Pharmacology of botulinum toxin

A multicenter, double-blind, randomized, parallel-group, active-controlled, phase 3 clinical trial to compare the effectiveness and safety of two botulinum toxin type A formulations for improving moderate to severe glabellar wrinkles in Asians

Botulinum toxin type A (BoNT-A) was first isolated in 1946, and since then, several formulations have been developed and widely used to treat wrinkles by inducing muscle paralysis. This multicenter, double-blind, randomized, parallel-group, active-controlled phase 3 clinical trial was designed to evaluate the efficacy and safety of a newly developed BoNT-A formulation, BMI2006, in improving moderate to severe glabellar wrinkles and to compare with existing onabotulinumtoxin A (OBoNT) injections. A total of 276 subjects were enrolled and received 20 units of the randomized material, which was intramuscularly injected into five different locations on the forehead. The primary endpoint, assessed at 4 weeks, showed no statistically significant difference in the improvement rate of glabellar wrinkles between the two groups, with BMI2006 demonstrating non-inferiority to comparator BoNT-A. Secondary endpoints, evaluated by both treating investigators and independent investigators, also exhibited similar improvement rates throughout the study period. Both groups reported high levels of satisfaction with no statistical difference between the two groups. Safety evaluations indicated mild and transient adverse events, with no serious reactions observed. In conclusion, BMI2006 is an effective and safe BoNT-A for treating glabellar wrinkles with an expected duration of action between 8 and 12 weeks.

New and Future Developments in Neurotoxins

BACKGROUND

There are 7 known serotypes of botulinum neurotoxins (A through G). Currently, commercially available toxins are those in serotypes A and B. This paper will discuss new toxins on the horizon, developments in prolonging and shortening the duration of outcomes, and novel therapeutic indications on the horizon.

OBJECTIVE

To provide insight into new toxins and new therapeutic modalities surrounding toxins on the horizon.

METHODS

The authors have reviewed the relevant literature and shared their insights and opinions as to future developments in toxin research and potential clinical applications.

CONCLUSION

Botulinum neurotoxin type E's faster onset and shorter duration of effect represent true clinical differentiators. Future development of botulinum neurotoxin type E for aesthetic and therapeutic uses will be in areas where fast onset and short duration of effect are desirable. Current challenges with neuromodulators include the need for frequent treatments and lack of reversal agents. Agents to address both challenges and novel indications, including inhibition of melanogenesis, are being developed.

Neuronal Membrane-Derived Nanodiscs for Broad-Spectrum Neurotoxin Detoxification

Neurotoxins pose significant challenges in defense and healthcare due to their disruptive effects on nervous tissues. Their extreme potency and enormous structural diversity have hindered the development of effective antidotes. Motivated by the properties of cell membrane-derived nanodiscs, such as their ultrasmall size, disc shape, and inherent cell membrane functions, here, we develop neuronal membrane-derived nanodiscs (denoted "Neuron-NDs") as a countermeasure nanomedicine for broad-spectrum neurotoxin detoxification. We fabricate Neuron-NDs using the plasma membrane of human SH-SY5Y neurons and demonstrate their effectiveness in detoxifying tetrodotoxin (TTX) and botulinum toxin (BoNT), two model toxins with distinct mechanisms of action. Cell-based assays confirm the ability of Neuron-NDs to inhibit TTX-induced ion channel blockage and BoNT-mediated inhibition of synaptic vesicle recycling. In mouse models of TTX and BoNT intoxication, treatment with Neuron-NDs effectively improves survival rates in both therapeutic and preventative settings. Importantly, high-dose administration of Neuron-NDs shows no observable acute toxicity in mice, indicating its safety profile. Overall, our study highlights the facile fabrication of Neuron-NDs and their broad-spectrum detoxification capabilities, offering promising solutions for neurotoxin-related challenges in biodefense and therapeutic applications.

Does botulinum toxin affect psycho-social aspects in dystonia?

Dystonia is a movement disorder in which sustained muscle contractions give rise to abnormal postures or involuntary movements. It is a disabling and disfiguring disorder that affects activities of daily living and gives people a bizarre appearance often associated with psychological morbidity, embarrassment and social avoidance. Intramuscular injection of botulinum toxin (BoNT) is the most effective treatment for motor symptoms in focal dystonia, but little is known about its impact on the psycho-social dimension. The main aim of this study was to evaluate psycho-social changes in patients with focal dystonia after starting BoNT treatment using self-reported scales. The Beck Depression Inventory (BDI-II), the 36-Item Short Form Health Survey (SF-36), the Body Uneasiness Test (BUT), the State-Trait Anxiety Inventory (STAI) and the Visual Analogue Scale (VAS) assessing body self-image, satisfaction with physical aspects, social avoidance, self-reported depression, and self-distress were completed by 11 patients with dystonia and 9 patients with hyperhidrosis as a control group before BoNT (T0). VAS was then performed after four weeks (T1) to assess whether BoNT induced changes in the psychosocial dimension. Our results showed that only depressive symptoms and rumination about body defects improved in patients with dystonia after BoNT treatment, while improvement in self-distress and satisfaction with physical aspects was also found in hyperhidrosis. Individuals with hyperhidrosis experience poorer psychological well-being and suffer from higher levels of distress compared to dystonic patients. This suggests that individuals with this disabling condition are more vulnerable to social impact than dystonic patients.

Botulinum Toxin Enhanced Foker Process for Long Gap Esophageal Atresia

BACKGROUND

The traction-induced esophageal growth (Foker) process for the treatment of long gap esophageal atresia (LGEA) relies on applying progressive tension to the esophagus to induce growth. Due to its anti-fibrotic and muscle-relaxing properties, we hypothesize that Botulinum Toxin A (BTX) can enhance traction-induced esophageal growth.

METHODS

A retrospective two-center cohort study was conducted on children who underwent a BTX-enhanced Foker process for LGEA repair from 2021 to 2023. BTX (10 units/ml, 2 units/kg, per esophageal pouch) was applied at the time of traction initiation. Time on traction, complications, and anastomotic outcomes were compared against historical controls (Foker process without BTX) from 2014 to 2021.

RESULTS

Twenty infants (LGEA type A:12, B:4, C:4; 35% reoperative; median [IQR] age 3 [2-5] months), underwent BTX-enhanced Foker process (thoracotomy with external traction: 9; minimally invasive [MIS] multi-staged internal traction: 11). Mean gap lengths were similar between BTX-enhanced external and external traction control patients (mean [SD], 50.6 mm [12.6] vs. 44.5 mm [11.9], p = 0.21). When compared to controls, the BTX-enhanced external traction process was significantly faster (mean [SD], 12.1 [1.6] days vs. 16.6 [13.2] without BTX, p = 0.04) despite similar preoperative gap lengths. There was no difference in time on traction for those undergoing a minimally invasive process. There were no significant differences in complications or anastomotic outcomes in either cohort.

CONCLUSION

Botulinum toxin may play a role in accelerating the traction-induced esophageal growth process for LGEA repair. Minimizing time on traction can decrease sedation and paralysis burden while on external traction. Further studies are needed to elucidate the effects of BTX on the esophagus.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective, Two-center, Cohort study.

Comparative study between the efficacy of prabotulinum toxin-A versus onabotulinum toxin-A for the treatment of upper facial expression lines

BACKGROUND

Botulinum Toxin (BoNTA) is the most used nonsurgical aesthetic procedure to treat facial expression lines.

AIMS

This study compared the efficacy of Prabotulinum toxin-A, a novel BoNTA that originates from Clostridium botulinum Hall-A, with onabotulinum toxin-A in treating facial expression lines using the Facial Wrinkle Scale (FWS) and FACE-Q questionnaires.

METHODS

This was an experimental, comparative, longitudinal, open-label, and prospective study. Patients aged between 25 and 40 years with upper-third facial expression lines were included. Follow-ups were made at three, seven, 30, and 120 days.

RESULTS

A total of 26 patients were included: 20 female, and six males, with a mean age of 28.26 years. An average of 31.00 IU and 31.38 IU were administered to the onabotulinum and prabotulinum groups, respectively. The prabotulinum group demonstrated superiority in FWS and Face-Q scores between the first and third days (p ≤ 0.001, p < 0.001, respectively), which continued on day 7. By day 30, there were no differences in the scores of the two questionnaires.

CONCLUSIONS

Prabotulinum toxin-A is a safe and effective treatment for upper-third facial wrinkles. On day three and seven, the results suggest that prabotulinum toxin-A has a quicker onset of action than onabotulinum toxin-A. On days 30 and 120, both groups showed similar FWS and Face-Q scores.

Sensory ASIC3 channel exacerbates psoriatic inflammation via a neurogenic pathway in female mice

Psoriasis is an immune-mediated skin disease associated with neurogenic inflammation, but the underlying molecular mechanism remains unclear. We demonstrate here that acid-sensing ion channel 3 (ASIC3) exacerbates psoriatic inflammation through a sensory neurogenic pathway. Global or nociceptor-specific Asic3 knockout (KO) in female mice alleviates imiquimod-induced psoriatic acanthosis and type 17 inflammation to the same extent as nociceptor ablation. However, ASIC3 is dispensable for IL-23-induced psoriatic inflammation that bypasses the need for nociceptors. Mechanistically, ASIC3 activation induces the activity-dependent release of calcitonin gene-related peptide (CGRP) from sensory neurons to promote neurogenic inflammation. Botulinum neurotoxin A and CGRP antagonists prevent sensory neuron-mediated exacerbation of psoriatic inflammation to similar extents as Asic3 KO. In contrast, replenishing CGRP in the skin of Asic3 KO mice restores the inflammatory response. These findings establish sensory ASIC3 as a critical constituent in psoriatic inflammation, and a promising target for neurogenic inflammation management.

Facial Painting and 3D Stereophotogrammetric Analysis of Facial Dynamics: A Reliable Anatomical Educational Method

(1) Background: Accurate knowledge of the dynamic anatomy of facial muscles is crucial for the use of functional and aesthetic botulinum toxin injections. We studied the reliability and relevance of facial painting as a pedagogic tool for the dynamic anatomy of facial muscles. (2) Methods: Different facial expressions were performed by a female model after a professional makeup artist applied makeup to the various facial muscles on her left hemiface. A 3D photograph was taken at the beginning and end of each movement using the VECTRA H2 Imaging System device. Cutaneous movements were visualized using displacement vectors. The correlation between the theoretical and dynamic positions of the makeup-muscle was assessed by two facial anatomy experts, thanks to a correlation scale. (3) Results: The overall average score for the 11 analyzed muscles or muscle groups was 3.36 out of 4, indicating a "strong" to "very strong" estimated correlation. There was a moderate agreement between Evaluator 1 and Evaluator 2 (ICC: 0.64; 95%CI: [0.244; 0.852]; p-value: 0.005). (4) Conclusions: The educational model with facial makeup provides an indirect but nonetheless precise and reliable representation of all facial muscles on the skin's surface. It is presented as a reliable and reproducible method, which exhibits great potential as a teaching tool.

Botulinum toxin: a new differential diagnosis for a lytic bone lesion

BACKGROUND

Botulinum toxin, produced by the Gram-positive anaerobe Clostridium botulinum, is composed of seven antigenic subtypes (A, B, C, D, E, F, and G). Currently, only Botulinum toxin type A, commonly referred to as "Botox," is approved for clinical use, given its relatively safe clinical profile. Botulinum toxin type A has a wide range of therapeutic indications, including treatment for dystonia, migraine headache, neurogenic bladder, and large muscle spastic disorders. However, the toxin is most widely known for its cosmetic effects in treating wrinkles and facial lines.

CASE PRESENTATION

This article describes a 62-year-old Caucasian female who presented for investigation and workup of an isolated lytic lesion of her frontal bone a few weeks after administration of botulinum toxin injection into the corresponding site in the frontalis muscle. This presented as a large, palpable, painless forehead lump causing significant psychological distress. After no neoplastic cause for the lesion was found and histopathology was performed, our researchers concluded that the most likely explanation was that the bony lytic lesion resulted from inadvertent injection of the "Botox" neurotoxin through the intended target muscle and into the cortex of the underlying bone.

CONCLUSIONS

Our search of the literature failed to identify any previous cases of this occurring. However, as the popularity of this cosmetic procedure only increases, we believe that this represents an important possible differential for isolated lytic lesion after administration of "Botox" injection.

Efficacy and Safety of AbobotulinumtoxinA for Treatment of Moderate-to-Severe Glabellar Lines: A Meta-Analysis

PURPOSE

This meta-analysis aimed to evaluate the safety and efficacy of abobotulinumtoxinA (ABO) and ABO solution for injection (ASI) for treating moderate-to-severe glabellar lines.

METHODS

The EMBASE, PubMed, and web of science databases were systematically searched. Methodological quality was checked using the Cochrane Risk of Bias tool. We also performed statistical analyses using Stata software to examine the efficacy and safety of ABO.

RESULTS

Nine randomized controlled trials were included in the meta-analysis. The results showed that at maximum frown, the proportion of responders as measured by the investigator's live assessment and subject's self-assessment of moderate-to-severe glabellar lines were significantly higher in the ABO and ASI treatment groups than in the placebo group. In addition, from baseline to maximum frown, the ≥1-grade improvement rate in moderate-to-severe glabellar lines severity was also significantly higher in the ABO and ASI treatment groups than in the placebo group. No significant differences in adverse events were found between ABO, ASI and placebo groups, indicating that ABO and ASI have good safety.

CONCLUSIONS

ABO and ASI are effective and safe options for the treatment of moderate-to-severe glabellar lines. More high-quality studies are needed to verify these conclusions.

Potential role of the cell-penetrating peptide-conjugated soluble N-ethylmaleimide-sensitive factor attachment protein receptor motif of vesicle-associated membrane protein 2-patterned peptide in novel cosmeceutical skin product development

AIM

This study aimed to investigate and verify the effect of cell-penetrating peptide (CPP)-conjugated soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) motif of vesicle-associated membrane protein 2 (VAMP2)-patterned peptide (INCI name: Acetyl sh-Oligopeptide-26 sh-Oligopeptide-27 SP, trade name: M.Biome-BT) on improving skin function in vitro.

METHODS

The cytotoxicity of CPP-conjugated SNARE motif of VAMP2-patterned peptide (CVP) was investigated using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay against B16-F10 cells and human dermal fibroblasts (HDFs) and a reconstructed skin irritation test. The anti-wrinkle activity of M.Biome-BT was determined by assessing the release of norepinephrine and dopamine in PC-12 cells via ELISA. The skin-whitening effects of CVP were assessed in B16-F10 cells by measuring the intra- and extracellular melanin contents and expression levels of melanin production-related genes, such as microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and TRP-2.

RESULTS

CVP is not cytotoxic to B16-F10 cells and HDFs, and no skin irritation was observed. CVP treatment considerably diminished K+ -induced norepinephrine and dopamine secretion compared with the non-treated control group (62% and 40%, respectively). Additionally, the inhibition ability of CVP on norepinephrine and dopamine release was comparable to that of botulinum neurotoxin type A (BoNT/A). CVP also increased intracellular melanin content in a dose-dependent manner, whereas extracellular melanin content decreased (76%-85%). However, CVP treatment did not affect the mRNA expression of MITF, TYR, TRP-1, and TRP-2. These results suggest that CVP does not inhibit melanin production; however, it may induce a whitening effect by inhibiting melanin transport.

CONCLUSIONS

Taken together, our findings indicate that CVP could be used as an active and safe cosmeceutical ingredient for antiaging applications.

Safety of esthetic procedures in rheumatic patients: single-center survey of patients

The popularity of esthetic medicine is growing every year, also among patients with autoimmune inflammatory rheumatic diseases (AIRD). The objective of this study was to evaluate the safety of esthetic medicine (AM) procedures in patients with AIRD. A semi-structured, anonymous questionnaire regarding rheumatic and concomitant diseases and AM procedures was distributed among adult patients hospitalized in the rheumatology department or attending outpatient clinic in the National Institute of Geriatrics, Rheumatology, and Rehabilitation, Warsaw. The main outcome was the occurrence of an adverse event. A number of 512 patients took part in the survey and 15 were excluded (AM procedure preceded the diagnosis of AIRD). The study group consisted of 497 patients, of whom 47 had undergone AM procedures. The procedures performed included: tattooing (22 patients), piercing (16 patients), hyaluronic acid (7 patients), botulinum toxin (5 patients) injections, laser procedures (6 patients), plastic surgery (4 patients), mesotherapy (3 patients) and others. The vast majority of patients had these performed during remission or low disease activity. 70.2% of patients received treatment with disease-modifying antirheumatic drugs (DMARDs) during the AM procedure, with TNF-alfa inhibitors being the most common (63.6%). Adverse events occurred in 15% of patients. All were mild and transient site reactions. Most patients would like to repeat the AM procedure in the future. The use of esthetic medicine procedures in patients with AIRD, including those treated with biologic DMARDs, was associated with a risk of mild site reactions. Most of the patients expressed satisfaction with the results of the AM procedure.

A practical guide to botulinum neurotoxin treatment of teres major muscle in shoulder spasticity: Intramuscular neural distribution of teres major muscle in cadaver model

BACKGROUND

Botulinum neurotoxin treatment typically focuses on the teres major muscle as a primary target for addressing shoulder spasticity. The muscle is located deep within a large muscle group and optimal injection locations have not been identified.

OBJECTIVE

To identify the preferred location for administering botulinum toxin injections in the teres major muscle.

METHODS

Teres major specimens were removed from 18 cadaveric models and stained with Sihler's method to reveal the neural distribution within the muscle. The muscles were systematically divided into equal lengths from origin to insertion. The neural density in each section was evaluated to determine the location that would be likely to increase effectiveness of the injection.

RESULTS

The greatest density of intramuscular nerve endings was located in the middle 20% of the muscle. The tendinous portion was observed at the ends of the muscle.

CONCLUSIONS

The results suggest that botulinum neurotoxin should be delivered in the middle 20% of the teres major muscle.

Neuromodulator Assessment and Treatment for the Upper Face: An Update

Neuromodulator treatment of the upper face has been extensively studied and serves as an excellent tool to enhance facial appearance, non-verbal communication, and social functioning. Optimal outcomes are best achieved when health care providers take an individualized approach, based on knowledge of structural and functional anatomy, thorough facial assessment, and customized injection techniques and patterns.

Prolonged Antipruritic Effect of Botulinum Toxin Type A on Cowhage-induced Itch: A Randomized, Single-blind, Placebo-controlled Trial

Botulinum toxin type A (Botox) is thought to have antipruritic effects through inhibition of pruritic factors, including acetylcholine, substance P, and glutamate. The aim of this randomized, single-blind, placebo-controlled trial was to test the effect of botulinum toxin type A on cowhage, a non-histaminergic model for chronic itch. Botulinum toxin type A was injected into the arm of 35 healthy subjects, with a saline control injected into the contralateral arm. Thermal sensory parameters (warmth and heat thresholds and heat pain intensity) and itch intensity after cowhage application were examined on test areas. Botulinum toxin type A reduced itch intensity, overall perceived itch (area under the curve (AUC); percentage change from baseline), and peak itch intensity compared with the control at 1 week, 1 month, and 3 months. Botulinum toxin type A had no effect on thermal thresholds or heat pain intensity. In conclusion, botulinum toxin type A reduced cowhage itch for at least 3 months, which suggests that botulinum toxin type A is a potential long-lasting treatment for localized, non-histaminergic itch.

Dynamic Evaluation of Skin Displacement by the Frontalis Muscle Contraction Using Three-Dimensional Skin Displacement Vector Analysis

PURPOSE

Understanding the muscle actions and resultant skin movement can enable more safe and effective botulinum toxin injection for the treatment of forehead wrinkles. We aimed to investigate skin displacement patterns of the forehead and adjacent skin due to frontalis muscle contraction using three-dimensional skin vector displacement analysis.

MATERIALS AND METHODS

Thirty healthy individuals were enrolled. Photographs of the face were taken at rest and during maximal contraction of the frontalis muscle. Each expression image was aligned to its respective static image to compute the differences in the skin position.

RESULTS

When frontalis muscle contracts, forehead skin displacement vectors were mostly vertical (63.4%), followed by lateral oblique (33.3%) and medial oblique (3.3%). In 53.3%, only the lower part of the forehead moved upward, while 40.0% showed bidirectional skin movement with transition line at a mean distance of 59.4 mm above the pupil. Moreover, 86.7% showed asymmetric skin displacement, and 83.3% showed both glabellar and eyebrow skin displacement. Frontalis muscle contraction also induced medial 2/3 (50.0%) or entire (33.3%) skin movement of the temple.

CONCLUSION

Botulinum toxin injection into the forehead can be individualized by considering the vector and asymmetry of skin displacement. Vertical or medial vector requires more centrally located injections, while laterial vector requires more laterally located injections. The presence and location of the vertical transition line are important for preventing ptosis when treating forehead lines with botulinum toxin. Glabellar movement during frontalis contraction suggests the need for a concomitant injection into the glabella to prevent glabella wrinkle accentuation.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Safety of Botulinum Toxin A Injections for Facial Rejuvenation: A Meta-Analysis of 9,669 Patients

PURPOSE

To quantitatively evaluate safety profile for botulinum toxin A (BTX-A) injections among patients undergoing treatment for cosmetic indications is produced, with special attention to clinically relevant covariates and their relative impact on safety.

METHODS

A systematic literature search was performed using PubMed (1996-January 2020) and Embase (1947-January 2020) to identify all randomized controlled trials (RCTs) that reported safety data for patients receiving BTX-A for cosmetic indications compared to placebo. A meta-analysis was performed to determine pooled risk ratios (RR) for treatment-related adverse events (TRAEs) and for specific adverse events. Meta-regression and additional analyses were performed for significant and/or clinically relevant covariates.

RESULTS

Following the review of 8,690 studies, 32 RCTs involving 9,669 patients were included. The pooled RR of any TRAE occurring after BTX-A injection compared to placebo injection was 1.53 (95% CI, 1.33-1.77; p < 0.001). Statistically significant covariates included individual injection volume and total injection volume. The type of BTX-A formulation, treatment site, total BTX-A units, and BTX-A units per injection were not significant. Specific adverse events more likely to occur following BTX-A injection rather than placebo injection included eyelid/eyebrow malposition (RR 3.55; p < 0.001), facial paresis (RR 2.42; p = 0.316), and headache (RR 1.45; p = 0.003). Injection site reactions and injection site bruising occurred at similar rates in both groups.

CONCLUSIONS

The overall safety profile of BTX-A is acceptable and consistent with previous publications. The authors' additional analyses provide a relative comparison of the impact of various treatment parameters on safety.

Efficacy, Safety, and Accuracy of Intra-articular Therapies for Hand Osteoarthritis: Current Evidence

The lifetime risk of symptomatic hand osteoarthritis (OA) is 39.8%, with one in two women and one in four men developing the disease by age 85 years and no disease-modifying drug (DMOAD) available so far. Intra-articular (IA) therapy is one of the options commonly used for symptomatic alleviation of OA disease as it can circumvent systemic exposure and potential side effects of oral medications. The current narrative review focuses on the efficacy and safety profiles of the currently available IA agents in hand OA (thumb-base OA or interphalangeal OA) such as corticosteroids and hyaluronic acid (HA), as well as the efficacy and safety of IA investigational injectates in phase 2/3 clinical trials such as prolotherapy, platelet-rich plasma, stem cells, infliximab, interferon-? and botulinum toxin, based on the published randomized controlled trials on PubMed database. The limited published literature revealed the short-term symptomatic benefits of corticosteroids in interphalangeal OA while long-term data are lacking. Most of the short-term studies showed no significant difference between corticosteroids and hyaluronic acid in thumb-base OA, usually with a faster onset of pain relief in the corticosteroid group and a slower but greater (statistically insignificant) pain improvement in the HA group. The majority of studies in investigational agents were limited by small sample size, short-term follow-up, and presence of serious side effects. In addition, we reported higher accuracy rates of drug administrations under imaging guidance than landmark guidance (blind method), and then briefly describe challenges for the long-term efficacy and prospects of IA therapeutics.

Lidocaine alleviates inflammation and pruritus in atopic dermatitis by blocking different population of sensory neurons

BACKGROUND AND PURPOSE

Atopic dermatitis is a common chronic pruritic inflammatory disease of the skin involving neuro-immune communication. Neuronal mechanism-based therapeutic treatments remain lacking. We investigated the efficacy of intravenous lidocaine therapy on atopic dermatitis and the underlying neuro-immune mechanism.

EXPERIMENTAL APPROACH

Pharmacological intervention, immunofluorescence, RNA-sequencing, genetic modification and immunoassay were performed to dissect the neuro-immune basis of itch and inflammation in atopic dermatitis-like mouse model and in patients.

KEY RESULTS

Lidocaine alleviated skin lesions and itch in both atopic dermatitis patients and calcipotriol (MC903)-induced atopic dermatitis model by blocking subpopulation of sensory neurons. QX-314, a charged Na_V blocker that enters through pathologically activated large-pore ion channels and selectivity inhibits a subpopulation of sensory neurons, has the same effects as lidocaine in atopic dermatitis model. Genetic silencing Na_V 1.8-expressing sensory neurons was sufficient to restrict cutaneous inflammation and itch in the atopic dermatitis model. However, pharmacological blockade of TRPV1-positive nociceptors only abolished persistent itch but did not affect skin inflammation in the atopic dermatitis model, indicating a difference between sensory neuronal modulation of skin inflammation and itch. Inhibition of activity-dependent release of calcitonin gene-related peptide (CGRP) from sensory neurons by lidocaine largely accounts for the therapeutic effect of lidocaine in the atopic dermatitis model.

CONCLUSION AND IMPLICATIONS

Na_V 1.8⁺ sensory neurons play a critical role in pathogenesis of atopic dermatitis and lidocaine is a potential anti-inflammatory and anti-pruritic agent for atopic dermatitis. A dissociable difference for sensory neuronal modulation of skin inflammation and itch contributes to further understanding of pathogenesis in atopic dermatitis.

Current and emerging treatment options for premature ejaculation

Premature ejaculation (PE) is a prevalent male sexual dysfunction. Current standard treatment regimens include behavioural therapies, topical anaesthetics, dapoxetine and other selective serotonin reuptake inhibitors (SSRIs). Most of the pharmacotherapeutic options target neurotransmitters (such as serotonin and oxytocin) that have a role in the ejaculation mechanism. However, these treatments are mildly effective and only provide a temporary delay in the ejaculation latency time, and PE recurs when the treatment is stopped. Thus, a treatment for PE is urgently needed and research is ongoing to find the ideal PE therapy. The efficacy and safety of topical anaesthetics and SSRIs in delaying ejaculation have been confirmed in many well-designed controlled trials. Both preclinical and clinical studies on new-generation SSRIs are ongoing. Moreover, promising results came from clinical trials in which the efficacy of on-demand PE therapies targeting neurotransmitters other than serotonin, such as α1-adrenoceptor antagonists and oxytocin antagonists, was assessed. Surgical intervention and neuromodulation have been proposed as potential treatment options for PE; however, current PE guidelines do not recommend these treatments owing to safety concerns.

Comparison of botulinum toxin (BoNT) injection and lateral internal sphincterotomy (redo-LIS) for recurrent anal fissure treatment

Objective

Today's gold standard for treating chronic anal fissure is the Lateral Internal Sphincterotomy (LIS). Botulinum Toxin (BoNT) injection is, on the other hand, an alternative treatment for patients who do not want to have surgical treatment, patients undergoing chemotherapy, patients of high risk for surgery, and those who have the risk of anal incontinence (e.g., elderly, past anorectal surgery, vaginal multiple births, etc.). The aim of this study is to compare the effectiveness of BoNT and redo-LIS for treatment of post-LIS recurrent chronic anal fissure, and reveal differences if any.This study aims to compare redo-LIS and BoNT injection for treating post-LIS recurrent anal fissure.

Material and method

Nineteen patients who received LIS treatment and then redo-LIS or BoNT injection due to recurrence in the follow-up were included in this study. Group I (redo-LIS group) include 11 patients and group 2 (BoNT group) includes 8 patients. Their data on age, sex, anal incontinence scores and pain (VAS score) score as well.

Results

During the 3-month post-surgery follow-up period, there was statistically significant difference (p < 0.01) between groups by pain. No deterioration in the incontinence scores of patients in the group during the 6-month post-surgery period.

Conclusion

This study demonstrates that redo lateral internal sphincterotomy (LIS) is a reliable method for patients who received LIS but developed recurrent chronic anal fissure, and achieves successful results in terms of recurrence and relief of pain.

Botulinum Toxin Therapy for Spasmodic Dysphonia in Japan: The History and an Update

Spasmodic dysphonia (SD) is a rare neurological disorder that impairs phonatory function by triggering involuntary and intermittent contractions of the intrinsic laryngeal muscles. SD is classified into three types: adductor SD (AdSD), abductor SD (AbSD), and mixed SD. Of these, AdSD accounts for 90–95% of disease; younger females are predominantly affected. Botulinum toxin injection into the laryngeal muscles is safe, minimally invasive, and very effective. Here, we review the history of clinical research for SD conducted in Japan. The first use of botulinum toxin injection therapy to treat SD in Japan was by Kobayashi et al. in 1989. The group developed an objective mora (syllable) method to evaluate SD severity. Recently, we conducted a placebo-controlled, randomized, double-blinded clinical trial of botulinum toxin therapy for AdSD and an open-label trial for AbSD to obtain the approval of such therapy by the Japanese medical insurance system. The mora method revealed significant voice improvement and the evidence was of high quality. Additionally, a clinical trial of type 2 thyroplasty using titanium bridges confirmed the efficacy and safety of such therapy. These studies broadened the SD treatment options and have significantly benefited patients.

Off-Label Use of Botulinum Toxin in Dermatology—Current State of the Art

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacteria. Among seven different isoforms, only BoNT-A and BoNT-B are commercially used. Currently, botulinum toxin has been indicated by the U.S. Food and Drug Administration in several disorders, among others: chronic migraine, hyperhidrosis, urinary incontinence from detrusor overactivity, or cosmetics. However, there are numerous promising reports based on off-label BTX usage, indicating its potential effectiveness in other diseases, which remains unknown to many. Among them, dermatological conditions, such as rosacea, annal fissure, Raynaud phenomenon, hypertrophic scars and keloids, and also hidradenitis suppurativa, are currently being investigated. This article aims to provide a comprehensive update on the off-label use of botulinum toxin in dermatology, based on an analysis and summary of the published literature.

The listed, delisted, and sustainability of therapeutic medicines for dementia patients: the study is specific to South Korea

The Dementia Management Act (DMA) came into effect on August 4, 2011, in South Korea. Diagnosis and medication were rapidly performed for dementia in a short time. We investigated the cardiac effects of increased drug prescription following DMA. We observed a correlation between Alzheimer’s disease (AD) and anti-AD drug (AAD) groups from 2010 to 2019 on the National Health Insurance System (NHIS) of South Korea. This study investigated the increase and decrease in deaths of AD patients with AAD. We analysed the mortality per 100,000 population with the R² Calculator. Moreover, we made the up or down datum line for the simple decision on the listed, delisted, and sustainable drug examined by a linear equation and R². We observed that life expectancy was diminished by AAD in Sorokdo National Hospital. In the NHIS, donepezil and rivastigmine increased the number of deaths decided on R² > 0.75. Memantine was sustainable. We could not decide on galantamine because it is one of the other groups. We made a straightforward decision-maker of delisted, listed, or sustainable criteria based on mortality and datum line.

Cutaneous nerve fibers participate in the progression of psoriasis by linking epidermal keratinocytes and immunocytes

Recent studies have illustrated that psoriatic lesions are innervated by dense sensory nerve fibers. Psoriatic plaques appeared to improve after central or peripheral nerve injury. Therefore, the nervous system may play a vital role in psoriasis. We aimed to clarify the expression of nerve fibers in psoriasis and their relationship with immune cells and keratinocytes, and to explore the effect of skin nerve impairment. Our results illustrated that nerve fibers in psoriatic lesions increased and were closely innervated around immune cells and keratinocytes. RNA-seq analysis showed that peripheral sensory nerve-related genes were disrupted in psoriasis. In spinal cord hemi-section mice, sensory impairment improved psoriasiform dermatitis and inhibited the abnormal proliferation of keratinocytes. Botulinum toxin A alleviated psoriasiform dermatitis by inhibiting the secretion of calcitonin gene-related peptide. Collectively, cutaneous nerve fibers participate in the progression of psoriasis by linking epidermal keratinocytes and immunocytes. Neurological intervention may be a new treatment strategy for psoriasis.

Prospective Evaluation of Intradetrusor Injections of OnabotulinumtoxinA in Adults With Spinal Dysraphism

OBJECTIVE

To prospectively evaluate the effectiveness of OnabotulinumtoxinA (BTX-A) on neurogenic overactive bladder (nOAB) in adults with congenital spinal dysraphism (CSD).

METHODS

We conducted a prospective, nonrandomized pilot study of 24 adults with CSD and neurogenic overactive bladder. Patients were evaluated with baseline video-urodynamics (UDS) and validated questionnaires, underwent injection 200U BTX-A, and then underwent repeat evaluation with questionnaires and UDS 1-3 months postinjection. A high-risk subgroup was separately analyzed based on adverse clinical characteristics (ie, decrease bladder compliance, vesicoureteral reflux, hydronephrosis, chronic kidney disease).

RESULTS

BTX-A injection improved patient recorded outcome measures seen in both I-QOL Score total (67.9 vs 75.5, P = .007) and Neurogenic Bladder Symptom Score total (38.0 vs 29.0, P = .001). On UDS, BTX-A injection significantly improved end filling pressure (16.0 vs 8.8, P = .036) and also improved bladder compliance (mL/cm H2O) (89.38 vs 135.81, P = .445). High-risk patients were found to have similar improvements in most subjective questionnaire scoring, a significant decrease in end filling pressures, and improved bladder compliance on UDS.

CONCLUSION

BTX-A can be used as an effective treatment in adults with CSD. We found that BTX-A significantly improved quality of life from patient reported outcome measurements as well as improving end filling pressures and bladder compliance. These improvements were seen even within our high-risk subgroup. Further studies are needed to evaluate long-term efficacy and appropriate follow-up of this at-risk population.

The efficacy of botulinum toxin type-A for intractable chronic migraine patients with no pain-free time

AIM

This is a retrospective report of the efficacy of botulinum toxin-A, Botox^® (Allergan), in intractable chronic migraine patients non-responsive to previous pharmacological management and with largely no pain-free time, including those with new onset daily persistent headache.

METHODS

Thirty-three patients, all with severe Headache Impact Test (HIT)-6 scores at baseline, received 3-monthly injections of Botox^® as per Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PRE-EMPT) protocol over a maximum 33-month period. Response criteria were a sustained reduction of HIT-6 scores below 60.

RESULTS

Four patients had headache on at least 20 days a month; the remaining patients had daily headache with no pain-free time, including nine patients with new onset persistent migraine. There was a significant reduction in HIT-6 scores following Botox^® therapy (x̅ = -5.45, p = 0.000920). Twenty-one percent of the cohort exhibited a sustained reduction in HIT-6 scores below 60. The number of headache days and pain-free time did not change in five of the six responders, but disability improved. There was no difference between patients with episodic migraine evolving to chronic as opposed to those with chronic migraine from onset.

CONCLUSION

This report suggests that Botox^® treatment is efficacious in intractable chronic migraine without pain-free time. The HIT-6 is a reliable and practical parameter to assess disability in this patient group. Use of such validated parameters should be considered with greater weight in future International Classification of Headache Disorders (ICHD) guidelines for controlled clinical trials.

Is botulinum toxin a cause or a cure for headaches?

BACKGROUND

Botulinum toxin is used in the treatment of headache as well as cosmetic indications. In recent years, headache cases have been encountered after botulinum toxin injections for cosmetic purposes. However, no clinical studies have been conducted on this seemingly paradoxical issue.

OBJECTIVE

In our study, the aim was to evaluate the frequency of occurrence of headache and its clinical features in patients who had undergone botulinum toxin application for cosmetic purposes.

METHODS

A total of 186 patients who were treated with onabotulinum toxin A for cosmetic purposes in our clinic between January 2019 and January 2021 were retrospectively screened, and the clinical and demographic characteristics of the patients who reported headache complaints were examined.

RESULTS

Headache was reported in 19 (10.2%) of the 186 patients included in the study. Of the 19 patients who reported headaches, 17 (89.4%) had the onset of the complaint within the first 24 h, the complaint was resolved within the first 3 days in 16 (84.2%), and 12 (63.1%) reported spontaneous regression without the need for painkillers. The rate of development of headache complaints after the procedure was found to be statistically significantly higher in patients diagnosed with hypertension (p = 0.000) and patients treated for bunny line (p = 0.016). Ten patients (52.6%) described constant, 17 patients (89.5%) had diffuse, and 11 patients (57.9%) had throbbing-type headaches.

CONCLUSION

Botulinum toxin application causes diffuse, constant, throbbing-type headaches that start in the early period and ends within a short time without the need for treatment.

Perianal Hyperhidrosis Successfully Treated with Botulinum Toxin A

Perianal hyperhidrosis (HH) is a rare form of primary focal HH and may become a major problem for the patient with a significant psychosocial burden and negative impact on the quality of life. Botulinum toxin injections are widely used as a second-line treatment option for axillary, palmar, and plantar HH with a good safety profile. Herein, we pre-sent a case of primary perianal HH successfully treated with Botulinum toxin A at a dose higher than that previously reported in literature, with a longer response, a higher degree of satisfaction, and no adverse effects. Moreover, we review the main aspects of the perianal anatomy that are essential to carry out the technique correctly and make dermatologists achieve expertise with the procedure.

A Review of Tolerance and Safety Profiles of Long-Term Botulinum Neurotoxin Type A in Asian Patients with Hemifacial Spasm and Benign Essential Blepharospasm

This article reports the tolerance and long-term safety profiles of botulinum neurotoxin type A among Asian patients with benign essential blepharospasm (BEB) and hemifacial spasm (HFS). We performed a retrospective review of clinical documents and procedure records of consecutive BEB and HFS patients receiving onabotulinum toxin A (Botox) treatment in our clinic over the past 20 years. We reviewed the information of 105 patients diagnosed with BEB (n = 31) and HFS (n = 74). All of the patients were Asian. The mean age of disease onset was 59 (range 37-80) years old for BEB and 61 (range 31-83) for HFS. The mean follow up was 84 (range 12-240) months and the mean number of sessions per patient was 19 (range 1-61). The botulinum toxin dose per session increased significantly in both BEB (16.5 versus 21.6 units, p < .05) and HFS (22.6 versus 26.9 units, p < .05) patients after a mean of 18 sessions; however, the onset time, effective duration and subjective treatment outcome were similar over time in both BEB and HFS patients. At least one local complication was reported among 26% and 41% of patients with BEB and HFS respectively, with ptosis (32%) being most frequent.

Utilities of Botulinum Toxins in Dermatology and Cosmetology

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacterium with a well-known efficacy and safety profile in the focal idiopathic hyperhidrosis treatment. BoNT comprises seven different neurotoxins; however, only toxins A and B are clinically employed. BoNT is lately practiced in off-label therapies for a variety of skin diseases. Scar prevention, hyperhidrosis, rhytides, eccrine nevus, alopecia, psoriasis, Darier disease, bullous skin disease, pompholyx and Raynaud's phenomenon are some of the novel indications for BoNT in cosmetic and notably non-cosmetic aspects of dermatology. To employ BoNT correctly in clinical practice, we must have a thorough understanding of the functional anatomy of the mimetic muscles. An intensive literature search was conducted to update all dermatology-oriented experiments and clinical trials on the described element of BoNT for this general overview of BoNT use in dermatology. This review aims to analyse the role of BoNT in dermatology and cosmetology.

The Use of Botulinum Toxin to Prevent Anastomotic Thrombosis and Promote Flap Survival: A Bridge to Developing Clinical Studies

BACKGROUND

Despite the possibility of using botulinum toxin to improve perfusion and prevent vasospasm, only a few studies have examined the use of botulinum toxin in the setting of flap surgery and thrombosis, and the mechanisms have not been fully explained.

OBJECTIVE

The primary objective of this study was to provide a comprehensive review of the effectiveness of botulinum toxin in anastomotic thrombosis prevention and surgical flap survival to determine the value of conducting large-scale human trials.

METHODS

Using the SYRCLE and CAMRADES criteria, a systematic review was performed. PubMed, Medline, EmBase, and the Cochrane Library were searched for studies that met our eligibility criteria.

RESULTS

Twenty studies were included in the final selection. A total of 397 subjects were included. Eighteen studies used botulinum toxin type A alone, one used botulinum toxin type B alone, and only one used both botulinum toxin type A and botulinum toxin type B. The most commonly used injection technique was a preoperative intradermal injection. The most common procedure performed was a pedicled flap with random pattern skin flaps (65%). The mean injection dose was 28.17 ± 49.21 IU, whereas the mean reported injection time for studies using animal models was 7.4 ± 6.84 days.

CONCLUSIONS

Similar mechanisms demonstrated in animal models may be replicable in humans, allowing botulinum toxin to be used to prolong flap survival. However, many factors, such as optimal injection techniques, dosages, and long-term outcomes of botulinum use in flap surgery, need to be further assessed before applying this to clinical practice.

Dynamic evaluation of facial muscles: 3D skin displacement vector analysis using a facial painting model

BACKGROUND

Botulinum toxin A can be used to eliminate dynamic wrinkles by relaxing the muscles involved in facial expressions. Therefore, it is essential to know the location, origin, insertion, function, and changes of the facial expression muscles according to their contraction.

METHODS

After drawing the muscles on the face of a model, pictures were taken at rest. The model was then asked to make facial expressions that cause facial wrinkles. All images were taken with the Vectra H1 camera system (Canfield Scientific, Inc., Fairfield, New Jersey). Each expression image was aligned to its respective static image to compute the differences in skin position, so as to calculate the skin displacement vectors. The values for local changes in skin displacement were calculated by applying the automated algorithms of the Vectra Software Mirror Suite and visualized using the color and size of the arrow.

RESULTS

Face painting and 3D skin vector displacement analyses enabled visualization of all the facial muscles involved in facial expressions working dynamically, allowing us to visualize the effect of each muscle in the creation of hyperkinetic wrinkles. Face painting and 3D skin vector displacement analyses can be combined to determine the location of the wrinkles, extent of the muscle, part of the muscle that contracts, presence of asymmetry, direction in which the muscle contracts, and correlation between the antagonists and synergistic muscles.

CONCLUSION

The botulinum toxin A injection educational model using body painting and 3D skin vector displacement analyses can provide a deeper understanding of actual moving muscle anatomy.

LEVEL OF EVIDENCE

4.

Ophthalmic adverse events following facial injections of botulinum toxin A: A systemic literature review

BACKGROUND

Over the years, botulinum toxin has found its place as a neuromuscular blocking agent in numerous medical fields. Since the approval of botulinum toxin by the FDA for cosmetic indications in 2002, it had become the most commonly performed esthetic procedure worldwide, with ever-growing demand. The characteristics of the toxin, along with the facial areas it is injected to, could possibly account for a wide array of complication.

METHODS

The authors conducted a literature search for reported cases of ophthalmic adverse events following Botulinum toxin facial injections in the electronic databases of PubMed and Cochrane Library databases.

RESULTS

The authors found 25 publications, reporting 49 cases of ophthalmic adverse events following botulinum toxin injections. Injections for cosmetic indications accounted for 51% of all injections, treatment of blepharospasms for 22% of cases, protective ptosis for 11% of cases, and treatment of hemifacial spams for 8% of cases. The average quantity of botulinum toxin injected to a single patient ranged between 1.25 and 75 units, with a median of 13.75 units.Majority of injections for cosmetic indications were performed to the lateral canthal area (56%), followed by the glabella (28%) and the forehead (20%).Adverse events following injections included diplopia (64%), ptosis (14%), and decrease in visual acuity or vision loss (8%).

CONCLUSIONS

Botulinum toxin is gaining extreme popularity in the management of a wide area of diseases and for cosmetic indications. Proper knowledge of potential adverse events is crucial for the clinician in attempt to decrease complications.

Complications and Adverse Effects of Periocular Aesthetic Treatments

The popularity and variety of temporary and permanent periocular aesthetic treatments has increased over the past decade. Patients frequently present to eye clinics with ocular complications and side effects following these treatments, their severity ranging from ocular irritation from dry eyes to visual loss from vascular occlusion. A careful, thorough history is essential, as many patients may not associate aesthetic procedures with ocular complications, and some may be embarrassed to disclose this information. All ophthalmologists should understand the potential ocular sequelae of these treatments and be able to initiate treatment in sight-threatening cases. Wesummarises the current literature on ophthalmic complications of the most common periocular aesthetic treatments.

Hereditary geniospasm in a mother and son treated with botulinum toxin injection: A case report

Hereditary geniospasm is a rare and benign disorder that can cause distress and social embarrassment to patients. There are only a handful of possible treatment options available. Due to the rarity of the condition, practices differ across the world and the results are varied. These include beta-blockers, benzodiazepines and anti-epileptics. These treatments can have significant side-effects when used long term. However, botulinum toxin injections have been successfully used in a handful of cases. We report a successful botulinum treatment of hereditary geniospasm in a mother and son, with the injection protocols.

Randomized, double-blind, active-controlled, multicentre, phase III clinical trial with two stages to assess the safety and efficacy of letibotulinum toxin a vs. onabotulinum toxin a for subjects with moderate to severe crow's feet

BACKGROUND

Letibotulinum toxin A (LeBA) was approved by the Ministry of Food and Drug Safety (known as the Korea Food & Drug Administration) for cosmetic indications in 2012. However, the efficacy and safety of this newly introduced LeBA have not been investigated in crow's feet lines (CFL) treatment and standardization before its universal use.

OBJECTIVE

The aim of this multicentre, double-blind, randomized, parallel, active-controlled Phase III clinical trial with two stages (ClinicalTrials.gov identifier: NCT03408236) was to investigate the non-inferiority of LeBA vs. the existing onabotulinum toxin A (OnBA) for the treatment of CFL.

METHODS

A total of 240 subjects were randomized to either the test (LeBA) or control (OnBA) group. At the baseline and at weeks 4 while maximum smiling (primary efficacy assessment), 8, 12 and 16, investigator's on-site evaluation, independent evaluator, evaluation by the subjects, subjects' satisfaction assessment and safety assessment were performed.

RESULTS

At week 4, the response rate of primary efficacy assessment was 69.75% and 68.33% in the test (LeBA) and control (OnBA) groups, respectively, without a significant difference. Other minor secondary evaluation results showed significant differences suggesting that LeBA offered better improvement than OnBA, but the overall results did not show significant differences between the two groups.

CONCLUSION

This study showed that LeBA was as effective and safe as OnBA for the treatment of CFL at the same doses.

Use of AbobotulinumtoxinA for Cosmetic Treatments in the Neck, and Middle and Lower Areas of the Face: A Systematic Review

AbobotulinumtoxinA (aboBoNT-A) has been used for various cosmetic purposes, including minimization of moderate to severe lines, or other cosmetic indications, in the face and neck. We carried out a systematic review to identify all relevant evidence on the treatment approaches and outcomes of aboBoNT-A as a cosmetic treatment of the middle and lower areas of the face, and the neck. Embase, MEDLINE, Cochrane Library, congress proceedings and review bibliographies were searched for relevant studies. Identified articles were screened against pre-specified eligibility criteria. Of 560 unique articles identified, 10 were included for data extraction (three observational studies, 1 randomized controlled trial [with two articles] and five non-randomized trials). The articles provided data on gummy/asymmetric smile (2), marionette lines (5), masseter muscle volume (2), nasal wrinkles (2), perioral wrinkles (3) and the platysma muscle (4). All articles reporting on efficacy of aboBoNT-A demonstrated positive results, including reduction of wrinkles (5), reduction of masseter muscle (2) and degree of gummy smile (1) compared with before treatment. No serious adverse events were reported and patient satisfaction was high. In conclusion, positive findings support further research of aboBoNT-A for the middle and lower areas of the face, and in the neck, which are largely unapproved indications.

Scientific review of the aesthetic uses of botulinum toxin type A

Botulinum toxin type A (BoNT-A), onabotulinumtoxinA (Botox) was approved by the United States Food and Drug Administration for temporary improvement of glabellar lines in patients 65 years and younger in 2002, and has also been used widely for aesthetic purposes such as hyperhidrosis, body shape contouring, and other noninvasive facial procedures. BoNT-A inhibits presynaptic exocytosis of acetylcholine (ACh)-containing vesicles into the neuromuscular junction at cholinergic nerve endings of the peripheral nervous system, thereby paralyzing skeletal muscles. ACh is the most broadly used neurotransmitter in the somatic nervous system, preganglionic and postganglionic fibers of parasympathetic nerves, and preganglionic fibers or postganglionic sudomotor nerves of sympathetic nerves. The scientific basis for using BoNT-A in various cosmetic procedures is that its function goes beyond the dual role of muscle paralysis and neuromodulation by inhibiting the secretion of ACh. Although the major target organs for aesthetic procedures are facial expression muscles, skeletal body muscles, salivary glands, and sweat glands, which are innervated by the somatic or autonomic nerves of the peripheral cholinergic nerve system, few studies have attempted to directly explain the anatomy of the areas targeted for injection by addressing the neural physiology and rationale for specific aesthetic applications of BoNT-A therapy. In this article, we classify the various cosmetic uses of BoNT-A according to the relevant component of the peripheral nervous system, and describe scientific theories regarding the anatomy and physiology of the cholinergic nervous system. We also review critical physiological factors and conditions influencing the efficacy of BoNT-A for the rational aesthetic use of BoNT-A. We hope that this comprehensive review helps promote management policies to support long-term, safe, successful practice. Furthermore, based on this, we look forward to developing and expanding new advanced indications for the aesthetic use of BoNT-A in the future.

Ethyl Alcohol Versus Botulinum Toxin A: A Comparative Study of the Visual and Histopathological Outcomes in the Rabbit Anterior Auricular Muscle Model

BACKGROUND

Botulinum toxin has long been known for its paralytic effects at the neuromuscular junction. Although it has been widely used for vascular and nervous tissues, there has been no study of the aesthetic effects of the application of ethanol to muscle tissues to date.

OBJECTIVE

The authors aimed to demonstrate the effects of the application of ethanol to muscle tissues after an intramuscular injection and to compare the effects of botulinum toxin A (BTA) and ethanol.

METHODS AND MATERIALS

A total of 28 rabbits were divided into 4 groups (n = 7 each). Botulinum toxin A (5 units) and different concentrations of ethanol (5 cc) were injected into the left and right anterior auricular muscles of all rabbits, respectively. Ear ptosis was assessed, and histopathological examination was performed after all rabbits were euthanized in the eighth week.

RESULTS

Muscle function was affected earlier in ethanol-treated ears than in botulinum-treated ears; however, the ptotic effect lasted for a significantly shorter duration in ethanol-injected ears than in BTA-applied ears.

CONCLUSION

Ethanol can block muscle function reversibly and can serve as an alternative to BTA, particularly when rapid results are desirable.

Tissue Modification in Nonsurgical Facelift Options

Nonsurgical facelifts are a term for a heterogeneous group of procedures used by physicians to improve facial rejuvenation without the use of operative techniques. Patients demand these services due to the reduced recovery time and generally lower risk. However, nonsurgical techniques, to be effective, must induce conformational change in the cells and tissues of the face. Therefore, these techniques are significant procedures that have associated risks. Understanding the tissue modifications and mechanisms of action of these techniques is vital to their safe and effective use. The purpose of this article is to provide a background of tissue modification in nonsurgical facelift options.

Wound Botulism Caused by Botulinum Neurotoxin Type A in a Chronic Parenteral Drug Abuser

Botulism is an acute paralytic disease caused by botulinum neurotoxin (BoNT)-mediated inhibition of neurosignaling at the neuromuscular junction. BoNTs are produced by gram positive, anaerobic, spore-forming bacteria from the genus <i>Clostridium,</i>most commonly<i> Clostridium botulinum</i>. Over the last decade, a previously uncommon form of botulism, wound botulism, has increased in prevalence possibly due to the rise in parenteral drug abuse. A 53-year-old patient with a history of drug abuse presents to a rural emergency department with rapidly progressing lower extremity weakness over the past few days. He reports a recent heroin injection into right buttock and diffuse skin-popping scarring was observed throughout. The patient was treated with heptavalent botulinum antitoxin obtained from the Center for Disease Control and Prevention (CDC). A right thigh abscess culture was positive for<i> Clostridium tertium</i>, a left hip abscess culture was positive for methicillin-susceptible <i>Staphylococcus aureus</i> (MSSA), and blood culture confirmed multi-microbial bacteremia caused by <i>Staphylococcus epidermidis</i> and <i>Streptococcus mitis</i>. Serum analysis was positive for BoNT type A from a suspected concurrent<i> Clostridium botulinum</i> infection as <i>C. tertium</i> is not known to produce BoNT type A. This case report highlights the importance of early antitoxin treatment for patients with suspected wound botulism.

Abobotulinum toxin A for periorbital facial rejuvenation: impact on ocular refractive parameters

CLINICAL RELEVANCE

Botulinum toxin is commonly used for cosmetic facial rejuvenation and can result in pain at the injected site, bruising and ecchymosis, erythema and oedema, headache, diplopia, blurred vision, focal facial weakness. This study evaluates the impact of botulinum toxin on refractive error and binocular vision.

BACKGROUND

Botulinum toxin (trade name: Dysport) is a neurotoxic protein which is made from a Gram-positive anaerobic bacterium known as Clostridium botulinum. In this study, we aimed to evaluate the impact of Dysport injection on refractive error, near point of accommodation and convergence, and palpebral fissure height.

METHODS

Twenty-eight subjects were treated for facial wrinkles, using Dysport. A 500-unit vial of Dysport was diluted with 2.5-ml preserved normal saline, and injected doses were 30-units for crow's feet, six units for lower eyelid wrinkles, 25 to 50-units for glabellar lines (five points), and 20 to 40 for forehead creases on four points. The refractive error, near point of accommodation and convergence and palpebral fissure heights were assessed before and two weeks after injection.

RESULTS

The participants comprised 23 women and five men at a mean age of 53.51 ± 14.1-years. The means of the equivalent sphere before and after injection were -0.07 ± 1.34 and -0.08 ± 1.35 (p = 0.36). The means of near point of accommodation monocularly before and after injection were 29.75 ± 6.16-cm and 26.75 ± 6.00, respectively. The means of near point of convergence before and after injection were 16.03 ± 5.27-cm and 15.55 ± 6.14, respectively (p = 0.30). The means of palpebral fissure height before and after injection were 10.33 ± 1.69-mm and 10.20 ± 1.46-mm, respectively. The changes in equivalent spherical refractive error, binocular near point of accommodation and convergence were not statistically significant.

CONCLUSION

Dysport injection for the correction of upper face animation lines, if performed at the appropriate sites and the appropriate concentration, has no significant impact on refractive error, near point of accommodation and convergence, and palpebral fissure height.

The good toxin: 10 years of experience with botulinum toxin A in the treatment of benign essential blepharospasm

PURPOSE

To describe the efficacy and safety of botulinum toxin A (Botox) in patients with benign essential blepharospasm.

METHODS

Retrospective review of operation, injection, and medical records.

RESULTS

Information of 29 patients (nine males) was reviewed, and the average age of benign essential blepharospasm onset was 59.1 years. The average number of injections per patient was 14.2 ± 8.2 (5-44) and the average follow-up was 75.8 ± 47.3 months (15-180). The average unit dose was 14.2 ± 8.2 (10-30) ipsilaterally in the patient's first year and was 21.4 ± 5.0 (12.5-30) ipsilaterally in their last year (p = 0.00458). The average onset time was 3.8 ± 1.9 (1-7) days in a patient's first year and was 3.6 ± 1.7 (2-7) days in their last year (p = 0.549). The average effective duration was 2.86 ± 1.1 months in a patient's first year and was 2.53 ± 0.9 in their final year (p = 0.187). The Subjective Spasm Alleviation Scale was 1.72 ± 0.4 at the first year and was 1.79 ± 0.5 in the last year (p = 0.187). Ten (34.5%) patients with eyelid disease had surgical correction. The Subjective Spasm Alleviation Scale was 1.50 ± 0.5 before and was 2.0 ± 0 six months after the operation (p = 0.0268). Post-injection complications were experienced in eight (27.6%) patients. The most common complication was ptosis (n = 7), followed by diplopia (n = 1), dry eye (n = 1), and tearing (n = 1). No life-threatening complication was reported.

CONCLUSION

Botox was a safe and effective treatment in benign essential blepharospasm which required an increased dosage over time. Ptosis was the most common complication and no life-threatening condition was reported. Surgical correction of those with eyelid diseases showed subjective improvement of subsequent Botox treatment.

Use of Botulinum Toxin in Ophthalmology

Botulinum toxin is an important treatment for many conditions in ophthalmology, including strabismus, nystagmus, blepharospasm, hemifacial spasm, spastic and congenital entropion, corneal exposure, and persistent epithelial defects. The mechanism of action of botulinum toxin for both strabismus and nystagmus is the neuromuscular blockade and transient paralysis of extraocular muscles, but when botulinum toxin is used for some forms of strabismus, a single injection can convey indefinite benefits. There are two unique mechanisms of action that account for the long-term effect on ocular alignment: (1) the disruption of a balanced system of agonist-antagonist extraocular muscles and (2) the reestablishment of central control of alignment by the binocular visual system. For other ocular conditions, botulinum toxin acts through transient paralysis of periocular muscles. Botulinum toxin is a powerful tool in ophthalmology, achieving its therapeutic effects by direct neuromuscular blockade of extraocular and periocular muscles and by unique mechanisms related to the underlying structure and function of the visual system.

Updates on Botulinum Neurotoxins in Dermatology

Being the most popular non-surgical cosmetic procedure, botulinum neurotoxin (BoNT) injections are increasingly of interest to all cosmetic practitioners across the globe. This article serves to update readers on the new botulinum toxins that are currently in development or close to market in the USA and Canada, including daxibotulinumtoxin A, prabotulinumtoxin A, letibotulinumtoxin A, and botulinum toxin E. Despite having relatively similar characteristics and equivalent clinical efficacies, these neurotoxins manifest a multitude of unique potential advantages that will be explored in this review, including but not limited to a longer duration of action, the absence of animal-derived components or human albumin, and a rapid onset with short duration of action.

Botulinum toxin: Pharmacology and injectable administration for the treatment of primary hyperhidrosis

Hyperhidrosis is a dermatological condition defined by excessive sweating beyond thermoregulatory needs with significant effects on patients' quality of life. Hyperhidrosis is categorized as primary or secondary: primary hyperhidrosis is mostly focal and idiopathic, whereas secondary hyperhidrosis is commonly generalized and caused by an underlying medical condition or use of medications. Various surgical and nonsurgical therapies exist for primary hyperhidrosis. Although botulinum toxin is one of the deadliest toxins known, when used in small doses, it is one of the most effective therapies for primary hyperhidrosis. Botulinum toxin injections are widely used as a second-line primary hyperhidrosis treatment option once topical treatment strategies have failed. This article provides an overview of the commercially available botulinum toxin formulations and their applications in the treatment of primary hyperhidrosis.