotulinumtoxinA for the preventive treatment of CM. Evidence from this study may inform healthcare stakeholders in treatment selection and optimization for patients with CM.

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.

The efficacy of botulinum toxin type-A for intractable chronic migraine patients with no pain-free time

AIM

This is a retrospective report of the efficacy of botulinum toxin-A, Botox^® (Allergan), in intractable chronic migraine patients non-responsive to previous pharmacological management and with largely no pain-free time, including those with new onset daily persistent headache.

METHODS

Thirty-three patients, all with severe Headache Impact Test (HIT)-6 scores at baseline, received 3-monthly injections of Botox^® as per Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PRE-EMPT) protocol over a maximum 33-month period. Response criteria were a sustained reduction of HIT-6 scores below 60.

RESULTS

Four patients had headache on at least 20 days a month; the remaining patients had daily headache with no pain-free time, including nine patients with new onset persistent migraine. There was a significant reduction in HIT-6 scores following Botox^® therapy (x̅ = -5.45, p = 0.000920). Twenty-one percent of the cohort exhibited a sustained reduction in HIT-6 scores below 60. The number of headache days and pain-free time did not change in five of the six responders, but disability improved. There was no difference between patients with episodic migraine evolving to chronic as opposed to those with chronic migraine from onset.

CONCLUSION

This report suggests that Botox^® treatment is efficacious in intractable chronic migraine without pain-free time. The HIT-6 is a reliable and practical parameter to assess disability in this patient group. Use of such validated parameters should be considered with greater weight in future International Classification of Headache Disorders (ICHD) guidelines for controlled clinical trials.

OnabotulinumtoxinA for the prophylactic treatment of headaches in adult patients with chronic migraine: a safety evaluation

Introduction: Existing oral prophylaxis for chronic migraine (CM) are often ineffective or poorly tolerated. OnabotulinumtoxinA (onabotA) is approved for headache prophylaxis in CM and ameliorates headaches in patients refractory to multiple preventatives.Areas covered: We appraise evidence regarding action mechanisms, pharmacodynamics, and pharmacokinetics of onabotA in CM prophylaxis. We critically evaluate salient clinical and real-world studies demonstrating its efficacy in improving multiple aspects of CM. We discuss onabotA safety, tolerability, and adverse events (AEs) for CM prophylaxis from clinical trials, post-authorization studies and meta-analyses, including novel pregnancy safety data and comparisons with oral prophylactics. We explore areas of future interest, particularly onabotA safety and efficacy in the context of novel antibody-based prophylaxis.Expert opinion: Clinical and real-world evidence demonstrate onabotA safety, tolerability and efficacy for CM prophylaxis. Most AEs are mild/moderate and self-limiting, with few serious AEs and no treatment-related deaths. Common AEs include neck pain, ptosis, muscle weakness, and stiffness. Modifying existing responder-criteria enables more patients to benefit from onabotA. OnabotA shows superior safety and efficacy to oral preventatives, and appears safe in pregnancy. Future pregnancy-risk register will clarify pregnancy and lactation safety further. Future research comparing onabotA safety and efficacy with newly emergent antibody-based prophylaxis is keenly awaited.

Surgical Options for Migraine: An Overview

Objective

The goal of this manuscript was to provide a comprehensive review of the surgical treatment for migraine headaches with a focus on trigger points and their clinical presentations, and to emphasize the importance of appropriate patient selection.

Background

Migraine is a prevalent neurological disease with headache being a disabling component of it. Surgical treatment for migraine headache became available two decades ago, which is based on proper identification and the deactivation of the specific trigger sites in the head and neck area.

Design

This manuscript reviews the discovery and evolution of migraine surgery with changes in patients' selection throughout the years.

Conclusion

Patients with migraine headaches who do not respond or cannot tolerate the medical treatment might benefit from trigger site deactivation surgery. The success of the surgery is closely related to proper identification of trigger point (s) and close collaboration with a neurologist or a headache specialist. This collaboration would enhance patients' positive outcomes and help to rule out other causes of the headache.

The Paramedian Forehead Flap: A Retrospective Clinical Model for Understanding the Connection Between Supraorbital and Supratrochlear Nerve Pathology and Headaches

Background:

In the later stages of a paramedian forehead flap (PMFF) surgery, the supratrochlear (STN) and branches of the supraorbital nerve (SON) are transected during flap inset above the supraorbital rim. This can lead to either a nerve release if the compression point was previously distal to the transection point or a new nerve compression through neuroma or scar tissue formation. We inferred that PMFF could be a model for understanding the correlation between STN/SON pathology and migraines headaches (MH). We hypothesized that patients undergoing PMFF would experience either a change in severity or an onset of a new headache (HA) or MH.

Methods:

One hundred ninety-nine patients who underwent a PMFF at a tertiary medical centre were identified and contacted by phone. Patients were asked about the presence of MH or HA before and after the procedure. If a patient reported a perioperative history of MH/HA, their pre- and postoperative MH/HA characteristics were recorded.

Results:

Of the 199 patients contacted, 74 reported no perioperative HA/MH history and 14 reported a perioperative history of HA/MH. Of these 14 patients, 5 had stable HA/MH pre- and post-surgery, and 9 reported a change in HA/MH post-surgery. In this subset of 9 patients, 3 reported change in HA/MH quality post-surgery, 1 reported HA/MH resolution post-surgery, and 5 reported new onset HA/MH post-surgery.

Conclusion:

Sixty-four percent of patients with perioperative HA/MH experienced a change in headache quality following surgery. These results suggest a potential connection between SON and STN pathology and HA/MH pathophysiology; further work is warranted.

Characterizing the providers of and reimbursement for chronic migraine chemodenervation among the Medicare population

OBJECTIVE

To characterize reimbursement trends and providers for chronic migraine (CM) chemodenervation treatment within the Medicare population since the introduction of the migraine-specific CPT code in 2013.

METHODS

We describe trends in procedure volume and total allowed charge on cross-sectional data obtained from 2013 to 2018 Medicare Part B National Summary files. We also utilized the 2017 Medicare Provider Utilization and Payment Data to analyze higher volume providers (>10 procedures) of this treatment modality.

RESULTS

The total number of CM chemodenervation treatments rose from 37,863 in 2013 to 135,023 in 2018 in a near-linear pattern (r = 0.999) and total allowed charges rose from ~$5,217,712 to $19,166,160 (r = 0.999). The majority of high-volume providers were neurologists (78.4%; 1060 of 1352), but a substantial proportion were advanced practice providers (APPs) (10.2%; 138 of 1352). Of the physicians, neurologists performed a higher mean number of procedures per physician compared to non-neurologists (59.6 [95% CI: 56.6-62.6] vs. 45.4 [95% CI: 41.0-50.0], p < 0.001). When comparing physicians and APPs, APPs were paid significantly less ($146.5 [95% CI: $145.6-$147.5] vs. $119.7 [95% CI: $117.6-$121.8], p < 0.001). As a percent of the number of total beneficiaries in each state, the percent of Medicare patients receiving ≥1 CM chemodenervation treatment from a high-volume provider in 2017 ranged from 0.024% (24 patients of 98,033 beneficiaries) in Wyoming to 0.135% (997 of 736,521) in Arizona, with six states falling outside of this range.

CONCLUSION

Chemodenervation is an increasingly popular treatment for CM among neurologists and other providers, but the reason for this increase is unclear. There is substantial geographic variation in its use.

Botulinum Toxin in the Treatment of Headache

Botulinum toxin type A has been used in the treatment of chronic migraine for over a decade and has become established as a well-tolerated option for the preventive therapy of chronic migraine. Ongoing research is gradually shedding light on its mechanism of action in migraine prevention. Given that its mechanism of action is quite different from that of the new monoclonal antibodies directed against calcitonin gene-related peptide (CGRP) or its receptor, it is unlikely to be displaced to any major extent by them. Both will likely remain as important tools for patients with chronic migraine and the clinicians assisting them. New types of botulinum toxin selective for sensory pain neurons may well be discovered or produced by recombinant DNA techniques in the coming decade, and this may greatly enhance its therapeutic usefulness. This review summarizes the evolution of botulinum toxin use in headache management over the past several decades and its role in the preventive treatment of chronic migraine and other headache disorders.

Postmarketing safety surveillance data reveals antidepressant effects of botulinum toxin across various indications and injection sites

The World Health Organization estimates the number of people suffering from depression to be over 264 million. Current monoamine transmission modulating therapeutics, even with proper adherence and acceptable tolerability, are not effective for nearly one third of the patients, leading clinicians to explore other therapeutic options such as electroconvulsive therapy, transcranial magnetic stimulation, ketamine infusions, and, more recently, glabellar botulinum toxin, BoNT, injections. The scale and mechanism of antidepressant action of BoNT is unclear and maybe hypothetically attributed to the disruption of proprioceptive facial feedback reinforcing negative emotions. Here we verify the antidepressant effect of botulinum toxin by analysis of over 40 thousand BoNT treatment reports out of thirteen million postmarketing safety reports in the FDA Adverse Event Reporting System, FAERS. The results of the analysis indicate that patients who received BoNT injections to treat hyperhidrosis, facial wrinkles, migraine prophylaxis, spasticity, and spasms, had a significantly lower number of depression reports when compared to patients undergoing different treatments for the same conditions. These findings suggest that the antidepressant effect of BoNT is significant, and, surprisingly, is observed for a broad range of injection sites.

OnabotulinumtoxinA injection in the treatment of chronic migraine

The earliest descriptions of botulism were in the early 19th century, and was reported by the German physician Justinus Kerner. The term "botulism" was derived from the Latin word botulus, indicating its original association with sausages. It took another 150 years or so to come into clinical use. The first clinical application was strabismus, and was developed by the American ophthalmologist Alan B. Scott, whose effort led to the pharmaceutical product known as onabotulinumtoxinA today. The therapeutic benefit in migraine was an incidental finding in a report by the American plastic surgeon William J. Binder, which inspired a series of clinical studies in headache disorders. The doses and injection techniques in the earlier reports were variable, so were the results. It was until the Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) 1 and 2 studies when its efficacy and safety, as well as the indication, i.e., chronic migraine (CM), were ascertained. Even though there were criticisms regarding the heterogeneities in the results between the PREEMPT 1 and 2 studies, the data on efficacy endpoints and safety were generally consistent, which were subsequently confirmed by the open-label extension of the PREEMPT 1 and 2 studies, and three open-label studies, namely the Chronic Migraine OnabotulinuMtoxinA Prolonged Efficacy open Label (COMPEL), the REal-life use of botulinum toxin for the symptomatic treatment of adults with chronic migraine, measuring healthcare resource utilization, and Patient-reported OutcomeS observed in practice (REPOSE) studies, and the CM Post-Authorization Safety Study (CM PASS) studies. On the other hand, the results were challenged by the Chronification and Reversibility of Migraine (CHARM) study, which involved CM patients with medication overuse. It was concluded that the clinical improvement was attributed to early withdrawal of the overused acute medications, rather than onabotulinumtoxinA injections. However, fundamental differences in the patient profile and methodology between the CHARM and PREEMPT studies existed, and cautious should be exercised when interpreting and comparing the results. According to the practical guidelines and reimbursement regulations in many countries, its use is limited to CM patients, and is reserved for those who fail at least 2-3 preventive medications, due to either lack of efficacy or intolerability. Cessation of treatment is recommended in patients who do not respond to 2-3 injection cycles, or in patients whose headache frequency has dropped to <10-15 days a month. Even in the era of calcitonin-gene-related peptide monoclonal antibodies, onabotulinumtoxinA injection remains a treatment option of reasonable cost-effectiveness in carefully selected patients.

Mechanism of Action of OnabotulinumtoxinA in Chronic Migraine: A Narrative Review

Objective

To review the literature on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Background

OnabotulinumtoxinA is a chronic migraine preventive treatment that significantly reduces headache frequency. The traditional mechanism described for onabotulinumtoxinA – reducing muscle contractions – is insufficient to explain its efficacy in migraine, which is primarily a sensory neurological disease.

Methods

A narrative literature review on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Results

Following injection into tissues, onabotulinumtoxinA inhibits soluble N‐ethylmaleimide‐sensitive fusion attachment protein receptor (SNARE)‐mediated vesicle trafficking by cleaving one of its essential proteins, soluble N‐ethylmaleimide‐sensitive fusion attachment protein (SNAP‐25), which occurs in both motor and sensory nerves. OnabotulinumtoxinA inhibits regulated exocytosis of motor and sensory neurochemicals and proteins, as well as membrane insertion of peripheral receptors that convey pain from the periphery to the brain, because both processes are SNARE dependent. OnabotulinumtoxinA can decrease exocytosis of pro‐inflammatory and excitatory neurotransmitters and neuropeptides such as substance P, calcitonin gene‐related peptide, and glutamate from primary afferent fibers that transmit nociceptive pain and participate in the development of peripheral and central sensitization. OnabotulinumtoxinA also decreases the insertion of pain‐sensitive ion channels such as transient receptor potential cation channel subfamily V member 1 (TRPV1) into the membranes of nociceptive neurons; this is likely enhanced in the sensitized neuron. For chronic migraine prevention, onabotulinumtoxinA is injected into 31‐39 sites in 7 muscles of the head and neck. Sensory nerve endings of neurons whose cell bodies are located in trigeminal and cervical ganglia are distributed throughout the injected muscles, and are overactive in people with migraine. Through inhibition of these sensory nerve endings, onabotulinumtoxinA reduces the number of pain signals that reach the brain and consequently prevents activation and sensitization of central neurons postulated to be involved in migraine chronification.

Conclusion

OnabotulinumtoxinA likely acts via sensory mechanisms to treat chronic migraine.

New Engineered-Botulinum Toxins Inhibit the Release of Pain-Related Mediators

Targeted delivery of potent inhibitor of cytokine/pain-mediator into inflammatory or pain-sensing cells is a promising avenue for treating chronic pain, a world-wide major healthcare burden. An unmet need exists for a specific and effective delivery strategy. Herein, we describe a new approach using sortase to site-specifically ligate a non-toxic botulinum neurotoxin D (BoNT/D) core-therapeutic (synaptobrevin-cleaving protease and translocation domains) to cell-specific targeting ligands. An engineered core-therapeutic was efficiently ligated to IL-1β ligand within minutes. The resultant conjugate specifically entered into cultured murine primary macrophages, cleaved synaptobrevin 3 and inhibited LPS/IFN-γ evoked IL-6 release. Likewise, a CGRP receptor antagonist ligand delivered BoNT/D protease into sensory neurons and inhibited K⁺-evoked substance P release. As cytokines and neuropeptides are major regulators of inflammation and pain, blocking their release by novel engineered inhibitors highlights their therapeutic potential. Our report describes a new and widely-applicable strategy for the production of targeted bio-therapeutics for numerous chronic diseases.

Application of botulinum toxin in pregnancy and its impact on female reproductive health

Introduction: Botulinum toxin (BoNT) is a protein secreted by the anaerobic Gram-negative bacterium Clostridium botulinum. Among the seven known subtypes, type A is the most commonly used in women to treat diseases. It primarily blocks presynaptic release of acetylcholine at the neuromuscular junction, resulting in temporary muscle paralysis; thus, it is suitable for treating dystonia and other systemic diseases. BoNT is used widely for treating diseases that persist throughout, and may worsen during, pregnancy, such as cervical dystonia and achalasia. Thus, it is important to investigate whether BoNT injection during pregnancy causes side effects in pregnant women, fetuses, or newborns.Areas covered: This review highlights the efficiency and safety of BoNT injection in pregnancy. and assessed current literature with respect to the use of BoNT for disease treatment during pregnancy.Expert opinion: BoNT injection does not increase the risk of complications in pregnant women and fetuses. However, the use of BoNT to treat disease during pregnancy requires fully informed consent from patients. In addition, further research is needed to determine how to reduce the side effects of BoNT injection during pregnancy (e.g., by improving drug composition, or adjusting the amount of BoNT or the injection interval).

Application of botulinum toxin in maxillofacial field: Part II. Wrinkle, intraoral ulcer, and cranio-maxillofacial pain

Botulinum toxin (BTX) is used in various ways such as temporarily resolving muscular problems in musculoskeletal temporomandibular disorders, inducing a decrease in bruxism through a change in muscular patterns in a patient’s bruxism, and solving problems in patients with tension headache. And also, BTX is widely used in cosmetic applications for the treatment of facial wrinkles after local injection, but conditions such as temporomandibular joint disorders, headache, and neuropathic facial pain could be treated with this drug. In this report, we will discuss the clinical use of BTX for facial wrinkle, intraoral ulcer, and cranio-maxillofacial pain with previous studies and share our case.

Botulinum Toxin a Valuable Prophylactic Agent for Migraines and a Possible Future Option for the Prevention of Hormonal Variations-Triggered Migraines

BACKGROUND

In 1989, Botulinum toxin (BoNT) was accepted by the FDA for the management of some ophthalmic disorders. Although it was initially considered a lethal toxin, in recent times, Botulinum toxin A (BoNT-A), which is the more used serotype, has expanded to cover different clinical conditions, primarily characterized by neuropathic pain, including migraines and headaches. Evidence suggests that migraines are influenced by hormonal factors, particularly by estrogen levels, but very few studies have investigated the prevalence and management strategies for migraines according to the hormonal status. The effects of several therapeutic regimens on migraines have been investigated, but the medications used varied widely in proven efficacies and mechanisms of action. BoNT-A is increasingly used in the management of migraine and several placebo-controlled trials of episodic and chronic migraine are currently underway. This paper is a review of the recently published data concerning the administration of BoNT-A in the prevention of chronic migraines. Considering the lack of population-based studies about the effectiveness of BoNT-A in the alleviation of premenstrual and perimenopausal migraines, this study proposes a new perspective of the therapeutic approach of migraine syndrome associated with menopausal transition and the premenstrual period.

METHODS

We selected the reviewed papers from CrossRef, PubMed, Medline, and GoogleScholar, and a total of 21 studies met our inclusion criteria.

RESULTS

To date, no specific preventive measures have been recommended for menopausal women with migraines. BoNT-A often reduces the frequency and intensity of migraine attacks per month; the treatment is well tolerated and does not exhibit a significantly higher rate of treatment-related side effects. No population-based studies were conducted in order to highlight the role of BoNT-A in menopause-related migraines, neither in menstrual migraines.

CONCLUSION

There is a need for further research in order to quantify the real burden of menstrual and perimenopausal migraines and to clarify if BoNT-A could be used in the treatment of refractory postmenopausal and premenstrual migraines.

A Critical Review of Botulinum Toxin Type A in the Prophylactic Treatment of Chronic Migraine in Adults

BACKGROUND

Migraine is a severe, disabling condition, ranked by World Health Organization as the sixth highest cause of disability worldwide. It greatly affects patients' quality of life, functionality, and physical and mental health. The financial burden of migraine on the UK economy is conservatively estimated at £3.42 billion per year.

OBJECTIVES

The authors sought to perform an evidence-based literature review of the safety and efficacy of botulinum toxin type A (onaBoNTA) in the prophylactic treatment of adult patients suffering with chronic migraine (CM) compared to placebo. After the best evidence is identified, it will be utilized to formulate a protocol for doctors managing CM in their aesthetic clinic.

METHODS

A comprehensive search of the current literature on the topic was performed by H.M. using Pubmed MEDLINE electronic database on March 1, 2018. All articles up to and inclusive of this date were included. Articles were limited to human studies and those in the English language. In vitro and animal studies were excluded.

RESULTS

A total of 260 articles were identified. Of these, the excellent-quality, high-strength (level 1A) trials were short-listed to answer the research question.

CONCLUSIONS

There is high-quality, level 1A evidence to support onaBoNTA treatment in adults with CM is well tolerated and considered safe. However, it is associated with increased risk of adverse events and still some uncertainty exists associated with the degree onaBoNTA improves outcome measures compared to placebo. These data have been used to formulate The London Aesthetic Migraine Protocol (LAMP) to provide safe, evidence-based guidance for appropriately trained and experienced aesthetic practitioners to manage CM in their aesthetic clinics.

LEVEL OF EVIDENCE: 1

Ultrasound-guided greater occipital nerve block with botulinum toxin for patients with chronic headache in the occipital area: a randomized controlled trial

Background

Ultrasound-guided greater occipital nerve (GON) block has been frequently used to treat various types of headaches, and botulinum toxin has recently begun to be used in patients with headache. Our study presents the long-term effect of botulinum toxin on GON block using ultrasound in patients with chronic headache in occipital area.

Methods

Patients with occipital headache were divided into two groups (bupivacaine: BUP group [n = 27], botulinum toxin: BTX group [n = 27]), and ultrasound-guided GON block was performed at the C2 level. GON was detected with ultrasound and distance from GON to midline, from the skin surface to GON, and size of GON were measured in both groups. Visual analogue scale (VAS) scores and Likert scale were assessed at pretreatment and at 1, 4, 8, and 24 weeks after treatment in both groups.

Results

The distance from GON to midline was 18.9 ± 4.4 mm (right) and 17.3 ± 3.8 mm (left). The depth from the skin was 12.9 ± 1.5 mm (right) and 13.4 ± 1.6 mm (left). GON size was 3.1 mm on both sides. The VAS score and patient satisfaction score (Likert scale) in 4, 8, and 24 weeks after injection were superior for the BTX than the BUP group.

Conclusions

Ultrasound-guided GON block using BTX is effective in reducing short-term and long-term pain in patients with chronic headache in the occipital area.

OnabotulinumtoxinA injections: treatment of reversible cerebral vasoconstriction syndrome chronic daily headaches

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare condition characterised by repetitive, multifocal, vasofluctuations of cerebral arteries. A key symptom is chronic, disabling ‘thunderclap’ headaches, which are extremely difficult to treat as established medications may exacerbate the pathophysiology of RCVS. OnabotulinumtoxinA (OBT-A) injections are used for the prophylaxis of chronic daily headaches (CDH). The mechanism of action of OBT-A significantly differs from oral headache treatments. Thus, OBT-A may be an effective, safe treatment of RCVS-CDH. A 51-year-old woman with RCVS-CDH presented to outpatient clinic. This case report describes the first, believed, documented treatment of RCVS-CDH by OBT-A injections. In 2018, the consented patient received a total of 200 units of OBT-A, 155 units to the 31 approved U.S. Food and Drug Administration (FDA) sites and 45 units injected into the bilateral occipital belly of occipitofrontalis muscles. The patient reported 3 months of excellent pain relief (60% reduction). Three rounds of OBT-A injection, each 3 months apart, resulted in 80% reduction. OBT-A injections may prove a successful, novel treatment for RCVS-CDH.

Entrapment Neuropathy: A Concept for Pathogenesis and Treatment of Headaches-A Narrative Review

Entrapment neuropathy is a known cause of neurological disorders. In the head and neck area, this pathophysiological mechanism could be a trigger for headache. Over the last few decades, injection of botulinum toxin type A in the muscles that are causing the compression as well as surgical decompression have proved to be effective treatment methods worldwide for large numbers of patients with daily headaches. In particular the entrapment of the supraorbital nerves in the glabellar musculature and the occipital nerves in the neck musculature are triggers for headache disorders for which many patients are still seeking an effective treatment. This article reviews the literature and aims to bring the concept of neural entrapment to the attention of a wider audience. By doing so, we hope to give more exposure to an effective and relatively safe headache treatment.

Botulinum Neurotoxin Light Chains Expressed by Defective Herpes Simplex Virus Type-1 Vectors Cleave SNARE Proteins and Inhibit CGRP Release in Rat Sensory Neurons

A set of herpes simplex virus type 1 (HSV-1) amplicon vectors expressing the light chains (LC) of botulinum neurotoxins (BoNT) A, B, C, D, E and F was constructed. Their properties have been assessed in primary cultures of rat embryonic dorsal root ganglia (DRG) neurons, and in organotypic cultures of explanted DRG from adult rats. Following infection of primary cultures of rat embryonic DRG neurons, the different BoNT LC induced efficient cleavage of their corresponding target Soluble N-ethylmaleimide-sensitive-factor Attachment protein Receptor (SNARE) protein (VAMP, SNAP25, syntaxin). A similar effect was observed following infection by BoNT-A LC of organotypic cultures of adult rat DRG. To quantify and compare the functional activities of the different BoNT LC, the inhibition of calcitonin gene-related protein (CGRP) secretion was assessed in DRG neurons following infection by the different vectors. All BoNT-LC were able to inhibit CGRP secretion although to different levels. Vectors expressing BoNT-F LC displayed the highest inhibitory activity, while those expressing BoNT-D and -E LC induced a significantly lower CGRP release inhibition. Cleavage of SNARE proteins and inhibition of CGRP release could be detected in neuron cultures infected at less than one transducing unit (TU) per neuron, showing the extreme efficacy of these vectors. To our knowledge this is the first study investigating the impact of vector-expressed transgenic BoNT LC in sensory neurons.

The role of the otolaryngologist in the evaluation and management of headaches

BACKGROUND

Headaches are commonly evaluated in otolaryngology and often represent a diagnostic dilemma. This review addresses rhinogenic headache as well as trigeminal neuralgia and migraine, both of which can masquerade as sinus headache and whose management increasingly involves otolaryngology intervention. Discussion considers diagnostic criteria and novel therapies and derives an algorithm for clinical decision-making.

DATA SOURCES

OVID MEDLINE, Cochrane Library, and Google Scholar databases.

METHODS

A literature search was performed to identify relevant articles published in the past 10 years addressing the diagnosis and management of rhinogenic headache, trigeminal neuralgia and/or migraine.

FINDINGS

Rhinogenic headache: Identification of the specific cause must be achieved before treatment. No studies have mentioned the effect of certain therapies on the amelioration of headache. New techniques of balloon dilation for sinusitis are controversial, and their use remains contingent on surgeon preference. Removal of mucosal contact points has been shown to benefit quality of life in patients with contact point headache. Trigeminal neuralgia: Microvascular decompression is considered the gold standard for treatment, but percutaneous therapies can be effective for achieving pain control. Migraine: Patients who report amelioration of symptoms after targeted botulinum toxin injection may benefit from definitive decompression or nerve avulsion. Patients with mucosal contact points may have less favorable outcomes with migraine surgery if they are not simultaneously addressed.

CONCLUSIONS

A comprehensive understanding of the diagnostic workup and therapeutic options available for common headache etiologies is key to the management of a patient presenting with headache attributed to a rhinogenic cause.

Evaluation of OnabotulinumtoxinA Treatment in Patients with Concomitant Chronic Migraine and Temporomandibular Disorders

Introduction

Migraine and temporomandibular disorders (TMD) are both common diseases and TMD are reported as a risk factor in migraine progression. OnabotulinumtoxinA is used in the treatment of chronic migraine (CM), and also has a potential role in TMD treatment. In this study, it is aimed to compare the efficacy of onabotulinumtoxinA treatment in CM patients with and without TMD.

Methods

In this retrospective study, 30 CM patients (age range: 18-65 years), satisfying the inclusion and follow-up criteria in their medical records were investigated. The PREEMPT injection protocol was taken as reference and onabotulinumtoxinA 155-195 U with fixed-dose has been administered into 31 specific sites within the head/neck muscles in included subjects. Two cycles of treatment were assessed in all patients at the baseline and 12 weeks later. The headache diaries, which were completed routinely one month before, and during 6 months follow-up after the treatment, were assessed. The effect of onabotulinumtoxinA treatment was compared between CM patients with and without TMD/bruxism.

Results

Of 30 female patients, 17 had concomitant TMD. In week 24, there were significant improvement in the groups with and without TMD regarding to the mean change of frequencies in the days with migraine compared to the initial findings (p<0.001). However, there was no significant difference between the two groups.

Conclusions

OnabotulinumtoxinA is an effective and safe treatment for CM. Its efficacy appears to be similar in CM patients with and without TM, speculating that the comorbidity of TMD did not play a role for the treatment response.

Botulinum toxin: A review of the mode of action in migraine

Botulinum toxin serotype A (BoNT/A) was originally used in neurology for the treatment of dystonia and blepharospasms, but is now clinically used worldwide for the treatment of chronic migraine. Still, the possible mode of action of BoNT/A in migraine is not fully known. However, the mode of action of BoNT/A has been investigated in experimental pain as well as migraine models, which may elucidate the underlying mechanisms in migraine. The aim of this study was to review studies on the possible mode of action of BoNT/A in relation to chronic migraine treatment. Observations suggest that the mode of action of BoNT/A may not be limited to the injection site, but also includes anatomically connected sites due to axonal transport. The mechanisms behind the effect of BoNT/A in chronic migraine may also include modulation of neurotransmitter release, changes in surface expression of receptors and cytokines as well as enhancement of opioidergic transmission. Clinical and experimental studies with botulinum toxin in the last decade have advanced our understanding of headache and other pain states. More research into botulinum toxin as treatment for headache is warranted as it can be an attractive alternative for patients who do not respond positively to other drugs.

Botulinum Toxin Type A-A Modulator of Spinal Neuron-Glia Interactions under Neuropathic Pain Conditions

Neuropathic pain represents a significant clinical problem because it is a chronic condition often refractory to available therapy. Therefore, there is still a strong need for new analgesics. Botulinum neurotoxin A (BoNT/A) is used to treat a variety of clinical diseases associated with pain. Glia are in continuous bi-directional communication with neurons to direct the formation and refinement of synaptic connectivity. This review addresses the effects of BoNT/A on the relationship between glia and neurons under neuropathic pain. The inhibitory action of BoNT/A on synaptic vesicle fusion that blocks the release of miscellaneous pain-related neurotransmitters is known. However, increasing evidence suggests that the analgesic effect of BoNT/A is mediated through neurons and glial cells, especially microglia. In vitro studies provide evidence that BoNT/A exerts its anti-inflammatory effect by diminishing NF-κB, p38 and ERK1/2 phosphorylation in microglia and directly interacts with Toll-like receptor 2 (TLR2). Furthermore, BoNT/A appears to have no more than a slight effect on astroglia. The full activation of TLR2 in astroglia appears to require the presence of functional TLR4 in microglia, emphasizing the significant interaction between those cell types. In this review, we discuss whether and how BoNT/A affects the spinal neuron–glia interaction and reduces the development of neuropathy.

Evidence to Use Botulinum Toxin Injections in Tension-Type Headache Management: A Systematic Review

Tension-type headache (TTH) is the most common type of chronic recurring head pain. It can occur twice as often in women as in men. It is the most common type of headache. Its lifetime prevalence is 30% to 78% in the general population. TTH treatment should be multilevel. It often consists of taking pain medication, muscle relaxants, antidepressants, using biofeedback therapy, acupuncture, and attending behavioral therapy. Several clinical trials also suggest that botulinum toxin (BTX) may be an effective treatment option for such patients. The aim of this study was to evaluate if BTX can be used as a treatment method in TTH in the light of current medical literature. The authors searched the PubMed, EBSCOhost, OVID, Web of Knowledge, Cochrane Library and CINAHL databases to identify relevant publications. The authors finally included 11 papers-prospective and retrospective cohort studies. Among most of the selected studies, there was a significant correlation between using BTX and reduction of TTH pain intensity and severity. By analyzing qualified studies, it can be concluded that botulinum toxin seems to be effective in TTH management.

Onabotulinum toxin A in the treatment of chronic migraine: patient selection and special considerations

Discovered by serendipity, onabotulinum toxin A (BoNT-A) is the only US Food and Drug Administration-approved treatment for the prevention of chronic migraine (CM), one of the most disabling and burdensome human conditions. Its efficacy, safety and tolerability, proved by the largest and longest migraine therapeutic trial (the Phase III Research Evaluating Migraine Prophylaxis Therapy program [PREEMPT]), have been replicated by various real-life studies also in the presence of medication overuse. The benefit of BoNT-A prophylaxis is likely due to its ability to counteract peripheral and central nociceptive sensitization through reversible chemical denervation of pericranial sensitive afferents. Its efficacy increases considerably over time during long-term treatments, significantly varying among patients. The present review focuses on the state-of-the art of current knowledge on putative instrumental, biochemical and clinical predictors of BoNT-A responsiveness, outlining the need for a thorough characterization of the full phenotypic migraine picture when trying to predict good responders. Available evidence suggests that disentangling the BoNT-A responsiveness puzzle requires 1) a reappraisal of easy-obtainable clinical details (eg, site and quality of pain, presence of cranial autonomic symptoms), 2) a proper stratification of patients with CM according to their headache frequency, 3) the evaluation of potential synergistic effects of concomitant prophylaxis/treatment and 4) a detailed assessment of modifiable risk factors evolution during treatment.

Insights into the Functional Anatomy Behind the PREEMPT Injection Paradigm: Guidance on Achieving Optimal Outcomes

OBJECTIVE

To provide clinically relevant insights on the identification of the muscles and techniques involved in the safe and effective use of onabotulinumtoxinA for chronic migraine prophylaxis.

BACKGROUND

Although guidance on the use of onabotulinumtoxinA for chronic migraine is available, based on the Phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) clinical program, clinical experience has shown that insufficient understanding of the anatomy and function of the head and neck muscles may lead to undesirable outcomes and suboptimal efficacy.

DESIGN/METHODS

Each muscle involved in the standardized PREEMPT injection paradigm is reviewed with a thorough description of each muscle's anatomy (ie, muscle description and location, innervation, vascular supply) and function. Key insights based on clinical experience are also provided to help improve outcomes.

RESULTS

The identification of the muscles in the PREEMPT injection paradigm should be based on each patient's unique anatomy and injections should be administered using the advised techniques. A thorough examination of the patient prior to treatment is also critical to determine if any preexisting conditions may increase the risk for unwanted outcomes and appropriate expectations should be communicated.

CONCLUSIONS

Thorough knowledge of the functional anatomy of the muscles involved in the standardized PREEMPT injection paradigm is critical to achieve the efficacy and safety observed in clinical trials. In addition, it is important to assess a patient's baseline condition to anticipate the risk for unwanted outcomes that may result from treatment.

Botulinum toxin in the management of chronic migraine: clinical evidence and experience

Chronic migraine (CM) is a severely disabling neurological condition characterized by episodes of pulsating unilateral or bilateral headache. The United States Food and Drug Administration (FDA) approved onabotulinumtoxinA (Botox®) for the prophylactic treatment of CM in 2010. It has been shown that onabotulinumtoxinA is effective in the reduction of headache frequency and severity in patients with CM. Treatment is well tolerated by the patients. This review reports on the history of botulinum neurotoxin (BoNT) in CM and presents the current clinical evidence for the use of onabotulinumtoxinA in the treatment of CM.

Botulinum Toxin a for Chronic Daily Headache: A Randomized, Placebo-Controlled, Parallel Design Study

Sixty patients with headaches of more than 15 days per month were recruited for this double-blind, placebo-controlled, parallel study of botulinum toxin type A (BTX) for chronic tension type and chronic migraine headaches. The primary efficacy point was the number of headache-free days as assessed by diary for 12 weeks after BTX injection. Secondary efficacy points included global impressions, the use of abortive headache medications, and palpation. After recruitment, subjects kept diaries for 4 weeks prior to randomization, at which time they received either 200 U of BTX or matching placebo and were followed. After the week-12 evaluation, patients were offered 200 U of BTX (open label), and were similarly followed for another 12 weeks. The mean days with headache of the 60 subjects (49 female, mean age 47 ± 11 years) was 23 ± 7 out of 30. Both groups were demographically similar (58 completed). Over a 12-week period after injections, headache-free days had improved in the BTX group from week 8 to 12 ( P < 0.05), and strongly tended to improve over the entire 12-week period, 33 ± 23 vs. 24 ± 16 days without headache ( P = 0.07), but did not meet the a priori significance criteria. The subject global impressions ( P < 0.05), subject change in headache impressions ( P < 0.005), and investigator global impressions ( P < 0.001) all improved in the BTX group compared with placebo. Adverse events were mild and did not differ between groups. At week 24 (open label), headache-free days were less in the twice BTX injected group compared with the once injected group, 40 ± 26 vs. 26 ± 19 ( P < 0.05). BTX may help chronic daily headache and appears to have a cumulative effect with subsequent injections. The treatment was very well tolerated.

Neuralgias of the Head: Occipital Neuralgia

Occipital neuralgia is defined by the International Headache Society as paroxysmal shooting or stabbing pain in the dermatomes of the greater or lesser occipital nerve. Various treatment methods exist, from medical treatment to open surgical procedures. Local injection with corticosteroid can improve symptoms, though generally only temporarily. More invasive procedures can be considered for cases that do not respond adequately to medical therapies or repeated injections. Radiofrequency lesioning of the greater occipital nerve can relieve symptoms, but there is a tendency for the pain to recur during follow-up. There also remains a substantial group of intractable patients that do not benefit from local injections and conventional procedures. Moreover, treatment of occipital neuralgia is sometimes challenging. More invasive procedures, such as C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, neurectomy, and neurolysis with or without sectioning of the inferior oblique muscle, are now rarely performed for medically refractory patients. Recently, a few reports have described positive results following peripheral nerve stimulation of the greater or lesser occipital nerve. Although this procedure is less invasive, the significance of the results is hampered by the small sample size and the lack of long-term data. Clinicians should always remember that destructive procedures carry grave risks: once an anatomic structure is destroyed, it cannot be easily recovered, if at all, and with any destructive procedure there is always the risk of the development of painful neuroma or causalgia, conditions that may be even harder to control than the original complaint.

Long-term treatment of chronic migraine with OnabotulinumtoxinA: efficacy, quality of life and tolerability in a real-life setting

Botulinum toxin was shown to be effective in treatment of chronic migraine. We wanted to explore its efficacy and tolerability in chronic application under real-life conditions. For this, 27 consecutive patients (age 45.6 ± 10.8 years, 25 females, 2 males) received altogether 176 injection series (IS) with 189.7 ± 45.8MU onabotulinumtoxinA (Botox(®)) according to the PREEMPT scheme. During the study period altogether 6.5 ± 2.9 (min 4, max 13) IS were applied per patient (total treatment time of 73.1 ± 36.9 weeks). 96 % of the patients reported benefit. Monthly headache days were reduced from 18.9 ± 3.9 to 8.7 ± 4.5 (p < 0.001, -53.7 %), migraine days from 16.8 ± 4.9 to 7.4 ± 4.6 (p < 0.001, -55.1 %), autonomic days from 8.6 ± 7.5 to 2.7 ± 4.2 (p < 0.001, -71.9 %) and medication days from 14.2 ± 4.6 to 8.3 ± 4.2 (p < 0.001, -71.1 %). Health-related quality of life improved by 0.6-1.5 standard deviations (SD) (Short Form Health Survey), migraine-related quality of life by 1.4-2.0 SD (Migraine-Specific Quality of Life Questionnaire) and by 1.9 SD (Headache Impact Test), depression by 1.1 SD (Beck Depression Inventory). Subjective global clinical improvement was 2.6 ± 0.6 (Global Clinical Improvement Scale). All improvements were stable throughout the entire study period. Adverse effects were infrequent, mild and transient. Botulinum toxin provides highly effective and safe long-term treatment of chronic migraine.