Search Results (493)

Objectives: To investigate current Canadian physicians’ practice patterns of treating upper limb post-stroke spasticity (PSS) and hemiplegic shoulder pain (HSP) acutely after a stroke. In addition, by examining Canadian physicians’ diagnostic capabilities, time till treatment, minimum criteria to begin treatment, mechanisms of treatment, targeting of muscles, and benefits and adverse effects of treatment, we aim to learn about areas of improvement to optimize PSS management for Canadians. Design: The present study was a cross-sectional survey, polling practicing Canadian physicians. Results: A total of 17 physicians completed the survey, all PM&R specialists, save one neurologist. Four provinces were represented in the responses. Participants had, on average, over ten years of experience managing post-stroke spasticity in outpatient and inpatient clinics. All 17 perform botulinum neurotoxin A (BoNT-A) injections for HSP associated with PSS. Most participants reported that they will begin BoNT-A treatments 2–3 weeks post-stroke, most commonly targeting the pectoralis major, subscapularis, and latissimus dorsi. Participants reported the mean median dosage they use as onabotulinum toxin A (169.12 units, SD = 73.70), incobotulinum toxin A (178.13 units, SD = 65.75), and abobotulinum toxin A (470.83 units, SD = 171.17). For injection guidance, participants responded that they use ultrasound for the largest percentage of their caseload, followed by electromyography, then electrical stimulation, then palpation. Very seldom did participants use palpation alone. Conclusions: From the limited sample included in analyses, the Canadian physicians respondents seem to be treating HSP and associated PSS with variable strategies. Further research is required to align dosages, targets, and guidance strategies as they vary considerably. Full article

Triple-negative breast cancer (TNBC) continues to be a medical challenge requiring multiple treatment options. SV2A, a protein involved in vesicular release, has emerged as a promising biomarker for various cancers. Research shows that botulinum neurotoxin type A (BoNT/A), which binds to SV2A, the BoNT/A receptor, can inhibit the growth of prostate and breast cancer cells, suggesting its potential as an alternative treatment for breast cancer. The purpose of this study was to determine the potential of BoNT/A to inhibit tumor growth in a mouse preclinical model. BoNT/A was evaluated for its effects in an in vitro model employing 4T1 cells and in an in vivo model of orthotopically inoculated 4T1 cells in BALB/c mice. BoNT/A inhibited the proliferation of 4T1 cells, which express the SV2A protein; decreased tumor growth in the preclinical model; and decreased inflammation, associated with fewer blood neutrophils and monocytes, suggesting an immunomodulatory and anti-inflammatory effect. The effect of BoNT/A on the TNBC model supports its use as a repurposed drug for this type of aggressive cancer. Our results emphasize the significance of the SV2A receptor and its interaction with BoNT/A as promising therapeutic targets, particularly for TNBC. Full article

Botulinum neurotoxins (BoNTs) act on peripheral cholinergic nerve terminals, inducing reversible muscle paralysis and profound therapeutic effects. However, their limited cell-type specificity and narrow therapeutic window have motivated the development of engineered variants. Here, a modular strategy was employed to construct full-length chimeric BoNTs, grafting receptor-binding segments from BoNT/B or BoNT/F onto the BoNT/A framework. The novel chimeras AAAF and AAFF efficiently cleaved rSNAP-25 in cell-free assays. Firstly, both toxins showed effective cellular uptake and cleaved endogenous SNAP-25 in Neuro-2a cells, with cleavage efficiencies of approximately 46% for AAAF and 73% for AAFF, highlighting the enhanced activity of AAFF. Secondly, AAAF induced faster recovery from reversible muscle paralysis compared to rBoNT/A-WT, whereas AAFF produced more sustained paralysis, with both exhibiting reduced systemic toxicity. Despite these altered pharmacological profiles, the chimeras required higher doses than rBoNT/A-WT to induce neuromuscular effects. Collectively, this study presents the design of novel chimeric BoNT/A-F proteins, characterizes their functional activities, and provides a preliminary exploration of how domain grafting affects cellular uptake, enzymatic activity, and neuromuscular pharmacodynamics. Full article

A highly potent antitoxin for botulinum neurotoxin (BoNT) serotypes A and B has been developed that comprises three monoclonal antibodies (mAbs) targeting BoNT/A and three targeting BoNT/B. These oligoclonal antibody combinations neutralize toxin by simultaneously binding non-overlapping epitopes, thereby promoting rapid toxin clearance. All six mAbs use the same human Fc and framework and have been individually manufactured using the same expression platform and purification process. To minimize the time and labor required to produce the divalent antitoxin, we tested a co-expression and co-purification strategy for the three mAbs per serotype. The mAbs were expressed in CHO-K1 cells, and the media were optimized for co-expression in 10 L bioreactors. Chromatographic co-purification consisted of Protein A capture, followed by strong anion exchange chromatography in flow-through mode and cation-exchange chromatography in bind-elute mode. Co-expression experiments demonstrated that expression of the three anti-BoNT/A antibodies remained within approximately ±30% of the optimal equimolar ratio, whereas the anti-BoNT/B antibodies showed greater variability. Downstream purification steps achieved recoveries greater than 95% per chromatographic step, resulting in overall process yields of approximately 63–75%. This strategy provided sufficient purity of all six mAbs while largely preserving their relative ratios. These results demonstrate the feasibility of producing oligoclonal antitoxin antibodies using co-expression and shared purification strategies. Such approaches may simplify the manufacturing of antibody cocktails while maintaining product quality and biological activity. Full article

Background: Botulinum neurotoxin type A is widely used in the management of post-stroke upper-limb spasticity; however, many studies report total injected doses rather than muscle-specific dosing, limiting clinical applicability. This study aimed to evaluate how frequently muscle-level dosing protocols of onabotulinumtoxinA are reported and to assess consistency of dosing patterns across published studies. Methods: A literature search was conducted in PubMed, Wiley/Cochrane Library, and EBSCO/CINAHL using a structured search strategy informed by PRISMA guidelines. Studies published within the last 10 years reporting on onabotulinumtoxinA treatment in post-stroke upper-limb spasticity with muscle-specific dosing data were included. Studies not providing muscle-level dosing or not allowing extraction of post-stroke upper-limb data were excluded. Data were summarized descriptively and compared across studies. Results: Twenty-seven full-text articles were assessed, and five studies met the inclusion criteria. Muscle-specific dosing was consistently reported for commonly treated muscles such as biceps brachii and wrist and finger flexors, whereas other muscles were less frequently targeted. Variability in dosing between studies was observed, particularly in multicenter real-world datasets. Standardized high-dose protocols contrasted with individualized dosing strategies, which generally showed more moderate dose ranges. Expert recommendations often suggest higher doses than those observed in routine clinical practice. Conclusions: Muscle-specific dosing of onabotulinumtoxinA in post-stroke upper-limb spasticity is reported infrequently, and substantial variability exists between studies and clinical practice. Standardized reporting of muscle-level dosing and its relationship to baseline spasticity severity is needed to improve clinical applicability and reproducibility. Full article

Botulinum neurotoxin (BoNT) treatment outcomes are commonly assessed through visual evaluation of facial wrinkle patterns, a process that remains inherently subjective despite structured grading systems. This study evaluated whether contemporary multimodal artificial intelligence (AI) systems can identify facial changes associated with BoNT treatment, using region-specific wrinkle patterns as surrogate markers of underlying muscle activity. A dataset of 46 facial images (23 pre-treatment, 23 post-treatment) was analyzed using four multimodal models, each assessed across five independent runs. Models were tasked with classifying treatment state from single images, detecting wrinkle presence in the forehead, glabella, and periorbital regions, and generating exploratory severity scores and age estimates. Two models achieved 100% accuracy in distinguishing pre- from post-treatment images in this dataset, while region-specific wrinkle detection was variable and frequently did not exceed majority-class baselines. Inter-run reliability varied substantially across models. Exploratory wrinkle severity scores showed directional differences between treatment states, whereas apparent age estimates demonstrated minimal systematic variation. These findings suggest that global facial changes associated with BoNT treatment appear to be detectable in model outputs, but region-specific assessment remains limited, underscoring the need for cautious interpretation and further validation. Full article

Patients with cervical dystonia (CD) often believe that disease severity would have progressed beyond the pre-treatment level if botulinum neurotoxin (BoNT) therapy had not been initiated. The aim of the present study was to assess the perceptions of long-term BoNT-treated patients with CD regarding the expected course of disease severity over the next 10 years under the hypothetical assumption that BoNT therapy is discontinued. Fifty patients with idiopathic CD receiving long-term BoNT therapy were screened, and 43 patients were included. Disease severity at the day of recruitment was assessed as a percentage of CD severity at the onset of BoNT therapy (PAS-%). Patients also generated, in a standardized manner, a graph illustrating the development of CD severity since initiation of BoNT therapy. Subsequently, patients estimated the expected severity of CD after 10 years, expressed as a percentage of severity at BoNT therapy onset (PAS-STD), under the hypothetical assumption that BoNT therapy was discontinued at the time of recruitment. They additionally drew a graph depicting the anticipated progression of CD severity over the subsequent 10 years under this assumption. Furthermore, 33 of these 43 patients had previously assessed the expected development of CD severity under the assumption that no BoNT therapy had ever been performed (PAS-NO%) in an earlier study. Mean PAS-STD was significantly higher than mean PAS-% (p < 0.001). Comparison of mean PAS-STD with mean PAS-NO% in the 33 patients who participated in both studies demonstrated that mean PAS-STD was significantly lower than mean PAS-NO% (p < 0.001). Long-term BoNT-treated patients with CD believe that disease severity would worsen again if BoNT therapy were discontinued. However, they do not expect CD severity to deteriorate to the level that they believe would have been reached if no BoNT therapy had been administered. We interpret this finding as suggesting that patients perceive a preventive effect of long-term BoNT therapy. Full article

Botulinum neurotoxin injections are used off-label to treat chronic pain, but their efficacy is limited and paralytic effects restrict clinical utility in these applications. Here, we investigated whether combining the light chain and translocation domains of botulinum neurotoxin A (BoNT/A) with the GM1-binding B subunit of cholera toxin would be beneficial in silencing pain-associated sensory neurons. Chimeric ChoBot was assembled via a coiled-coil linking technology and was shown to retain the enzymatic activity of BoNT/A in vitro and in vivo. In cultured dorsal root ganglion neurons, ChoBot cleaved SNAP25 in a calcitonin gene-related peptide (CGRP)-rich subpopulation of sensory neurons, resulting in marked inhibition of CGRP release. ChoBot had a lesser effect on the compound muscle action potentials of the rat gastrocnemius muscle than BoNT/A following subcutaneous injections. In rat models of pain, including chemotherapy-induced peripheral neuropathy, intraplantar administration of ChoBot significantly attenuated mechanical allodynia. Immunohistochemical analysis confirmed SNAP25 cleavage in NF200- and CGRP-expressing sensory fibres in the epidermis following a single injection. ChoBot also mediated SNAP25 cleavage in human neuroblastoma cells in culture. Together, these findings indicate that ChoBot enables a silencing of pain-associated sensory pathways, providing a new strategy for the development of new long-lasting analgesics for chronic pain. Full article

Foodborne botulism, caused by ingestion of pre-formed botulinum neurotoxin, is the most common form of botulism. While large outbreaks linked to commercial foods are rare, smaller outbreaks associated with home-processed products are more frequent, reflecting local dietary habits and traditional preservation practices. The aim of this paper is to provide a public health overview of reported foodborne botulism outbreaks in Romania over an 18-year period to raise awareness among clinicians and public health officials. Between 2007 and 2024, a total of 337 foodborne botulism cases were reported in Romania, of which 43% (147) were related to 55 outbreaks (median number of cases per outbreak: 2; IQR: 2–3). Most outbreaks were reported in Bihor County (11 outbreaks with 29 cases) and its neighboring county, Satu Mare (seven outbreaks, accounting for a total number of 20 cases). Outbreak-related cases were observed in younger persons with a median age of 31 years (compared to 45 years for sporadic cases) and were statistically significantly associated with consumption of pork products (p < 0.001). Fifteen deaths occurred (case fatality ratio: 4%), including three outbreak-related cases (case fatality ratio: 2%). These findings highlight the ongoing public health challenge of foodborne botulism in Romania and the need for robust surveillance, targeted educational initiatives in high-incidence counties to deliver information about safe food preparation and preservation practices, and the continuous availability of botulinum antitoxin supplies. Full article

Aesthetic patients in East Asia are commonly concerned about small apparent eye size. Simultaneous treatment of the glabellar and lateral canthal areas with botulinum neurotoxin has potential to provide improvements. This case series evaluated changes in eye size following treatment of these two areas using standard on-label doses of onabotulinumtoxinA in patients from Japan or China. Outcomes were assessed based on standardised frontal photographs taken before and after treatment (at rest, maximum smile, and maximum frowning). Changes in eye size were examined using a 4-point Likert scale, as evaluated by three independent groups: six injectors; six non-injecting observers; and treated patients. Furthermore, improvements in overall facial impression were analysed using two established tools: ‘emotional attributes’ and ‘social attributes’. Twenty East Asian subjects were included (n = 17 women; mean age: 37.5 ± 6.4 years). The majority of evaluators in all three groups rated patients’ eye size as ‘significantly’ or ‘mildly’ improved post-treatment, whether assessed at rest, when smiling, or during frowning. Furthermore, almost all evaluators noted improvements in one or more emotional and social attributes. This approach has significant potential as a culturally adapted aesthetic technique for improving eye size in East Asian patients. Larger multicentre studies are warranted. Full article

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

Botulism is a neuroparalytic disease caused by exposure to botulinum neurotoxins produced by anaerobic spore-forming bacteria of the genus Clostridium. This disease occurs in both humans and wild and domestic animals, and is currently becoming an increasingly serious problem worldwide due to high animal mortality and economic losses. The clinical signs observed during the progression of botulism are nonspecific and difficult to unequivocally associate with this disease entity. The aim of this study is to present laboratory diagnostics of suspected botulism cases reported in Poland in 2022–2024, as well as to present the challenges encountered during laboratory investigations. The material for the study consisted of samples of liver, serum, digestive tract, feed, feces, straw, and water from drinking lines, sent to the National Veterinary Research Institute (NVRI) in relation to thirteen suspected cases of botulism, predominantly reported in poultry, but also in mink and cattle farms. The samples were analyzed using a mouse bioassay and conventional culture methods, as well as real-time PCR methods aimed at detecting the ntnh and bont genes, which determine the production of botulinum neurotoxins. Of the thirteen suspected cases analyzed, ten were confirmed by the detection of botulinum toxin (BoNTs) and/or the presence of the ntnh and bont genes in the tested material. Based on the results obtained, it was concluded that botulinum toxin type C was the etiological factor of botulism poisoning in most of the analyzed cases. In one case reported in cattle, poisoning occurred as a result of the mosaic variant of BoNT D/C. Due to the nonspecific signs of botulism and the time required for them to appear, laboratory diagnostics play a key role in detecting the disease. However, this process is complicated due to the high heterogeneity observed among Clostridium spp. strains, as well as difficulties encountered during the isolation of the microorganism and the possibility of loss of toxin-producing capacity at later stages of analysis. Full article

DaxibotulinumtoxinA for injection (DAXI) is a botulinum neurotoxin (BoNT) drug product comprising the 150 kDa pure BoNT/A1 as the drug substance formulated with a proprietary stabilizing excipient, RTP004. We hypothesized that RTP004 facilitates localization of BoNT/A1 to the neuronal membrane, resulting in increased BoNT internalization and cleavage of the synaptosomal-associated protein of 25 kDa (SNAP-25) within synaptic terminals. We characterized the interaction between RTP004 and BoNT/A1 using in silico and in vitro techniques. In vitro analyses revealed that negative charges on the BoNT/A1 surface were located on the light chain (LC, the catalytic domain) and the C-terminus of the heavy chain (H_C, the receptor-binding domain), potentially providing sites for interaction with the positively charged RTP004 peptide. RTP004 bound to BoNT/A1, but not to human serum albumin (HSA), in both static and dynamic conditions. RTP004, not HSA, enhanced binding of BoNT to artificial membranes and RTP004 dissociated from BoNT under conditions that mimicked physiological conditions of the synaptic vesicle. RTP004 also increased binding of BoNT to the synaptosomal cell membrane and enhanced cleavage of SNAP-25 in a dose-dependent manner. These findings demonstrate that RTP004, not the excipient HSA common in other BoNT/A1 drug products, enhances binding of BoNT to the cell surface, facilitates internalization of BoNT into the cell, and increases SNAP-25 cleavage. 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

Botulinum neurotoxins (BoNTs), among the most potent biological toxins, rely on co-produced nontoxic proteins to survive harsh gastrointestinal conditions and achieve efficient systemic dissemination after oral exposure. Recent structural and functional studies have revealed how BoNTs bind to the nontoxic non-hemagglutinin (NTNH) factors to engage in interactions with either OrfXs/P47 or hemagglutinins (HAs) components for systemic dissemination. This review synthesizes recent findings that elucidate the molecular basis of NTNH-specific anchoring to the HA70 triskelion-like element or to the host protease-activated form of OrfX2, thereby highlighting divergent pathways that enhance oral toxicity. We also discuss current perspectives on the molecular mechanisms through which BoNTs, in cooperation with associated nontoxic proteins, are absorbed from the intestine. Full article