Conversion Ratio between Botox®, Dysport®, and Xeomin® in Clinical Practice

Protocol and Demographics of the RELY-CD Study: Assessing Long-Term Clinical Response to Botulinum Neurotoxin in Cervical Dystonia

The RELY-CD study investigated the long-term clinical response to botulinum neurotoxin type A in cervical dystonia within a multicenter, real-world setting. This retrospective study focused on patients treated with complex-free (incobotulinumtoxinA) and complex-containing (onabotulinumtoxinA and abobotulinumtoxinA) BoNT/A formulations over an up to 10-year period. The novel dose-effect parameter "DEff" was introduced to quantify the relationship between dose adjustments and clinical outcomes, enabling the identification of partial treatment failures. The primary endpoint was a comparison of a clinically meaningful worsening in DEff in treatment year 7 compared to year 2 between complex-free and complex-containing botulinum neurotoxin type A. The RELY-CD study provides unique insights into long-term treatment patterns, clinical resistance phenomena, and the implications of formulation differences on treatment outcomes, addressing a critical gap in the literature on real-world botulinum neurotoxin type A application. The study methodology, including the definition and calculation of the novel DEff, as well as clinical baseline characteristics, are presented.

Why Dosing Matters: A Closer Look at the Dose-Response Relationship With OnabotulinumtoxinA

BACKGROUND

OnabotulinumtoxinA is licensed in many countries for simultaneous treatment of three areas of the upper face: glabellar lines, 20 U; lateral canthal lines, 24 U; and forehead lines, 20 U.

AIMS

To assess the onabotulinumtoxinA dosing science and dose-response relationship in the treatment of upper facial lines (UFL).

METHODS

Key practical questions are addressed using available data.

RESULTS

OnabotulinumtoxinA doses were selected for Phase 3 registrational trials based on rigorous dose-ranging studies. In clinical practice, it is important to consider the relationship between dose and efficacy outcomes, duration, and safety. Interstudy comparison of duration analyses is complicated by the lack of a single comprehensive definition, but trial data with standard onabotulinumtoxinA dosing in the glabella suggest a median effect duration of ~4 months. Treatment of UFL at below the approved dose is associated with a shorter duration, inferior response rates, and lower patient satisfaction; there is no evidence that underdosing reduces adverse event risk. It may therefore be advisable to avoid going below the licensed dose unless there is a clear clinical rationale. By contrast, there is growing evidence that treatment outcomes can be further improved using doses above those currently licensed, without adversely affecting safety-as demonstrated in the glabella. Further studies are needed to assess this in lateral canthal and forehead lines. Additional work is also required to examine potential ceiling doses and better understand the dose-response relationship in patient subgroups.

CONCLUSIONS

Appropriate dosing of onabotulinumtoxinA is essential for maximizing benefit and ensuring patient satisfaction.

The effectiveness and safety of intracavernosal botulinum toxin injections in the management of erectile dysfunction: a systematic review and meta-analysis of clinical studies

Background

Patients with erectile dysfunction (ED) are often left with limited nonsurgical options when conventional pharmacotherapies become ineffective. Botulinum neurotoxin serotype A (BoNT-A) intracavernosal injections (ICIs) have been demonstrated in a few clinical studies to be effective and safe in managing ED and may serve as a first- or second-line option.

Aim

To perform a systematic review and meta-analysis on the effectiveness and safety of BoNT-A ICI in managing ED with a focus on human studies.

Methods

A systematic review and meta-analysis of clinical studies was performed in accordance with the PRISMA 2020 statement. Adult men with ED who received BoNT-A were included in the study. The risk of bias assessment of included studies was performed using the JBI assessment checklists.

Outcomes

The effectiveness and safety of BoNT-A ICI. Measures of effectiveness included the increase or change in International Index for Erectile Function (IIEF-EF) score/Sexual Health Inventory for Men (SHIM) score/Erection Hardness Score (EHS) or change in Doppler ultrasound parameters and the percentage of patients achieving the minimal clinically important difference (MCID) score.

Results

The search retrieved 61 articles, and 2 randomized controlled trials (RCTs) and 4 retrospective studies met the inclusion criteria. Three types of BoNT-A were evaluated: onaBoNT-A, aboBoNT-A, and incoBoNT-A. At least 40% of the patients achieved the MCID (2-7 points increase in the IIEF-EF/SHIM score) depending on the severity of ED) at ≥1 month. When directly comparing all 3 BoNT-A, the overall response rate was 77.5%, with no statistically difference between the 3 types. For aboBoNT-A, 500 U appeared to sustain the effectiveness longer compared to 250 U. OnaBoNT-A improved peak systolic velocity on Doppler ultrasound compared with saline. Meta-analysis of the 2 RCTs demonstrated a mean difference of 4.35 (P = .008) in the SHIM score at 12 weeks in favor of onaBoNT-A over normal saline. No systemic side effects have been reported, and the only infrequent local side effect was transient penile pain. Only one case of priapism was reported.

Strengths and Limitations

This is the first systematic review summarizing data from human studies on ED and BoNT-A ICI. The inclusion criteria and outcomes of the included studies varied, which limited the number of studies included and parameters assessed in the meta-analysis.

Conclusion

BoNT-A may become an acceptable non-surgical option. However, there is a lack of clinical randomized or observational studies on this topic, and more randomized studies with standardized reporting are required to replicate current results and investigate the long-term benefits of BoNT-A as a monotherapy or adjunct therapy in the management of ED.

Evaluation of Retinal and Choroidal Microvascularity in Patients with Benign Essential Blepharospasm

PURPOSE

To assess the retinal and choroidal microvascular changes in patients with benign essential blepharospasm (BEB) and to investigate the factors that may be effective on microvascularity.

METHODS

This study included patients with BEB and healthy controls. All participants underwent a comprehensive examination followed by optical coherence tomography angiography (OCTA). Macular vascular perfusion density (VPD), foveal avascular zone (FAZ), and subfoveal choroidal thickness (CT) were measured. The clinical findings of the BEB group and the administration of botulinum toxin A (BTx-A) prior to OCTA imaging were recorded retrospectively from the medical records.

RESULTS

A total of 16 patients with BEB and 20 healthy controls were included in this study. VPD values in all quadrants of the superficial and deep macular capillary plexus were significantly different in the BEB group compared to the control group (each p-value <0.05). In the choriocapillaris layer, VPD was significantly higher in the superior, nasal, and temporal quadrants compared to the control group (each p-value <0.05). The BEB group exhibited significantly smaller superficial and deep FAZ values compared to the control group, consistent with the observed increase in vascular density (each p-value <0.05). CT was thinner in the BEB group, although not statistically significant (p = 0.138). No correlation was found between the total dose of BTx-A administered to the BEB group and OCTA parameters (each p-value >0.05).

CONCLUSION

Benign essential blepharospasm may be associated with increased retinal vascular density in the superficial and deep capillary plexus and decreased FAZ area.

Switox: Retrospective Analysis of Botulinum Toxin Switching in Management of Spasticity

This retrospective study investigates botulinum toxin changes in 206 patients with spasticity, following reimbursement adjustments in France. The main objective was to evaluate the tolerance and efficacy of these changes, a topic underexplored due to the common practice of maintaining the same toxin brand. The majority of patients switched from Botox to Xeomin (73.66%), while others switched from Botox to Dysport (14.63%) or from Xeomin to Dysport (11.71%). Dose adjustments varied depending on the switch, with the change from Botox to Xeomin showing the greatest diversity in adjustments. Overall, tolerance was good, with few adverse effects reported, primarily fatigue. Perceived efficacy fluctuated, with some patients noting improvement while others experienced deterioration, but the median remained stable. A majority of patients (57.06%) chose to continue with their new treatment, indicating general satisfaction, though 42.93% preferred to return to their initial treatment. This study highlights the importance of an individualized approach and careful monitoring during toxin changes. The results suggest that toxin switches can be made without an increase in adverse effects. While differences between groups were observed, they were not statistically significant. Placebo and nocebo effects may influence perceptions of efficacy and side effects during treatment changes.

Excitation-contraction coupling inhibitors potentiate the actions of botulinum neurotoxin type A at the neuromuscular junction

BACKGROUND AND PURPOSE

Botulinum neurotoxin type A1 (BoNT/A) is one of the most potent neurotoxins known. At the same time, it is also one of the safest therapeutic agents used for the treatment of several human disorders and in aesthetic medicine. Notwithstanding great effectiveness, strategies to accelerate the onset and prolong BoNT/A action would significantly ameliorate its pharmacological effects with beneficial outcomes for clinical use.

EXPERIMENTAL APPROACH

Here, we combined BoNT/A with two fast-acting inhibitors of excitation-contraction coupling inhibitors (ECCI), either the μ-conotoxin CnIIIC or dantrolene, and tested the effect of their co-injection on a model of hind-limb paralysis in rodents using behavioural, biochemical, imaging and electrophysiological assays.

KEY RESULTS

The BoNT/A-ECCI combinations accelerated the onset of muscle relaxation. Surprisingly, they also potentiated the peak effect and extended the duration of the three BoNT/A commercial preparations OnabotulinumtoxinA, AbobotulinumtoxinA and IncobotulinumtoxinA. ECCI co-injection increased the number of BoNT/A molecules entering motoneuron terminals, which induced a faster and greater cleavage of SNAP-25 during the onset and peak phases, and prolonged the attenuation of nerve-muscle neurotransmission during the recovery phase. We estimate that ECCI co-injection yields a threefold potentiation in BoNT/A pharmacological activity.

CONCLUSIONS AND IMPLICATIONS

Overall, our results show that the pharmacological activity of BoNT/A can be combined and synergized with other bioactive molecules and uncover a novel strategy to enhance the neuromuscular effects of BoNT/A without altering the neurotoxin moiety or intrinsic activity, thus maintaining its exceptional safety profile.

Dosage of botulinum toxin in patients undergoing treatment for hemifacial spasm: is there modification during follow-up?

BACKGROUND

 The movement disorder known as hemifacial spasm is characterized by involuntary contractions of the muscles that are innervated by the facial nerve. The treatment of choice for this condition is botulinum toxin injections.

OBJECTIVE

 To analyze the botulinum toxin dosage in patients undergoing treatment for hemifacial spasm during a 14-year period.

METHODS

 A retrospective study of medical records from patients treated at the Neurology Service of Hospital Universitário Onofre Lopes, Universidade Federal do Rio Grande do Norte, from 2010 to 2024, was performed.

RESULTS

 A total of 151 patients met the inclusion criteria. The dose of botulinum toxin revealed a statistically significant increase during the first 3.46 years of follow-up. In the long-term, a trend toward dose stabilization was identified. The median latency for the onset of effect was 4 days, while the median duration of effect was 3 months. All side effects were temporary, with the most common being hemifacial weakness (17.9%) and palpebral ptosis (3.3%). Most patients presented primary hemifacial spasm (88.1%), with a neurovascular conflict identified in 24.1% of cases.

CONCLUSION

 The increase in botulinum toxin dosage during the first years may be explained by dosage adjustment to control hemifacial spasm with the lowest possible doses. A prolonged interval between applications may also be associated with this increase. Dose stabilization tends to be achieved over time, indicating disease control.

Prospects for Use of Botulinum Toxin Type A for Prevention of Hypertrophic and Keloid Scars after Surgeries

Objective  To evaluate the possibility of improving and preventing the formation of postoperative hypertrophic and keloid scars using botulinum toxin type A (BTA). Materials and Methods  Scientific articles published in English have been systematically screened in PubMed/MEDLINE database over the entire period. The following information about the studies was analyzed: first author surname; year of publication; number of patients; average age; scar location; dosage of the drug administered; follow-up duration; scar assessment methods; results, incidence of hypertrophic and keloid scars formation. The odds ratio and 95% confidence interval were calculated for each of the estimated parameters. The statistical heterogeneity of publications assessed using the criteria of chi-square test and I 2 . The differences were considered significant at p  < 0.05. Results  A total of 18 prospective randomized studies were selected for evaluation, containing data on the use of BTA in 363 cases. Patients receiving botulinum toxin had a lower Vancouver scar scale index, higher visual analog scale index, and higher Stony Brook scar evaluation scale score. The use of BTA reduces the risk of perceptible scar formation, the incidence of hypertrophic and keloid scars. Conclusion  The use of BTA to obtain imperceptible scar and prevent hypertrophic and keloid postoperative scars demonstrates good prospects. However, there is no consensus regarding the pathophysiological mechanisms underlying the positive effect of BTA on the prevention of hypertrophic and keloid scars.

Diagnostic Nerve Block to Guide Botulinum Neurotoxin Type A Injection for Clonus in Spastic Equinovarus Foot: A Retrospective Study

Clonus is characterized by involuntary, rhythmic, oscillatory muscle contractions, typically triggered by rapid muscle stretching and is frequently associated with spastic equinovarus foot (SEVF), where it may increase risk of falls and cause discomfort, pain, and sleep disorders. We hypothesize that selective diagnostic nerve block (DNB) of the tibial nerve motor branches can help identify which muscle is primarily responsible for clonus in patients with SEVF and provide useful information for botulinum neurotoxin type A (BoNT-A) treatment. This retrospective study explored which calf muscles contributed to clonus in 91 patients with SEFV after stroke (n = 31), multiple sclerosis (n = 21), and cerebral palsy (n = 39), using selective DNB. We found that SEVF-associated clonus was most commonly driven by the soleus muscle, followed by the gastrocnemius lateralis and medialis, tibialis posterior, and flexor digitorum longus, and that frequency differed according to SEVF etiology. Our data suggest that identifying the muscles involved in SEVF-associated clonus may aid clinicians in personalizing BoNT-A treatment to single patients. Also, the findings of this study suggest that applying a 'stroke model' to treating spasticity secondary to other etiologies may not always be appropriate.

A Six-Year Examination of the Influence of Surgical Technique and Intraoperative Intraglandular Clostridium Botulinum Toxin Application in Salivary Gland Tumor Operations

Introduction: Salivary gland tumor operations are associated with complications including facial nerve dysfunction (FND) and salivary fistula. The objective of this study was to investigate the effect of extracapsular dissection (ECD) and the application of Clostridium botulinum toxin (CBT) in contrast to partial and lateral parotidectomy on complications. Methods: All salivary gland tumor operations performed within the last 6 years were retrospectively examined. Data were collected from electronic patient files from our otorhinolaryngology clinic. Total parotidectomies and submandibulectomies were not included in the analysis of CBT application. Results: In total, 418 cases were examined, including 84 (20%) malignant tumors. In total, 18 patients underwent ECD, 93 partial parotidectomy, 199 lateral parotidectomy, 76 total parotidectomy, and 32 submandibulectomy. The most common complication was transient FND (49%; n = 205; data available for 415 patients), which was measured at four days. Additional complications included salivary fistula (n = 56), infection (n = 49), bleeding or hematoma (n = 21). Preoperative facial nerve paralysis (p < 0.0001), pain (p < 0.0001), and a history of squamous cell skin carcinoma (SCC) (p < 0.001) were predictive of malignancy. The application of CBT did not reduce the risk of salivary fistula (p-value: 0.0182) and was associated with a higher combined complication rate (p-value: 0.0199). ECD was not associated with a lower likelihood for FND (p = 0.350). Conclusions: Preoperative pain, facial paralysis, or a history of SCC are predictors of malignancy. Use of CBT was not associated with a reduced risk of salivary fistula, but rather a higher complication rate.

Response to Treatment with Botulinum Neurotoxin A (BoNT-A) in Children and Adolescents with Neurogenic Lower Urinary Tract Dysfunction and Idiopathic Overactive Bladder: A Systematic Review and Meta-Analysis

INTRODUCTION

Botulinum neurotoxin A (BoNT-A) is a treatment option for neurogenic lower urinary tract dysfunctions (NLUTD) and idiopathic overactive bladder (OAB) in adults. Recently, its use has gained popularity in paediatric urology. Transitional urology deals with adolescents affected by congenital urological issues, who mature into adulthood. The aim of this systematic review was to update the current knowledge on the use of BoNT-A in children and adolescents.

METHODS

A comprehensive search in PubMed, Scopus, and Web of Science databases was performed from articles published up to September 2024. Both prospective and retrospective single-cohort or comparative studies evaluating outcomes of interest were included. These consisted of the amelioration of urinary incontinence (UI), continence rates, improvement of urodynamic parameters (maximum detrusor pressure during voiding, maximum bladder capacity, and bladder compliance), and type and prevalence of adverse/side effects. Qualitative and quantitative data syntheses were provided. Moderators and meta-regression analyses were carried out as well.

RESULTS

Forty-one full-text manuscripts were selected of which 26 focused on children with NLUTD, 13 on idiopathic OAB, and two on both conditions. Overall, 1521 patients were included of whom 715 were male, 646 female, and 160 of unknown sex. Mean age varied between 5.6 and 15.6 years. No studies specifically focused on transitional urology, despite patients up to at least 17 years of age being included. Several differences existed in design, type, dose, way of administration, outcomes measured and follow-up time; however, all studies independently showed an improvement of UI and urodynamic parameters with no major side/adverse events. Pooled analysis showed a mean rate of improvement in UI scores/episodes of 75.87% within a period of 3-6 months following BoNT-A treatment. Meta-regression analyses demonstrated a significant correlation between dryness rate and both patients' age (negative) and bladder compliance (positive).

CONCLUSIONS

Several uncontrolled or comparative studies provided significative evidence of the clinical benefit and safety of BoNT-A administration in children in terms of UI relief and improvement of urodynamic parameters, with neurogenic aetiologies being the most investigated conditions. A reduced bladder compliance was identified as one of the potential predictors of poor response to BoNT-A. Moreover, the earlier the treatment was started the higher the success rate that was reached in terms of dryness/urinary continence achievement.

Doses of Botulinum Toxin in Cervical Dystonia: Does Ultrasound Guidance Change Injection Practices?

BACKGROUND

Cervical dystonia is widely understood to benefit from botulinum toxin injections. The injection practices may be influenced by specific factors, including the method of injection. Three main guidance methods can be used: palpation of anatomical landmarks, ultrasound, and electromyography. We investigated how target muscles and doses of botulinum toxin were modified after the transition from surface anatomy (non-guided) to ultrasound (US-guided), in patients with cervical dystonia. We also determined the long-term dose trend.

METHODS

We studied a group of 82 patients, who received non-guided injections (median: 16.5 cycles/5.1 years) followed by US-guided injections (median: 12.0 cycles/3.8 years).

RESULTS

More muscles, and especially deep muscles, were injected during the US-guided period. The total dose and number of injected muscles were higher when US guidance was used, but the mean dose per muscle was lower. Over the long term, the total dose stabilized, and the mean dose per muscle decreased during the US-guided period.

CONCLUSIONS

According to our results, the guidance method has a strong impact on the botulinum toxin injection strategy in cervical dystonia (target muscles and dose). Also, the treatment appeared more stable when using US guidance; this could be explained by the good precision of such injections.

Do Diagnostic Nerve Blocks Affect the Starting Dose of Botulinum Neurotoxin Type A for Spasticity? A Case-Control Study

One of the aims of diagnostic nerve blocks is to identify the overactive muscles that lead to a specific spasticity pattern. However, to date, there is no evidence on how nerve blocks may affect botulinum neurotoxin-A (BoNT-A) dose in patients with spasticity. This case-control study aims to assess the role of diagnostic nerve block in defining BoNT-A starting dose at first treatment. Patients with upper and lower limb spasticity treated for the first time with BoNT-A were retrospectively divided into two groups: Group 1 (n = 43) was evaluated with clinical assessment and diagnostic nerve block; Group 2 (n = 56) underwent clinical assessment only. Group 1 was injected with higher BoNT-A doses in some muscles (i.e., flexor digitorum profundus, soleus), and received a higher BoNT-A cumulative dose with a larger number of injected muscles for some spasticity patterns (i.e., "clenched fist", "flexed fingers", "adducted thigh"). Diagnostic nerve block may help the clinician to optimize and personalize the BoNT-A dose since the first BoNT-A treatment.

Long-Term Management of Post-Stroke Spasticity with Botulinum Toxin: A Retrospective Study

Stroke-induced spasticity is a prevalent condition affecting stroke survivors, significantly impacting their quality of life. Botulinum Toxin A injections are widely used for its management, yet the long-term effects and optimal management strategies remain uncertain. This retrospective study analyzed medical records of 95 chronic stroke patients undergoing long-term BoNT-A treatment for spasticity. Demographic data, treatment duration, dosage variability, and dropout rates were assessed over a period ranging from 2 to 14 years. The study revealed a notable extension of the interval between BoNT-A injections throughout the treatment duration. Dropout rates peaked during the initial 5 years of treatment, perhaps due to perceived treatment ineffectiveness. Additionally, a trend of escalating dosage was observed across all groups, indicating a potential rise in the severity of spasticity or changes in treatment response over time. BoNT-A injections emerged as the predominant treatment choice for managing post-stroke spasticity. The delayed initiation of BoNT-A treatment underscores the need for heightened awareness among healthcare providers to recognize and manage spasticity promptly post-stroke. Patients' expectations and treatment goals should be clearly defined to optimize treatment adherence, while the observed escalation in dosage and treatment intervals emphasizes the dynamic nature of spasticity and underscores the importance of monitoring long-term treatment outcomes.

Tirbanibulin (KX2-391) analog KX2-361 inhibits botulinum neurotoxin serotype A mediated SNAP-25 cleavage in pre- and post-intoxication models in cells

Botulinum neurotoxins (BoNT) inhibit neuroexocytosis, leading to the potentially lethal disease botulism. BoNT serotype A is responsible for most human botulism cases, and there are no approved therapeutics to treat already intoxicated patients. A growing body of research has demonstrated that BoNT/A can escape into the central nervous system, and therefore, identification of BoNT/A inhibitors that can penetrate BBB and neutralize the toxin within intoxicated neurons would be important. We previously identified an FDA-approved, orally bioavailable compound, KX2-391 (Tirbanibulin) that inhibits BoNT/A in motor neuron assays. Recently, a structural analog of KX2-391, KX2-361, has been shown to exhibit good oral bioavailability and cross BBB with high efficiency in mouse experiments. Therefore, in this work, we evaluated the inhibitory effects of KX2-361 against BoNT/A. Toward this goal, we first evaluated the compound for its effects on cell viability in PC12 cells, via MTT assay, and in mouse embryonic stem cell (mESC)-derived motor neurons, with imaging-based assays. Following, we tested KX2-361 in mESC-derived motor neurons intoxicated with BoNT/A holotoxin, and the compound exhibited activity against the toxin in both pre- and post-intoxication conditions. Excitingly, KX2-361 also inhibited BoNT/A enzymatic component (light chain; LC) in PC12 cells transfected with BoNT/A LC. Furthermore, our molecular docking analyses suggested that KX2-361 can directly bind to BoNT/A LC. Medicinal chemistry approaches to develop structural analogs of KX2-361 to increase its efficacy against BoNT/A may provide a critical lead compound with BBB penetration capacity for drug development efforts against BoNT/A intoxication.

Efficacy and safety of intradetrusor abobotulinumtoxinA and incobotulinumtoxinA in women with overactive bladder and the value of local anesthesia: a randomized clinical study

BACKGROUND

A non-inferiority clinical study evaluated the efficacy and safety of abobotulinumtoxinA vs. incobotulinumtoxinA intradetrusor injections in women with overactive bladder and urge urinary incontinence. Also, the effect of local anesthesia on the pain level of the procedure was assessed.

METHODS

Patients were randomized to receive 20 intradetrusor injections of either 300 U abobotulinumtoxinA or 100 U incobotulinumtoxinA. They were further randomized to receive either local anesthesia (40 ml 1% lidocaine solution) or placebo before botulinum toxin injection. Before the procedure and 4 months after the procedure each patient reported urinary incontinence episodes, frequency, nocturia, completed the Urogenital Distress Inventory (UDI-6) score, Incontinence Impact Questionnaire (IIQ-7), and Incontinence Quality of Life (I-QOL) questionnaire. Each patient completed a patient satisfaction survey 4 months after the procedure. During the procedure, the patients graded the pain intensity of every injection on a visual analog scale (VAS). The total score of each questionnaire was considered.

RESULTS

A total of 54 patients with a mean age of 66 ± 13 (SD) years completed the study. Total scores of UDI‑6, IIQ‑7, I‑QOL, patient satisfaction, urinary incontinence episodes, frequency, nocturia and VAS questionnaires did not show differences between the abobotulinumtoxinA (n = 26) or incobotulinumtoxinA (n = 28) group. Urinary retention requiring catheterization was noted in five patients. The VAS and patient satisfaction questionnaire values did not show significant differences between the group receiving bladder instillation with lidocaine solution (n = 28) or the group receiving placebo (n = 26).

CONCLUSION

In women with overactive bladder and urge urinary incontinence where conservative treatment failed, abobotulinumtoxinA vs. incobotulinumtoxinA intradetrusor injections showed comparable results regarding improved clinical outcome and patient satisfaction. Local anesthesia before the procedure did not reduce the pain level in comparison with the placebo.

Current use of neurotoxins for alleviating symptoms of cervical dystonia

INTRODUCTION

Cervical dystonia (CD) causes involuntary movements and postures of the head, neck, and shoulders, as well as nonmotor symptoms including pain, mood, and sleep dysfunction, and impacts quality of life. The first-line treatment for CD is botulinum neurotoxin (BoNT) injections.

AREAS COVERED

The clinical presentation and diagnosis of CD, as well as where BoNT resides in the treatment landscape, is reviewed first. Next, the mechanism of action and the pharmacological differences in the available preparations of BoNT products are explained. The evidence base for motor and nonmotor efficacy and safety of the available BoNT formulations is reviewed, with attention to duration of benefit as a driver of patient satisfaction. Practical determinants of BoNT efficacy are reviewed including muscle selection, accurate muscle injection, factors related to poor or deteriorating response, and immunogenicity.

EXPERT OPINION

BoNT represents a significant advancement in the treatment of CD. More accurate diagnosis, muscle selection and targeting, and dosing can improve outcomes with existing BoNT formulations. Further refinement of BoNT potency, duration of action, safety, and immunogenicity will help reduce unmet needs in the magnitude and duration of benefit. Additional validation of DBS and MRI-guided focused ultrasound may expand options for patients with toxin nonresponse.

Exploring botulinum toxin's impact on masseter hypertrophy: a randomized, triple-blinded clinical trial

The present study aimed to assess the effectiveness and functional adverse effects of a single and multiple injections of botulinum toxin A (BoNT-A) for masseter hypertrophy (MH). Twenty-six women complaining about lower third facial enlargement due to MH, received 75 U of BoNT-A (abobotulinum toxin) in each masseter muscles. After 3 months, patients were randomly assigned to receive a second treatment session of Saline Solution: (G1; n = 11) or BoNT-A: (G2; n = 12). Muscle thickness (ultrasound), electrical activity (electromyography; EMG), masticatory performance, and subjective perception of MH were evaluated. Follow-up was performed at 1, 3 and 6 months. Muscle thickness, EMG activity, and masticatory performance were analyzed using ANOVA two-way and Sidak test as post-hoc. Masticatory performance was analyzed by the Friedman's test and Mann-Whitney test. Regarding inter-groups comparisons, there was a significant decrease in the left masseter muscle thickness in the G2 group at the 6 month follow-up (p < 0.02). For EMG, significant differences were evident at the 6 month assessment, with higher masseter activity for G1 (p < 0.05). For masticatory performance, no significant differences were observed throughout the study (p > 0.05) and a higher improvement in subjective perception of MH was observed in the 1 month follow-up for G2 (p < 0.05). In conclusion, BoNT-A is effective for MH, however multiple injections cause functional adverse effects in masseter muscle.

Botulinum Toxin and Deep Brain Stimulation in Dystonia

Deep Brain Stimulation (DBS) is a recognized treatment for different dystonia subtypes and has been approved by the Food and Drug Administration (FDA) since 2003. The European Federation of Neurological Societies (EFNS) and the International Parkinson and Movement Disorders Society (MDS) recommend DBS for dystonia after failure of botulinum toxin (BoNT) and other oral medications for dystonia treatment. In addition, several long-term studies have demonstrated the continuous efficacy of DBS on motor and quality of life (QoL) scores. However, there are only a few reports comparing the overall impact of surgical treatment in BoNT protocols (e.g., dosage and number of selected muscles before and after surgery). This retrospective multicenter chart-review study analyzed botulinum toxin total dosage and dosage per muscle in 23 dystonic patients before and after DBS surgery. The study's primary outcome was to analyze whether there was a reduction in BoNT dosage after DBS surgery. The mean BoNT dosages difference between baseline and post-surgery was 293.4 units for 6 months, 292.6 units for 12 months, and 295.2 units at the last visit. The median total dose of BoNT in the preoperative period was 800 units (N = 23). At the last visit, the median was 700 units (p = 0.05). This represents a 12.5% reduction in BoNT median dosage. In conclusion, despite the limitations of this retrospective study, there was a significant reduction in BoNT doses after DBS surgery in patients with generalized dystonia.

Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications

Botulinum neurotoxins (BoNTs) have been used for almost half a century in the treatment of excessive muscle contractility. BoNTs are routinely used to treat movement disorders such as cervical dystonia, spastic conditions, blepharospasm, and hyperhidrosis, as well as for cosmetic purposes. In addition to the conventional indications, the use of BoNTs to reduce pain has gained increased recognition, giving rise to an increasing number of indications in disorders associated with chronic pain. Furthermore, BoNT-derived formulations are benefiting a much wider range of patients suffering from overactive bladder, erectile dysfunction, arthropathy, neuropathic pain, and cancer. BoNTs are categorised into seven toxinotypes, two of which are in clinical use, and each toxinotype is divided into multiple subtypes. With the development of bioinformatic tools, new BoNT-like toxins have been identified in non-Clostridial organisms. In addition to the expanding indications of existing formulations, the rich variety of toxinotypes or subtypes in the wild-type BoNTs associated with new BoNT-like toxins expand the BoNT superfamily, forming the basis on which to develop new BoNT-based therapeutics as well as research tools. An overview of the diversity of the BoNT family along with their conventional therapeutic uses is presented in this review followed by the engineering and formulation opportunities opening avenues in therapy.

Role of Diagnostic Nerve Blocks in the Goal-Oriented Treatment of Spasticity with Botulinum Toxin Type A: A Case-Control Study

The goal-setting process is pivotal in managing patients with disabling spasticity. This case-control study assessed the role of diagnostic nerve blocks in guiding the goal-setting process within goal-targeted treatment of spasticity with botulinum neurotoxin-A. In this case-control study, patients with disabling spasticity underwent either a goal-setting process based on the patient's needs and clinical evaluation (control group) or additional diagnostic nerve block procedures (case group). All enrolled patients underwent a focal treatment with botulinum neurotoxin-A injection and a 1-month follow-up evaluation during which goal achievement was quantified using the goal attainment scaling-light score system. Data showed a higher goal achievement rate in the case group (70%) than in the control group (40%). In conclusion, diagnostic nerve blocks may help guide the goal-setting process within goal-targeted treatment of spasticity with botulinum neurotoxin-A towards more realistic and achievable goals, thereby improving the outcomes of botulinum neurotoxin-A injection. Future studies should better explore the role of diagnostic nerve blocks to further personalize botulinum neurotoxin-A according to individual patients' preferences and requirements.

Concomitant Botulinum Toxin Injections for Neurogenic Detrusor Overactivity and Spasticity-A Retrospective Analysis of Practice and Safety

As multiple indications for botulinum toxin injections (BTIs) can coexist for neurological patients, there are to date no description of concomitant injections (CIs) to treat both spasticity and neurogenic detrusor overactivity incontinence (NDOI) in patients with spinal cord injuries (SCIs) and multiple sclerosis (MS). We therefore identified patients followed at our institution by health data hub digging, using a specific procedure coding system in use in France, who have been treated at least once with detrusor and skeletal muscle BTIs within the same 1-month period, over the past 5 years (2017-2021). We analyzed 72 patients representing 319 CIs. Fifty (69%) were male, and the patients were mostly SCI (76%) and MS (18%) patients and were treated by a mean number of CIs of 4.4 ± 3.6 [1-14]. The mean cumulative dose was 442.1 ± 98.8 U, and 95% of CIs were performed within a 72 h timeframe. Among all CIs, five patients had symptoms evocative of distant spread but only one had a confirmed pathological jitter in single-fiber EMG. Eleven discontinued CIs for surgical alternatives: enterocystoplasty (five), tenotomy (three), intrathecal baclofen (two) and neurotomy (one). Concomitant BTIs for treating both spasticity and NDOI at the same time appeared safe when performed within a short delay and in compliance with actual knowledge for maximum doses.

Comparative Study on the Duration and Efficacy of Various Botulinum Toxin Type A Injections for Reducing Masseteric Muscle Bite Force and Treating Facial Wrinkles

OBJECTIVE

Botulinum toxin serotype A (BoNT/A) is widely used for minimal invasive aesthetic treatments. Different brands of BoNT/A exhibit structural variations. The aim of this study was to compare the duration and efficacy of various BoNT/A brands available in Thailand for reducing bite force and treating wrinkles.

METHODS

Fifty participants were randomly assigned to one of five groups, with each group receiving a different BoNT/A brand, namely, incobotulinumtoxinA (IncoA), onabotulinumtoxinA (OnaA), abobotulinumtoxinA (AboA), letibotulinumtoxinA (LetiA), and prabotulinumtoxinA (PraboA). BoNT/A was administered to the masseter muscle and the upper face. Bite force was measured before injection and at 2, 4, 8, 12, 16, 20, and 24 weeks post-injection. Evaluation scores for wrinkle improvement were assessed after the treatment.

RESULTS

The most significant reduction in bite force occurred between 2 and 4 weeks post-injection. PraboA demonstrated the most substantial reduction in bite force, while IncoA had the least effect. However, the percentage of bite force reduction did not exhibit statistical significance between BoNT/A types. Additionally, the reduction in bite force for all BoNT/A types was reversed at 4 months post-injection. More than half of the participants experienced improvement beyond 16 weeks.

CONCLUSIONS

The structural differences among BoNT/A brands did not significantly affect the longevity and efficacy of bite force reduction and wrinkle treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: TCTR20211205001 (registered 4 Dec 2021).

Botulinum Toxin in Chronic Lateral Epicondylitis, from Tendon to Muscle Approach-A Review

BACKGROUND

Chronic lateral epicondylitis challenges the therapeutical approach; underlying mechanisms are incompletely understood; neuropathic pain and central and peripheral sensitization may explain the fact that botulinum toxin has been found to play a role in pain and function management.

METHODS

We searched the literature for MeSH terms: lateral epicondylitis or synonyms and botulinum toxin.

RESULTS

We found 14 papers containing trials on botulinum toxin injection into the tendon or into the extensor muscles (specifically, extensor carpi radialis brevis and extensor communis digitorum). We followed the administration pathways, doses, timing, and side effects.

CONCLUSIONS

With a chronic course, the focus of the therapy shifts from the afflicted tendon to the inserting muscles, as muscle contracture may create a vicious loop to perpetuate and aggravate the disease. Doses, timing, and side effects are discussed.

The Role of Botulinum Toxin Type-A in Spasticity: Research Trends from a Bibliometric Analysis

Botulinum toxin type-A (BoNT-A) has emerged as a key therapeutic agent for the management of spasticity. This paper presents a comprehensive bibliometric and visual analysis of research concerning BoNT-A treatment of spasticity to elucidate current trends and future directions in this research area. A search was conducted in the Web of Science database for articles focused on the use of BoNT-A in spasticity published between 2000 and 2022. We extracted various metrics, including counts of publications and contributions from different countries, institutions, authors, and journals. Analytical methods in CiteSpace were employed for the examination of co-citations, collaborations, and the co-occurrence of keywords. Our search yielded 1489 publications. Analysis revealed a consistent annual increase in research output. The United States, United Kingdom, and Italy were the leading contributors. The top institution in this research was Assistance Publique Hopitaux, Paris. The journal containing the highest number of relevant publications was Toxins. Key frequently occurring keywords were 'stroke', 'cerebral palsy', 'adult spasticity', and 'upper extremity'. This study identified 12 clusters of keywords and 15 clusters of co-cited references, indicating the main focus areas and emerging themes in this field. This study comprehensively analyzed and summarized trends in BoNT-A research in the field of spasticity over the past 22 years.

Real-world differences in dosing and clinical utilization of OnabotulinumtoxinA and AbobotulinumtoxinA in the treatment of upper limb spasticity

According to prescribing information, potency units are not interchangeable between botulinum toxin A products. This exploratory study compared real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA in adults with upper limb spasticity. In this retrospective study, 101 clinicians provided chart data via online surveys for 215 US post-stroke patients treated for upper limb spasticity with ≥3 onabotulinumtoxinA or abobotulinumtoxinA doses (phase 1: 9/18/2020-12/10/2020; phase 2: 9/30/2021-12/7/2021). Most participating clinicians were physicians (70.3%) specializing in neurology (71.3%) or physiatry (20.8%). In the onabotulinumtoxinA (n = 107) and abobotulinumtoxinA (n = 108) groups, ∼75% of patients had moderate-to-severe spasticity. A range of onabotulinumtoxinA:abobotulinumtoxinA dose ratios (1:2.2 [95%CI: 1.8-2.6] to 1:4.1 [95%CI: 3.0-6.0]) was observed across muscles. For the most recent dose, mean number of muscles injected was greater for onabotulinumtoxinA (4.3) versus abobotulinumtoxinA (3.1; P = 0.0003). For onabotulinumtoxinA versus abobotulinumtoxinA, the proportion of injections was 81.3% versus 63.9% (P = 0.0067) in forearm muscles and 23.4% versus 3.7% (P = 0.0001) in hand muscles. Mean injection intervals were similar (onabotulinumtoxinA: 102.0 days; abobotulinumtoxinA: 99.1 days). Differences in real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA for upper limb spasticity were observed. There was no standard dose-conversion ratio, consistent with each product's prescribing information.

Robotic gait training and botulinum toxin injection improve gait in the chronic post-stroke phase: A randomized controlled trial

BACKGROUND

Improving walking ability is one of the main goals of rehabilitation after stroke. When lower limb spasticity increases walking difficulty, botulinum toxin type A (BTx-A) injections can be combined with non-pharmacologic interventions such as intensive rehabilitation using a robotic approach. To the best of our knowledge, no comparisons have been made between the efficacy of robotic gait training and conventional physical therapy in combination with BTx-A injections.

OBJECTIVE

To conduct a randomized controlled trial to compare the efficacy on gait of robotic gait training versus conventional physiotherapy after BTx-A injection into the spastic triceps surae in people after stroke.

METHOD

Thirty-three participants in the chronic stroke phase with triceps surae spasticity inducing gait impairment were included. After BTx-A injection, participants were randomized into 2 groups. Group A underwent robotic gait training (Lokomat®) for 2 weeks, followed by conventional physiotherapy for 2 weeks (n = 15) and Group B underwent the same treatment in reverse order (n = 18). The efficacy of these methods was tested using the 6-minute walk test (6MWT), comparing post-test 1 and post-test 2 with the pre-test.

RESULTS

After the first period, the 6MWT increased significantly more in Group A than in Group B: the mean difference between the interventions was 33 m (95%CI 9; 58 p = 0.007; g = 0.95), in favor of Group A; after the second period, the 6MWT increased in both groups, but the 30 m difference between the groups still remained (95%CI 5; 55 p = 0.019; g = 0.73).

CONCLUSION

Two weeks of robotic gait training performed 2 weeks after BTx-A injections improved walking performance more than conventional physiotherapy. Large-scale studies are now required on the timing of robotic rehabilitation after BTx-A injection.

[Safety and efficacy of Relatox in comparison with Dysport in the treatment of focal spasticity of the upper limb in patients after stroke and traumatic brain injury (results of a prospective simple blind randomized comparative study in parallel groups)]

OBJECTIVE

Evaluation of the safety and effectiveness of Relatox, botulinum toxin type A in patients with focal spasticity (FS) of the upper limb as a result of a cerebrovascular accident (CVA) or traumatic brain injury (TBI).

MATERIAL AND METHODS

A multicenter, prospective, single-blinded, randomized, comparative clinical study included 210 patients of both sexes aged 18-75 years after moderate to severe TBI and CVA in seven sites in the Russian Federation. The patients were randomized into two groups. Group 1 patients (n=105) with focal spasticity of the upper limb received Relatox injections into the muscles of the target pathological patterns (flexion of the elbow, hand, or fingers); Group 2 patients (n=105) received Dysport injections (reference agent). The drugs were injected with electromyographic (EMG) or ultrasound (US) control at a dose of no more than 400 Units of Relatox or 1000 Units of Dysport. Botulinum therapy was administered to patients for the first time or repeatedly, but not earlier than 3 months after CVA or TBI and 3 months (12 weeks) after the previous injection. At 4 and 12 weeks, spasticity was assessed using the Modified Ashworth Scale (MAS) for the muscles of the target spasticity pattern of the upper limb, the severity of disability was used to assess the Disability Assessment Scale (DAS), the severity of pain was evaluated using to the Numerical Pain Rating Scale (NPRS), and the satisfaction with treatment was measured by the Patient Global Impression of Improvement (PGI-I). The rate of adverse events (AEs) was reported.

RESULTS

A decrease in spasticity (decrease in MAS values) was shown in both groups without statistically significant intergroup differences at 4 weeks after injection for the muscles of the leading spasticity pattern of the upper limb (efficacy was assessed jointly for all target patterns) compared to the total score at the screening visit. The effect persisted for 12 weeks (more pronounced in the Relatox group). A significant decrease in pain severity according to the NPRS scale without significant intergroup differences was reported in both groups (slightly greater in Relatox group patients). The decrease in the mean DAS score with a statistically significant intergroup difference in hygiene, dressing, and overall well-being according to the PGI-I overall improvement scale was also greater in patients who received Relatox. Few local and systemic AEs were reported in both groups, with no intergroup differences. There were no significant deviations in laboratory parameters.

CONCLUSION

The results indicate the safety, good tolerability, and efficacy of Relatox in patients with focal spasticity of the upper limb after focal brain damage due to CVA or TBI, comparable and even slightly longer in duration than those of Dysport, which supports its widespread use in the rehabilitation.

The use of botulinum toxin type a to prepare patients with large ventral hernias for laparoscopic hernioplasty: Our experience

OBJECTIVE

Aim: To study the effectiveness of BTA in a total dose of 100 IU as the preparation for patients with primary and incisional ventral hernias (VH).

PATIENTS AND METHODS

Materials and Methods: The prospective study included 59 patients with large VH (defect ³10 cm). All patients received 100 IU of BTA in abdominal wall muscles 4-5 weeks before surgery from June 2017 to December 2022. An average age of the patients was 59.13 ± 9.07 years, body mass index - 32.20 ± 4.95 kg/m2.

RESULTS

Results: An average width of the hernia defect after BTA decreased by 4.5 ± 1.11 cm (p<0.001). An average length of the hernia defect after BTA also decreased, without clinical significance. A significant increase in the length of the abdominal wall and a decrease in its thickness were observed. The abdominal cavity volume after BTA increased by 4.04 ± 4.55% (p=0.008) and the hernial sac volume decreased by 21.43 ± 16.57% (p=0.005). All patients underwent surgery with hernia defect suturing and without component separation: laparoscopic IPOM hernioplasty - 50 (84.7%) patients, open IPOM hernia repair - 7 (11.9%) patients, open sublay hernioplasty - 2 (3.4%) patients. There was no recurrence of hernia during 12 months after surgery.

CONCLUSION

Conclusions: The administration of 100 IU BTA allows to increase the length of the abdominal wall muscles and to perform laparoscopic IPOM hernioplasty for patients with large VH.

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.

Botulinum toxin injection in vulva and vagina. Evidence from a literature systematic review

INTRODUCTION

Botulinum toxin (BoNT) administration has been proposed in the gynecologic field for pelvic, vulvar and vaginal disorders. On this regard, we aimed assessing the therapeutic effectiveness and safety of BoNT usage in the treatment of vaginal, vulvar and pelvic pain disorders.

METHODS

We searched for all the original articles without date restriction until 31.12.2021. We included all the original articles which administered botulinum toxin in the vulva or vagina of women suffering from vaginismus, dyspareunia, and chronic pelvic pain. Only English language studies and those performed in humans were eligible. We excluded all case reports and pilot study from the qualitative analysis, although we accurately evaluated them. 22 original studies were finally included in the systematic review.

RESULTS

Botulinum toxin injection was found to be effective in improving vulvar and vaginal dyspareunia, vaginismus, and chronic pelvic pain. No irreversible side effects were detected. Major side effects reported were transient urinary or fecal incontinence, constipation and rectal pain. The risk of bias assessment proved original articles to be of medium quality. No metanalysis could have been performed since lack of congruency in the definition of pathology and methods of botulinum toxin administration.

CONCLUSION

Data extraction pointed out different endpoints and different methods of analysis. Studies focus on different types of participants and use various techniques and timing. According to the best evidence available, different techniques provide evidence about positive outcomes, with the need for a standardized protocol.

Tailored Indications for Different Neurotoxins

Background

Minimally invasive procedures have become increasingly popular because they require minimal downtime and are effective for achieving a more youthful appearance. All U.S. Food and Drug Administration-approved neurotoxins are indicated for achieving similar effects, even though they are different in regard to structure, manufacturing technique, and storage requirements. It is agreed upon that each neurotoxin is unique and therefore not interchangeable. The aim of the author is to provide an approach for choosing the optimal toxin in different indications regarding the area of treatment, the age and characteristics of the patient, potential risks, and ultimate goals.

Methods

As the country that the author practices carries onabotulinum (ONA), prabotulinum (PRA), and abobotulinum (ABO) toxin type-A, one of these three toxins was preferred for each category. ABO toxins were preferred in wide areas due to the broader action halo. Typical examples include hyperhidrosis treatment, wide forehead area, and calf slimming. In areas where very precise and targeted treatment is required, PRA and ONA toxins were preferred to limit potential side effects due to wider diffusion. First-time patients were typically treated with PRA toxins for a softer trial periods where as "repeat" patients were successfully treated with ABO toxins.

Results

No toxin is superior to the other in terms of producing effects. Yet, small differences in their properties can allow the plastic surgeon to cater to each patient's needs while yielding the most optimal results.

Conclusions

This study is meant to serve as a guideline for choosing the ideal toxin in different patient settings and indications.

Botulinum Toxin Treatment of Adult Muscle Stem Cells from Children with Cerebral Palsy and hiPSC-Derived Neuromuscular Junctions

Botulinum neurotoxin type-A (BoNT) injections are commonly used as spasticity treatment in cerebral palsy (CP). Despite improved clinical outcomes, concerns regarding harmful effects on muscle morphology have been raised, and the BoNT effect on muscle stem cells remains not well defined. This study aims at clarifying the impact of BoNT on growing muscles (1) by analyzing the in vitro effect of BoNT on satellite cell (SC)-derived myoblasts and fibroblasts obtained from medial gastrocnemius microbiopsies collected in young BoNT-naïve children (t0) compared to age ranged typically developing children; (2) by following the effect of in vivo BoNT administration on these cells obtained from the same children with CP at 3 (t1) and 6 (t2) months post BoNT; (3) by determining the direct effect of a single and repeated in vitro BoNT treatment on neuromuscular junctions (NMJs) differentiated from hiPSCs. In vitro BoNT did not affect myogenic differentiation or collagen production. The fusion index significantly decreased in CP at t2 compared to t0. In NMJ cocultures, BoNT treatment caused axonal swelling and fragmentation. Repeated treatments impaired the autophagic-lysosomal system. Further studies are warranted to understand the long-term and collateral effects of BoNT in the muscles of children with CP.

Botulinum Toxin for Drooling in Adults with Diseases of the Central Nervous System: A Meta-Analysis

(1) Background: The purpose of this study was to determine whether the drooling of adult patients with diverse central nervous system diseases can be treated with botulinum toxin type A. (2) Methods: The Cochrane Library, MEDLINE, and Embase were all searched for studies that fit the inclusion criteria. The patients in the studies had to be adults (>18 years old), and the studies had to be randomized placebo-controlled trials, controlled trials, or prospective studies. Each study had to have enough quantifiable data available for meta-analysis. The primary outcome measure was the Drooling Severity and Frequency Scale (DSFS). (3) Results: The meta-analysis comprised three studies. A statistically significant difference in DSFS score between the treatment and control groups was observed in the meta-analysis, with an overall standardized mean difference of -0.9377 (95% CI, -1.2919 to -0.5836; p < 0.0001). A total of seven studies were ineligible for inclusion in the meta-analysis and were only assessed as qualitative data. All qualitative studies showed a significant reduction in DSFS score a few weeks or months after the injection of botulinum toxin. (4) Conclusions: Botulinum toxin type A is safe and effective as a treatment for drooling in adult patients with central nervous system diseases.

Long-Term Muscular Atrophy and Weakness Following Cessation of Botulinum Toxin Type A Injections in the Flexor Digitorum Muscle of Musicians with Focal Hand Dystonia

The present study assessed muscular atrophy and weakness of the flexor digitorum superficialis (FDS) and profundus (FDP) muscle as possible long-term side effects of botulinum toxin (BoNT) injections in hand dystonia patients after the termination of their treatment. For the assessment of both parameters, a group of 12 musicians diagnosed with focal hand dystonia was compared with a group of 12 healthy matched musicians. The minimum and maximum times since the last injection across patients were 0.5 to 3.5 years, respectively. The thickness and strength of the FDS and FDP were assessed via ultrasonography and a strength measurement device. Group differences were estimated through the calculation of the symmetry index between the dominant and non-dominant hand. The results revealed that compared to the control group, thickness and flexion strength of the injected FDS and FDP were decreased by 10.6% ± 5.3% (95% CI) and 12.5% ± 6.4% (95% CI), respectively, in the patient group. The amount of weakness and atrophy was predicted significantly by the total amount of BoNT injected throughout the entire treatment period. In contrast, the time after the last injection did not predict the amount of strength and muscle mass recovery after the cessation of the treatment. The current study revealed that even up to 3.5 years after the termination of BoNT injections, long-term side effects such as weakness and atrophy can still be observed. We suggest that the total BoNT dose should remain as small as possible to reduce long-lasting side effects to the minimum. Although side effects differ significantly among patients, a potential full recovery of atrophy and weakness after the cessation of BoNT treatment might be observed after periods longer than 3.5 years.

Is there a role for botulinum toxin A in the emergency setting for delayed abdominal wall closure in the management of the open abdomen? A systematic review

INTRODUCTION

Emergency laparotomy for either trauma or non-trauma indications is common and management is varied. Use of the open abdomen technique allowing for planned re-look is an option; however, performing delayed definitive fascial closure (DFC) following this can be a challenge. The use of botulinum toxin-A (BTX) infiltration into the lateral abdominal wall has been well documented within the elective setting; its use within the emergency setting is undecided. This systematic review assesses the efficacy and safety of BTX injection into the lateral abdominal wall muscles in the emergency setting. The primary outcome is DFC rate.

METHODS

Systematic review was performed according to the PROSPERO registered protocol (CRD42020205130). Papers were dual screened for eligibility, and included if they met pre-stated criteria where the primary outcome was DFC. Articles reporting fewer than five cases were excluded. Bias was assessed using the Cochrane Risk of Bias and Joanna Brigg's appraisal tools.

FINDINGS

Fourteen studies were screened for eligibility, twelve full texts were reviewed and two studies were included. Both studies showed evidence of bias due to confounding factors and lack of reporting. Both studies suggested significantly higher rates of DFC than reported in the literature against standard technique (90.7% vs 66%); however, these data are difficult to interpret due to strict study inclusion criteria or lack of a control population.

CONCLUSION

The use of BTX is deemed safe and its effects in the emergency situation may have great potential. Unfortunately, to date, there is insufficient evidence to facilitate opinion.

A Bayesian Network Meta-Analysis and Systematic Review of Guidance Techniques in Botulinum Toxin Injections and Their Hierarchy in the Treatment of Limb Spasticity

Accurate targeting of overactive muscles is fundamental for successful botulinum neurotoxin (BoNT) injections in the treatment of spasticity. The necessity of instrumented guidance and the superiority of one or more guidance techniques are ambiguous. Here, we sought to investigate if guided BoNT injections lead to a better clinical outcome in adults with limb spasticity compared to non-guided injections. We also aimed to elucidate the hierarchy of common guidance techniques including electromyography, electrostimulation, manual needle placement and ultrasound. To this end, we conducted a Bayesian network meta-analysis and systematic review with 245 patients using the MetaInsight software, R and the Cochrane Review Manager. Our study provided, for the first time, quantitative evidence supporting the superiority of guided BoNT injections over the non-guided ones. The hierarchy comprised ultrasound on the first level, electrostimulation on the second, electromyography on the third and manual needle placement on the last level. The difference between ultrasound and electrostimulation was minor and, thus, appropriate contextualization is essential for decision making. Taken together, guided BoNT injections based on ultrasound and electrostimulation performed by experienced practitioners lead to a better clinical outcome within the first month post-injection in adults with limb spasticity. In the present study, ultrasound performed slightly better, but large-scale trials should shed more light on which modality is superior.

The safety of botulinum neurotoxin type A's intraarticular application in experimental animals

In vivo studies of botulinum neurotoxin type A (BoNT-A) enabled characterization of its activity in the nociceptive sensory system separate from its preferred action in motor and autonomic nerve terminals. However, in the recent rodent studies of arthritic pain which employed high intra-articular (i.a.) doses (expressed as a total number of units (U) per animal or U/kg), possible systemic effects have not been conclusively excluded. Herein we assessed the effect of two pharmaceutical preparations, abobotulinumtoxinA (aboBoNT-A, 10, 20, and 40 U/kg corresponding to 0.05, 0.11, and 0.22 ng/kg neurotoxin) and onabotulinumtoxinA (onaBoNT-A, 10 and 20 U/kg corresponding to 0.09 and 0.18 ng/kg, respectively) injected into the rat knee, on safety-relevant readouts: digit abduction, motor performance and weight gain during 14 days post-treatment. The i. a. toxin produced dose-dependent impairment of the toe spreading reflex and rotarod performance, which was moderate and transient after 10 U/kg onaBoNT-A and ≤20 U/kg aboBoNT-A doses, and severe and long-lasting (examined up to 14 days) after ≥20 U/kg of onaBoNT-A and 40 U/kg aboBoNT-A. In addition, lower toxin doses prevented the normal weight gain compared to controls, while higher doses induced marked weight loss (≥20 U/kg of onaBoNT-A and 40 U/kg aboBoNT-A). Commonly employed BoNT-A formulations, depending on the doses, cause local relaxation of the surrounding muscles and systemic adverse effects in rats. Thus, to evade possible toxin unwanted local or systemic spread, careful dosing and motor testing should be mandatory in preclinical behavioral studies, irrespective of the sites and doses of toxin application.

Anatomical Proposal for Botulinum Neurotoxin Injection Targeting the Platysma Muscle for Treating Platysmal Band and Jawline Lifting: A Review

The platysma muscle is a thin superficial muscle that covers the entire neck and lower part of the face. The platysma muscle is the primary target muscle for botulinum neurotoxin injection therapy aimed at treating platysmal band and lower facial lifting. In the procedure of botulinum neurotoxin injection therapy, a lack of knowledge of the anatomy of the platysma muscle and the properties of botulinum neurotoxin can lead to side effects such as dysphagia, dysphonia, and weakness of the neck muscles. Anatomically safe injection sites have been proposed for the platysma muscle, and the appropriate injection technique has been reviewed. We proposed optimal injection sites based on the external anatomical features of the mandible. The aim of these proposal was to standardize the procedure for the effective use of botulinum neurotoxin injections by minimizing the dose unit and injection points and thereby preventing adverse events.

A novel technique of botulinum toxin injection around skull sutures for chronic migraine: A randomized controlled clinical trial

Background

Migraine is a chronic headache manifested with attacks. Here we aimed to evaluate and compare the efficacy of 15-point Dysport injection with 31-point Xeomin injections.

Materials and Methods

This is a randomized clinical trial performed in 2020-2021 in Isfahan on patients with refractory chronic migraine. A total number of 60 patients entered the study. The pain of patients was also determined using headache impact test (HIT) questionnaire. Patients were randomized into two groups: Group 1 underwent 31-point Xeomin injection and Group 2 underwent 1 vial of Dysport injection into 15 points of the scalp.

Results

Our study revealed that the data regarding aura, nausea, vomit, photosensitivity, sensitivity to sounds and smells did not change significantly between two groups compared to the beginning of the study. Frequency, duration, intensity of headaches, and the mean HIT score of all patients improved significantly within 3 months after interventions. Comparing both groups showed no significant differences (P > 0.05). HIT score was decreased from 21.26 ± 3.58 before intervention to 15.51 ± 4.58 after 3 months in Group 1 and 22.23 ± 2.59-10.33 ± 2.26 in Group 2. In both groups, these changes were statistically significant (P < 0.001). Although we found more decrease of HIT score in Group 2 comparing with Group 1 (10.33 ± 2.26 vs. 15.51 ± 4.58), this difference was not statistically significant (P = 0.12).

Conclusion

Although Xeomin and Dysport injections are both effective and reduced pain in patients with chronic migraine, our new technique is probably better than the standard technique. Because the injection points are halved, increase patients comfort and reduce overall cost.

Botulinum toxin type A for the treatment of excessive gingival display - A systematic review

Gummy smile has traditionally been treated with invasive or demanding surgical and orthodontic techniques. Several studies have shown that targeted injection of the upper lip elevator muscles with botulinum toxin is an effective treatment for this condition. However, no standardized injection protocol with reproducible results has yet been published. A systematic review of the literature has been performed using Medline, Scopus, and Embase. All articles relevant to the research question were analyzed. After removing duplicates, 162 articles were selected, of which 9 were included in the analysis after applying exclusion and inclusion criteria, for a total of 269 patients. Onabotulinum toxin type A (ONA-BoNTA) was used in 7 studies and abobotulinum toxin type A (ABO- BoNTA) in 2 studies, at various dilutions. The number of sites injected varied from 1 to 3 per side, with variable targeting of the Levator labii superioris alaeque nasalis, Levator labii superioris, Zygomaticus minor, Zygomaticus major and Orbicularis oris. The dose used per side varied from 1.25 to 6 U of ONA-BoNTA and from 2.5 to 7.5 U of ABO- BoNTA. The injection protocol was tailored to the type of gingival smile in one study only, another study compared results of targeting two different muscles, and one study evaluated different dosages of toxin for the same injection site. The average improvement ranged from 24.85% to 99.65% and the effect persisted from 12 to 36 weeks. Very good patient satisfaction was reported in 6 studies. Fourteen adverse events were reported, all of them mild and transient. The treatment of gummy smile by botulinum toxin injection is effective, safe, rapid, minimally invasive and reversible. Protocols vary widely in the literature and no standardized procedure emerges. A patient-specific approach, adapted to their anatomy, type of gummy smile and the severity of the exposure seems to be the most appropriate. Randomized controlled studies are needed to make this approach more systematic.

Safety and Efficacy of HU-014 in the Treatment of Post-Stroke Upper Limb Spasticity: A Phase I Pilot Study

Botulinum toxin type A (BTX-A) is widely used for treating post-stroke upper limb spasticity. We evaluated the safety and efficacy of HU-014 in treating post-stroke upper limb spasticity. Thirteen patients were administered with HU-014. The primary outcome was safety, including adverse events, vital signs, physical examination, laboratory tests, and antibody formation test. The secondary outcomes were changes in the Modified Ashworth Scale (MAS) score for wrist, elbow, and finger flexor; Disability Assessment Scale (DAS); Investigator's Global Assessment (IGA) and Subject's Global Assessment (SGA); Caregiver Burden Scale (CBS); and Columbia Suicide Severity Rating Scale (C-SSRS) at weeks 4, 8, and 12 from baseline. No notable safety-related issues were reported. MAS and DAS scores were significantly decreased from those at baseline at 4, 8, and 12 weeks (p < 0.05). At weeks 4, 8, and 12, the IGA and SGA scores were 5.85 ± 0.55, 5.69 ± 0.48, and 5.62 ± 0.65 and 5.46 ± 1.20, 5.85 ± 0.38, and 5.77 ± 0.73, respectively. CBS scores decreased at all timepoints and those for cutting fingernails significantly decreased at 8 and 12 weeks compared with baseline (p < 0.05). C-SSRS scores showed that suicidal ideation in all patients was "low" at all timepoints. HU-014 is a safe treatment that can improve post-stroke upper limb spasticity.

Adjuvant medical therapy in cervical dystonia after deep brain stimulation: A retrospective analysis

Background

There is limited information on optimization of symptomatic management of cervical dystonia (CD) after implantation of pallidal deep brain stimulation (DBS).

Objectives

To describe the long-term, “real-world” management of CD patients after DBS implantation and the role of reintroduction of pharmacologic and botulinum toxin (BoNT) therapy.

Methods

A retrospective analysis of patients with focal cervical or segmental craniocervical dystonia implanted with DBS was conducted.

Results

Nine patients were identified with a mean follow-up of 41.7 ± 15.7 months. All patients continued adjuvant oral medication(s) to optimize symptom control post-operatively. Three stopped BoNT and four reduced BoNT dose by an average of 22%. All patients remained on at least one medication used to treat dystonia post-operatively.

Conclusion

Optimal symptom control was achieved with DBS combined with either BoNT and/or medication. We suggest utilization of adjuvant therapies such as BoNT and/or medications if DBS monotherapy does not achieve optimal symptom control.

Comparison of Botulinum neurotoxin efficiency in dystonia associated with Parkinson's disease and atypical parkinsonism: a retrospective study with a self-reported improvement scale

Botulinum neurotoxin (BoNT) is a useful therapeutic option to treat dystonic manifestations. Data on its efficiency on dystonia associated with Parkinson's disease (PD) or atypical parkinsonism (AP) are scarce and no comparison of the efficiency of BoNT has been performed between these diseases and between the different localizations of dystonia in these pathologies. We retrospectively collected from patients' medical records the result of 611 BoNT injections in 63 dystonic parkinsonian patients (44 PD and 19 AP) using a self-reported clinical improvement scale and duration of effect. Using these data, we modeled the degree of improvement and its duration after BoNT treatment with a linear mixed model. This allowed us to assess the influence of clinical parameters on the reported treatment efficiency. On a scale from 0 to 100, patients with PD and AP, respectively, report a mean improvement of 69% and 55% after BoNT injection and it is similar regarding the different localizations of dystonia. Duration of effect is, however, longer in PD compared to AP (P = 0.023). Patients' demographic and clinical characteristics had no effect on the degree of improvement or duration of effect. Overall, our results support the use of BoNT in the various dystonic phenomena associated with degenerative parkinsonian syndromes. Shorter delays between injection sessions should be considered in AP compared to PD.Trial registration: This study was registered on Clinicaltrial.gov (NCT04948684).

Use of Cosmetic Facial Injectables After Facial Aesthetic Surgery

BACKGROUND

Over the last two decades, both invasive and minimally-invasive aesthetic procedures have proliferated. Aesthetic surgeons often recommend injectable treatments after cosmetic facial surgery for multiple reasons. Yet, literature is lacking on how cosmetic surgery affects post-operative facial injectable use.

OBJECTIVES

The authors aim to identify predictors of facial injectable use after cosmetic facial surgery.

METHODS

All adult patients operated on by a single surgeon between 2013 and 2021 were retrospectively reviewed. Patients who had any of the following cosmetic facial surgeries were included: rhytidectomy, blepharoplasty, rhinoplasty, or genioplasty. Patient demographics, clinical history, intraoperative factors, and use of cosmetic facial injectables (neurotoxin, facial fillers, deoxycholic acid, poly-L-lactic acid) were recorded.

RESULTS

A total of 227 patients who underwent facial cosmetic surgery were reviewed, of which 158 were included. 89 patients had rhytidectomy (56.3%), 112 had blepharoplasty (70.9%), 28 had rhinoplasty (17.7%), and 7 had genioplasty (4.4%). 44.3% patients received injectables after their surgery (n=73), compared to only 17.7% before surgery (n=28) (p<0.001). The most common post-operative injectables were neurotoxins (48.5%) and facial fillers (46.0%), followed by deoxycholic acid (2.7%) and poly-L-lactic acid (2.7%). Multivariate regression revealed factors positively correlated with future injectable use were index blepharoplasty or rhinoplasty, and history of pre-operative neurotoxin injection (p<0.05).

CONCLUSIONS

Cosmetic facial injectables are an important consideration in achieving and maintaining optimal facial aesthetics. Their use, especially neurotoxins and facial fillers, increases among patients post-operatively. These results highlight the contribution of injectable procedures in the context of multidimensional care for augmenting facial aesthetics.

Therapeutic Approach to Botulinum Injections for Hemifacial Spasm, Synkinesis and Blepharospasm

The aim of this study was to show our therapeutic outcome of botulinum injection to the facial muscles and thereby to find the best therapeutic concept which should be embraced. The decision to treat the lower eyelid with 1-point or 2-points injection was randomly taken as there is no consensus regarding this debate. Injections of the lateral end of the upper eyelid were performed more laterally to the conventional injection point, just lateral to the conjunction of the upper and lower eyelids. Twenty-three patients (12 hemifacial spasm, 6 blepharospasm, 5 post facial palsy synkinesis) were enrolled. Data were retrieved from 112 visits between 2019 and 2022. Overall, 84.9% of the treatments had moderate or marked improvement. The most common side effect was facial weakness (11.8%). Neither ptosis nor diplopia were noted. Two-points regimen in the lower eyelid was associated with a lower risk of facial weakness (p = 0.01), compared to 1-point regimen, with a better therapeutic outcome as reflected by more favorable PGI-C scores (p = 0.04). Injection of the pretarsal segment of the upper eyelid, just onto or even lateral to the conjunction of the upper and lower eyelids, lowers the risk of ptosis.

Efficacy and safety of botulinum A toxin for the treatment of chronic peripheral neuropathic pain: A systematic review of randomized controlled trials and meta-analysis

BACKGROUND AND OBJECTIVE

Botulinum toxin type A (BTX-A) is a recently developed treatment for the management of peripheral neuropathic pain. The objective of this study was to provide a synthesis of the evidence concerning the efficacy and safety of subcutaneous botulinum toxin type A injections.

DATABASES AND DATA TREATMENT

We searched the MEDLINE, EMBASE, LILACS, Cochrane, and Clinical Trial Register databases for randomized controlled trials comparing subcutaneous BTX-A to placebo injections for treating chronic peripheral neuropathic pain. The primary endpoint was the assessment of pain 1 month after the injection. The secondary outcomes were the assessment of pain at 3 months, neuropathic pain intensity and quality of life at 1 and 3 months, and adverse effects. A random-effect meta-analysis was performed on the combined data. Evidence quality was rated by the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) method.

RESULTS

Ten randomized controlled trials including 505 patients were included in this review (registration number CRD42021239108). At 1 and 3 months after injection, the BTX-A groups had a lower mean difference (MD) in pain score (MD -1.87 (confidence intervals [CIs] -2.91; -0.83) and -1.38 (CI -1.95; -0.81), respectively). Subgroup analysis showed greater efficacy for diabetic polyneuropathy (MD -2.48, [-3.22; -1.74]). We found no impact of BTX-A on quality of life and no difference in adverse effect between BTX-A and placebo. The evidence was considered of moderate quality.

CONCLUSION

The pooled data suggest that subcutaneous BTX-A injections have a clinically significant effect, decreasing pain for three months after the injection, but no benefit in terms of quality of life has yet been demonstrated.

SIGNIFICANCE

We found that botulinum toxin is efficient and safe for the treatment of neuropathic pain, especially for diabetic polyneuropathy. Botulinum toxin type A, used for years in neurology, rehabilitation and physical medicine, has proved innocuous and effective, and should be considered as a serious alternative for pain treatment.

Effectiveness and Safety of Intracavernosal IncobotulinumtoxinA (Xeomin®) 100 U as an Add-on Therapy to Standard Pharmacological Treatment for Difficult-to-Treat Erectile Dysfunction: A Case Series

Registered pharmacological treatments are insufficiently effective for erectile dysfunction (ED) in around 30% of affected men. Intracavernosal injection (ICI) of ona- and abobotulinumtoxinA can reduce ED in insufficient responders. We aimed to assess the safety and effectiveness of incobotulinumtoxinA ICI as an add-on therapy to phosphodiesterase-type 5 inhibitors (PDE5-Is) or prostaglandinE1 ICIs (PGE1 ICIs) to treat ED that did not respond sufficiently to this treatment alone. We retrospectively analyzed data from 66 men with difficult to treat ED treated with single or repeated incobotulinumtoxinA 100U ICI as an add-on therapy. Response rate (increase in International Index of Erectile Function-Erectile Function domain score ≥ the minimum clinically important difference) was 52% (median (1st–3rd quartile) 43.5 (34–71) days post-incobotulinumtoxinA ICI). ED etiology (except spinal cord injury) and severity did not influence effectiveness. Only a clinically significant response to the 1st injection predicted a request for a 2nd injection (OR = 5.6, 95%, CI 1.6–19.4). Three men reported mild penile pain during the injection. These results provide preliminary evidence for the effectiveness and safety of incobotulinumtoxinA ICI as an add-on therapy to treat ED that is insufficiently responsive to standard care and provides support for the multicenter randomized clinical trial NCT05196308.

Complications of Cosmetic Botulinum Toxin A Injections to the Upper Face: A Systematic Review and Meta-Analysis

Background

Botulinum toxin A (BoNT-A) injections are a popular non-surgical procedure for facial rejuvenation. Its increase in popularity and utilization is met with limited regulations, potentially posing a significant risk to patient safety and public health.

Objectives

The authors sought to assess the safety profile of cosmetic glabellar and forehead BoNT-A injections and evaluate BoNT-A type on complication rate.

Methods

A systematic search of MEDLINE and EMBASE was performed for studies reporting complications after cosmetic BoNT-A in the glabellar or in the forehead region in the glabellar or in the forehead region. A random effects meta-analysis was carried out to assess complication rate. Where there were sufficient randomized-controlled trials, a network meta-analysis was performed.

Results

Of 556 identified articles, 24 were included in the final quantitative analysis, with 4268 BoNT-A injection sessions and 1234 placebos. Frequently observed treatment-related complications in the BoNT-A intervention group included headache, local skin reactions, and facial neuromuscular symptoms. The overall BoNT-A complication rate was 16%. The odds ratio of developing complications from abobotulinum toxin injections compared with placebo was 1.62 (1.15, 2.27; P > 0.05) and that from onabotulinum toxin injections compared with placebo was 1.34 (0.52, 3.48; P > 0.05). In 30% of the studies, the injectors were doctors, whereas the training status of the practitioner was not reported in the remaining 70%.

Conclusions

Cosmetic BoNT-A injections in the glabellar and forehead region appear to be safe, and most complications are mild and transient. Nevertheless, the literature demonstrates heterogeneous reporting of complications and a lack of consistency of the definition of treatment-related complications.

Level of Evidence: 2