Search Results (336)

Botulinum toxin type A (BoNT-A) is an established preventive therapy for chronic migraines; however, uncertainty remains regarding its comparative efficacy and safety. Thus, we aimed to summarize current evidence from high-quality systematic reviews of the therapeutic effects of BoNT-A in migraine management. An umbrella review was conducted following PRISMA guidelines and registered in PROSPERO. High-quality systematic reviews with meta-analysis evaluating BoNT-A efficacy were identified through five databases up to August 2024. Primary outcomes included monthly headache frequency and severity. Methodological quality and risk of bias were assessed using the umbrella review checklist. Fourteen articles were included. Overall, quantitative evidence indicated favorable effects of BoNT-A compared with placebo for chronic migraines, across headache frequency, headache severity, and acute medication use, but less efficacy than topiramate and the CGRP monoclonal antibodies (CGRPmAbs) galcanezumab and fremanezumab. Though the adverse events were frequent, BoNT-A was generally well-tolerated. Comparative data suggested superior tolerability versus topiramate and a safety profile like CGRPmAbs. Although botulinum toxin type A is widely used as a preventive treatment for chronic migraines, the available evidence supports its efficacy at a moderate level. Further head-to-head and long-term analyses are needed to clarify its comparative role alongside newer biologic treatments. Full article

Temporomandibular disorders (TMDs) are common musculoskeletal chronic orofacial pain conditions involving peripheral and central sensitization within trigeminal nociceptive pathways, manifesting as mechanical allodynia and functional impairment. Botulinum toxin type A (BoNT-A) has been explored as a treatment targeting both muscle hyperactivity and nociceptive modulation. Preclinical and clinical evidence demonstrate that BoNT-A reduces peripheral neurotransmitter release, neurogenic inflammation, and central neuronal excitability, leading to attenuation of mechanical allodynia in TMD models and patients. Clinical trials show modest and variable analgesic effects, with patients displaying sensory sensitization appearing to respond more favorably, though methodological heterogeneity limits definitive conclusions. Safety concerns related to muscle weakening, changes in bone density, and structural changes underscore the need for standardized protocols optimizing dosing and monitoring, in addition to prospective studies. These findings suggest that BoNT-A may serve as an adjunctive, mechanism-based therapy within multimodal TMD management. Future research should focus on standardized sensory phenotyping and trial design to clarify BoNT-A’s role in modulating central sensitization and improving patient outcomes. Full article

While distinguishing between collis and caput patterns in cervical dystonia (CD) has clear clinical and therapeutic relevance, the effects of botulinum toxin type A (BoNT-A) on segmental spinal excitability and inhibitory function in caput-pattern CD have not been previously investigated. This study aimed to advance understanding of the effects of BoNT-A and its broader neurophysiological impact in cervical dystonia, particularly in the caput subtype. The study utilised non-invasive neurophysiological methods to assess F-wave and cutaneous silent period (CSP or CuSP) parameters in 21 CD patients with caput motor patterns at waning and peak response phases of BoNT-A therapy. Significant prolongation of Fmin latency, increased F–M interlatency, reduced F-wave amplitude, and a marked increase in CSP duration and onset latencies were observed following BoNT-A administration, indicating that BoNT-A not only reduces spinal motoneuron excitability and strengthens spinal inhibitory processes, but also highlights its capacity to modulate central sensorimotor pathways beyond local chemodenervation. Together, the observed changes in CSP support its use as a potential biomarker for nervous system effects of BoNT-A in dystonia; however, further validation in controlled studies is warranted. Full article

(1) Background: As an innovative drug derived from botulinum neurotoxin serotype E, TrenibotulinumtoxinE^® demonstrates a rapid onset and shorter effect. Due to concerns regarding specificity, test throughput, and animal welfare, a new cell-based potency assay (CBPA) method was developed for BoNT/E drug substance and drug product; independent evaluation of this new CBPA was required. (2) Methods: The CBPA for BoNT/E is a quantitative assay that measures the accumulated cleaved SNAP25₁₈₀ in human neuroblastoma cells. It involves sequential culturing, differentiation of cells, and then treatment with drug products. Data were analyzed using a quadratic parallel model via statistical software. Linearity was determined using five effective concentration levels. Key assay parameters including accuracy, linearity, repeatability, intermediate precision and range were evaluated. (3) Results: The overall assay’s accuracy was 98%, and the intermediate precision was 6.3%. The coefficient of determination (R²) and slope were determined as 0.963 and 0.942, respectively. The root mean squared error (RMSE) was 0.057, and the intercept was 0.032 for the combined data. The repeatability was 2.4%, which is well within the acceptance criterion of ≤8%. (4) Conclusions: The evaluation was carried out within a single laboratory under controlled conditions; the new CBPA meets all acceptance criteria and can be used for BoNT/E potency determination. Full article

Recent advances in the understanding of facial anatomy have contributed significantly to the refinement of injection techniques for the treatment of dynamic forehead lines. A comprehensive assessment of eyebrow shape, position, and the aging process is essential, as the latter are closely linked to the functional balance between the frontalis muscle and the upper facial depressors. Optimal outcomes also depend on the accurate determination of dosage per injection point, injection depth, and strategic distribution of injection sites within the frontalis, which should be carefully considered and tailored to the individual’s anatomical characteristics and therapeutic goals—whether the aim is neuromodulation for muscle activity reduction or intradermal application for skin quality enhancement. A round table discussion session among three experienced international dermatology experts in aesthetic botulinum toxin type A was performed during a MERZ LATAM-sponsored medical education session. Recent insights in facial anatomy, including the precise location and distribution of motor endplates, as well as the direction of muscular force vectors during contraction; aging processes; and interindividual variability in facial musculature and mimicry patterns are discussed, and the results are described herein. These factors play a critical role in customizing personalized injection strategies and improving aesthetic outcomes in the treatment of forehead lines. Full article

Facial palsy affects millions worldwide. Botulinum toxin Type A (BoNT-A) is an established treatment for non-flaccid facial palsy, yet objective evidence remains limited. This study evaluates the effects of BoNT-A using AI-based tools and patient-reported outcome measures (PROMs). In this prospective observational study, patients with non-flaccid facial palsy received individualized BoNT-A injections. Exclusion criteria included age < 18, hypersensitivity to BoNT-A, or lack of follow-up. Assessments were conducted before and 3 weeks after treatment, including facial symmetry (Emotrics^®), emotion expression (FaceReader™), and PROMs (FaCE and FDI). Eleven patients (mean age 50.1 ± 18 years) were included. BoNT-A significantly improved dynamic facial symmetry: eyebrow raising (p = 0.032), smile angle (p = 0.005), and lower lip height (p = 0.042). Emotion analysis showed no significant changes. PROMs revealed improvements in social well-being (FDI, p = 0.004) and aesthetic satisfaction (FaCE, p = 0.035), while functional FDI scores remained unchanged (p = 0.406). BoNT-A improves objective symmetry and patient satisfaction in non-flaccid facial palsy. The lack of change in emotional expression may reflect improved symmetry at the cost of dynamic muscle activation. Full article

Background: Erectile dysfunction (ED) affects approximately 20% of men worldwide, significantly affecting their quality of life. While phosphodiesterase type 5 inhibitors (PDE5-Is) are the standard first-line treatment, a substantial number of patients are non-responders. Second-line treatments, such as intracavernosal alprostadil, are effective but often limited by their invasive nature and the need for frequent injections. Intracavernosal onabotulinumtoxinA (BoNT-A) offers a promising new option. By inhibiting acetylcholine release and norepinephrine, as well as other neurotransmitters involved in detumescence, it facilitates cavernosal smooth muscle relaxation and enhances penile blood flow. Its effects may persist for up to six months following a single injection, potentially reducing treatment burden and improving adherence among men with refractory ED. Methods: A systematic review was performed in accordance with the PRISMA guidelines. Literature searches were conducted in PubMed, Embase, Cochrane Library, Scopus, and Clinicaltrials.gov from inception until August 2025 using a combination of keywords and MeSH terms related to ‘erectile dysfunction’ and ‘botulinum toxin’. After screening, 51 studies met the inclusion criteria. Due to significant heterogeneity in interventions (e.g., BoNT-A dosage, co-therapies), patient populations, and reported outcomes, the data were not suitable for meta-analysis. Consequently, a narrative synthesis was performed to summarize the findings. Results: Among the included studies, intracavernosal BoNT-A was associated with improvements in validated erectile function scores. Reported response rates, variably defined across studies, ranged from 40% to 77.5%. Several studies suggested that efficacy was higher in patients with mild-to-moderate ED and with repeated administration of 100 U doses. The treatment exhibited a favorable safety profile. The most common adverse event was mild, transient penile pain (reported incidence 1.5–6%). No studies reported serious systemic adverse events. The overall strength of the evidence was limited by significant heterogeneity among the included studies and their generally small sample sizes. Conclusions: Based on this systematic review, intracavernosal onabotulinumtoxinA (BoNT-A) may be a beneficial therapeutic option for patients with refractory ED, offering potential improvements in sexual function while reducing the need for invasive therapies. Future large-scale, placebo-controlled studies are essential to confirm these benefits and standardize their clinical application. Full article

This study aimed to explore the potential role of artificial intelligence in optimizing botulinum toxin type A treatment for spasticity and to evaluate its alignment with expert clinical decisions. A comparative analysis was conducted using thirty hypothetical clinical cases involving individuals with spasticity resulting from various neurological conditions. Five rehabilitation physicians, each with more than five years of experience, participated in the study. An artificial intelligence model trained on scientific literature and clinical guidelines generated treatment recommendations, including target muscles and dosages, which were compared with those proposed independently by the physicians. The primary outcome was the level of agreement in muscle selection and dosage. The model demonstrated consistency and adherence to guidelines but showed limited adaptability in complex presentations, such as an adducted thigh and equinovarus foot. It generally recommended lower dosages and differed significantly from physicians in both muscle selection and treatment strategies. Artificial intelligence shows promise as a clinical support tool in spasticity management, offering standardized and reproducible recommendations. However, its limited capacity to interpret clinical subtleties currently restricts its practical application. Future models should integrate multimodal clinical data and real-time clinician feedback to better emulate expert decision-making processes. Full article

(1) Background: Post-stroke spasticity limits motor recovery and independence. Combining botulinum toxin type-A (BoNT-A) injection with intensive, task-specific robot-assisted therapy (RAT) might enhance neuroplasticity and functional gains, but its additive effect and optimal timing are uncertain. (2) Methods: We systematically searched major medical databases and trial registries up to April 2025 for randomized controlled trials in adults with post-stroke spasticity comparing botulinum toxin type-A injection plus RAT with toxin injection plus conventional therapy, or RAT alone with RAT combined with toxin injection. Risk of bias was assessed using the RoB 2 tool, and findings were synthesized narratively. (3) Results: Seven trials (n = 229) were included. Across all studies, toxin treatment reduced spasticity within groups, whereas additional spasticity reduction with RAT versus conventional rehabilitation was inconsistent. In contrast, several lower-limb trials reported greater improvements in walking capacity and balance when RAT was added, while upper-limb trials showed comparable motor recovery across treatment arms with occasional advantages in strength and movement quality. A pilot four-arm study suggested that starting RAT around four weeks after injection may maximize upper-limb motor gains. (4) Conclusions: The combination of BoNT-A with RAT appears safe and is particularly promising for gait rehabilitation, but further research is needed to define optimal timing and protocols. Full article

Background/Objectives: To investigate the impact of a routine botulinum toxin type A (BoNT-A) injection in combination with outpatient therapy on the daily activities of stroke survivors with upper extremity spasticity and to facilitate patient-centred assessment focusing on individual needs during daily life. Methods: Design: Observational study across one treatment cycle (3 months). Setting: Spasticity outpatient clinic of a neurorehabilitation hospital in Germany. Participants: Adult stroke survivors (n = 27) with upper extremity spasticity receiving routine BoNT-A treatment. Interventions: Participants received one BoNT-A injection and outpatient therapies as part of their routine management. Augmented assessment was conducted directly before the injection (T0), and at 4 to 6 weeks (Tmax1) and 12 to 14 weeks (T2) following the injection. Main outcome measures: The Canadian Occupational Performance Measure (COPM), Goal Attainment Scaling (GAS), and Arm Activity Measure (ArmA). Secondary outcome measures: The Resistance to Passive Movement Scale (REPAS), Motricity Index (MI), SF-12v2 Health Survey (SF-12v2), Global Clinical Impression (GCI), and importance of and satisfaction with the BoNT-A treatment. Results: Performance of individually selected daily activities and satisfaction with their performance (COPM), passive care tasks (ArmA, part A), and resistance to passive movement (REPAS) significantly improved from T0 to Tmax1. Improvements largely remained at T2. Individual goals were all set at the activities and participation levels of the International Classification of Functioning, Disability and Health. These improved for 75% of participants and were fully attained by 33.3% at Tmax1. Responder analysis indicated that COPM and ArmA improvements were clinically significant for up to 50% of participants. Active upper extremity use (ArmA, part B), health-related quality of life (SF-12v2), and upper extremity strength (MI) remained unchanged. Conclusions: Our results indicate that BoNT-A in combination with routine outpatient therapy positively influenced the individually valued daily activities of stroke survivors. COPM, GAS, and ArmA are suitable for facilitating a patient-centred and daily life-oriented spasticity management post-stroke. Full article

Background/Objectives: Cervical dystonia (CD) is the most common focal dystonia, but nationwide evidence on healthcare use is limited. This study assessed trends in utilization and expenditures in Korea. Methods: Using National Health Insurance Service claims (2017–2023), we identified CD patients (ICD-10 G24.3) and analyzed annual patients, visits, and expenditures by demographics, medical system, service type, and specialty. Results: A total of 6614 patients (33,896 claims) were included. Patient numbers declined until 2021 then slightly rebounded, and total expenditures fluctuated. Women were more prevalent, but men incurred higher costs. Western Medicine (WM) expenditures tended to increase while Korean Medicine (KM) tended to decline. Core botulinum toxin costs remained broadly stable; physiotherapy and diagnostic testing increased, particularly WM outpatient testing. Outpatient injection-related and anesthesia expenditures showed decreasing tendencies, while hospitalization and radiology exhibited modest or minimal changes. Neurology managed the most patients, while neurosurgery generated the highest costs. Conclusions: CD care in Korea showed declining patient numbers alongside overall stable total expenditures, with increasing use of rehabilitation and diagnostic services and continued stable use of botulinum toxin as a core therapy. Full article

Spasticity after stroke impairs motor control, delays recovery, and reduces quality of life. Botulinum toxin type A is the first-line treatment, but it is often administered in the chronic phase, potentially limiting its impact on rehabilitation. Emerging evidence suggests that earlier treatment may enhance recovery, though functional benefits remain uncertain. We conducted a secondary analysis of a multicenter, open-label, longitudinal cohort study to investigate whether the timing of the first botulinum toxin type A injection influences outcomes in post-stroke patients naïve to this treatment. All participants received botulinum toxin injections combined with conventional rehabilitation. Assessments were performed at baseline and at 4, 12, and 24 weeks post-injection. The primary outcome was muscle tone; secondary outcomes included motor strength, sensorimotor recovery, and global disability. Statistical analyses used mixed-effects models and trend tests. Patients treated within 90 days of stroke onset showed greater reductions in spasticity at 4 and 12 weeks compared with later treatment. Despite having more severe baseline impairments, early treated patients demonstrated faster and more pronounced improvements in upper-limb strength, sensorimotor recovery, and global disability. Early toxin administration is associated with enhanced reduction in spasticity and improved motor recovery, particularly in patients with severe initial deficits. Full article

Pediatric torticollis, predominantly resulting from congenital muscular torticollis, is characterized by unilateral shortening of the sternocleidomastoid muscle, leading to head tilt and limited cervical mobility. Conventional management primarily involves physical therapy and repositioning strategies, with most infants achieving full recovery. However, a subset of patients exhibits persistent symptoms despite conservative treatment. Botulinum toxin type A (BoNT-A) has emerged as a minimally invasive adjunct intervention that targets muscular hypertonicity by inhibiting acetylcholine release at neuromuscular junctions. This scoping review synthesizes clinical evidence from six studies, including randomized controlled trials and case reports, assessing the efficacy and safety of BoNT-A in pediatric torticollis. Results indicate consistent improvements in range of motion, head posture correction, and patient satisfaction, with rare and mild adverse events such as local bruising and transient muscle weakness. Despite promising outcomes, variability in dosing, injection protocols, and follow-up durations underscores the need for standardized treatment guidelines and further high-quality research. These findings support BoNT-A as a valuable therapeutic option for refractory pediatric torticollis, warranting integration into multidisciplinary care frameworks. 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

This study investigated bite force changes after botulinum toxin type A (BoNT-A) injection into different masticatory muscles. Thirty-five male participants were divided into three groups: masseter only (M), masseter and temporalis (MT), and masseter, temporalis, and medial pterygoid (MTP). Bite force was measured before and up to 6 months after injection with the Dental Prescale II system. Baseline values showed no significant group differences. Group M exhibited significant reduction at 1 and 2 weeks, with recovery within 1 month. Group MT showed a similar transient decrease, also recovering after 1 month. In contrast, Group MTP demonstrated a more pronounced and prolonged reduction, persisting up to 4 months before recovery. These results indicate that the extent and duration of BoNT-A effects depend on the number of muscles injected. Multi-muscle injections, including the medial pterygoid, provide more durable suppression. However, further research involving patient populations is needed to clarify whether multi-muscle injection strategies provide therapeutic benefits in clinical conditions such as temporomandibular disorders or oromandibular dystonia. Full article