Paradoxical masseteric bulging after botulinum neurotoxin type A injection.

Paradoxical masseteric bulging refers to an unexpected occurrence of masseter muscle bulging or protrusion following the administration of botulinum toxin injections, contrary to the anticipated muscle weakening effect. It may occur secondary to toxin failing to diffuse through the entire masseter muscle due to the presence of an inferior tendon structure within the superficial masseter that divides it into a superficial and deep belly. We report a clinical case of paradoxical masseteric bulging in a female in her late 40s who developed this adverse effect within a week of her masseter botulinum neurotoxin type A injections. We also describe the masseter two-site injection technique for the management of this complication.

Effectiveness and Safety of OnabotulinumtoxinA in Adolescent Patients with Chronic Migraine.

Chronic migraine (CM) significantly affects underage individuals. The study objectives are (1) to analyze the effectiveness and safety of onabotulinumtoxinA (BTX-A) in adolescents with CM; (2) to review the literature on BTX-A use in the pediatric population. This prospective observational study included patients under 18 years old with CM treated with BTX-A (PREEMPT protocol) as compassionate use. Demographic, efficacy (monthly headache days-MHD; monthly migraine days-MMD; acute medication days/month-AMDM) and side effect data were collected. A ≥ 50% reduction in MHD was considered as a response. Effectiveness and safety were analyzed at 6 and 12 months. A systematic review of the use of BTX-A in children/adolescents was conducted in July 2023. In total, 20 patients were included (median age 15 years [14.75-17], 70% (14/20) females). The median basal frequencies were 28.8 [20-28] MHD, 18 [10-28] MMD and 10 [7.5-21.2] AMDM. Compared with baseline, at 6 months (n = 20), 11 patients (55%) were responders, with a median reduction in MHD of -20 days/month (p = 0.001). At 12 months (n = 14), eight patients (57.1%) were responders, with a median reduction in MHD of -17.5 days/month (p = 0.002). No adverse effects were reported. The literature search showed similar results. Our data supports the concept that BTX-A is effective, well tolerated, and safe in adolescents with CM resistant to oral preventatives.

Botulinum Toxin-Induced Parotitis: A Postoperative Complication Following Masseter Muscle Injection.

Botulinum toxin (BTX) injection is a common treatment for bruxism, but there is no literature on potential salivary gland complications. This paper presents a case of acute parotitis in a 60-year-old female following BTX injections to the masseter muscle. This case highlights the possible salivary gland complications after injection of BTX into the masticatory muscles. An electronic search of PubMed and Embase databases was conducted to create a literature review in order to delve into the etiology behind the presented case and suggest potential preventive measures to avoid salivary gland complications. Thirty-one articles are reviewed and discussed. Currently, there is no consensus on the causes of the mentioned complication. However, various factors have been proposed, encompassing anatomical, physiological, biological, and physical aspects. Several methods have been recommended for the safe injection of BTX, which, along with better medical training and knowledge, are warranted to achieve predictable results.

Botulinum toxin: a new differential diagnosis for a lytic bone lesion.

BACKGROUND: Botulinum toxin, produced by the Gram-positive anaerobe Clostridium botulinum, is composed of seven antigenic subtypes (A, B, C, D, E, F, and G). Currently, only Botulinum toxin type A, commonly referred to as "Botox," is approved for clinical use, given its relatively safe clinical profile. Botulinum toxin type A has a wide range of therapeutic indications, including treatment for dystonia, migraine headache, neurogenic bladder, and large muscle spastic disorders. However, the toxin is most widely known for its cosmetic effects in treating wrinkles and facial lines. CASE PRESENTATION: This article describes a 62-year-old Caucasian female who presented for investigation and workup of an isolated lytic lesion of her frontal bone a few weeks after administration of botulinum toxin injection into the corresponding site in the frontalis muscle. This presented as a large, palpable, painless forehead lump causing significant psychological distress. After no neoplastic cause for the lesion was found and histopathology was performed, our researchers concluded that the most likely explanation was that the bony lytic lesion resulted from inadvertent injection of the "Botox" neurotoxin through the intended target muscle and into the cortex of the underlying bone. CONCLUSIONS: Our search of the literature failed to identify any previous cases of this occurring. However, as the popularity of this cosmetic procedure only increases, we believe that this represents an important possible differential for isolated lytic lesion after administration of "Botox" injection.

Efficacy and Safety of PrabotulinumtoxinA in Subjects With Benign Masseteric Hypertrophy: A Double-Blind, Randomized, Placebo-Controlled, Multicenter, Phase 3 Trial and Open-Label Extension Study.

BACKGROUND: Despite the widespread use of botulinum toxin (BTX) injection for the treatment of masseter muscle hypertrophy (MMH), there is no standard treatment option. OBJECTIVE: We report the efficacy and safety for BTX in MMH over a period of 48 weeks. METHODS: In double-blinded, placebo-controlled phase 3 trials, 180 patients (randomized 1:1) received treatment with placebo (normal saline) or prabotulinumtoxinA (48 units). Masseter muscle thickness (at maximal clenching and resting positions), 3D imaging analysis, and masseter muscle hypertrophy scale grades were analyzed at each time point. After the 24-week CORE study, all patients who met the same criteria of the CORE study at week 24 ( n = 114) received only prabotulinumtoxinA, regardless of previous treatment, for an additional 24 weeks (48 weeks in total) for the open-label extension study. RESULTS: The largest differences in mean and percent changes from baseline in masseter muscle thickness were observed at 12 weeks, and there were significant differences between the 2 groups at all time points (all p < .001). The effect was independent of the number of injections. No serious adverse event was observed. CONCLUSION: PrabotulinumtoxinA could effectively ameliorate MMH without major complications.

Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Trigeminal Neuralgia: An Update on Systematic Review With Meta-analyses.

OBJECTIVE: Pain management in patients with TN is challenging, as facial pain often does not respond well to conventional therapies. Botulinum toxin type A (BTX-A) has been suggested as a potential treatment option, but there is limited evidence regarding its long-term efficacy. This review aimed to analyze the current data for the use of in the treatment of trigeminal neuralgia (TN) and highlight the evidence for its efficacy and safety. METHODS: A comprehensive search was conducted in various databases (PubMed, Scopus, Embase, ClinicalTrials, and Cochrane Library) to identify clinical studies evaluating the use of BTX-A in TN until October 2023. Randomized controlled trials (RCTs), single-arm studies, and stratified studies were included in the analysis. The mean difference (MD), effect size (ES), and 95% confidence interval (CI) were estimated for visual analogue scale (VAS) scores, pain episode frequency, and the proportion of responders. RESULTS: The analysis included 23 studies, including 4 RCTs, 14 single-arm studies, and 5 stratified studies. In the RCTs, BTX-A was found to significantly reduce mean VAS scores compared with baseline (ES: -4.05; 95% CI: -6.13, -1.97; P =0.002). In 19 non-RCTs, the pooled single-arm analysis revealed that BTX-A decreased VAS scores (ES: -5.19, 95% CI: -6.05, -4.33, P <0.001) and pain attack frequency (ES: -17.85, 95% CI: -23.36, -12.34, P <0.001) from baseline to the end of follow-up. The overall proportion of responders to BTX-A treatment was also significant (95% CI: 0.653, 0.761, P =0.003). DISCUSSION: Current evidence indicates that BTX-A injection is an effective and safe option for patients with refractory TN or not responding to medical or surgical management. However, more high-quality studies are needed to further confirm its efficacy.

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.

A Phase III Clinical Study of the Efficacy and Safety of Botulinum Toxin Type A (MASPORT) with DYSPORT for the Treatment of Glabellar Lines.

BACKGROUND: Botulinum toxin type A is a widely used treatment of facial wrinkles. The objective of this study was to compare the efficacy and safety of a new botulinum toxin type A (Masport [abobotulinum toxin A], MasoonDarou Co) with DYSPORT® for the treatment of glabellar lines. METHODS: 262 subjects with moderate-to-severe glabellar lines received either a fixed dose of 50 units of MASPORT® or DYSPORT® (Ipsen Company, England). Subjects were followed up at 14, 30, 60, 90 and 120 days after injection. Efficacy was assessed by investigator at maximum frown and rest and also by Subject Global Assessment of Change (SGA). The responders were defined as persons with +2 grade improvement from baseline for both investigator and patient assessment. The occurrence and duration of adverse effects were recorded up throughout the study. RESULTS: According to the investigator evaluations, the responder rate at maximum frown were 94.5% for MASPORT and 95.6% for DYSPORT group on day 30 and at rest were 85.45% and 85.68% for MASPORT and DYSPORT group, respectively. According to the subject self-assessment, the proportion of responders in MASPORT group at day 30 was 95.28% versus 97.04% for DYSPORT group. No serious drug related adverse effect was recorded in either study groups, and the rates of adverse effects were similar for both groups. CONCLUSION: Abobotulinum toxin A [MASPORT] is equally safe and effective as commercial product [DYSPORT] for the treatment of glabellar lines with the dose of 50 units, up to 120 days. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy and Safety of DaxibotulinumtoxinA for Injection in Cervical Dystonia: ASPEN-1 Phase 3 Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: ASPEN-1 was a phase 3, randomized, double-blind, placebo-controlled study to evaluate the efficacy, duration of response, and safety of 2 doses of DaxibotulinumtoxinA for Injection (DAXI), a novel botulinum toxin type A formulation in participants with cervical dystonia (CD). METHODS: Adults (aged 18-80 years) with moderate-to-severe CD (Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] total score ≥20) were enrolled at 60 sites across 9 countries in Europe and North America. Participants were randomized (3:3:1) to single-dose intramuscular DAXI 125U, 250U, or placebo and followed for up to 36 weeks after injection. The primary end point was change from baseline in TWSTRS total score averaged across weeks 4 and 6. Key secondary end points included duration of effect, Clinical and Patient Global Impression of Change (CGIC, PGIC), TWSTRS subscale scores, and safety. Multiplicity-adjusted intent-to-treat hypothesis tests with multiple imputation were performed using ANCOVA and Cochran-Mantel-Haenszel analyses. RESULTS: Of 444 individuals screened, 301 were randomized to DAXI 125U (n = 125) or 250U (n = 130) or placebo (n = 46). DAXI 125U and 250U significantly improved the mean TWSTRS total score vs placebo (least squares mean [standard error] difference vs placebo: DAXI 125U, -8.5 [1.93], p < 0.0001; DAXI 250U, -6.6 [1.92], p = 0.0006). The median duration of effect (time from treatment until loss of ≥80% of the peak improvement in average TWSTRS total score achieved at weeks 4 and 6) was 24.0 (95% confidence interval 20.3-29.1) weeks with DAXI 125U and 20.3 (16.7-24.0) weeks with DAXI 250U. Significant improvements were also observed with DAXI in CGIC and PGIC responder rates and TWSTRS subscales. Treatment-related treatment-emergent adverse events (TEAEs) were reported by 29.6% of participants with DAXI 125U, 23.8% with DAXI 250U, and 17.4% with placebo, with injection site pain being the most common overall. The most frequently reported treatment-related TEAEs of interest in DAXI 125U, DAXI 250U, and placebo, respectively, were muscular weakness (4.8%, 2.3%, 0%), musculoskeletal pain (2.4%, 3.1%, 0%), and dysphagia (1.6%, 3.8%, 0%). DISCUSSION: This study demonstrated that DAXI, at doses of 125U and 250U, is an effective, safe, long-acting, and well-tolerated treatment for CD. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov identifier (NCT03608397, submitted July 11, 2018) and EU Clinical Trials Register (ClinicalTrialsRegister.eu EudraCT identifier 2018-000446-19, submitted September 13, 2018). First participant enrolled on June 11, 2018. Trial registration was performed in accordance with the Food and Drug Administration Amendments Act (FDAAA 801), which stipulates that the responsible party register an applicable clinical trial not later than 21 calendar days after enrolling the first human participant (42 CFR 11.24). CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in adults with moderate-to-severe idiopathic cervical dystonia, DAXI reduces dystonia more effectively than placebo.

Efficacy and safety of botulinum toxin for rosacea with positive impact on quality of life and self-esteem.

BACKGROUND: Rosacea is a prevalent chronic inflammatory skin disease with a multifactorial pathophysiology. It compromises several skin structures, including the proliferation and dilation of dermal blood vessels, primarily in the central areas of the face, accompanied by significant psychosocial impairment, leading to reduced quality of life (QoL) and self-esteem. There are consensus guidelines for its treatment, but few options for the erythema. This study hypothesizes that treating rosacea skin lesions with botulinum toxin (BTX) could improve signs and symptoms, resulting in enhanced QoL and self-esteem. METHODS: This interventional, open, uncontrolled, and prospective study, conducted at a single center, included 33 individuals diagnosed with rosacea, treated with standard therapeutic options according to the rosacea subtype plus superficial injections of BTX, and followed up for 90 days. Botulinum toxin injections were applied on Days 1 and 14. Clinical features and side effects were assessed at each visit; QoL, self-esteem, and medication adherence questionnaires were administered on Days 1 and 90. RESULTS: Treatment with BTX yielded improvement in the clinical signs of rosacea, registered by the investigators, and reported by 94% of the participants. Improved QoL scores (P < 0.05) and a notable increase in self-esteem scores (P < 0.001) were demonstrated. Rare adverse events were observed. CONCLUSIONS: The utilization of BTX superficial injections in patients with rosacea was safe and effective, improving the clinical appearance of the lesions. Despite some limitations, to our knowledge, this is the first study that showed the positive impact of this treatment modality on both QoL and self-esteem.

Safety of botulinum toxin injections in children less than one year old: A retrospective chart review.

PURPOSE: Infants can have muscle hypertonia due to cerebral palsy, muscle strength imbalances due to brachial plexus palsy, refractory clubfoot, and torticollis. These muscle problems can cause significant development impairments. A child with severe sialorrhea and dysphagia from leukodystrophy can aspirate, causing respiratory problems. Botulinum toxin (BoNT) injections can improve these conditions but may lead to adverse effects from the toxin spreading to non-targeted muscles, potentially impacting breathing, swallowing, and overall strength. This is particularly concerning in infants. This study assessed the safety of BoNT injections in children less than one year of age. METHODS: This was a retrospective cohort study. RESULTS: Forty-seven patients (22 male, 25 female) received BoNT injections before one year of age (three to 12 months). Thirty-seven received one round of injections and 10 were injected on multiple occasions. Forty-five received onabotulinumtoxinA (15-100 units [U], 1.9-15.2 U/kg), one received abobotulinumtoxinA (70 U, 9.0 U/kg), and one received incobotulinumtoxinA (25 U, 3.5 U/kg). Lower extremities were treated in 15 patients, upper extremities in 38, the sternocleidomastoid in two, and the salivary glands in one. Forty-five patients had no reported complications. One experienced transient fever, vomiting, and diarrhea. The parent of another reported subjective weakness in one muscle. CONCLUSION: BoNT injections in children less than one year of age appear to be safe.

A Randomized, Double-Blind, Active Control, Multicenter, Phase 3 Study to Evaluate the Efficacy and Safety of Liztox® versus Botox® in Post-Stroke Upper Limb Spasticity.

Botulinum toxin type A (BTX-A) injection is a commonly used therapeutic intervention for upper limb spasticity in stroke patients. This study was designed as a randomized, active-drug-controlled, double-blind, multicenter, phase 3 clinical trial to evaluate the safety and efficacy of Liztox® in comparison to onabotulinum toxin A (Botox®) for individuals with post-stroke upper limb spasticity. The primary outcome was the alteration in wrist flexor muscle tone from the initial assessment to the fourth week, evaluated using the modified Ashworth scale (MAS). Secondary outcomes included MAS score changes for the wrist at weeks 8 and 12 from baseline; MAS score changes for finger and elbow flexors; and changes in the Disability Assessment Scale (DAS), Subject's Global Assessment (SGA), the Investigator's Global Assessment (IGA), and Caregiver Burden Scale (CBS) at weeks 4, 8, and 12 from baseline. The MAS score for wrist flexor spasticity decreased by -1.14 ± 0.59 in the Liztox® group and -1.22 ± 0.59 in the Botox® group from baseline to week 4. The difference [97.5% confidence interval (CI)] between the test and control groups was 0.08 [-∞, 0.26], confirming the non-inferiority of the test group compared to the control group. Furthermore, there were consistent improvements in the IGA, SGA, and CBS scores across all assessment intervals, with no statistically significant variances detected between the two groups. No safety-related concerns were reported during the study. In conclusion, Liztox® injection proved to be a secure and efficacious intervention for managing upper extremity spasticity in post-stroke patients.

Trial of Botulinum Toxin for Isolated or Essential Head Tremor.

BACKGROUND: Local injections of botulinum toxin type A have been used to treat essential head tremor but have not been extensively studied in randomized trials. METHODS: In a multicenter, double-blind, randomized trial, we assigned, in a 1:1 ratio, adult patients with essential or isolated head tremor to receive botulinum toxin type A or placebo. Botulinum toxin or placebo was injected under electromyographic guidance into each splenius capitis muscle on the day of randomization (day 0) and during week 12. The primary outcome was improvement by at least 2 points on the Clinical Global Impression of Change (CGI) scale at week 6 after the second injection (week 18 after randomization). The CGI scale was used to record the patient's assessment of the degree of improvement or worsening of head tremor since baseline; scores range from 3 (very much improved) to -3 (very much worse). Secondary outcomes included changes in tremor characteristics from baseline to weeks 6, 12, and 24. RESULTS: A total of 120 patients were enrolled; 3 patients were excluded during screening, and 117 patients were randomly assigned to receive botulinum toxin (62 patients) or placebo (55 patients) and were included in the intention-to-treat analysis. Twelve patients in the botulinum toxin group and 2 patients in the placebo group did not receive injections during week 12. The primary outcome - improvement by at least 2 points on the CGI scale at week 18 - was met by 31% of the patients in the botulinum toxin group as compared with 9% of those in the placebo group (relative risk, 3.37; 95% confidence interval, 1.35 to 8.42; P = 0.009). Analyses of secondary outcomes at 6 and 12 weeks but not at 24 weeks were generally supportive of the primary-outcome analysis. Adverse events occurred in approximately half the patients in the botulinum toxin group and included head and neck pain, posterior cervical weakness, and dysphagia. CONCLUSIONS: Injection of botulinum toxin into each splenius capitis muscle on day 0 and during week 12 was more effective than placebo in reducing the severity of isolated or essential head tremor at 18 weeks but not at 24 weeks, when the effects of injection might be expected to wane, and was associated with adverse events. (Funded by the French Ministry of Health; Btx-HT ClinicalTrials.gov number, NCT02555982.).

Exploring the Interplay between the Clinical and Presumed Effect of Botulinum Injections for Cervical Dystonia: A Pilot Study.

BACKGROUND: Repetitive intramuscular injections of botulinum neurotoxin type A (BoNT/A) are the treatment of choice in patients with cervical dystonia (CD). As soon as BoNT therapy is initiated, the natural course of CD cannot be observed anymore. Nevertheless, the present study focuses on the "presumed" course of disease severity under the assumption that no BoNT therapy had been performed. The "experienced" benefit is compared with the "presumed" worsening. METHODS: Twenty-seven BoNT/A long-term-treated CD patients were recruited. They had to assess the remaining severity of CD in percent of its severity at the start of BoNT therapy (RS-%). Then, they had to draw the course of severity from the onset of symptoms to the start of BoNT/A therapy (CoDB graph), as well as the course of severity from the start of BoNT/A therapy until the day of recruitment (CoDA graph). Then, they were instructed to presume the development of CD severity from the day of the start of BoNT/A therapy until the day of recruitment under the assumption that no BoNT/A therapy had been performed, and to assess the maximal severity they could presume in percent of the severity at the start of BoNT therapy (IS-%). Then, they had to draw the "presumed" development of CD severity (CoDI graph). The "experienced" change in disease severity and the "presumed" change since the start of BoNT/A therapy were compared and correlated with a variety of demographical and treatment-related data, including the actual severity of CD at the day of recruitment, which was assessed using the TSUI score and the actual dose per session (ADOSE). RESULTS: No CD patients expected an improvement without BoNT therapy. "Presumed" worsening ((IS-%)-100) was about 50% in the mean and did not correlate with the "experienced" benefit (100-(RS-%)). However, IS-% was significantly correlated with ATSUI and ADOSE. CONCLUSION: Obviously, CD patients have the opinion that their CD would have further progressed and worsened if no BoNT/A therapy had been performed. Thus, the total benefit of BoNT/A therapy for a patient with CD is a combination of the "experienced" benefit under BoNT/A therapy and the prevented worsening of CD that the patient expects to occur without BoNT/A therapy.

Use of botulinum toxin in the management of radiotherapy side effects.

BACKGROUND: Many experimental and clinical studies are conducted to investigate the effects of various applications of botulinum toxin (BTx) in the treatment of radiation related side effects. There are no studies that show clear results about the positive and negative effects of its active clinical use in the long run, and discussions are ongoing. In addition, there is a need for various researches about how BTx can be used and how long it can be used, and the side effects it may cause. BTx-A, which is one of the options in the treatment of side effects that will occur due to radiotherapy, is an effective and safe option. Applying BTx injection to the right place with specific injection methods increases the effectiveness and safety of the treatment. PURPOSE: It has been investigated whether BTx will be a potential tool to perfect the esthetic and functional results in reducing the chronic side effects associated with radiotherapy.