Search Results (53)

Botulinum neurotoxin type A (BoNT/A) is intramuscularly injected for the treatment of, e.g., spasticity, cervical dystonia or facial lines. Several BoNT/A products with or without complexing proteins, with non-interchangeable dose units and various duration of effect claims, are approved but hard to compare. The goal of this study was to compare the complexing protein-free approved BoNT/A products IncobotulinumtoxinA (INCO), DaxibotulinumtoxinA (DAXI) and RelabotulinumtoxinA (RELA) in vitro and in vivo. BoNT/A protein content per 100 U was lowest in INCO and highest in DAXI (INCO 0.44, RELA 0.46, DAXI 0.58 ng/100 U). Relative bioactivity of INCO, DAXI and RELA was comparable (116, 104 and 117 U/100 labeled units). INCO and DAXI caused a maximum mouse digit abduction score (DAS) 2–3 days after IM injection of 20 or 40 U/kg. The DAS after 20 U/kg INCO was higher and showed a 10 days longer paralysis than DAXI at equivalent dosing. The in vivo spread of DAXI in the mouse gastrocnemius muscle was indistinguishable from that after INCO, and the spread of RELA ex vivo in porcine muscle was larger than INCO but equal to 0.9% NaCl. These results show the differences between 150 kDa botulinum type A toxin products beyond the published claims. Full article

Stiff person syndrome (SPS) is an autoimmune disorder with muscle stiffness and spasms, for which current therapies provide incomplete relief. Botulinum neurotoxin (BoNT) has been explored as an adjunctive symptomatic treatment. The aim of this review was to critically evaluate the clinical evidence for BoNT therapy in SPS. Using Medline, Scopus and Google Scholar, we identified nine reports that were published up to 1 January 2026. English articles and articles with information on study type, type/dose of BoNT and treatment results were included. One study was double-blind and placebo-controlled, one was retrospective and seven were single-case reports, comprising 46 patients. Open-label trials used botulinumtoxin-A (Botox, Dysport or Xeomin), while the blind study applied abobotulinumA (Dysport). All but one study (a case report) demonstrated motor improvement and a reduction in painful spasms associated with patient satisfaction. Reported doses ranged from 300 to 800 units for onabotulinumtoxinA and incobotulinumtoxinA and from 700 to 1000 units for abobotulinumtoxinA. The literature highlights the need for randomized clinical trials in larger cohorts, with careful selection of dose, injection sites, and adjunct physiotherapy, as well as an evaluation of early BoNT therapy in SPS. The novelty of this review lies in its critical synthesis of reported data and inclusion of most recent reports. Full article

This open-label, uncontrolled, single-arm, multicenter, phase 3 study evaluated the efficacy and safety of incobotulinumtoxinA in Japanese patients with blepharospasm. Eligible patients received incobotulinumtoxinA injections at fixed doses (50, 75, or 100 units [U] for those who had previously received botulinum toxin treatment; 50 U for treatment-naïve patients), followed by flexible doses up to 100 U for 48 weeks, with at least 6-week intervals. In total, 29 Japanese patients were enrolled (26 [89.7%] women, mean age 64.6 years, mean baseline Jankovic Rating Scale [JRS] severity score 3.24). The primary endpoint, the least squares mean of change in JRS severity scores from baseline to 6 weeks after the first injection, was −2.08 (95% confidence interval: −2.49, −1.66), meeting the prespecified efficacy criteria. The secondary endpoint results (JRS severity, frequency, and total scores for 48 weeks; Blepharospasm Disability Index; Patient Evaluation of Global Response; and fast blinking test) supported the efficacy of repeated incobotulinumtoxinA injections. Adverse events (AEs) occurred in 19 (65.5%) patients, with eyelid ptosis being the most common treatment-related AE (4 [13.8%] patients). No severe or serious AEs were reported. IncobotulinumtoxinA demonstrated sustained efficacy in Japanese patients with blepharospasm, without new safety concerns. (Japan Registry of Clinical Trials identifier, jRCT2031230711) Full article

Botulinum toxin type A (BoNT/A) formulations differ in their content of non-toxic accessory proteins, also known as complexing proteins (CPs), which may influence immunogenicity. Some BoNT/A products share structurally similar CPs, potentially leading to antibody cross-reactivity among formulations. This prospective study investigated whether patients treated with different BoNT/A products develop cross-reactive anti-CP antibody responses. One hundred participants were allocated into five treatment groups, each receiving a single BoNT/A formulation: incobotulinumtoxinA (IncoA), onabotulinumtoxinA (OnaA), abobotulinumtoxinA (AboA), letibotulinumtoxinA (LetiA), or prabotulinumtoxinA (PraboA). Each participant received 50 units or equivalent dosing. Serum samples were collected 180 days post-injection, and anti-CP antibodies were quantified using an absorption ELISA and compared with a toxin-naïve control group. IncoA did not induce significant anti-CP antibody responses. In contrast, higher antibody levels were observed in the OnaA, LetiA, and PraboA groups against multiple CPs, suggesting structural similarity and cross-reactivity. AboA primarily induced antibodies directed against its own CPs and those of PraboA. These findings demonstrate that CP-containing formulations can induce cross-reactive antibody responses, whereas CP-free incobotulinumtoxinA exhibits minimal immunogenicity. This study highlights the importance of CP composition in guiding clinical product selection, particularly in patients requiring repeated BoNT/A administration. Full article

Drooling and dysphagia are frequent and disabling complications in Parkinson’s disease (PD) and often coexist, with drooling mainly resulting from impaired saliva clearance due to reduced oral motor control and potentially worsening swallowing function. This study aimed to evaluate whether botulinum toxin type A (BoNT/A) injections into the major salivary glands, beyond controlling drooling, could also improve swallowing performance using clinical and neurophysiological measures. Twenty PD patients with severe drooling and dysphagia underwent bilateral ultrasound-guided BoNT/A injections into the parotid and submandibular glands. Assessments were performed at baseline and at 1, 8, and 12 weeks post-injection. Dysphagia severity was evaluated using the Penetration–Aspiration Scale and the Dysphagia Severity Rating Scale. Neurophysiological assessment included electromyographic recordings from suprahyoid/submental and cricopharyngeal muscles, together with mechanomyography analysis of laryngeal movement during swallowing. Following BoNT/A treatment, a consistent reduction in drooling was observed, accompanied by significant improvements in clinical dysphagia scores and neurophysiological swallowing parameters across all follow-up time points. These findings suggest that incobotulinumtoxinA injections into salivary glands not only reduce drooling but also enhance swallowing function in PD patients, possibly by facilitating oral floor and oropharyngeal motor coordination secondary to improved saliva management. Full article

Notalgia paresthetica is a condition characterized by pruritus and pain in the upper back, often associated with skin discoloration in the same area. Through Medline, Google Scholar, and Scopus search engines, we identified reports of eight clinical studies (published up to 1 December 2025) on the subject of botulinum neurotoxin therapy for Notalgia Paresthetica (NP). Only one of the eight studies was double-blind and placebo-controlled. The search strategy included only articles published in English and Spanish, and articles providing basic information such as the type of study, type and dose of the toxin, and results of the treatment. Articles not in English or Spanish, review articles, and articles failing basic information were excluded. A total of 34 patients were found across all studies. The injected toxin in the open-label studies was onabotulinumtoxin-A (Botox), whereas in the blinded study, the investigators used incobotulinumtoxinA (Xeomin). All open-label studies reported improvement in pruritus, and some reported improvement in pain, whereas the blinded study failed to do so. The possible reasons for this discrepancy between the blinded and the open-label studies are discussed. There is a need for double-blind, placebo-controlled studies with a larger number of patients, preferably using the same neurotoxin that has suggested efficacy in the open-label studies. The novelty of this review is that it represents a comprehensive and critical literature assessment on this topic and that it includes data not present in the previous reviews of this subject. Full article

Background: Cosmetic injection of botulinum neurotoxin type A (BoNT/A) into the submandibular glands is increasingly performed to enhance jawline contour. Although generally considered safe, unintended diffusion of the toxin can impair pharyngeal musculature and lead to dysphagia. Severe aspiration-prone dysphagia after esthetic submandibular gland injection has rarely been described. Case Presentation: A healthy 37-year-old woman developed acute oropharyngeal dysphagia the day after receiving cosmetic contouring injections with incobotulinumtoxinA (Xeomin^®), administered to both submandibular glands (20 units per gland, performed without ultrasound guidance). She presented to our rehabilitation medicine clinic 11 days later with severe difficulty swallowing solids and liquids. Her functional oral intake was severely restricted (Functional Oral Intake Scale [FOIS] score 3), and the Eating Assessment Tool-10 (EAT-10) score was 24. Videofluoroscopic swallowing study (VFSS) demonstrated markedly delayed pharyngeal swallow initiation, reduced palatal elevation, poor airway protection, consistent laryngeal penetration, and silent aspiration of thin liquids (Penetration–Aspiration Scale score 8). She underwent diet modification and structured dysphagia rehabilitation. At three months, repeat VFSS showed substantial improvement, with only occasional penetration of large-volume thin liquids, corresponding to FOIS 5 and EAT-10 score 8. By five months, VFSS confirmed complete resolution of penetration and aspiration with normalization of swallowing physiology, reflected by a FOIS score of 7 and EAT-10 score of 1. Conclusions: This case demonstrates that cosmetic incobotulinumtoxinA injection into the submandibular glands, particularly when performed without ultrasound guidance, can lead to significant oropharyngeal dysphagia. Clinicians performing esthetic lower-face procedures should be aware of this potential complication and ensure timely swallowing evaluation and rehabilitation when symptoms arise. Full article

Background/Objectives: The aim of this study was to compare the efficacy and safety of a single cycle of incobotulinumtoxinA versus placebo in pooled data from older patients (aged ≥65 years) with upper limb spasticity (ULS). Methods: This study was a post hoc analysis of pooled data from seven prospective, multicenter, phase II or III trials of incobotulinumtoxinA in adult patients aged ≥65 years from across the world with post-stroke ULS or upper and lower limb spasticity, including a subgroup with moderate-to-severe ULS. Changes from baseline in ULS severity were evaluated using the (modified) Ashworth Scale across different spasticity patterns at 4 and 12 weeks after incobotulinumtoxinA injection. Results: In 267 older patients with ULS, including a subgroup of 207 with moderate-to-severe ULS, all ULS patterns statistically analyzed (elbow flexion, thumb-in-palm, clenched fist, wrist flexion, and pronated forearm) were improved more by incobotulinumtoxinA than placebo at week 4 (p < 0.05). For most of these patterns, the difference remained significant at week 12 (p < 0.05). IncobotulinumtoxinA was generally well tolerated. Conclusions: This study, which analyzed data from the largest cohort of older patients in the literature, provides information regarding the use of incobotulinumtoxinA in ULS, the efficacy and favorable safety profile of incobotulinumtoxinA for the treatment of ULS in older patients, particularly in those with moderate-to-severe spasticity, was confirmed. Full article

Bruxism, defined as a repetitive jaw-muscle activity characterized by clenching or grinding of teeth and/or by bracing or thrusting of the mandible, is a prevalent behavior affecting up to 22% of adults worldwide. While traditionally viewed as a disorder, current understanding recognizes bruxism as a behavior that may have both positive and negative consequences. Objective assessment methods for evaluating the effectiveness of interventions in symptomatic patients remain limited. This article presents the first longitudinal study using myotonometry to quantify changes in masseter muscle following botulinum toxin type A (BoNT-A) treatment in patients with symptoms of bruxism. In total, 57 patients were recruited and their masseter muscle tone, stiffness, elasticity, relaxation time, and creep parameters were measured. Measurements were performed at baseline, 3 weeks, and 3 months post-injection during both rest and maximum voluntary contraction. BoNT-A treatment produced significant improvements in all biomechanical parameters, with the greatest effects observed in patients with the highest baseline muscle values. The objective biomechanical changes correlated with the duration of BoNT-A’s therapeutic effects. These findings establish myotonometry as a valuable tool for objective assessment of masticatory muscle function and demonstrate that BoNT-A produces measurable, long-lasting biomechanical changes in masseter muscle parameters, supporting its possible clinical application in this challenging condition. Full article

Using Medline and Scopus as search engines, we identified reports of 10 clinical studies (published up to 1 September 2025) on botulinum neurotoxin therapy for hereditary spastic paraplegia (HSP). Nine studies were conducted in adults and one in children. Only one of the ten studies was double-blind and placebo-controlled. The search strategy included only articles published in English and articles providing basic information such as the type of the study, type and dose of the toxin and results of the treatment. Articles not in English, case reports and review articles were excluded. A total of 258 patients were included across all studies. The injected toxin in the open-label studies was botulinumtoxin-A (Botox or Dysport or Xeomin), whereas in the blinded study, the investigators used Prosigne. All open-label studies, which used FDA approved botulinumtoxin-A neurotoxins, demonstrated a degree of motor and non-motor improvement, whereas treatment with Prosigne did not improve patients’ function. The possible reasons for this discrepancy between the blinded study and the open-label studies are discussed. We found no studies on the effect of BoNTs on bladder dysfunction in HSP. There is a need for double-blind, placebo-controlled studies assessing the efficacy of FDA-approved botulinum neurotoxins in children and adults affected by hereditary spastic paraparesis. Such studies should also investigate the effect(s) of early botulinum neurotoxin therapy in this disorder. The novelty of this review is that it represents a comprehensive and critical literature review on this subject, with no other studies of this kind published previously. It also includes data not present in previous reviews of this subject. Full article

The use of Botulinum Neurotoxin A (BoNT/A) to treat peripheral neuropathic pain from nerve injury has garnered interest for its long-lasting effects and safety. This study examined the effects of IncobotulinumtoxinA (Inco/A), a BoNT/A variant without accessory proteins, on nerve regeneration in rats using the chronic constriction injury (CCI) model. Inco/A was administered perineurally at two time points: on days 0 and 21 post CCI. Functional and histological assessments were conducted to evaluate the effect of Inco/A on nerve regeneration. Sciatic Functional Index (SFI) measurements and Compound Muscle Action Potential (CMAP) recordings were conducted at different time points following CCI. Inco/A-treated animals exhibited a 65% improved SFI and 22% reduction in CMAP onset latencies compared to the vehicle-treated group, suggesting accelerated functional nerve recovery. Tissue analysis revealed enhanced remyelination in Inco/A-treated animals and 60% reduction in CGRP and double S100β signal expression compared to controls. Strikingly, 30% reduced immune cell influx into the injury site was observed following Inco/A treatment, suggesting that its anti-inflammatory effect contributes to nerve regeneration. These findings show that two injections of Inco/A promote functional recovery by enhancing neuroregeneration and modulating inflammatory processes, supporting the hypothesis that Inco/A has a neuroprotective and restorative role in nerve injury conditions. Full article

Background: Cervical dystonia (CD) is a chronic neurological disorder characterized by involuntary neck muscle contractions, leading to abnormal head postures, pain, and functional impairment. Botulinum toxin type A (BoNT-A) remains the treatment of choice, but its efficacy is highly dependent on injection accuracy. Various techniques, including palpation-guided, ultrasound-guided, and electromyography-guided (EMG), have been developed to optimize delivery, each with distinct advantages and limitations. Methods: A systematic search of PubMed and Scopus was conducted up until 30 December 2024, using defined keywords related to BoNT-A, CD, and injection techniques. Studies were included if they reported clinical outcomes of BoNT-A injection methods in adult CD patients. Data on efficacy, safety, accuracy, and muscle targeting were extracted and synthesized. Results: Seven studies comprising 239 patients were included: two randomized controlled trials, one retrospective study, one cohort study, one systematic review, one literature review, and one cadaveric study. The most common CD subtype was torticollis/torticaput (49.79%). Frequently targeted muscles included the trapezius (56.9%), levator scapulae (51.7%), and splenius capitis (48.3%). Ultrasound guidance consistently demonstrated superior injection accuracy and reduced adverse effects due to real-time anatomical visualization. EMG-guided techniques showed advantages in identifying dystonic muscles, especially when anatomy was unclear. In contrast, palpation-guided injections were less accurate and suitable only for superficial muscles. Dosing varied by product, with mean doses of 117–118 units for onabotulinumtoxinA and incobotulinumtoxinA, and 405 units for abobotulinumtoxinA. Adverse events were generally mild, including local discomfort, dysphagia, and transient muscle weakness. Conclusions: Ultrasound- and EMG-guided injections enhance the precision, safety, and efficacy of BoNT-A therapy for CD compared to anatomy-guided techniques. While ultrasound guidance improves anatomical accuracy, EMG remains valuable for functionally identifying dystonic muscles. Integration of both may offer optimal outcomes. However, further high-quality, standardized trials are needed to definitively establish best practices. Full article

Osteoarthritis (OA) is the most prevalent rheumatologic disease and a leading cause of years lived with disability worldwide. There are no disease-modifying drugs available to treat it. This study aimed to evaluate the effect of a single dose of 100U botulinum neurotoxin-A (BoNT-A) in patients with early knee OA. We designed a single-arm preliminary clinical trial in patients diagnosed with knee OA (KOA) grades I and II. 45 Patients received a single dose of 100U IncobotulinumtoxinA in the retro-patellar bursa and received nutritional and physical rehabilitation indications. Patients were evaluated at baseline and at days 5, 30, 60, and 90 after injection. The primary outcome was the reduction in pain using the visual analog scale (VAS). Knee function was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). We assessed secondary adverse effects and measured muscular strength in every consultation. Descriptive endpoint summaries and a generalized linear random-effect model were used to evaluate changes in each follow-up time compared to baseline. IncobotulinumtoxinA treatment significantly (p < 0.001) reduced pain in all treated patients at day 90 compared to day 0. Patients showed a significant reduction in total WOMAC score (p < 0.001), from a mean baseline of 44.6 (95% CI; 41.4, 47.8) to 4.4 at day 90 (95% CI; 0.2, 0.3). Our results show that IncobotulinumtoxinA applied in the retro-patellar bursa is a safe and effective treatment for pain in patients with early-stage KOA, offering a potential alternative for symptomatic control in KOA. Full article

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. Full article

Botulinum toxin type A1 is a first-line treatment for adult and pediatric spasticity. However, when considering the quantity of 150 kDa neurotoxin protein in relation to patient weight and the maximum recommended dose for treating adult and pediatric patients with spasticity, several concerns arise. First, the therapeutic margin (the ratio of the actual maximum quantity of toxin recommended for treating adult spasticity to its median lethal dose) appears to be relevant. Second, there is no consistency between adult and pediatric dosing of botulinum toxin type A1 for spasticity. The third point concerns the suitability of the recommended doses for treating spasticity in pediatric patients. Based on the average body weight of American children and adolescents, the maximum weight-based doses for abobotulinumtoxinA and onabotulinumtoxinA could be administered to children as young as 9 years old. Additionally, the maximum weight-based dose for incobotulinumtoxinA could be administered to children as young as 6 years old. The final point concerns managing the maximum dose of BoNT/A1 in pediatric patients with spasticity who weigh more than 25 kg for incobotulinumtoxinA, or more than 34 kg for abobotulinumtoxinA and onabotulinumtoxinA. No labeled recommendations are given on the weight cut-off for transitioning to adult dosing in pediatric patients. Full article