Search Results (185)

The eyebrows are a central element of facial harmony, influenced by individual and external factors such as gender, ethnicity, facial shape, age, culture, and fashion trends. Traditional methods for esthetically enhancing eyebrows include plucking, highlighting, and surgical interventions. Another minimally invasive option for altering, thus enhancing eyebrow positioning, is botulinum toxin type A (BoNT-A) injection. The objective was to demonstrate a systematic, customizable approach for BoNT-A injections to reshape and reposition eyebrows according to individual facial shape enhancing balance. To determine optimal BoNT-A dose and injection points, an individualized assessment of facial and eyebrow shape and position was performed, leading to a customized protocol of neurotoxin injections according to each patient’s needs. The assessment method aims for the best match between the individual facial shape and eyebrow form and position. This technique enables individualized modulation of eyebrow position and shape, improving facial balance while addressing dynamic upper facial rhytides, thereby promoting harmonious outcomes that preserve individual facial characteristics and providing an additional approach to conventional eyebrow enhancement techniques. Full article

The neurotoxin botulinum toxin type A (BoNT/A), produced by the bacteria Clostridium botulinum, is commonly injected intramuscularly (IM) for the management of chronic muscle hyperactivity, such as post-stroke spasticity. New indications such as peripheral neuropathic pain require alternative routes of BoNT/A administration, such as subcutaneous (SC) or intradermal (ID). While IM BoNT/A injections may elicit anti-drug-antibodies (ADAs), their occurrence following SC or ID administration is unknown. Therefore, we investigated whether repeated SC or ID injections of 150 kDa BoNT/A can elicit ADAs in a dose-dependent manner, and whether these differ depending upon the route of administration. Mice were injected 5 times ID or SC with 150 kDa BoNT/A or, for higher doses, inactive mutant BoNT/A (DRBoNT/A) or inactivated toxoid (IA-BoNT/A). Total ADAs were analyzed by an immunoassay and the subgroup of neutralizing ADAs by an in vivo digit abduction score (DAS) assay following a challenge of 0.6 U BoNT/A IM. DRBoNT/A and IA-BoNT/A injections elicit ADAs (22.7 U/mL vs. 460.5 U/mL for ID; 4.7 U/mL vs. 339.4 U/mL for SC), while therapeutic doses of 150 kDa BoNT/A do not. Whereas mice with repeated 150 kDa BoNT/A injections at therapeutic dose show an unrestricted DAS of 3.7 (ID) or 3.4 (SC), mice injected repeatedly with 1.8 µg/kg DRBoNT/A or 500 µg/kg IA-BoNT/A show only a minimal DAS of ≤0.7, indicating a high titer of neutralizing ADAs. No differences were observed between administration routes. Accordingly, repeated ID or SC injections of pure 150 kDa BoNT/A at therapeutic doses fail to induce ADA formation in mice. On the other hand, DRBoNT/A ID injections induce higher ADA concentrations than SC, but generate similar amounts of neutralizing ADAs. IA-BoNT/A injections induce ADAs and neutralizing ADAs similarly after ID and SC injections. ADA development at intermediate BoNT/A doses can be higher after ID injection, but does not lead to differences in neutralizing ADAs. Our data demonstrate that the antibody response to botulinum toxin depends predominantly on the protein load, and less on the administration route. Full article

Background/Objectives: Trigeminal neuralgia (TN) is a debilitating neurological condition characterized by recurrent, severe pain linked to peripheral and central sensitization within trigeminal pathways. Current pharmacologic treatments are limited by inadequate efficacy or dose-limiting side effects, and botulinum neurotoxin type A (BoNT/A) has emerged as a viable option. However, its potential use in the management of TN is hampered by methodological limitations in existing studies and a lack of pivotal clinical trials. This study investigated the efficacy, optimal treatment site, preventive utility, and duration of effect of incobotulinumtoxinA (Inco/A), a BoNT/A, in a model of TN. Methods: An infraorbital nerve chronic constriction injury model was used to induce mechanical allodynia in male Sprague–Dawley rats, reproducing the trigeminal sensitization seen in TN. The effects of subcutaneous Inco/A (1, 2, and 4 U) were measured using the mechanical sensitivity (von Frey) test to evaluate the dose response, effect of injection location, potential preventive nature of treatment, and duration of benefit. Results: Inco/A produced a robust, dose-dependent reduction in mechanical allodynia, predominantly via a local mechanism of action. Both preventive and therapeutic administration of Inco/A was efficacious, with significant reduction in allodynia even when administered up to 28 days before nerve injury. The anti-allodynic effect persisted up to 56 days post-injection. Conclusions: Inco/A is highly effective in alleviating mechanical allodynia in a validated rat model of TN. The findings highlight Inco/A as a promising candidate for clinical translation in TN and related neuropathic pain syndromes and support systematic investigation in well-controlled human trials. 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

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

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

Skeletal muscle is the largest metabolic demanding organ in human body. Alterations of skeletal muscle in shape and size significantly affect its biological functions. Botulinum neurotoxin type A1 (BoNT/A1) has been successfully used in clinics to treat masseter, trapezius and gastrocnemius hypertrophy. Here, we used a healthy rat-based skeletal muscle hypertrophy model to evaluate the muscle-reducing activity of recombinant BoNT/A1 (rBoNT/A1) with genetically fused cell-penetrating peptides (CPPs), which was previously reported to increase the cellular uptake of BoNT/A1. Analyses of treated muscle sections using hematoxylin–eosin and immunofluorescence staining showed that both wild-type rBoNT/A1 without modification (WT-rBoNT/A1) and rBoNT/A1 with CPP fusion (CPP-rBoNT/A1) could induce myocomma atrophy and altered gastrocnemius muscle fiber proportions as a result of denervation and reinnervation. Importantly, rBoNT/A1 with the fusion of a specific CPP, zinc finger protein (ZFP), resulted in the highest degree of muscle atrophy and greatest increase in the ratio of type I muscle fibers over type II fibers. An examination of gastrocnemius muscle cells at the subcellular levels using TEM staining revealed swelled mitochondria and diminished mitochondrial crista upon rBoNT/A1 administration. Transcriptomic RNA sequencing (RNA-Seq) analysis followed by RT-qPCR validation showed that rBoNT/A1 treatment also caused changes in mitochondrial biogenesis and mitophagy. Collectively, our results demonstrated that rBoNT/A1 proteins could alleviate skeletal muscle hypertrophy, with associated alterations of mitochondrial homeostasis. Full article

Background: Post-stroke spasticity (PSS) is a common complication in stroke survivors, significantly impairing functional recovery and quality of life. Despite its prevalence, Italy lacks national guidelines or structured good clinical practice documents, resulting in heterogeneous clinical management. Methods: An Italian Delphi study was conducted to establish expert-based recommendations for PSS management. A panel of 93 rehabilitation medicine specialists and neurologists, each with over 5 years of experience in PSS management with botulinum toxin A (BoNT-A), participated in two rounds of voting on 47 statements drafted and approved by seven Key Opinion Leaders (KOLs), recognized for their national and international expertise. Consensus was defined as ≥75% of respondents answering ‘strongly agree’ or ‘somewhat agree’. Results: In Round 1, consensus was reached for 90% of statements; five items did not achieve the threshold. After revision and a second round, consensus was achieved for all items, including consideration of lesion site in clinical management and the role of adjuvant post-injection interventions. The panel’s heterogeneity ensured broad representativeness. Conclusion: This Delphi study provides the first structured Italian expert recommendations for PSS management. Full consensus was reached in all 47 statements and in the Symptoms domain, particularly regarding pain, stiffness and heaviness, which highlights the importance of a structured framework to support consistent, individualized care. By standardizing patient assessment, treatment planning, and follow-up strategies, these findings provide a practical reference for clinicians. Full article

Cervical dystonia (CD) is the most common adult-onset focal dystonia, with heterogeneous clinical presentation and significant functional impairment. Currently, no structured Italian good clinical practice documents specifically addressing CD have been published. Optimizing CD management requires expert-based recommendations to guide diagnosis, treatment, and follow-up. A two-round Delphi process was conducted, involving a scientific board of six neurologists with expertise in CD management and an external panel of 56 Italian experts (neurologists and physiatrists managing CD patients). Fifty-two statements were developed, discussed, and voted using a 5-point Likert scale, with consensus defined as ≥75% agreement (‘strongly agree’ or ‘somewhat agree’). In Round 1, 48 of 52 statements (92.4%) reached consensus; the four remaining statements were revised, and two were re-voted in Round 2, both achieving consensus. Final recommendations emphasize comprehensive patient assessment in multiple postural conditions; individualized botulinum neurotoxin type A (BoNT-A) dosing taking into account tonic and phasic components, pain, and dysphagia; the use of instrumental guidance; standardized outcome measures; and integration of physiotherapy and psychological support. This article provides structured good clinical practice recommendations for CD management and offers clinicians, especially those with limited experience, a practical framework to standardize care, optimize treatment, and improve patient outcomes. Full article

Cervical dystonia (CD), blepharospasm (BSP), and idiopathic hemifacial spasm (HFS) are focal hyperkinetic movement disorders with distinct underlying mechanisms. While CD and BSP involve central network dysfunctions within the basal ganglia-thalamo-cortical and cerebellar circuits, HFS primarily results from peripheral facial nerve hyperexcitability. Still, people living with all three conditions often struggle with mood issues like depression and anxiety, which can originate from both the burden of illness and changes in brain biology. We studied 61 patients (CD, n = 30; BSP, n = 9; HFS, n = 22) and assessed depression and anxiety before and three weeks after botulinum neurotoxin type A (BoNT-A) therapy, considering injection site and dose. BoNT-A significantly reduced depressive and anxiety symptoms across all groups, regardless of disease type, dose, or glabellar injection. These psychiatric improvements were not associated with the degree of motor symptom reduction, suggesting a partially independent mechanism of mood modulation. Our findings indicate that BoNT-A’s mood benefits may extend beyond local motor effects, possibly involving broader sensorimotor-limbic interactions. These results highlight the therapeutic potential of BoNT-A for addressing non-motor symptoms in both dystonic and non-dystonic hyperkinetic disorders. Future studies employing imaging and neurophysiological methods are necessary to explain the neural pathways underlying these effects. Full article