Meta-analysis of neutralizing antibody conversion with onabotulinumtoxinA (BOTOX®) across multiple indications

Update on Non-Interchangeability of Botulinum Neurotoxin Products

The growing use of botulinum neurotoxins (BoNTs) for medical and aesthetic purposes has led to the development and marketing of an increasing number of BoNT products. Given that BoNTs are biological medications, their characteristics are heavily influenced by their manufacturing methods, leading to unique products with distinct clinical characteristics. The manufacturing and formulation processes for each BoNT are proprietary, including the potency determination of reference standards and other features of the assays used to measure unit potency. As a result of these differences, units of BoNT products are not interchangeable or convertible using dose ratios. The intrinsic, product-level differences among BoNTs are compounded by differences in the injected tissues, which are innervated by different nerve fiber types (e.g., motor, sensory, and/or autonomic nerves) and require unique dosing and injection sites that are particularly evident when treating complex therapeutic and aesthetic conditions. It is also difficult to compare across studies due to inherent differences in patient populations and trial methods, necessitating attention to study details underlying each outcome reported. Ultimately, each BoNT possesses a unique clinical profile for which unit doses and injection paradigms must be determined individually for each indication. This practice will help minimize unexpected adverse events and maximize efficacy, duration, and patient satisfaction. With this approach, BoNT is poised to continue as a unique tool for achieving individual goals for an increasing number of medical and aesthetic indications.

Microtoxin for Improving Pore Size, Skin Laxity, Sebum Control, and Scars: A Roundtable on Integrating Intradermal Botulinum Toxin Type A Microdoses Into Clinical Practice

BACKGROUND

In aesthetic clinical practice, botulinum toxin type A (BoNT-A) is best known for its use as a neuromodulator for the treatment of dynamic facial lines; however, when injected intradermally as microdroplets, BoNT-A can improve skin quality and overall skin appearance.

OBJECTIVES

To discuss key aspects of microtoxin use in clinical practice and provide expert guidance on utilization.

METHODS

As part of a continuing medical education lecture series and roundtable, the authors discussed key aspects of microtoxin patient selection, injection technique, and safety.

RESULTS

The experiences of expert faculty are shared here. Clinical experience is consistent with reported data. Microtoxin can be used to reduce pore size, sebum production, rosacea, acne, and fine lines, and to improve jawline and neck definition. Intradermal injection can also be employed for the improvement of transverse neck lines as well as for the safe prevention and management of scars and keloids.

CONCLUSIONS

Expanding the use of BoNT-A, a predictable, minimally invasive, and affordable treatment to address commonly encountered complaints is appealing. The authors have found that making patients aware of microtoxin as a treatment option results in an increased interest in and utilization of BoNT-A, and high satisfaction among appropriately selected patients.

Treatment of glabellar lines with Botox (onabotulinumtoxinA): Development, insights, and impact

OnabotulinumtoxinA is an injectable medication that produces muscle relaxation through local chemical denervation at the neuromuscular junction. Discovery of onabotulinumtoxinA's aesthetic benefits occurred serendipitously in the 1980s at the intersection of several medical disciplines, including ophthalmology, neurology, otolaryngology, and dermatology. Patients receiving onabotulinumtoxinA for blepharospasm, hemifacial spasm, and dystonia noticed their periorbital wrinkles disappearing, particularly frown lines between the eyebrows called glabellar lines (GL). Aesthetic use of onabotulinumtoxinA necessitated rigorous training programs and vigilant monitoring by Allergan. Approval for the GL indication was based on 2 similarly designed, double-blind, randomized, multicenter clinical studies. Subjects with moderate to severe GL receiving onabotulinumtoxinA achieved significantly greater improvement in GL severity than those receiving placebo. In subsequent studies, more than 80% of subjects were satisfied with onabotulinumtoxinA treatment through day 60, and many reported looking approximately 4 years younger at weeks 4 and 12 than at baseline. OnabotulinumtoxinA has a rapid onset of action, and peak effect occurs between 30 and 60 days. The median duration of response for dynamic GL in the initial studies was 120 days and response progressively improved with subsequent treatments. OnabotulinumtoxinA was well tolerated, and the 2 most common adverse events, headache and blepharoptosis, tended to decrease in frequency with repeat treatment. The novel use of onabotulinumtoxinA for treating GL was an important step in addressing the clinical need for a noninvasive, straightforward, office-based procedure for facial lines that also left patients extremely satisfied with its treatment effects and represented the beginning of its widespread use for numerous aesthetic indications.

Treatment of adult spasticity with Botox (onabotulinumtoxinA): Development, insights, and impact

Upper and lower limb spasticity (ULS, LLS) often occur following a stroke or in patients with other neurological disorders, leading to difficulties in mobility and daily living and decreased quality of life. Prior to the use of onabotulinumtoxinA, antispastic medications had limited efficacy and often caused sedation. Phenol injections were difficult for physicians to perform, painful, and led to tissue destruction. The success of onabotulinumtoxinA in treating cervical dystonia led to its use in spasticity. However, many challenges characterized the development of onabotulinumtoxinA for adult spasticity. The wide variability in the presentation of spasticity among patients rendered it difficult to determine which muscles to inject and how to measure improvement. Another challenge was the initial refusal of the Food and Drug Administration to accept the Ashworth Scale as a primary endpoint. Additional scales were designed to incorporate a goal-oriented, patient-centered approach that also accounted for the variability of spasticity presentations. Several randomized, double-blind, placebo-controlled trials of post-stroke spasticity of the elbow, wrist, and/or fingers showed significantly greater improvements in the modified Ashworth Scale and patient treatment goals and led to the approval of onabotulinumtoxinA for the treatment of ULS in adult patients. Lessons learned from the successful ULS trials were applied to design an LLS trial that led to approval for the latter indication. Additional observational trials mimicking real-world treatment have shown continued effectiveness and patient satisfaction. The use of onabotulinumtoxinA for spasticity has ushered in a more patient-centered treatment approach that has vastly improved patients' quality of life.

Neutralizing Antibody Formation with OnabotulinumtoxinA (BOTOX®) Treatment from Global Registration Studies across Multiple Indications: A Meta-Analysis

Though the formation of neutralizing antibodies (NAbs) during treatment with botulinum neurotoxin is rare, their presence may nonetheless affect the biological activity of botulinum toxin and negatively impact clinical response. The goal of this updated meta-analysis was to evaluate and characterize the rate of NAb formation using an expanded dataset composed of 33 prospective placebo-controlled and open-label clinical trials with nearly 30,000 longitudinal subject records prior to and following onabotulinumtoxinA treatment in 10 therapeutic and aesthetic indications. Total onabotulinumtoxinA doses per treatment ranged from 10 U to 600 U administered in ≤15 treatment cycles. The NAb formation at baseline and post-treatment was tested and examined for impact on clinical safety and efficacy. Overall, 27 of the 5876 evaluable subjects (0.5%) developed NAbs after onabotulinumtoxinA treatment. At study exit, 16 of the 5876 subjects (0.3%) remained NAb positive. Due to the low incidence of NAb formation, no clear relationship was discernable between positive NAb results and gender, indication, dose level, dosing interval, treatment cycles, or the site of injection. Only five subjects who developed NAbs post-treatment were considered secondary nonresponders. Subjects who developed NAbs revealed no other evidence of immunological reactions or clinical disorders. This comprehensive meta-analysis confirms the low NAb formation rate following onabotulinumtoxinA treatment across multiple indications, and its limited clinical impact on treatment safety and efficacy.

The Place of Botulinum Toxin in Spastic Hemiplegic Shoulder Pain after Stroke: A Scoping Review

Stroke is a common pathology worldwide, with an age-standardized global rate of new strokes of 150.5 per 100,000 population in 2017. Stroke causes upper motor neuron impairment leading to a spectrum of muscle weakness around the shoulder joint, changes in muscle tone, and subsequent soft tissue changes. Hemiplegic shoulder pain (HSP) is the most common pain condition in stroke patients and one of the four most common medical complications after stroke. The importance of the appropriate positioning and handling of the hemiplegic shoulder for prevention of HSP is therefore of high clinical relevance. Nevertheless, HSP remains a frequent and disabling problem after stroke, with a 1-year prevalence rate up to 39%. Furthermore, the severity of the motor impairment is one of the most important identified risk factors for HSP in literature. Spasticity is one of these motor impairments that is likely to be modifiable. After ruling out or treating other shoulder pathologies, spasticity must be assessed and treated because it could lead to a cascade of unwanted complications, including spastic HSP. In clinical practice, Botulinum toxin A (BTA) is regarded as the first-choice treatment of focal spasticity in the upper limb, as it gives the opportunity to target specifically selected muscles. It thereby provides the possibility of a unique patient tailored focal and reversible treatment for post stroke spasticity. This scoping review aims to summarize the current evidence of BTA treatment for spastic HSP. First, the clinical manifestation and outcome measures of spastic HSP will be addressed, and second the current evidence of BTA treatment of spastic HSP will be reviewed. We also go in-depth into the elements of BTA application that may optimize the therapeutic effect of BTA. Finally, future considerations for the use of BTA for spastic HSP in clinical practice and research settings will be discussed.

Emerging Trends in Botulinum Neurotoxin A Resistance: An International Multidisciplinary Review and Consensus

Botulinum neurotoxin A (BoNT-A) injection is the most widely performed aesthetic procedure and a first-line therapeutic option for various medical conditions. The potential for BoNT-A immunoresistance and secondary nonresponse related to neutralizing antibody (NAb) formation warrants attention as the range of BoNT-A aesthetic applications continues to expand.

Methods

An international multidisciplinary panel reviewed published evidence on BoNT-A immunoresistance in aesthetic and therapeutic applications and discussed best practices integrating clinical, ethical, and aesthetic considerations. Consensus statements relating to awareness, assessment, and management of the risk of NAb-related secondary nonresponse in aesthetic practice were developed.

Results

There was a consensus that, as doses used in aesthetic practice become like those in therapeutics, rates of NAb formation may be expected to increase. However, the true extent of NAb formation in aesthetics is likely underestimated due to limitations of published evidence and variability in treatment patterns of aesthetic patients. Since BoNT-A therapy is often lifelong, practitioners need to recognize immunogenicity as a potential complication that might affect future therapeutic use and strive to minimize modifiable risk factors. The selection and use of a BoNT-A product with the least immunogenic potential from the beginning may thus be advantageous, especially when treatment with high doses is planned.

Conclusions

In view of current trends in BoNT-A aesthetic use, it is essential for practitioners to conduct thorough clinical assessments, inform patients of treatment risks, and develop BoNT-A treatment plans to minimize immunogenicity. This can help preserve the option of continued or future BoNT-A treatment with satisfactory outcomes.

Botulinum Toxin Type A Immunogenicity across Multiple Indications: An Overview Systematic Review

BACKGROUND

Botulinum toxin type A has been used to treat a wide array of neurologic, medical, and aesthetic indications. Several factors contribute to the formation of neutralizing antibodies, such as shorter intervals of treatment, higher dosage, amounts of antigenic proteins, serotypes, and storage of formulations.

METHOD

This overview followed the Cochrane guideline for overview reviews. The AMSTAR-2 (revised version of A Measurement Tool to Assess Systematic Reviews) tool was used for the critical appraisal of the selected systematic reviews.

RESULTS

Five systematic reviews consisting of 203 studies (17,815 patients) were included, and their AMSTAR-2 scores were low to critically poor. There was high heterogeneity between the studies. Across the clinical indications, neutralizing antibody prevalence was significantly higher in dystonia, spasticity, and urologic conditions, and nil to insignificant in hyperhidrosis and aesthetic indications. The overall rate for the neutralizing antibody formation across three different formulations, abobotulinumtoxinA, incobotulinumtoxinA, and onabotulinumtoxinA, was 1 to 2.1 percent, with no significant difference between them.

RESULTS

Although there is debate on the prevalence rate across the different botulinum toxin type A formulations in individual systematic reviews, the overall frequency of the development of neutralizing antibodies and the immunogenicity of abobotulinumtoxinA, incobotulinumtoxinA, and onabotulinumtoxinA remain low to insignificant.

CONCLUSIONS

Properly designed comparative trials are required to explore the difference in the prevalence of neutralizing antibodies across the commercially available botulinum toxin type A products. Such studies should also examine the relevance of neutralizing antibody titer to clinical responsiveness and nonresponse.

Immunogenicity of botulinum toxin

Botulinum toxin treatment is the most common non-surgical cosmetic treatment. Although there are many available treatments using botulinum toxin, their effects are temporary and repeated injections are required. These frequent injections can trigger an immunological response. In addition, botulinum toxin acts as an antigen in the body; thus, its effect disappears progressively due to this immunological reaction, which may cause treatment failure. Active botulinum toxin consists of a core neurotoxin and complexing proteins, the exact effects of which remain unclear. However, the complexing proteins are closely related to the immune response and the formation of neutralizing antibodies. Since neutralizing antibodies can lead to treatment failure, their formation should be prevented. Furthermore, various methods of detecting neutralizing antibodies have been used to predict treatment failure.

Creating Lift in the Lower Face With Botulinum Toxin A Treatment: An Anatomical Overview With Videos and Case Studies Illustrating Patient Evaluation and Treatment

Background

Relaxation of depressor muscles in the lower face with botulinum toxin A (BoNT-A) can create a lifting effect and dramatically improve jawline contour and resting facial expression. Even with the recent increase in interest in lower face rejuvenation, BoNT-A is a relatively under-recognized tool for treatment of this area. When treating the lower face, an understanding of anatomy and the relationship between the facial muscles is especially important, as injection patterns must be customized for consistently positive outcomes.

Objectives

This study was aimed to provide basic knowledge of the activities of the muscles in the lower face and neck and to describe the basis for injecting BoNT-A to create lift in this area. Expert guidance for injection is also provided.

Methods

As part of a continuing medical education course on differentiating botulinum toxin products, a panel of 4 expert physician injectors participated in a live webinar to discuss the implications of increasing toxin use.

Results

The practical guidance in this manuscript is based on the most frequently requested information by audience members and the information considered critical for success by the authors. The authors outline the functional anatomy of the lower face most relevant for BoNT-A treatment and case studies as well as methods for patient evaluation and injection technique are also provided. Videos showing treatment planning and injection technique for the lower face and neck are included.

Conclusions

BoNT-A is an important nonsurgical tool for creating lift in the lower face.

Level of Evidence 5

Immunogenicity to Botulinum Toxin Type A: A Systematic Review With Meta-Analysis Across Therapeutic Indications

BACKGROUND

Botulinum toxin A (BTX-A) is commonly employed as a neuromodulator in several neurological diseases and aesthetic indications. Formation of neutralizing antibodies (NAbs) after BTX-A injections may be responsible for treatment failure.

OBJECTIVES

The authors sought to quantify the prevalence of NAbs following treatment with Abobotulinumtoxin A, Incobotulinumtoxin A, and Onabotulinumtoxin A for therapeutic indications.

METHODS

An electronic systematic search (2000-2020) of PubMed, Scopus, Web of Science, and Embase was conducted. Original studies reporting prevalence of NAbs were included. Data analysis was carried out through open meta-analysis softwares.

RESULTS

Forty-three studies involving 8833 patients were included in this meta-analysis. The incidence of NAbs was 1.8% (summary estimate = 0.018, 95% CI [0.012, 0.023]); a meta-regression analysis revealed that BTX-A duration was significantly associated with increased incidence of NAbs (P = 0.007). Patients with dystonia had the highest incidence (7.4%) of NAbs against BTX-A (summary estimate = 0.074, 95% CI = [0.045, 0.103], I2 = 93.%, P < 0.00) followed by patients with spasticity (6.7%) and urological indications (6.2%). Abobotulinumtoxin A was associated with the highest incidence of NAbs (7.4%) (summary estimate = 0.074, 95% CI = [0.053, 0.096], I2 = 97.24%, P < 0.00) by the Incobotulinumtoxin A and Onabotulinumtoxin A 0.3% (summary estimate <0.003%, 95% CI = [-0.001, 0.007], P < 0.003).

CONCLUSIONS

Although the overall incidence of NAbs following BTX-A injections is relatively low, patients with secondary nonresponse to BTX-A with no apparent causes should be investigated for NAbs. A consensus needs to be developed for the optimal management of such patients.

LEVEL OF EVIDENCE: 2

Antibody Development in Patients Treated Long-Term With OnabotulinumtoxinA for Benign Essential Blepharospasm and Hemifacial Spasm

BACKGROUND

Report the development of onabotulinumtoxinA neutralizing antibodies in patients treated consecutively for 20 years or longer for benign essential blepharospasm (BEB), hemifacial spasm (HFS), and Meige Syndrome.

METHODS

Prospective, randomized, cross-sectional study of 12 randomly selected patients from a single clinical practice that have been treated consecutively for 20 or more years with onabotulinumtoxinA for BEB, HFS, or Meige Syndrome. Serum samples were collected from each subject and analyzed for neutralizing antibody formation using the Mouse Protection Assay.

RESULTS

None of the tested patients (0%) displayed neutralizing antibodies to onabotulinumtoxinA. The mean duration of treatment was 27.5 years (range 22.1-34.1, SD 3.1, 95% confidence interval 25.45-29.50). Nine of the patients had a diagnosis of BEB, 2 HFS, and one Meige. Eleven of the 12 patients were women. There was no statistically significant difference in treatment dosage or interval over the course of treatment.

CONCLUSIONS

The data support previous studies showing low incidence of antibody formation for botulinum A toxins with this subset of long-term treated patients. The results also provide further evidence for studies that have suggested increased onabotulinumtoxinA treatment volumes and/or decreased intervals between treatments are not due to neutralizing antibody formation and secondary non-response, but rather study designs that do not consider the titration phase of initial treatments. This study is specific to long-term treated patients, and the results cannot be generalized to patients naive to treatment.

High-Dose Neuromodulators: A Roundtable on Making Sense of the Data in Real-World Clinical Practice

BACKGROUND

For aesthetic treatment with botulinum neurotoxin type A (BoNTA), interest in maximizing treatment duration and efficacy has prompted study of doses higher than those used in registration studies. As data emerge, it is important that physicians understand how to apply study findings to their own practice so that patient demand is satisfied.

OBJECTIVES

To bring together leading experts in neuromodulators for a roundtable discussion on the implications of high-dose BoNTA studies for patient care.

METHODS

The authors reviewed and discussed recent data from high-dose BoNTA studies for abobotulinum toxin A, incobotulinum toxin A, and Oonobotulinumtoxin A.

RESULTS

Discussion focused on the challenges of data interpretation and extrapolation of study findings for real-world patient care. The authors participated in a candid discussion of whether the observed improvements in treatment duration and patient satisfaction warrant treatment with high-dose regimens delivered as high-concentration injections. Safety was also discussed, as well as economic considerations for both practices and patients. Of note, for BoNTA products, the registration dose, when administered in a smaller total volume, appears to give rise to more durable results than those observed in pivotal trials, implicating product concentration as an important consideration. Importantly, at higher doses, extended duration of effect does not appear to be at the expense of natural-looking results.

CONCLUSIONS

While the authors provide considerations for the development of individual clinical practice, there is no one-size-fits-all recommendation. It may be that "high-dose" BoNTA is in reality the optimal dose; however, important economic considerations may prevent rapid uptake for all patients.

To evaluate the effect and longevity of Botulinum toxin type A (Botox®) in the management of gummy smile - A longitudinal study upto 4 years follow-up

AIM

the current study was aimed (1) To study the effect of Botulinum toxin (BT) A on gummy smile (2) To determine the efficacy, predictability & longevity of the effect of Botox® in the management of gummy smile and lastly (3)To identify the treatment groups for Botox® as a single modality for the non-surgical treatment of gummy smile.

MATERIAL AND METHOD

only patients who were willing to get the treatment done with Botox® injection were enrolled in the study, irrespective for the need for the surgery. Thus, total of 32 patients were divided into two groups, group 1, having a gummy smile with less than 5 ​mm who were treated with 3 units of Botox® and group II, having gummy smile of more than 5 ​mm who were treated with 5 units of Botox® and each group underwent 2 cycles of injection 7 months apart given at the Yonsei's point and were followed for a period of 14 months.

RESULTS

the procedure was tolerated well by the patients; none developed any allergic reaction or antibodies related to BT. In the less that 5 ​mm and more than 5 ​mm of gingival show group the results remain excellent till 3 months after which gummy smile gradually reaches to the baseline levels. Significant changes start to reappear by the 5th month.

CONCLUSION

Authors recommend use of BT for the treatment of gummy smile as the technique is safe, economical and easy to use. Though not long lasting, it may motivate patients to go for surgical procedure, mainly who have gummy smile of more than 5 ​mm because of maxillary vertical excess.

The Use of Botulinum Toxin for Treatment of Spasticity

Spasticity is one component of the upper motor neuron (UMN) syndrome resulting from a multitude of neurologic conditions, such as stroke, brain injury, spinal cord injury, multiple sclerosis, and cerebral palsy. It is clinically recognized as a phenomenon of velocity-dependent increase in resistance, i.e., hypertonia. Recent advances in the pathophysiology of spasticity improve our understanding of mechanisms underlying this complex phenomenon and its relations to other components of UMN syndrome (weakness and disordered motor control), as well as the resultant clinical problems. This theoretical framework provides a foundation to set up treatment goals and to guide goal-oriented clinical assessment and treatment. Among a spectrum of treatment options, botulinum toxin (BoNT) therapy is the preferred treatment for focal spasticity. The evidence is very robust that BoNT therapy effectively reduces spasticity; however, it does not improve voluntary movement. In this chapter, we highlight a few issues on how to achieve the best clinical outcomes of BoNT therapy, such as dosing, dilution, guidance techniques, adjunctive therapies, early treatment, repeated injections, and central effects, as well as the ways to improve motor function in selected subgroups of patients with spasticity. We also discuss the reasons of poor responses to BoNT therapy and when not to use BoNT therapy.

Wearing Off Response to OnabotulinumtoxinA in Chronic Migraine: Analysis in a Series of 193 Patients

OBJECTIVE

Long-term real-life studies have supported a cumulative effect of OnabotulinumtoxinA (OnabotA) for the prophylactic treatment of chronic migraine (CM) during consecutive cycles, and individual adaptations have been described to improve clinical response.

METHODS

This was a cohort longitudinal retrospective study of consecutive adult patients from the Headache Unit of the Hospital Clínico Universitario de Valladolid and the Hospital Universitario de La Princesa (Madrid) on OnabotA treatment for chronic migraine from May 2012 to December 2017. All patients were followed for 24 weeks. Full-length response to OnabotA was defined as ≥50% reduction in headache days for at least 12 weeks, and wearing off response was defined as a clinical response but with duration shorter than 10 weeks. We have analyzed the incidence and clinical predictors of this wearing off response.

RESULTS

A total of 193 patients were included, of whom 91 (47.1%) were considered full-length responders and 45 (23.3%) wearing off responders. No statistically significant clinical predictors (including demographic variables and baseline headache characteristics) of full-length response or wearing off response were detected in our study. An increase in dose during the second treatment cycle was attempted in 68.9% of the wearing off patients, achieving a longer duration of response of up to 12 weeks in 74.2%.

CONCLUSIONS

Wearing off response to OnabotA during the first treatment cycle is not uncommon in patients with CM. Increasing the dose in subsequent cycles could improve clinical response, but further multicenter long-term studies are needed to establish predictors and solutions to this problem.

Antibody-induced botulinum toxin treatment failure: A review and novel management approach

BACKGROUND

Botulinum neurotoxin A (BoNT/A) has been used for cosmetic indications for many decades. Consumption of BoNT/A usage has been markedly increased for a few years. Even new formulations of BoNT/A to decrease immunogenicity have been released, repeated treatment to maintain efficacy outcome is inevitable and could finally provoke immune response. In the past, prevalence of botulinum treatment failure (BTF) in cosmetic indication was rare leading to less medical concern. Current decade, case reports on BTF, especially antibody-induced botulinum toxin treatment failure (ABTF), have been increasingly revealed and risk factors associated with ABTF have been intensively studied.

AIMS

In this article, we will review antibody-induced botulinum toxin treatment failure (ABTF), risk-associated ABTF, prevalence and recent case reports of ABTF, and new approach to deal with ABTF.

METHODS

Literature search was conducted using PubMed. The relevant literatures published between January 2000 and May 2020 concerning BTF and ABTF including investigation for ABTF were included and analyzed.

RESULTS

Possible causes of BTF were summarized. ABTF could be a tip of iceberg of BTF, its prevalence, and currently, 10-year case reports of ABTF were published evidence. Risk factors and investigation methods for ABTF were also summarized. Based on previous studies and our experience, novel approach to management of ABTF was described.

CONCLUSION

Effective management of BTF is to explore causes of treatment failure. Antibodies against BoNT/A complex could be one of many possibilities. Laboratory in vitro tests could be alternative tools to decrease adverse effect and rebooting immune responses in BTF patients.

High Dosage of Botulinum Toxin Type A in Adult Subjects with Spasticity Following Acquired Central Nervous System Damage: Where Are We at?

Spasticity is a common disabling disorder in adult subjects suffering from stroke, brain injury, multiple sclerosis (MS) and spinal cord injury (SCI). Spasticity may be a disabling symptom in people during rehabilitation and botulinum toxin type A (BTX-A) has become the first-line therapy for the local form. High BTX-A doses are often used in clinical practice. Advantages and limitations are debated and the evidence is unclear. Therefore, we analysed the efficacy, safety and evidence for BTX-A high doses. Studies published from January 1989 to February 2020 were retrieved from MEDLINE/PubMed, Embase, Cochrane Central Register. Only obabotulinumtoxinA (obaBTX-A), onabotulinumtoxinA (onaBTX-A), and incobotulinumtoxinA (incoBTX-A) were considered. The term “high dosage” indicated ≥ 600 U. Thirteen studies met the inclusion criteria. Studies had variable method designs, sample sizes and aims, with only two randomised controlled trials. IncoBTX-A and onaBTX-A were injected in three and eight studies, respectively. BTX-A high doses were used predominantly in treating post-stroke spasticity. No studies were retrieved regarding treating spasticity in MS and SCI. Dosage of BTX-A up to 840 U resulted efficacious and safety without no serious adverse events (AEs). Evidence is insufficient to recommend high BTX-A use in clinical practice, but in selected patients, the benefits of high dose BTX-A may be clinically acceptable.

Frequency and risk factors of antibody-induced secondary failure of botulinum neurotoxin therapy

Objective

To investigate the risk factors of neutralizing antibody (NAB)–induced complete secondary treatment failure (cSTF) during long-term botulinum neurotoxin (BoNT) treatment in various neurologic indications.

Methods

This monocenter retrospective cohort study analyzed the data of 471 patients started on BoNT therapy between 1995 and 2015. Blood samples of 173 patients were investigated for NABs using the mouse hemidiaphragm test (93 with suspected therapy failure, 80 prospective study participants). The frequency of NAB-cSTF was assessed for various indications: hemifacial spasm, blepharospasm, cervical dystonia, other dystonia, and spasticity. A priori defined potential risk factors for NAB-cSTF were evaluated, and a stepwise binary logistic regression analysis was performed to identify independent risk factors.

Results

Treatment duration was 9.8 ± 6.2 years (range, 0.5–30 years; adherence, 70.6%) and number of treatment cycles 31.2 ± 22.5 (3–112). Twenty-eight of 471 patients (5.9%) had NAB-cSTF at earliest after 3 and at latest after 103 treatment cycles. None of the 49 patients treated exclusively with incobotulinumtoxinA over 8.4 ± 4.2 (1–14) years developed NAB-cSTF. Independent risk factors for NAB-cSTF were high BoNT dose per treatment, switching between onabotulinumtoxinA and other BoNT formulations (except for switching to incobotulinumtoxinA), and treatment of neck muscles.

Conclusions

We present a follow-up study with the longest duration to date on the incidence of NAB-cSTF in patients treated with various BoNT formulations, including incobotulinumtoxinA. Whereas the overall risk of NAB-cSTF is low across indications and BoNT formulations, our findings underpin the recommendations to use the lowest possible dose particularly in cervical dystonia, and to avoid unnecessary switching between different formulations.

Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain

We did a clinical service evaluation of patient-reported outcomes for pain and change in interincisal distance in patients treated with botulinum toxin A (BTX-A) for temporomandibular myofascial pain at nurse-led clinics. We retrospectively reviewed the clinical records of 100 patients and the prescribing patterns of two OMFS consultants. The mean starting pain score of 7.54 out of 10 was reduced by a mean (SD) of 2.48 (2.1) points after the intervention (p<0.001). The most common prescription was for 100 units (n=59 prescriptions). The change in the mean pain scores did not differ significantly whether 100 or 200 units were prescribed (p=0.19). Interincisal distance increased by a mean (SD) of 0.5 (5.24) mm after treatment with BTX-A, which was not significant (p=0.35). In most cases the treatment helped to manage and reduce the symptoms of temporomandibular myofascial pain. Considerable improvement in interincisal distance as a result of this treatment alone, however, is unlikely, but it may have a role in a multifaceted approach, particularly when other conservative methods have failed. The use of a pro forma may allow for more consistent record keeping and the detailed assessment of patient-reported pain scores in the weeks and months after treatment. Development of an electronic patient-reported outcome (ePRO) tool may facilitate this further.

Botulinum toxin: Pharmacology and injectable administration for the treatment of primary hyperhidrosis

Hyperhidrosis is a dermatological condition defined by excessive sweating beyond thermoregulatory needs with significant effects on patients' quality of life. Hyperhidrosis is categorized as primary or secondary: primary hyperhidrosis is mostly focal and idiopathic, whereas secondary hyperhidrosis is commonly generalized and caused by an underlying medical condition or use of medications. Various surgical and nonsurgical therapies exist for primary hyperhidrosis. Although botulinum toxin is one of the deadliest toxins known, when used in small doses, it is one of the most effective therapies for primary hyperhidrosis. Botulinum toxin injections are widely used as a second-line primary hyperhidrosis treatment option once topical treatment strategies have failed. This article provides an overview of the commercially available botulinum toxin formulations and their applications in the treatment of primary hyperhidrosis.

Wearing Off Effect of OnabotulinumtoxinA Near the End of Treatment Cycle for Chronic Migraine: A 4-Year Clinical Experience

INTRODUCTION

The injection interval for onabotulinumtoxinA (BoNTA) in the management of chronic migraine (CM) is 12 weeks (78-84 days). The aim of this study was to review patient-reported wearing off effect (WOE) of the therapeutic benefit of BoNTA near the end of the treatment cycle. We intended to describe the demographics of patients at baseline and compare groups of patients with multiple episodes of WOE.

METHODS

We conducted a retrospective review of patients with CM who received uninterrupted BoNTA therapy from January 2014 to March 2018. The data from patient-reported WOE (worsening headache variables and neck pain) that occurred during the 4 weeks (28 days) prior to the scheduled re-injection of BoNTA for treatment cycles with injection interval ≤13 weeks and without obvious confounding factors were reviewed.

RESULTS

We identified 98 eligible patients and analyzed 471 treatment cycles. Forty-three unique patients reported at least 1 occurrence of WOE. About 24/43 patients reported 1 WOE event and 19/43 patients reported ≥2 WOE events. Between the 2 groups, anxiety disorder and opioid use for headache were statistically significantly different. In the former group, the median interquartile range (IQR) dose of BoNTA was 165 (155, 175) units and the median IQR duration of the antinociceptive effect of BoNTA was 66.5 (63, 71.5) days. In the latter group, the median IQR dose of BoNTA was 167 (155, 173.3) units and the median IQR duration of the antinociceptive effect of BoNTA was 65.3 (62.5, 68.8) days. Up to 32% of these patients reported an increase in the use of abortive therapies to manage the symptoms of WOE.

DISCUSSION

The primary goal of BoNTA in the treatment of CM is to mitigate the development of central sensitization. Since the 12-week injection paradigm may not provide sustained antinociceptive effect in all patients, it may account for the failure of response to BoNTA. Repeated occurrences of the WOE can potentially lead to medication overuse and impact quality of life.

Safety, Efficacy, and Patient Satisfaction With OnabotulinumtoxinA for the Treatment of Upper Facial Lines in Japanese Subjects

BACKGROUND

OnabotulinumtoxinA treatment for glabellar lines (GL) or crow's-feet lines (CFL) was previously studied in Japanese subjects.

OBJECTIVE

To assess safety and efficacy of repeated onabotulinumtoxinA for moderate to severe GL and CFL in Japanese subjects.

METHODS

This 13-month, double-blind, Phase 3 study randomized subjects to onabotulinumtoxinA 44 U (n = 48) or 32 U (n = 53) for CFL and GL for up to 5 treatments (CFL: 24 U or 12 U; GL: 20 U). Outcomes included proportion of subjects achieving none/mild severity at maximum smile (CFL) and maximum frown (GL), using the Facial Wrinkle Scale with Asian Photonumeric Guide (FWS-A); proportion of ≥1-grade improvement responders at maximum smile and at rest (CFL), at maximum frown and at rest (GL); subject-reported outcomes; and safety.

RESULTS

Most subjects were responders (none/mild on FWS-A; CFL: 89.6% [44 U], 84.9% [32 U]; GL: 93.8% [44 U], 98.1% [32 U]) on Day 30. Across treatment groups, responder rates were consistent over time and treatments. Most subjects were satisfied with improved CFL appearance and with treatment. Incidence of treatment-emergent adverse events (TEAEs) and treatment-related TEAEs across groups was similar. All TEAEs but one (peritonitis) were mild or moderate.

CONCLUSION

Repeated onabotulinumtoxinA was effective and well tolerated.

Immunogenicity Associated with Botulinum Toxin Treatment

Botulinum toxin (BoNT) has been used for the treatment of a variety of neurologic, medical and cosmetic conditions. Two serotypes, type A (BoNT-A) and type B (BoNT-B), are currently in clinical use. While considered safe and effective, their use has been rarely complicated by the development of antibodies that reduce or negate their therapeutic effect. The presence of antibodies has been attributed to shorter dosing intervals (and booster injections), higher doses per injection cycle, and higher amounts of antigenic protein. Other factors contributing to the immunogenicity of BoNT include properties of each serotype, such as formulation, manufacturing, and storage of the toxin. Some newer formulations with purified core neurotoxin devoid of accessory proteins may have lower overall immunogenicity. Several assays are available for the detection of antibodies, including both structural assays such as ELISA and mouse-based bioassays, but there is no consistent correlation between these antibodies and clinical response. Prevention and treatment of antibody-associated non-responsiveness is challenging and primarily involves the use of less immunogenic formulations of BoNT, waiting for the spontaneous disappearance of the neutralizing antibody, and switching to an immunologically alternate type of BoNT.

Development of inhibition ELISA to detect antibody-induced failure of botulinum toxin a therapy in cosmetic indications

Secondary treatment failure (STF) of botulinum toxin A (BoNT/A) therapy in cosmetic indication has been postulated as production of antibody against active sites of BoNT/A in unresponsive patients. To prove of concept, detection of anti-BoNT/A antibody is required, however, current enzyme-linked immunosorbent assay (ELISA) detects human IgGs against whole BoNT/A molecule. We developed an inhibition ELISA to quantify antibodies bound to the active sites of BoNT/A using three mouse monoclonal antibodies targeting translocation domain, receptor binding site and catalytic domain of BoNT/A prior to processing ELISA to detect human IgG (hIgG) against BoNT/A. Adults naïve to BoNT/A, or treated and responsive (toxin-response), or treated but unresponsive (toxin-tolerance) were recruited. Detection of hIgG revealed that naïve volunteers had basal level of hIgG against whole BoNT/A, whereas its level was significantly lower than those hIgG in BoNT/A-exposed cohorts. Higher anti-BoNT/A levels in sera from volunteers ever-exposed to BoNT/A indicates that BoNT/A may provoke immune responses in BoNT/A-treated cohorts. Inhibition ELISA demonstrated that levels of BoNT/A-specific hIgG in tolerance patients had a dramatic decrease in mouse monoclonal antibody blockage, suggesting presence of hIgG specific to BoNT/A's three active sites in STF patients. Therefore, our ELISA detected hIgG against whole BoNT/A protein and BoNT/A active sites suggesting that human antibodies may cause STF. To compare with frontalis test, our inhibition ELISA provided good accuracy at 83.1% (50% sensitivity and 89.9% specificity). Our test may help clinicians to diagnose possibility of STF and also to monitor immune status against BoNT/A.

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

Immunogenicity induced by botulinum toxin injections for limb spasticity: A systematic review

BACKGROUND

The imputability of neutralizing antibodies (NABs) in secondary non-response (SnR) to botulinum toxin (BoNT) injections for limb spasticity is still debated.

OBJECTIVE

This systematic literature review aimed to determine the prevalence of NABs after BoNT injections for limb spasticity and analyze their determinants and their causal role in SnR.

METHODS

We searched MEDLINE via PubMed, Cochrane and Embase databases for articles published during 1990-2018. Two independent reviewers extracted the data and assessed the quality of studies with a specific scale (according to PRISMA and STROBE guidelines). Because the techniques used to detect NABs did not influence the results, we calculated the global (all studies) sensitivity and specificity of NAB positivity to reveal SnR.

RESULTS

We included 14 articles published from 2002 to 2018 (including an epublication) describing 5 randomized controlled trials and 5 interventional and 4 observational studies. The quality was satisfactory (mean score 18/28 arbitrary units). NAB detection was the primary criterion in 5 studies and a secondary criterion in 9. In total, 1234 serum samples for 1234 participants (91% with stroke) were tested after injection. NAB prevalence was about 1%, with no significant difference among formulations. NAB positivity seemed favoured by long-duration therapy with high doses and a short interval between injections. The identification of non-response by NAB positivity had poor global sensitivity (56%) but very high specificity (99.6%). No consensual criteria were used to diagnose non-response to BoNT injection.

CONCLUSIONS

NAB prevalence is much lower after BoNT treatment for limb spasticity than cervical dystonia. Consensual criteria must be defined to diagnose non-response to BoNT injection. Because immunogenicity is not the most common cause of non-response to BoNT injection, NABs should be sought in individuals with SnR with no other cause explaining the treatment inefficacy. A test with 100% specificity is recommended. In cases for which immunogenicity is the most likely cause of non-response to BoNT injections, some biological arguments suggest trying another BoNT, but no clinical evidence supports this strategy.

Neurostimulation-guided Anal Intrasphincteric Botulinum Toxin Injection in Children With Hirschsprung Disease

OBJECTIVES

In Hirschsprung disease (HD), despite successful surgical treatment, 50% of children experience long-term functional gastrointestinal problems, particularly chronic functional obstructive symptoms. We report our experience regarding clinical effects of neurostimulation-guided anal intrasphincteric botulinum toxin (BT) injections on postoperative obstructive symptoms attributed to a nonrelaxing anal sphincter complex in HD patients.

METHODS

In this monocenter cohort study, 15 HD patients with postoperative functional intestinal obstructive symptoms received neurostimulation-guided anal intrasphincteric BT injections. Short-, medium-, and long-term effects were evaluated. The Bristol stool form scale was used to assess stool consistency, and the Jorge-Wexner (JW) score to assess fecal continence.

RESULTS

The median age at first injection was 4 years. In the short-term, a significant improvement in stool consistency was noted in 12 of 14 patients (P = 0.0001) and JW score decreased for 14 of 15 patients (P = 0.001). In the medium-term, JW score significantly decreased for all patients (P = 0.0001), with an improvement of 50% or more for 10 patients (66.7%). In the long term, 83.3% of patients had normal stool consistency and JW score was <3 for all. Recurrent enterocolitis decreased from 86.7% to 8.3%. A complete resolution of all symptoms without further medication was observed in 66.7% of patients in the long term.

CONCLUSIONS

Intrasphincteric BT injection was a safe, effective, and durable option for the management of postoperative functional intestinal obstructive symptoms in HD. The use of neurostimulator guidance for specific delivery of BT to muscular fibers of nonrelaxing anal sphincter complex takes into consideration the variability of patient's anatomy secondary to curative surgery.

OnabotulinumtoxinA for adductor spasmodic dysphonia (ADSD): Functional results and the role of dosage

OBJECTIVE

To report the results of functional outcome, dose trend and relationship between onabotulinumtoxinA (onabotA) dosage and the severity of disease or time between therapy sessions in patients affected by adductor spasmodic dysphonia (ADSD).

PATIENTS AND METHODS

Thirty-two patients underwent 193 EMG-guided intracordal injections of a starting dose of 2 MU of onabotA. At enrollment, each subject was administered the VHI. The response was evaluated using a subjective rating scale (0-100% of normal phonation).

RESULTS

The quality of voice improved significantly after 1 month and stabilized by 3 months. The percentage of normal voice improved 33.34 ± 11.5% (min 26 - max 68). The functional gain was significantly worse in patients presenting with ADSD associated with dystonias in other body regions (31% vs 45% - p < 0.05). The mean dose employed was 3.64 MU (min 1 - max 6) with a trend of increasing dosages up to the 5th treatment after which the doses stabilized over time. The pre-treatment VHI showed a weakly positive correlation with the cumulative dose at the 5th and 10th injections. Benefit duration and the mean between treatment interval were 103 and 136 days respectively. The correlation between dose and inter-injection time is weakly negative (r = -0.22, p < 0.05), however, this is influenced predominantly by the first-to-second injection. After this initial treatment effect, the correlation becomes weakly positive (r = 0.12).

CONCLUSIONS

Our data confirm the efficacy of onabotA to improve the quality of voice in cases of ADSD. The trial period for optimal dosage lasted up to a mean of five injections. The dosage of onabotA impacted the length of response and was influenced by the severity of ADSD. Finally the efficacy of onabotA did not change significantly after repeated administrations.

High prevalence of neutralizing antibodies after long-term botulinum neurotoxin therapy

Objective

To investigate the prevalence of neutralizing antibodies (NAbs) against botulinum neurotoxin type A (BoNT/A) during long-term BoNT/A treatment in different neurologic indications.

Methods

In this monocentric, observational cross-sectional study, 596 outpatients treated with BoNT/A for different indications were tested for BoNT/A binding antibodies by ELISA. Positive samples were investigated for NAbs with the mouse hemidiaphragm test. The prevalence of NAbs was analyzed for different indications: facial hemispasm, blepharospasm, cervical dystonia, other dystonia, and spasticity. Besides the rate of NAb-positive patients overall and per patient subgroup, a Kaplan-Meier analysis of the probability of remaining NAb negative with duration of treatment is provided, and a stepwise binary logistic regression analysis is performed to identify factors significantly contributing to the induction of NAbs.

Results

Overall, 83 of 596 patients (13.9%) had measurable NAbs. The probability of developing NAbs increased with the single and cumulative dose of treatment and was influenced by the BoNT/A formulation, while all other factors analyzed, including disease entity and treatment duration, had no additional influence.

Conclusions

We present the largest study to date of the prevalence of BoNT/A NAbs in a large unbiased cohort of patients including the relevant neurologic indications. Repeated injections of BoNT/A inevitably bear the risk of developing NAbs. However, in addition to avoiding booster injections and providing short intervals between injections, reducing the individual injected doses may diminish the risk of NAb induction independently of the indication for which BoNT/A is used.

Botulinum Toxin in Aesthetic Medicine: Myths and Realities

Several formulations of Botulinum toxin serotype A (BoNT-A) for aesthetic indications are available, with numbers likely to increase. Preparations are not interchangeable, based on dose unit comparisons.

Long-term Treatment Benefits and Prolonged Efficacy of OnabotulinumtoxinA in Patients Affected by Chronic Migraine and Medication Overuse Headache over 3 Years of Therapy

Background

Chronic migraine (CM) affects about the 2% of the general population and it has been recognized as one of the most-disabling conditions worldwide by the World Health Organization. CM is often associated with the overuse of abortive medication, which determines the worsening of headache itself and the development of a secondary headache called medication overuse headache. The management of these associated conditions is difficult, but a growing amount of evidence is pointing out the effectiveness and the good safety profile of OnabotulinumtoxinA (OnabotA). Despite this, data on OnabotA effects and safety in long-term use lack. The purpose of the present article is to retrospectively assess the efficacy and safety of OnabotA in a cohort of chronic migraineurs with drug overuse from the 18th month of treatment until the third year.

Materials and methods

90 chronic migraineurs with medication overuse were enrolled between January 2013 and February 2017. All patients were treated with OnabotA according to PREEMPT dictates. Before every injection session the headache index, the analgesic consumption, the visual analog scale for pain score, the 36-items short form health survey questionnaire score, the 6-items headache impact test (HIT-6) score and the Zung self-rating anxiety and depression scale scores were collected. Adverse events were carefully registered. A simple linear regression was performed to explore the mean changes in the abovementioned parameters for a single injection session and mean comparison tests were performed using the one-way analysis of variance followed by Tukey–Kramer post-hoc test.

Results

A significantly improvement for a single injection was registered for all the above-mentioned parameters. Headache index, analgesic consumption, visual analog pain scale, and 6-items HIT-6 scores were significantly lower than baseline from the 18th month of treatment onwards. The 36-items short form health survey questionnaire scores were significantly higher than baseline at every injections session from the 18th months onwards. Zung scales did not change. No serious adverse events were assessed and no adverse events-related drop-outs were seen.

Conclusion

OnabotA effectiveness and safety last until 3 years of therapy, raising the possibility of the use of this therapy even for many years in CM prevention.

Safety of available and emerging drug therapies for hyperhidrosis

INTRODUCTION

Hyperhidrosis affects 4.8% of the U.S. population and has been underestimated by physicians for long time despite considerable interference with quality of life. Many patients suffer from primary (idiopathic) hyperhidrosis which results from over-activity of sympathetic nerves and is restricted to specific body areas, mostly the axillae, palms, soles, or head. Secondary hyperhidrosis is caused by an underlying disease or the intake of medications and often involves large parts of the body. Numerous effective therapies with topical or systemic drugs and surgical options are available. Areas covered: Efficacy and safety data on aluminum salts, anticholinergic drugs for topical or systemic application, and on intradermal botulinum toxin injections used to treat hyperhidrosis are critically evaluated, including data from clinical trials with focus on possible side effects and long-term complications in dispute. Expert opinion: Hyperhidrosis often responds well to available therapies. Depending on the type of hyperhidrosis treatment should be topical/local or systemic. Most of the side effects are mild, transient and easily manageable. In case of systemic treatment with anticholinergics low dosing and up-titration of medication is necessary to avoid severe adverse effects. Concerns about the promotion of breast cancer and Alzheimer disease by topical aluminum salts are unsolved.

Key Parameters for the Use of AbobotulinumtoxinA in Aesthetics: Onset and Duration

Time to onset of response and duration of response are key measures of botulinum toxin efficacy that have a considerable influence on patient satisfaction with aesthetic treatment. However, there is no overall accepted definition of efficacy for aesthetic uses of botulinumtoxinA (BoNT-A). Mechanical methods of assessment do not lend themselves to clinical practice and clinicians rely instead on assessment scales such as the Frontalis Activity Measurement Standard, Frontalis Rating Scale, Wrinkle Severity Scale, and Subject Global Assessment Scale, but not all of these have been fully validated. Onset of activity is typically seen within 5 days of injection, but has also been recorded within 12 hours with abobotulinumtoxinA. Duration of effect is more variable, and is influenced by parameters such as muscle mass (including the effects of age and sex) and type of product used. Even when larger muscles are treated with higher doses of BoNT-A, the duration of effect is still shorter than that for smaller muscles. Muscle injection technique, including dilution of the toxin, the volume of solution injected, and the positioning of the injections, can also have an important influence on onset and duration of activity. Comparison of the efficacy of different forms of BoNT-A must be made with the full understanding that the dosing units are not equivalent. Range of equivalence studies for abobotulinumtoxinA (Azzalure; Ipsen Limited, Slough UK/Galderma, Lausanne CH/Dysport, Ipsen Biopharm Limited, Wrexham UK/Galderma LP, Fort Worth, TX) and onabotulinumtoxinA (Botox; Allergan, Parsippany, NJ) have been conducted, and results indicate that the number of units of abobotulinumtoxinA needs to be approximately twice as high as that of onabotulinumtoxinA to achieve the same effect. An appreciation of the potential influence of all of the parameters that influence onset and duration of activity of BoNT-A, along with a thorough understanding of the anatomy of the face and potency of doses, are essential to tailoring treatment to individual patient needs and expectations.

Switch to Abobotulinum toxin A may be useful in the treatment of neurogenic detrusor overactivity when intradetrusor injections of Onabotulinum toxin A failed

AIMS

To assess the outcomes of switching to a different brand of botulinum toxin A (BTA, from Botox® to Dysport®) in case of failure of intradetrusor injections (IDI) of Botox® in the treatment of neurogenic detrusor overactivity (NDO).

METHODS

The charts of all patients who underwent a switch to IDI of Dysport® after failure of an IDI of Botox® at six departments of neurourology were retrospectively reviewed. The main outcomes of interest were the bladder diary data and four urodynamic parameters: maximum cystometric capacity (MCC), maximum detrusor pressure (PDET max), and volume at first uninhibited detrusor contraction (UDC).

RESULTS

Fifty-seven patients were included. After the first injection of Dysport®, no adverse events were reported. A significant decrease in number of urinary incontinence episodes per day was observed in 52.63% of patients (P < 0.001) and all patients experienced a reduction in PDET Max (-8.1 cmH20 on average; P = 0.003). MCC significantly increased by a mean of 41.2 (P = 0.02). The proportion of patients with no UDC increased significantly at week 6 after ATA injections (from 15.79% to 43.9%; P = 0.0002). Hence, 32 patients draw clinical and/or urodynamic benefits from the botulinum toxin switch from (56.14%). After a median follow up of 21 months, 87% of responders to BTA switch were still treated successfully with BTA.

CONCLUSION

Most patients refractory to Botox® (56.14%) draw benefits from the switch to Dysport®.

Anatomical Regional Targeted (ART) BOTOX Injection Technique: A Novel Paradigm for Migraines and Chronic Headaches

Supplemental Digital Content is available in the text.

Migraine headaches are a debilitating disease that causes significant socioeconomic problems. One of the speculated etiologies of the generation of migraines is peripheral nerve irritation at different trigger points. The use of Onabotulinum toxin A (BOTOX), although initially a novel approach, has now been determined to be a valid treatment for chronic headaches and migraines as described in the Phase III Research Evaluating Migraine Prophylaxis Therapy trials that prompted the approval by the Food and Drug Administration for treatment of chronic migraines. The injection paradigm established by this trial was one of a broad injection pattern across large muscle groups that did not always correspond to the anatomical locations of nerves. The senior author developed the Anatomical Regional Targeted BOTOX injection paradigm as an alternative to the current injection model. This technique targets both the anatomical location of nerves known to have causal effects with migraines and the region where the pain localizes, to provide relief across a wide distribution of the peripheral nerve. This article serves as a guide to the Anatomical Regional Targeted injection technique, which, to our knowledge, is the first comprehensive BOTOX injection paradigm described in the literature for treatment of migraines that targets nerves and nerve areas rather than purely muscle groups. This technique is based on the most up-to-date anatomical and scientific studies and large-volume migraine surgery experience.

Medium- to long-term outcomes of botulinum toxin A for idiopathic overactive bladder

Botulinum toxin A (BoNT-A) has become an important therapeutic tool in the management of refractory overactive bladder (OAB). Over the last decade, there have been growing numbers of patients receiving repeat injections and these outcomes have begun to be reported in large, high-quality cohorts. This article reviews the current evidence for the medium- to long-term use of BoNT-A in adults with idiopathic detrusor overactivity (IDO) receiving repeat injections. We find that medium-term outcomes are encouraging but long-term outcomes are not as extensively reported. There is high-quality evidence that efficacy following the first injection persists across multiple treatment cycles. There are no additional safety concerns from repeat injections up to six treatment cycles. However, there is a need for further data to confirm the efficacy and safety of BoNT-A beyond the follow-up period in the current literature.

Submolecular recognition regions of the HN domain of the heavy chain of botulinum neurotoxin type A by T cells from toxin-treated cervical dystonia patients

We have recently reported the submolecular T-cell recognition profile of the C-terminal half (H_C, residues 855-1296) of the heavy (H) chain of botulinum neurotoxin type A (BoNT/A) with peripheral blood lymphocytes (PBL) from 25 BoNT-treated cervical dystonia (CD) patients. In the current study, we describe the mapping of the T-cell responses of the patients to the N-terminal half (H_N, residues 449-859) of the heavy chain by using 29 synthetic overlapping peptides encompassing the entire H_N domain of BoNT/A. The profiles of the T-cell responses to the peptides varied among the patients. Samples from 14 patients treated solely with BoNT/A recognized 1-9 (average 3.7) peptides/sample at Z>3.0 level. Three peptide regions representing residues 631-649, 659-677 and 743-761 were frequently recognized by 29-64% of the patients. In patients with positive anti-BoNT/A antibody responses the overall positive T cell responses to the H_N peptides were significantly increased compared to antibody-negative patients. Influence of treatment parameters on the T-cell recognition of the H_N peptides was also observed. The results were compared with those of previously identified H_C region.

High Botulinum Toxin-Neutralizing Antibody Prevalence Under Long-Term Cervical Dystonia Treatment

BACKGROUND

The aim of this study was to determine the prevalence of neutralizing antibodies in a large cohort of long-term treated patients with cervical dystonia (CD) still responding to repetitive injections with botulinum toxin (BoNT).

METHODS

Consecutively recruited CD patients (n = 221) under long-term BoNT treatment (≥2-21 years) underwent a clinical examination at the same time blood samples were taken for neutralizing antibody determination. Collected data included demographics, mean dose of the last 10 botulinum injections, treatment duration, Tsui score for CD severity, and patients' subjective impression of treatment effect. Blood samples were screened for antibody presence by ELISA; positive samples were further analyzed by mouse hemidiaphragm test. The two laboratories performing antibody testing were blinded to the coded samples.

RESULTS

Antibody status could be determined for 212 patients; 39 (18.4%) were ELISA positive and 31 (14.6%) additionally positive in the mouse hemidiaphragm test. Patients with positive neutralizing antibody titers had significantly higher Tsui scores and were treated for a significantly longer time with significantly higher doses. There were no differences between male and female patients and between onabotulinumtoxinA- and abobotulinumtoxinA-treated patients. When BoNT preparations had been switched during the last 10 injections, a significantly higher proportion of neutralizing antibody-positive patients was detected.

CONCLUSIONS

Neutralizing antibody prevalence in long-term treated, still responding CD patients is substantially higher than suggested by follow-up studies with a shorter time frame. It should therefore be emphasized that antigenicity of BoTN preparations is still a relevant problem and should be taken into account in long-term treatment decisions.

Overview of Botulinum Toxins for Aesthetic Uses

Botulinum toxin type A (BTA) can be used for facial aesthetics. The 3 currently available BTA types include onabotulinumtoxinA (Botox; Botox Cosmetic, Allergan, Irvine, CA), abobotulinumtoxinA (Dysport; Ipsen, Ltd, Berkshire, UK), and incobotulinumtoxinA (Xeomin; Merz Pharmaceuticals, Frankfurt, Germany). The mechanism of action and clinical uses for treatment of dynamic lines of the forehead, brow, glabella, lateral orbit, nose, and lips are presented, as well as treatment of masseter hypertrophy, platysmal bands, and improvements of the perioral region. Specific BTA injection sites and suggested doses are presented.

Global Aesthetics Consensus: Hyaluronic Acid Fillers and Botulinum Toxin Type A-Recommendations for Combined Treatment and Optimizing Outcomes in Diverse Patient Populations

BACKGROUND

Combination of fillers and botulinum toxin for aesthetic applications is increasingly popular. Patient demographics continue to diversify, and include an expanding population receiving maintenance treatments over decades.

METHODS

A multinational panel of plastic surgeons and dermatologists convened the Global Aesthetics Consensus Group to develop updated guidelines with a worldwide perspective for hyaluronic acid fillers and botulinum toxin. This publication considers strategies for combined treatments, and how patient diversity influences treatment planning and outcomes.

RESULTS

Global Aesthetics Consensus Group recommendations reflect increased use of combined treatments in the lower and upper face, and some midface regions. A fully patient-tailored approach considers physiologic and chronologic age, ethnically associated facial morphotypes, and aesthetic ideals based on sex and culture. Lower toxin dosing, to modulate rather than paralyze muscles, is indicated where volume deficits influence muscular activity. Combination of toxin with fillers is appropriate for several indications addressed previously with toxin alone. New scientific data regarding hyaluronic acid fillers foster an evidence-based approach to selection of products and injection techniques. Focus on aesthetic units, rather than isolated rhytides, optimizes results from toxin and fillers. It also informs longitudinal treatment planning, and analysis of toxin nonresponders.

CONCLUSIONS

The emerging objective of injectable treatment is facial harmonization rather than rejuvenation. Combined treatment is now a standard of care. Its use will increase further as we refine the concept that aspects of aging are intimately related, and that successful treatment entails identifying and addressing the primary causes of each.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Spotlight on botulinum toxin and its potential in the treatment of stroke-related spasticity

Poststroke spasticity affects up to one-half of stroke patients and has debilitating effects, contributing to diminished activities of daily living, quality of life, pain, and functional impairments. Botulinum toxin (BoNT) is proven to be safe and effective in the treatment of focal poststroke spasticity. The aim of this review is to highlight BoNT and its potential in the treatment of upper and lower limb poststroke spasticity. We review evidence for the efficacy of BoNT type A and B formulations and address considerations of optimal injection technique, patient and caregiver satisfaction, and potential adverse effects of BoNT.