Application Of Botulinum Toxin Type A Research Articles

Facial Acne Management and Sebum Reduction via Botulinum Toxin Type a Treatment: A Review

Context: Acne is a common skin condition characterized by chronic inflammation of the pilosebaceous unit. Increased sebum production is a key component of acne pathogenesis. Various therapies are available for acne, including topical, systemic, and physical treatments. Botulinum toxin is increasingly used in facial cosmetic procedures. Observations suggest that botulinum toxin type A (BoNT-A) may reduce sebum levels in the face. This finding could potentially lead to the development of a new treatment for oily skin and acne. Evidence Acquisition: A retrospective literature review was conducted by searching the PubMed, Web of Science, EMBASE, and SCOPUS databases using keywords such as "acne," "acne treatment," "oily skin," and "botulinum toxin type A." The review focused on studies that assessed the impact of BoNT-A on patients with acne vulgaris and oily skin, as well as studies that measured skin sebum levels and pore size following BoNT-A application. Results: Nine studies were reviewed. Of these, two evaluated the effects of BoNT-A on 30 and 35 patients with acne vulgaris. Four studies assessed sebum reduction in 20, 50, 42, and 20 patients. Three studies evaluated both sebum reduction and pore size tightening in 10, 25, and 20 patients. Eight studies demonstrated that the application of BoNT-A has a positive effect on patients with acne and reduces sebum production in facial skin. Only one study, which evaluated both sebum reduction and pore size tightening, found no significant effect. Overall, the studies indicate that BoNT-A application can positively impact acne and reduce facial sebum production. Specifically, intradermal application of BoNT-A at low dosages can help reduce acne, sebum production, and tighten pores. Conclusions: BoNT-A shows promise as a treatment for acne and oily skin. While cost-effectiveness may be a challenge for some patients, the benefits of BoNT-A make it a treatment option worth considering. With further studies to optimize dosages and determine the longest duration of efficacy, BoNT-A has the potential to revolutionize the treatment of acne and oily skin.

Botulinum toxin type A inhibits M1 macrophage polarization by deactivation of JAK2/STAT1 and IκB/NFκB pathway and contributes to scar alleviation in aseptic skin wound healing

The non-neuronal and non-muscular effects of botulinum toxin type A (BTXA) on scar reduction has been discovered. This study was designed to investigate the effects of BTXA on macrophages polarization during the early stage of skin repair. A skin defect model was established on the dorsal skin of SD rats. BTXA was intracutaneous injected into the edge of wound immediately as the model was established. Histological examinations were performed on scar samples. Raw 264.7 was selected as the cell model of recruited circulating macrophages, and was induced for M1 polarization by LPS. Identify the signaling pathways that primarily regulated M1 polarization and respond to BTXA treatment. Application of BTXA at early stage of injury significantly reduced the scar diameter without delaying wound closure. BTXA treatment improved fiber proliferation and arrangement, and inhibited angiogenesis in scar granular tissue. The number of M1 macrophages and the levels of pro-inflammation were decreased after treated with BTXA in scar tissues. LPS activated JAK2/STAT1 and IκB/NFκB pathways were downregulated by BTXA, as well as LPS induced M1 polarization. At early stage of skin wound healing, injection of BTXA effectively reduced the number of M1 macrophages and the levels of pro-inflammatory mediators which contributes to scar alleviation. BTXA resisted the M1 polarization of macrophages induced by LPS via deactivating the JAK2/STAT1 and IκB/NFκB pathways.

Influence of unilateral eyelid spasms and botulinum toxin treatment on intraocular pressure measured by transpalpebral tonometer.

Eyelid spasms might be associated with elevated intraocular pressure (IOP) in hemifacial spasm (HFS) patients. IOP assessment using a Goldmann applanation tonometer (GAT) is often compromised by eyelid spasms. This study aimed to assess the effect of HFS on IOP measurements using the transpalpebral tonometer Diaton® before and after treatment with botulinum toxin type A (BTX-A) and compared Diaton® and GAT measurements after treatment with BTX-A. IOP measurements were obtained with Diaton® in 27 patients with moderate-to-severe HFS before and after treatment with BTX-A. After treatment, the IOP was also measured using GAT and the results were compared with the ones measured with a Diaton®. The patients underwent automated perimetry, OCT, and pachymetry for screening to glaucoma. Mean IOP with Diaton® was 11 ± 3.42mmHg before treatment in the affected eye and 9 ± 2.98mmHg in the contralateral eye. This difference was statistically significant (P = 0.012). However, after treatment with BTX-A, no interocular difference was found in IOP obtained with Diaton® (P = 0.204) or GAT (P = 0.971). Comparison between GAT and Diaton® measurements showed no significant differences after BTX-A treatment between the affected (P = 0.212) and contralateral eye (P = 0.971). A significant reduction in IOP measurements on the affected side of HFS patients was observed after treatment with BTX-A, demonstrating that eyelid spasms may increase the IOP. No significant difference was observed between Diaton® and GAT measurements after the application of BTX-A. No differences were found in automated perimetry, OCT, and CCT when comparing affected eyes with contralateral eyes.

Volumetry after botulinum toxin A: the impact on abdominal wall compliance and endotracheal pressure.

Botulinum toxin type A (BTA) is an adjuvant tool used in the preoperative optimization of complex hernias before abdominal wall reconstruction (AWR). This study aims to investigate changes in the abdominal cavity and hernia sac dimensions after BTA application. A prospective study with 27 patients with a hernia defect of ≥ 10cm and loss of domain (LOD) ≥ 20% underwent AWR. Computed tomography (CT) measurements and volumetry before and after the application of BTA were performed. Intraoperative and postoperative outcomes were evaluated. Imaging post-BTA revealed hernia width reduction of 1.9cm (p = 0.002), lateral abdominal wall muscle elongation of 3.1cm (p < 0.001), hernia volume reduction (HV) from 2.9 ± 0.9L to 2.4 ± 0.8L (p < 0.001), increase in abdominal cavity volume (ACV) from 9.7 ± 2.5L to 10.3L ± 2.4L (p = 0.003), and a reduction in the HV/ACV ratio from 30.2 ± 5% to 23.4 ± 6% (p < 0.001). Fascial closure was achieved in 92.6% of cases and component separation was required in 78%. The average variation in pulmonary plateau pressure was 3.53 cmH2O, and there were no postoperative respiratory failure recorded. At the 90-day follow-up, the wound morbidity rate was 25%, unplanned readmissions were 11%, and hernia recurrence 7.4%. BTA produces measurable volumetric changes in abdominal wall and appears to facilitate fascial closure. Further studies are required to determine the role of BTA in the surgical armamentarium for complex hernia repair.

Osteoarthritis of the hip conservative treatment with type A botulinum toxin.

Osteoarthritis (OA) of the hip is a low-grade inflammatory disease of multiple etiology that has a limited conservative management and insufficiently explored. The application of botulinum toxin type A (BoNT-A) produces in the applied muscle a temporary, delimitable and reversible flaccid paralysis, which applied in a strategic way achieves to reduce mechanical stress and pain. To evaluate the effect on pain perception, functionality and rigidity and changes in flexibility, internal and external rotation, before and 90 days after the application of BoNT-A. Clinical, experimental, longitudinal, open study, with a total of 35 patients and 45 hips treated. BoNT-A of 500 U was applied in iliac, adductor brevis and longus muscles. The Wilcoxon test was used to compare the evaluation scores on days 0-90, observing the decrease in referred pain (p < 0.0001), rigidity (p < 0.002), improved perceived function (p < 0.001) and mobility arcs: flexion, internal and external rotation (p < 0.0001). The treatment with BoNT-A provides a conservative and safe option for the management of symptoms and physical restraint caused by hip OA.

Local injection of botulinum toxin type A (BTX-A) prevents scarring esophageal stricture caused by electrocautery in rabbit models.

BackgroundBenign esophageal strictures are common in clinical practice. The commonly used methods for preventing benign esophageal strictures still have many shortcomings. In this study, we investigated the preventive effect and possible mechanism of endoscopic local injection of botulinum toxin type A (BTX-A) on scarring esophageal stricture caused by electrocautery in rabbit models, with an attempt to provide a theoretical basis for the clinical application of BTX-A in the prevention of benign esophageal stricture.MethodsAdult male New Zealand rabbits were randomly divided into 4 groups: cautery group (cauterized with 30 W electrocoagulation power without other intervention), saline group (injected with normal saline at 4 spots in the local esophagus after modeling), BTX-A I group (injected with 10 U of BTX-A after modeling), and BTX-A II group (injected with 20 U of BTX-A after modeling). Body weight was measured at postoperative weeks 1, 2, and 4. Esophagography was performed, and the internal diameter of the esophagus was measured. The esophageal tissues were harvested for hematoxylin and eosin (HE) staining and Masson staining. Type I, type III collagen levels and the mRNA expression of transforming growth factor β1 (TGF-β1) in esophageal tissues were detected.ResultsCompared with the cautery and saline groups, the BTX-A I and BTX-A II groups had significantly higher body weight, larger esophageal internal diameter, lower type I and type III collagen levels, and lower TGF-β1 mRNA expression levels in esophageal tissues at postoperative week 4. Comparisons between the BTX-A I and BTX-A II groups showed no significant differences in terms of body weight, esophageal internal diameter, and type I collagen level at postoperative week 4. However, the BTX-A II group had a significantly lower type III collagen level and TGF-β1 mRNA expression level than the BTX-A I group.ConclusionsLocal injection of BTX-A can alleviate esophageal stricture after electrocautery and has a preventive effect on benign esophageal stricture caused by electrocautery in rabbits. The mechanism may be that BTX-A down-regulates the expression of TGF-β1 in the esophageal tissue at the burn site and reduces the deposition of collagen.

Histological and mast cells evaluation after application of botulinum toxin type a in masseter muscles of rats.

Botulinum Toxin Type A (BTX-A) has been largely used to reduce muscle strength of masseter and temporal muscles by producing a temporary weakening of their activity. This study aimed to evaluate the histological changes and the number of mast cells after the injection of BTX-A. In the masseter muscle of rats in the periods of 1, 7, 15, and 30 days. These muscles were stained with hematoxylin and eosin (H&E) and toluidine blue (TBO). The presence or absence of an inflammatory process and necrosis were analyzed by H&E in all area of the slide at 10X magnification. The number of mast cells was evaluated by counting 10 "hotspots" in the intra-muscular region on TBO-stained slides, 400X magnification. Statistical analysis was performed through two-way analysis of variance and Tukey's test. As a result, the inflammatory process and necrosis were not observed in any periods studied in both groups Regarding mast cells, there was no statistically significant increase in their quantity in the study group when compared to the control group in the evaluation periods of 7 days and 15 days. However, these mast cells increased significantly during the periods of 1 and 30 days. This study showed that even in the absence of an inflammatory process, there was an increase in the number of mast cells in the first 24 hours after the application of BTX-A, with a subsequent balance between the numbers of mast cells at 7 and 15 days, and again an increase after 30 days. Key words:Botulinum toxins type A, mast cells, masseter muscle.

Clinical application and mechanism of botulinum toxin type A in scar treatment

Pathological scars cause both local physical discomforts and mental disorders for patients. With the development of research, botulinum toxin type A (BTX-A) has been gradually used in the clinical treatment of scars. This article summarizes three potential mechanisms of BTX-A, including early tension reduction, inhibition of connective tissue hyperplasia, and alleviation of skin inflammation, as well as the clinical application of BTX-A in treating different types of scars. However, at present there is no uniform standard for the time, method, and proportioning of BTX-A injection for scar treatment, and there is also a lack of long-term follow-up results. Further researches are needed in future to clarify the mechanism of BTX-A in inhibiting scars, establish a uniform protocol of BTX-A injection, and provide a more effective treatment plan for scars.

The Central Effects of Botulinum Toxin in Dystonia and Spasticity.

In dystonic and spastic movement disorders, however different in their pathophysiological mechanisms, a similar impairment of sensorimotor control with special emphasis on afferentation is assumed. Peripheral intervention on afferent inputs evokes plastic changes within the central sensorimotor system. Intramuscular application of botulinum toxin type A (BoNT-A) is a standard evidence-based treatment for both conditions. Apart from its peripheral action on muscle spindles, a growing body of evidence suggests that BoNT-A effects could also be mediated by changes at the central level including cerebral cortex. We review recent studies employing electrophysiology and neuroimaging to investigate how intramuscular application of BoNT-A influences cortical reorganization. Based on such data, BoNT-A becomes gradually accepted as a promising tool to correct the maladaptive plastic changes within the sensorimotor cortex. In summary, electrophysiology and especially neuroimaging studies with BoNT-A further our understanding of pathophysiology underlying dystonic and spastic movement disorders and may consequently help develop novel treatment strategies based on neural plasticity.

Clinical trial to evaluate the efficacy of botulinum toxin type A injection for reducing scars in patients with forehead laceration: A double-blinded, randomized controlled study.

Background:Botulinum toxin type A (BoNTA) is known to prevent fibroblast proliferation and expression of transforming growth factor beta 1 (TGF-β1). It also induces temporary muscle paralysis and decreases tension vectors. Fibroblasts induce scar contracture and hypertrophy by producing collagen fibers in wound healing processes. The aim of this study is to identify the effect of BoNTA on the scar formation.Methods:Forty-five patients with forehead laceration were enrolled in this study and randomized into 2 groups with or without injection of BoNTA. When the patients presented to the clinic to remove the stitches, BoNTA was injected to the BoNTA group with 24 patients and saline was injected to the control group with 21 patients. The BoNTA was injected on dermal layer with 5 IU/cm. After that, follow-up was done in 1, 3, and 6 months. The scars were analyzed with the patient and observer scar assessment scale, Stony Brook scar evaluation scales (SBSESs), and visual analog scale (VAS) and analyzed with independent T-test, along with clinical photographs, cutometer, and biopsies.Results:In all scar scales, the scores changed into favorable direction in both groups and the changes were larger in BoNTA group compared with the control group. On SBSES and VAS, better improvements on BoNTA group showed statistical significance. Skin biopsy showed less collagen deposition on dermal layer in BoNTA group.Conclusion:Improvement of aesthetic, functional, and emotional aspect of the scar formation in the groups treated with BoNTA was illustrated. The application of BoNTA may be expanded to prevent hypertrophic scar after trauma, burns, or operations.

Tratamiento conservador de la osteoartrosis de cadera con toxina botulínica tipo A

Osteoarthritis (OA) of the hip is a low-grade inflammatory disease of multiple etiology that has a limited conservative management and insufficiently explored. The application of botulinum toxin type A (BoNT-A) produces in the applied muscle a temporary, delimitable and reversible flaccid paralysis, which applicated in a strategic way achives to reduce mechanical stress and pain. To evaluate the effect on pain perception, functionality and rigidity and changes in flexibility, internal and external rotation, before and 90 days after the application of BoNT-A. Clinical, experimental, longitudinal, open study, with a total of 35 patients and 45 hips treated. BoNT-A of 500 U was applied in iliac, adductor brevis and longus muscles. The Wilcoxon test was used to compare the evaluation scores on days 0-90, observing the decrease in referred pain (p < 0.0001), rigidity (p < 0.002), improved perceived function (p < 0.001) and mobility arcs: flexion, internal and external rotation (p < 0.0001). The treatment with BoNT-A provides a conservative and safe option for the management of symptoms and physical restraint caused by hip OA.

Effect of Botulinum toxin Aapplication in neuro-ophtalmologic indications on Schirmerstest and tears osmolarity.

Botulinum toxin type A(BT-A) is used in the treatment of neuro-ophthalmologic disorders such as essential blepharospasm and facial hemispasm for more than 20 years. Although the long-term effect of repeated application of the BT-Awas confirmed, the BT-Aeffect on tears production and retention is not clear. In our work we investigated whether applied BT-Ain patients with blepharospasm and hemifacial spasm affect tears production. Tears quality was measured with Schirmersand tear osmolarity test during neuro-ophthalmologic diseases treatment, which was evaluated before and 14 days after application of BT-A(Botox inj, Allergan, Irvine, USA) into the orbicularis oculi muscle. BT-Adoses of 16-18 Uwith unilateral and 32 to 36 Ubilateral applications were used. The mean tear production in Schirmerstest before BT-Aapplication was 8.38 ± 0.63 mm, and 2 weeks after BT-Aapplication was 7.12 ± 0,6 mm (n = 50). Tear osmolarity was 305.4 ± 9.2 mOsm before BT-Aapplication, and 2 weeks after BT-Aapplication it was 305.2 ± 8,6 mOsm (n = 13). We found significant difference between two groups in tear quantity (p &lt; 0.012), but not quality (p &gt; 0.05). Application of the BT-Areduced the amount of tears measured by Schirmerstest. These results confirm rational basis of the empirical clinical experience where an artificial tears substitution is recommended for patients with neuro-ophthalmologic disorders treated by BT-A.

Botulinum toxin type A in the treatment of sialorrhea - Our experience

Sialorrhea consists of an involuntary loss of saliva, and is considered pathological after 4YO. The aim of this study is to describe our methodology and evaluate the efficacy and safety of Botulinum Toxin Type A (BTX-A) in sialorrhea in children and adults with cerebral palsy (CP) or cognitive deficit, referenced to PMR consultation between 2002–2017. Longitudinal descriptive study with clinical records analysis and consultation of drooling rate scale (DRS) and teacher drool scale (TDS) prior to BTX-A injections and 1-month after. Injection of BTX-A performed with ultrasound and sedation. Total of 104 patients, 86 patients selected, 32 female (37.21%), 54 male (62.79%), current ages 7–29YO (mean 18), age of the 1st application 3–22YO (mean 9.76), age of last application 4–23YO (mean 11.83). Fifty patients (58.14%) diagnosed with CP. Two hundred and three total applications (average 2.36), maximum 10 applications. Parotids (55.56%), submandibular (9.09%) or both (35.35%), mean periodicity of 11.81 months. Sedation: 49.38% midazolam, 41.36% nitrogen protoxide, 0.62% Chloral-Hydrate and 8.64% without. Surveys: mean pre-application-DRS of 33.98 (minimum 19, maximum 58), mean post-application-DRS of 28.46 (min 15, max 54), with P = 6.48–5, average difference 4.28 points in DRS (min −27, max 22). Mean pre-application-TDS of 4.04 (min 2, max 5), mean post-applicantion-TDS of 3.38 (min 1, max 4), with P = 2.80–5, average difference of 0.69 points in TDS (min −1, max 3). Difference in DRS and TDS of 0.76 and 0.24 respectively in the parotids, 6.33 and 0.83 in the submandibular and 8.52 and 1.43 in both. Improvements were statistically significant. Surgery: 6 (6.98%). Side effects: 5 children (5.81%) insomnia/vomiting. No complications related to the administration technique. The application of BTX-A in the treatment of sialorrhea is a safe, easy-to-apply technique, with statistically significant improvement in QoL and severity. Benefit in the application of BTX-A in both glands treatment is shown.

Botulinum toxin type A in the treatment of sialorrhea - Our experience

Sialorrhea consists of an involuntary loss of saliva, and is considered pathological after 4YO. The aim of this study is to describe our methodology and evaluate the efficacy and safety of botulinum toxin type A (BTX-A) in sialorrhea in children and adults with cerebral palsy (CP) or cognitive deficit, referenced to PMR consultation between 2002–2017. Longitudinal descriptive study with clinical records analysis and consultation of Drooling Rate Scale (DRS) and Teacher Drool Scale (TDS) prior to BTX-A injections and 1-month after. Injection of BTX-A performed with ultrasound and sedation. Total of 104 patients, 86 patients selected, 32 female (37.21%), 54 male (62.79%), current ages 7–29YO (mean 18), age of the 1st application 3–22YO (mean 9.76), age of last application 4–23YO (mean 11.83). Fifty patients (58.14%) diagnosed with CP. Two hundred and three total applications (average 2.36), maximum 10 applications. Parotids (55.56%), submandibular (9.09%) or both (35.35%), mean periodicity of 11.81 months. Sedation: 49.38% midazolam, 41.36% nitrogen protoxide, 0.62% chloral-hydrate and 8.64% without. Surveys: mean pre-application-DRS of 33.98 (minimum 19, maximum 58), mean post-application-DRS of 28.46 (min 15, max 54), with P = 6.48–5, average difference 4.28 points in DRS (min −27, max 22). Mean pre-application-TDS of 4.04 (min 2, max 5), mean post-applicantion-TDS of 3.38 (min 1, max 4), with P = 2.80–5, an average difference of 0.69 points in TDS (min −1, max 3). Difference in DRS and TDS of 0.76 and 0.24 respectively in the parotids, 6.33 and 0.83 in the submandibular and 8.52 and 1.43 in both. Improvements were statistically significant. Surgery: 6 (6.98%). Side effects: 5 children (5.81%) insomnia/vomiting. No complications related to the administration technique. The application of BTX-A in the treatment of sialorrhea is a safe, easy-to-apply technique, with statistically significant improvement in QoL and severity. Benefit in the application of BTX-A in both glands treatment is shown.

Efficacy and possible mechanisms of Botulinum Toxin type A on hypertrophic scarring.

Clinical observations indicate that Botulinum toxin type A (BTXA) can inhibit the growth and improve the eventual appearance of hypertrophic scarring. However, the molecular mechanism remains unclear. We used human keloid fibroblasts to investigate the molecular mechanism of BTXA on hypertrophic scarring. Different concentrations of BTXA (0.01, 0.1, 1, and 10U/L) were used to treat keloid fibroblasts. Changes in cellular morphology, viability, proliferation, cell cycle, and apoptosis were observed by immunofluorescence, MTT assay, and flow cytometry. In addition, real-time qPCR and Western blotting were used to explore the potential molecular mechanisms. Keloid fibroblast viability decreased with increasing BTXA dose. After BTXA treatment, the volume of keloid fibroblasts cells increased, but the nucleus of cells shrunk. Long thin dendrites were formed as the concentration of BTXA increased. Furthermore, the proliferation and S phase of keloid fibroblasts were inhibited by BTXA. Matrix metalloproteinase (, MMP)-1 and -2 RNA and protein showed high expression, but TGF-β1 and MMP-9 showed low expression than the control. Botulinum toxin type A may promote the healing of scars by inhibiting the proliferation of keloid fibroblasts and regulating the expression of TGF-β1, which could affect the expression of MMP-1 and MMP-2. This study provides theoretical support for the clinical application of BTXA to control hypertrophic scarring.

Applicability of botulinum toxin type A in paediatric neurogenic bladder management.

The purpose of this article is to provide an overview about the applicability of botulinum toxin type A (BTX-A) in paediatric neurogenic bladder based on the recently published literature combined with hypothetical notes and future perspectives. The indications, clinical outcomes, urodynamic outcome parameters and cost-effectiveness are presented from recent publications. Also, alternative routes of application of BTX-A in the bladder are discussed as well as the influence of BTX-A on conservative and invasive treatment. Intradetrusor BTX-A injections for neurogenic bladder dysfunction are effective in resolving both urinary incontinence and improving urodynamic parameters in most children with a sustained response at repeated injections. In low-compliance bladders, however, if no response is seen after initial BTX-A injection, repeated injections seem to be unnecessary. Because general anaesthesia is mandatory for BTX-A injections in children, alternative routes of application have been investigated such as intravesical installation, electromotive drug application and liposomal drug delivery; however, no definite results have been found in a paediatric clinical setting.

Botulinum Toxin Type A Inhibits α-Smooth Muscle Actin and Myosin II Expression in Fibroblasts Derived From Scar Contracture.

Scar contracture (SC) is one of the most common complications resulting from major burn injuries. Numerous treatments are currently available but they do not always yield excellent therapeutic results. Recent reports suggest that botulinum toxin type A (BTXA) is effective at reducing SC clinically, but the molecular mechanism for this action is unknown. α-Smooth muscle actin (α-SMA) and myosin II are the main components of stress fibers, which are the contractile structures of fibroblasts. The effects of BTXA on α-SMA and myosin II in SC are still unknown. This study aimed to explore the effect of BTXA on α-SMA and myosin II expression in fibroblasts derived from SC and to elucidate its actual mechanism further. Fibroblasts were isolated from tissue specimens of SC. Fibroblasts were cultured in Dulbecco modified Eagle medium with different concentrations of BTXA and their proliferation was analyzed through the tetrazolium-based colorimetric method at 1, 4, and 7 days. Proteins of α-SMA and myosin II were checked using Western blot in fibroblasts treated with different concentrations of BTXA at 1, 4, and 7 days. Fibroblasts without BTXA treatment had a higher proliferation than that in other groups, which indicated that the proliferation of fibroblasts was significantly inhibited by BTXA (P < 0.05). Proteins of α-SMA and myosin II between fibroblasts with BTXA and fibroblasts without BTXA are statistically significant (P < 0.05). These results suggest that BTXA effectively inhibited the growth of fibroblasts derived from SC and reduced the expression of α-SMA and myosin II, which provided theoretical support for the application of BTXA to control SC.

The Efficacy and Safety of Fractional CO₂ Laser Combined with Topical Type A Botulinum Toxin for Facial Rejuvenation: A Randomized Controlled Split-Face Study.

Objective. We evaluated synergistic efficacy and safety of combined topical application of Botulinum Toxin Type A (BTX-A) with fractional CO2 laser for facial rejuvenation. Methods. Twenty female subjects were included for this split-face comparative study. One side of each subject's cheek was treated with fractional CO2 plus saline solution, and the other side was treated with fractional CO2 laser plus topical application of BTX-A. Patients received one session of treatment and evaluations were done at baseline, one, four, and twelve weeks after treatment. The outcome assessments included subjective satisfaction scale; blinded clinical assessment; and the biophysical parameters of roughness, elasticity, skin hydration, transepidermal water loss (TEWL), and the erythema and melanin index. Results. BTX-A combined with fractional CO2 laser sides showed higher physician's global assessment score, subject satisfaction score, roughness, skin hydration, and skin elasticity compared to that of fractional CO2 plus saline solution side at 12 weeks after treatment. TEWL and erythema and melanin index showed no significant differences between two sides at baseline, one, four, and twelve weeks after treatment. Conclusion. Topical application of BTX-A could enhance the rejuvenation effect of fractional CO2 laser.

A clinically relevant BTX-A injection protocol leads to persistent weakness, contractile material loss, and an altered mRNA expression phenotype in rabbit quadriceps muscles

Botulinum toxin type-A (BTX-A) injections have become a common treatment modality for patients suffering from muscle spasticity. Despite its benefits, BTX-A treatments have been associated with adverse effects on target muscles. Currently, application of BTX-A is largely based on clinical experience, and research quantifying muscle structure following BTX-A treatment has not been performed systematically. The purpose of this study was to evaluate strength, muscle mass, and contractile material six months following a single or repeated (2 and 3) BTX-A injections into the quadriceps femoris of New Zealand white rabbits. Twenty three skeletally mature rabbits were divided into four groups: experimental group rabbits received 1, 2, or 3 injections at intervals of 3 months (1-BTX-A, 2-BTX-A, 3-BTX-A, respectively) while control group rabbits received volume-matched saline injections. Knee extensor strength, quadriceps muscle mass, and quadriceps contractile material of the experimental group rabbits were expressed as a percentage change relative to the control group rabbits. One-way ANOVA was used to determine group differences in outcome measures (α=0.05). Muscle strength and contractile material were significantly reduced in experimental compared to control group rabbits but did not differ between experimental groups. Muscle mass was the same in experimental BTX-A and control group rabbits. We concluded from these results that muscle strength and contractile material do not fully recover within six months of BTX-A treatment.

Intrinsic properties and functional changes in spastic muscle after application of BTX-A in children with cerebral palsy: Systematic review

Objective: This article aimed to review the literature to verify the effect of botulinum toxin type A (BTX-A) on the intrinsic properties of spastic muscles and functionality in children with cerebral palsy (CP). Methods: A literature search was conducted in the following databases: CINAHL, SCOPUS, Web of Science and PubMed. Database searches were limited to the period from January 1993 to March 2014. Results: A total of 2182 papers were identified, and 17 met the inclusion criteria. Only one study analyzed the effect of the toxin on muscle intrinsic properties and others analyzed the effect on functionality. Conclusion: BTX-A application demonstrated no changes in the passive stiffness of spastic muscle. In relation to functional level, the evidence of BTX-A effect was controversial. These studies showed methodological quality limitations that restrict the interpretation of the results for the entire CP population, which justifies the need for further randomized controlled trials.