Therapeutic uses of botulinum toxin

Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications

Botulinum neurotoxins (BoNTs) have been used for almost half a century in the treatment of excessive muscle contractility. BoNTs are routinely used to treat movement disorders such as cervical dystonia, spastic conditions, blepharospasm, and hyperhidrosis, as well as for cosmetic purposes. In addition to the conventional indications, the use of BoNTs to reduce pain has gained increased recognition, giving rise to an increasing number of indications in disorders associated with chronic pain. Furthermore, BoNT-derived formulations are benefiting a much wider range of patients suffering from overactive bladder, erectile dysfunction, arthropathy, neuropathic pain, and cancer. BoNTs are categorised into seven toxinotypes, two of which are in clinical use, and each toxinotype is divided into multiple subtypes. With the development of bioinformatic tools, new BoNT-like toxins have been identified in non-Clostridial organisms. In addition to the expanding indications of existing formulations, the rich variety of toxinotypes or subtypes in the wild-type BoNTs associated with new BoNT-like toxins expand the BoNT superfamily, forming the basis on which to develop new BoNT-based therapeutics as well as research tools. An overview of the diversity of the BoNT family along with their conventional therapeutic uses is presented in this review followed by the engineering and formulation opportunities opening avenues in therapy.

Prevention of component separation in complex abdominal wall surgery by Botox prehabilitation: a propensity-matched study

AIM

To facilitate midline fascial closure in complex abdominal wall surgery, component separation techniques (CST) are usually required. However, CST is associated with an enlarged morbidity. Prehabilitation could increase the compliance of the abdominal wall and thereby decrease the necessity of myofascial release. This can be accomplished by administration of botulinum toxin type A (BTA) in the lateral abdominal wall musculature. The aim of this study was to determine the effect of BTA on the subsequent necessity to perform CST in patients with complex abdominal wall hernias.

METHODS

Patients with a complex abdominal wall hernia, planned to undergo CST between July 2020 and November 2022 were included. Outcome of procedures with 300U of BTA 4 (2-6) weeks prior to surgery, were retrospectively analyzed by comparison with propensity matched subjects of an historical group. Hernia width difference was assessed by CT and operative details were included.

RESULTS

A total of 13 patients with a median hernia width of 12 cm (IQR 9-14, range 24) were prehabilitated with BTA between July 2020 and November 2022. A CST was planned for all, however not required in 6/13 patients (46%) to accomplish midline fascial closure. A mean elongation of lateral abdominal wall musculature of 4.01 cm was seen in patients not requiring CST. Compared to the propensity score matched control group, a 27% reduction (p = 0.08) in the need for CST was observed.

CONCLUSION

There is a tendency for decrease of necessity for CST by preoperatively administered BTA in patients with complex abdominal wall defects. Although small, as this study used propensity matched comparison, further exploration of BTA should be encouraged.

Therapeutic proteins: developments, progress, challenges, and future perspectives

Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.

What is the role of microbial biotechnology and genetic engineering in medicine?

Microbial products are essential for developing various therapeutic agents, including antibiotics, anticancer drugs, vaccines, and therapeutic enzymes. Genetic engineering techniques, functional genomics, and synthetic biology unlock previously uncharacterized natural products. This review highlights major advances in microbial biotechnology, focusing on gene-based technologies for medical applications.

Preoperative Botulinum Toxin for Abdominal Wall Reconstruction in Massive Hernia Defects-A Propensity-Matched Analysis

PURPOSE

Reconstruction of massive incisional hernias (IHs) poses a significant challenge with high rates of recurrence. Preoperative chemodenervation using botulinum toxin (BTX) injections in the abdominal wall is a technique that has been used to facilitate primary fascial closure. However, there is limited data directly comparing primary fascial closure rates and postoperative outcomes after hernia repair between patients who do and do not receive preoperative BTX injections. The objective of our study was to compare the outcomes of patients who did and did not receive BTX injections before abdominal wall reconstruction.

METHODS

This is a retrospective cohort study including adult patients from 2019 to 2021 who underwent IH repair with and without preoperative BTX injections. Propensity score matching was performed based on body mass index, age, and intraoperative defect size. Demographic and clinical data were recorded and compared. The statistical significance level was set at P < 0.05.

RESULTS

Twenty patients underwent IH repair with preoperative BTX injections. Twenty patients who underwent IH repair without preoperative BTX injections were selected to comprise a 1:1 propensity-matched control cohort. The average defect size was 663.9 cm2 in the BTX group and 640.7 cm2 in the non-BTX group (P = 0.816). There was no difference in average age (58.6 vs 59.2 years, P = 0.911) and body mass index (33.0 vs 33.2 kg/m2, P = 0.911). However, there was a greater proportion of male patients in the BTX group (85% vs 55%, P = 0.082).Primary fascial closure was achieved in 95% of BTX patients and 90% of non-BTX patients (P = 1.0). Significantly fewer patients in the BTX group required component separation techniques to achieve primary fascial closure (65% vs 95%, P = 0.044). There was no significant difference in any postoperative surgical and medical outcomes. Hernia recurrence was 10% in the BTX group and 20% in non-BTX group (P = 0.661).

CONCLUSIONS

In our study, we observed a lower rate of component separations to achieve primary fascial closure among patients with massive hernia defects who received preoperative BTX injections. These results suggest that preoperative BTX injections may "downstage" the complexity of hernia repair with abdominal wall reconstruction in patients with massive hernia defects and reduce the need for component separation.

A computed tomography study investigating the effects of botulinum toxin injections prior to complex abdominal wall reconstruction

OBJECTIVE

To explore how intramuscular injection of botulinum toxin A (BTA) affects the lateral abdominal wall (LAW) musculature, abdominal- and hernia dimensions, and muscle structure on computed tomography (CT) in patients scheduled for complex abdominal wall reconstruction (CAWR).

METHODS

Retrospective analysis of prospectively registered patients who received bilateral intramuscular BTA injections into all three muscles of the LAW. Only patients for which a CT was available before and 3-6 weeks after BTA treatment prior to surgery were analyzed.

RESULTS

Fifty-two patients were analyzed. Median hernia width in all patients decreased with 0.4 cm (IQR - 2.1;0.6) (p = 0.023). Median intra-abdominal transverse diameter increased with 0.9 cm (IQR - 0.2;3.3) (p = 0.001) and the intra-abdominal anterior-posterior diameter decreased with 0.5 cm (IQR - 1.3;0.5) (p = 0.017), making the abdomen more oval. Median LAW muscle length increased with 0.9 cm (IQR 0.0;2.4) per side (p < 0.001), muscle thickness decreased with 0.5 cm (IQR - 0.8;- 0.2) (- 25.0%) per side (p < 0.001), and muscle mass decreased with 3.9 cm2 (IQR - 6.4;-1.5) (- 15.8%) per side (p < 0.001). Median HU of the psoas muscles (density) increased with 4.8 HU (IQR 0.4;9.7) (10.3%) per side (p < 0.001). Effects of BTA were more pronounced in patients with a loss of domain (LoD) ≥ 20%.

CONCLUSIONS

The main effect of BTA injections is elongation and thinning of the LAW muscles, more than a decrease in hernia width. Concomitantly, the abdomen becomes more oval. An increase of psoas muscles density is seen, associated with offloading of the LAW muscles. Patients with large LoD have a proportionally higher effect of BTA.

Laryngeal Sensory Symptoms in Spasmodic Dysphonia

OBJECTIVE

The purpose of this research was to determine whether an association between laryngeal hypersensitivity (LH) and spasmodic dysphonia (SD) exists using the LH Questionnaire (LHQ). This study also explored the prevalence of self-reported upper respiratory infection (URI) at the time of SD onset across SD phenotypes.

METHODS

Individuals with and without SD were recruited to complete an online survey measure. All respondents provided demographic information and completed the LHQ. Participants with SD were also asked to provide information about their diagnosed SD subtype and pattern of onset, including whether onset was associated with a URI. The percentage of respondents with and without SD who were classified with LH was determined based on the LHQ. Scores on the LHQ were also compared between the non-SD and the SD groups, as well as between SD phenotypes (adductor SD, abductor SD, and mixed)).

RESULTS AND CONCLUSIONS

Significant associations were found between ADSD and LH, mixed SD and LH, and URI at time of SD onset and increased severity of LH symptoms. These findings suggest that laryngeal sensory symptoms may potentially contribute to or result from motor spasms in SD and/or have implications for its pathophysiology.

Predictors of favorable outcome after pyloroplasty for gastroparesis: should response to pyloric dilation or Botox injection be used as a marker of surgical outcome?

INTRODUCTION

Pyloroplasty and gastric peroral endoscopic myotomy (G-POEM) are effective surgeries for gastroparesis. The primary aim of this study was to evaluate outcomes of pyloroplasty and G-POEM in patients with gastroparesis and determine factors associated with favorable outcome. The secondary aim was to assess the utility of clinical response to preoperative pyloric dilation or botulinum toxin injection (Botox) on surgical outcome, a factor conventionally used as a favorable marker.

METHODS

There were 204 patients who underwent pyloroplasty (n = 177) or G-POEM (n = 27) for gastroparesis at our institution from 2014 to 2021. Demographic and clinical parameters were analyzed to assess their impact on surgical outcome. A subgroup of patients who had pyloric dilation or Botox injection were assessed separately. Favorable outcome was defined as patient reported complete resolution of the predominant gastroparesis symptom.

RESULTS

Favorable outcome was achieved in 78.4% of patients (pyloroplasty: 79.7% and G-POEM: 70.4%, p = 0.274). Among 61 patients where pre- and postoperative gastric emptying studies (GES) were available, mean 4-hour retention significantly improved from 33.5 to 15.0% (p < 0.001) and 77.0% of patients achieved normalization. Favorable outcome was not significantly impacted by etiology of gastroparesis (p = 0.120), GERD (p = 0.518), or primary gastroparesis symptom (p = 0.244). Age ≥ 40 was a significant predictor of favorable surgical outcome on multivariate analysis [OR: 2.476 (1.224-5.008), p = 0.012]. Among the patients who had preoperative dilation (n = 82) or Botox injection (n = 46), response to these interventions was not a predictor of favorable surgical outcome (p = 0.192 and 0.979, respectively). However, preoperative Botox injection, regardless of response to injection, was associated with favorable surgical outcome [OR: 3.205 (CI 1.105-9.299), p = 0.032].

CONCLUSION

Symptomatic improvement after pyloroplasty or G-POEM is independent of etiology of gastroparesis, GERD, and primary symptom. Response to dilation or Botox are not markers of response to surgery. However, patients who receive Botox are 3.2 times more likely to improve postoperatively.

Effectiveness of Botulinum Toxin Injection on Bruxism: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The present study compiled evidence on the efficacy of botulinum toxin A (BTX) for management of bruxism.

METHODS

A literature review that included randomized control, cohort, as well as observational studies published between January 2000 and November 2022 was conducted. All studies related to BTX injections administered into the masseters of patients with bruxism were included. Primary outcomes were measured by performing a meta-analysis of changes in maximal biting forces and pain severity and meta-regression of the effects of the BTX dose.

RESULTS

Ten studies were included for quantitative analysis. The analysis of the maximal biting force after BTX injections demonstrated a significant reduction at 1 month or less compared with both oral splints (P < 0.000001) and saline injections (P = 0.01). BTX continued to outperform oral splinting (P = 0.001) and saline placebos (P = 0.03) at 3 months. Between 3 and 6 months, a significantly higher maximal biting strength was observed in the BTX group than the oral splinting group (P < 0.00001). No significant differences in the maximal biting force were observed between the BTX and saline placebo groups (P = 0.50). A similar trend was observed in the analysis of pain reduction after botulinum treatment. Additionally, for every unit increase in the BTX dose, pain severity decreased by 0.0831 points (P = 0.0011).

CONCLUSION

BTX is effective in reducing biting strength and pain severity. BTX effects are evident at less than 4 weeks, peak between 5 and 8 weeks, and last for up to 24 weeks. Higher BTX doses result in greater improvement in pain. Although BTX benefits manifest earlier, they gradually diminish, and oral splinting exerts a more enduring effect, especially after 9-12 weeks. BTX injections into masseters are recommended as management options for bruxers, especially for those having difficulties complying with wearing oral splints or those seeking earlier symptom relief. However, future studies should determine BTX effects beyond 24 weeks and after repetitive injections and how bruxers of different ages or genders respond to treatment.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Phytoplankton Toxins and Their Potential Therapeutic Applications: A Journey toward the Quest for Potent Pharmaceuticals

Phytoplankton are prominent organisms that contain numerous bioactive substances and secondary metabolites, including toxins, which can be valuable to pharmaceutical, nutraceutical, and biotechnological industries. Studies on toxins produced by phytoplankton such as cyanobacteria, diatoms, and dinoflagellates have become more prevalent in recent years and have sparked much interest in this field of research. Because of their richness and complexity, they have great potential as medicinal remedies and biological exploratory probes. Unfortunately, such toxins are still at the preclinical and clinical stages of development. Phytoplankton toxins are harmful to other organisms and are hazardous to animals and human health. However, they may be effective as therapeutic pharmacological agents for numerous disorders, including dyslipidemia, obesity, cancer, diabetes, and hypertension. In this review, we have focused on the properties of different toxins produced by phytoplankton, as well as their beneficial effects and potential biomedical applications. The anticancer properties exhibited by phytoplankton toxins are mainly attributed to their apoptotic effects. As a result, phytoplankton toxins are a promising strategy for avoiding postponement or cancer treatment. Moreover, they also displayed promising applications in other ailments and diseases such as Alzheimer’s disease, diabetes, AIDS, fungal, bacterial, schizophrenia, inflammation, allergy, osteoporosis, asthma, and pain. Preclinical and clinical applications of phytoplankton toxins, as well as future directions of their enhanced nano-formulations for improved clinical efficacy, have also been reviewed.

Botulinum Toxin Therapy for Oromandibular Dystonia and Other Movement Disorders in the Stomatognathic System

Various movement disorders, such as oromandibular dystonia, oral dyskinesia, bruxism, functional (psychogenic) movement disorder, and tremors, exist in the stomatognathic system. Most patients experiencing involuntary movements due to these disorders visit dentists or oral surgeons, who may be the first healthcare providers. However, differential diagnoses require neurological and dental knowledge. This study aimed to review scientific advances in botulinum toxin therapy for these conditions. The results indicated that botulinum toxin injection is effective and safe, with few side effects in most cases when properly administered by an experienced clinician. The diagnosis and treatment of movement disorders in the stomatognathic system require both neurological and dental or oral surgical knowledge and skills, and well-designed multicenter trials with a multidisciplinary team approach must be necessary to ensure accurate diagnosis and proper treatment.

The efficacy of botulinum toxin a injections in pelvic floor muscles in chronic pelvic pain patients: a systematic review and meta-analysis

Introduction and hypothesis

Chronic pelvic pain (CPP) is a common multifactorial condition affecting 6 to 27% of women aged 18–50 years worldwide. This study was conducted to review and meta-analyse the current literature on the reduction of chronic pelvic pain after botulinum toxin A (BTA) injection.

Method

In July 2021 we performed a systematic search in PubMed and EMBASE to assess the benefits of BTA injection in pelvic floor muscles in women with chronic pelvic pain. Primary outcome was reduction in visual analogue scale (VAS) after treatment. Secondary outcomes evaluated were: reduction of dyspareunia, pelvic floor resting pressure and quality of life. Identified reports were assessed on quality of reporting and risk of bias. Standardized mean difference (SMD) was used to combine and analyse outcomes of the included studies.

Results

Eight studies with 289 participants were considered eligible to be included in this systematic review and meta-analysis. After recalculating SMD into VAS scores (0–100), long-term follow-up (24–26 weeks) showed a significant 15-point improvement in VAS scores (95% CI: 8.8–21.5) for non-menstrual pelvic pain and a 13-point improvement (95% CI: 2.1–24.0) for dyspareunia. BTA injection had a significant effect on pelvic floor resting pressure and quality of life.

Conclusion

There is limited scientific evidence on the effectiveness of BTA injections in pelvic floor muscles in women with chronic pelvic pain. The available studies show that BTA injections significantly reduce pain levels and improve quality of life at 6 months follow-up.

Prospero ID

CRD42018105204.

Botulinum Toxin for Essential Tremor and Hands Tremor in the Neurological Diseases: A Meta-Analysis of Randomized Controlled Trials

Tremor is a common movement disorder. Essential tremor (ET) is the most common etiology of tremor, while hands tremor is the most disabling type of tremor. This study aimed to explore the effects of Botulinum toxin (BoNT) on tremor within 6 weeks of treatment, and the muscular weakness adverse effect within 6 weeks specifically in randomized controlled trials. PubMed, Embase, and Cochrane Library databases were searched. Tremor severity and grip strength after BoNT treatment were investigated. BoNT significantly attenuated hand tremor severity in patients with either essential tremor (ET), Parkinson’s disease or multiple sclerosis (Standardized mean difference [SMD] = −0.59, 95% confidence interval [CI], −0.95 to −0.24, p = 0.001, I2 = 46%). Regarding people with ET, BoNT significantly reduced their tremor severity, including hands tremor and head tremor within 6 weeks of treatment (SMD = −0.58, 95% CI, −0.28 to −0.88, p = 0.002, I2 = 0%). Electromyography (EMG) but not anatomical guidance BoNT injection provided significant benefit on the relief of tremor in both conditions. The principal adverse event was weakness, but it did not worse within 6 weeks of BoNT treatment (SMD = −0.35, 95% CI, −0.83 to 0.12, p = 0.07, I2 = 57%), as assessed by the subjective grip strength. In conclusion, BoNT was an effective treatment for the hand tremor and ET, and EMG guidance injection was preferred. In addition, the muscular weakness adverse effect was not significant.

Ultrasound-Guided OnabotulinumtoxinA Injections to Treat Oromandibular Dystonia in Cerebral Palsy

Cerebral palsy (CP) is a group of non-progressive disorders of motor function in children resulting from an injury to an immature brain. In addition to abnormal limb and trunk movement, individuals with CP can experience involuntary muscle contractions of the lower facial muscle groups, causing oromandibular dystonia (OMD). Contraction of the lateral pterygoids and submandibular muscles depresses the mandible. OMD involving the lateral pterygoids can therefore lead to involuntary jaw opening posture, affecting the ability to feed and speak effectively. We present a case series of five patients with CP and OMD that received novel ultrasound-guided onabotulinumtoxinA to the lateral pterygoid muscles. Our goal was to determine if chemodenervation would improve the mouth-closing ability, thus in turn improving the ability to swallow, chew, manage secretions, and communicate. We describe this unique injection method and report a subjective improvement in eating abilities and communication, in addition to a positive upward trend in most patients’ weights, with no significant adverse side effects.

Comparison between botulinum toxin and steroid septal injection in the treatment of allergic rhinitis

OBJECTIVE

To compare the effects of botulinum toxin and steroid septal injections in treating allergic rhinitis (AR) by evaluating improvements in the rhinitis control assessment test (RCAT), visual analog scale (VAS), nasal obstruction symptom evaluation (NOSE) scores, and active anterior rhinomanometry (RMM) measurements.

METHODS

This prospective, single-blinded cohort study was conducted at the Department of Otolaryngology, Taipei City Hospital between January 2017 and December 2018. Ninety-five patients were randomized to receive botulinum toxin, dexamethasone, or normal saline (group A, group B, and placebo, respectively). The main outcome measures were pretreatment subjective nasal symptoms (RCAT, VAS, and NOSE) and active anterior RMM measurements. All measurements were repeated during posttreatment 1, 2, and 3 months.

RESULTS

No significant difference was observed in pretreatment questionnaire scores and RMM values between the study and placebo groups. The mean posttreatment RCAT, VAS, and NOSE scores after 1 and 2 months significantly improved in the treatment groups compared to placebo. The VAS and NOSE at posttreatment 2 months and RCAT, VAS, and NOSE at posttreatment 3 months were significantly different comparing group A to group B. All RMM parameters showed better values in group A than in group B at 1, 2, and 3 months posttreatment, with significant differences in four parameters in posttreatment 3 months.

CONCLUSIONS

Botulinum toxin septal injection is a safe treatment option for AR and improves subjective nasal symptoms for 3 months. Botulinum toxin A injection tended to be more effective than steroid septal injection in terms of duration and degree.Level of Evidence: 2b, individual cohort study.

The Use of Fusion Images as a Diagnostic and Neurosurgical Planning Tool in Microvascular Decompression

Preoperative assessment of surgery using high-quality images can help surgeons to achieve best result of treatment. With the advances in computer technology, interactive multimodality fusion images have been developed. The use of fusion images as a preoperative planning tool is described with its examples in illustrative cases of trigeminal neuralgia and hemifacial spasm microvascular decompression (MVD). Interactive computer graphics such as multimodality fusion method is a useful tool to preoperatively predict the need of bone exposure and configuration of blood vessels with its correlation to cranial nerves in MVD.

Evolving concepts in progressive supranuclear palsy and other 4-repeat tauopathies

Tauopathies are classified according to whether tau deposits predominantly contain tau isoforms with three or four repeats of the microtubule-binding domain. Those in which four-repeat (4R) tau predominates are known as 4R-tauopathies, and include progressive supranuclear palsy, corticobasal degeneration, argyrophilic grain disease, globular glial tauopathies and conditions associated with specific MAPT mutations. In these diseases, 4R-tau deposits are found in various cell types and anatomical regions of the brain and the conditions share pathological, pathophysiological and clinical characteristics. Despite being considered 'prototype' tauopathies and, therefore, ideal for studying neuroprotective agents, 4R-tauopathies are still severe and untreatable diseases for which no validated biomarkers exist. However, advances in research have addressed the issues of phenotypic overlap, early clinical diagnosis, pathophysiology and identification of biomarkers, setting a road map towards development of treatments. New clinical criteria have been developed and large cohorts with early disease are being followed up in prospective studies. New clinical trial readouts are emerging and biomarker research is focused on molecular pathways that have been identified. Lessons learned from failed trials of neuroprotective drugs are being used to design new trials. In this Review, we present an overview of the latest research in 4R-tauopathies, with a focus on progressive supranuclear palsy, and discuss how current evidence dictates ongoing and future research goals.

A systematic review and meta-analysis of technical aspects and clinical outcomes of botulinum toxin prior to abdominal wall reconstruction

Purpose

To systematically review technical aspects and treatment regimens of botulinum toxin A (BTA) injections in the lateral abdominal wall musculature. We also investigated the effect of BTA on abdominal muscle- and hernia dimensions, and clinical outcome.

Methods

PubMed, EMBASE, CENTRAL, and CINAHL were searched for studies that investigate the injection of BTA in the lateral abdominal wall muscles. Study characteristics, BTA treatment regimens, surgical procedures, and clinical outcomes are presented descriptively. The effect of BTA on muscle- and hernia dimensions is analyzed using random-effects meta-analyses, and exclusively for studies that investigate ventral incisional hernia patients.

Results

We identified 23 studies, comprising 995 patients. Generally, either 500 units of Dysport^® or 200–300 units of Botox^® are injected at 3–5 locations bilaterally in all three muscles of the lateral abdominal wall, about 4 weeks prior to surgery. No major procedural complications are reported. Meta-analyses show that BTA provides significant elongation of the lateral abdominal wall of 3.2 cm per side (95% CI 2.0–4.3, I² = 0%, p < 0.001); 6.3 cm total elongation, and a significant but heterogeneous decrease in transverse hernia width (95% CI 0.2–6.8, I² = 94%, p = 0.04). Furthermore, meta-analysis shows that BTA pretreatment in ventral hernia patients significantly increases the fascial closure rate [RR 1.08 (95% CI 1.02–1.16, I² = 0%, p = 0.02)].

Conclusion

The injection technique and treatment regimens of botulinum toxin A as well as patient selection require standardization. Bilateral pretreatment in hernia patients significantly elongates the lateral abdominal wall muscles, making fascial closure during surgical hernia repair more likely.

Study registration

A review protocol for this meta-analysis was registered at PROSPERO (CRD42020198246).

Supplementary Information

The online version contains supplementary material available at 10.1007/s10029-021-02499-1.

Neutralizing Concentrations of Anti-Botulinum Toxin Antibodies Positively Correlate with Mouse Neutralization Assay Results in a Guinea Pig Model

Botulinum neurotoxins (BoNT) are some of the most toxic proteins known and can induce respiratory failure requiring long-term intensive care. Treatment of botulism includes the administration of antitoxins. Monoclonal antibodies (mAbs) hold considerable promise as BoNT therapeutics and prophylactics, due to their potency and safety. A three-mAb combination has been developed that specifically neutralizes BoNT serotype A (BoNT/A), and a separate three mAb combination has been developed that specifically neutralizes BoNT serotype B (BoNT/B). A six mAb cocktail, designated G03-52-01, has been developed that combines the anti-BoNT/A and anti-BoNT/B mAbs. The pharmacokinetics and neutralizing antibody concentration (NAC) of G03-52-01 has been determined in guinea pigs, and these parameters were correlated with protection against an inhalation challenge of BoNT/A1 or BoNT/B1. Previously, it was shown that each antibody demonstrated a dose-dependent mAb serum concentration and reached maximum circulating concentrations within 48 h after intramuscular (IM) or intraperitoneal (IP) injection and that a single IM injection of G03-52-01 administered 48 h pre-exposure protected guinea pigs against an inhalation challenge of up to 93 LD₅₀s of BoNT/A1 and 116 LD₅₀s of BoNT/B1. The data presented here advance our understanding of the relationship of the neutralizing NAC to the measured circulating antibody concentration and provide additional support that a single IM or intravenous (IV) administration of G03-52-01 will provide pre-exposure prophylaxis against botulism from an aerosol exposure of BoNT/A and BoNT/B.

Effects of Botulinum Toxin Type A on Pain among Trigeminal Neuralgia, Myofascial Temporomandibular Disorders, and Oromandibular Dystonia

The differences in analgesic effects of botulinum toxin type A were compared in 28 patients with trigeminal neuralgia, 53 patients with myofascial temporomandibular disorders, and 89 patients with the jaw closing oromandibular dystonia. The patients were treated by injection of botulinum toxin type A into the masseter, temporalis, medial pterygoid, and other muscles based on the symptoms of each patient. The pain severity was evaluated using the visual analog scale, pain frequency, and pain scale of the oromandibular dystonia rating scale. Botulinum toxin injection was performed 1068 times in all patients without significant adverse effects. The visual analog, pain frequency, and pain scales at baseline were reduced (p < 0.001) after two, four, eight, and 12 weeks after the first botulinum toxin therapy and at the endpoint. The effects differed significantly (p < 0.001) among the groups (repeated-measures analysis of variance). The mean improvement (0%, no effect; 100%, complete recovery) at the endpoint was 86.8% for trigeminal neuralgia, 80.8% for myofascial pain, and 75.4% for oromandibular dystonia. Injection of the botulinum toxin can be a highly effective and safe method to treat trigeminal neuralgia, myofascial pain, and oromandibular dystonia.

Human sensorimotor organoids derived from healthy and amyotrophic lateral sclerosis stem cells form neuromuscular junctions

Human induced pluripotent stem cells (iPSC) hold promise for modeling diseases in individual human genetic backgrounds and thus for developing precision medicine. Here, we generate sensorimotor organoids containing physiologically functional neuromuscular junctions (NMJs) and apply the model to different subgroups of amyotrophic lateral sclerosis (ALS). Using a range of molecular, genomic, and physiological techniques, we identify and characterize motor neurons and skeletal muscle, along with sensory neurons, astrocytes, microglia, and vasculature. Organoid cultures derived from multiple human iPSC lines generated from individuals with ALS and isogenic lines edited to harbor familial ALS mutations show impairment at the level of the NMJ, as detected by both contraction and immunocytochemical measurements. The physiological resolution of the human NMJ synapse, combined with the generation of major cellular cohorts exerting autonomous and non-cell autonomous effects in motor and sensory diseases, may prove valuable to understand the pathophysiological mechanisms of ALS.

Adverse Events Associated With Botox as Reported in a Food and Drug Administration Database

BACKGROUND

Botulinum toxin treatment is the most frequently performed noninvasive cosmetic procedure performed in the USA. Because of its widespread use, an analysis of the adverse event (AE) profile of Botox injections is needed.

METHODS

The FDA Adverse Event Report System was queried using an online web-based tool to determine the top 15 adverse events reported for four Botox brand names: Botox/Botox Cosmetic, Dysport, and Xeomin. The proportional reporting ratios (PRR) and relative odds ratios (ROR) were determined. A literature review was performed for eight AEs of clinical significance: eyelid/eyebrow ptosis, asthenia, muscular weakness, facial paresis, dysphagia, botulism, and death.

RESULTS

Botox/Botox Cosmetic had 38367 AEs. Dysport had 3582 AEs. Xeomin had 1405 AEs. All drugs with reported cases of eyelid and eyebrow ptosis had significant PRR and ROR values. The PRR and ROR values for asthenia were not significant in any of the drugs and only reached significance for Dysport for muscular weakness and dysphagia. Both Botox/Botox Cosmetic and Dysport had elevated PRRs and RORs for facial paresis and botulism. While all drugs had at least one reported case of death related to Botox injection use, none of the PRR or ROR values were significant.

CONCLUSION

Known AEs for Botox injection use include eyelid/brow ptosis and muscular weakness. Feared but rare complications of Botox injection use include dysphagia, botulism, and possibly death, owing to systemic spread of the toxin. This is the first study to analyze the AE data reported to the FDA on Botox injection use.

EBM LEVEL

III.

Botulinum Toxin in the Treatment of Vasopressor-associated Symmetric Peripheral Gangrene

Symmetric peripheral gangrene (SPG) affects peripheral tissues of critically ill patients and can have severe disfiguring and debilitating effects. It can occur in the setting of multiple conditions, and it is associated with the use of vasopressors. There are no evidence-based treatments available for patients who develop SPG. Botulinum toxin has emerged as a potential therapy in vasospastic disorders, and we hypothesized that it may be used in the treatment of tissue ischemia in critically ill patients on vasopressors. We present a case of a patient who developed vasopressor-associated SPG and who experienced complete resolution after local injection with botulinum toxin. While the action of botulinum toxin on skeletal muscle is best understood, it has also been demonstrated to attenuate the release of multiple vasoconstrictive factors that impact vascular smooth muscle and modulate calcium and nitric oxide. These effects may result in vasodilation and improvement of cutaneous ischemia when injected locally. Clinicians may consider this local therapy in the treatment of vasopressor-associated symmetric peripheral gangrene.

Cerebellar 5HT-2A receptor mediates stress-induced onset of dystonia

Stress is a key risk factor for dystonia, a debilitating motor disorder characterized by cocontractions of muscles leading to abnormal body posture. While the serotonin (5HT) system is known to control emotional responses to stress, its role in dystonia remains unclear. Here, we reveal that 5HT neurons in the dorsal raphe nuclei (DRN) send projections to the fastigial deep cerebellar nuclei (fDCN) and that photostimulation of 5HT-fDCN induces dystonia in wild-type mice. Moreover, we report that photoinhibition of 5HT-fDCN reduces dystonia in a1A ^tot/tot mice, a genetic model of stress-induced dystonia, and administration of a 5HT-2A receptor inverse agonist (MDL100907; 0.1 to 1 mg/kg) or shRNA-mediated knockdown of the ht2ar gene in fDCN can notably reduce the onset of dystonia in a1A ^tot/tot mice. These results support the serotonin theory of dystonia and suggest strategies for alleviating symptoms in human patients by blocking 5HT-2A receptors.

[Therapeutic strategies for oromandibular dystonia]

Oromandibular dystonia is characterized by tonic or clonic involuntary spasms of the masticatory, lingual and / or muscles in the stomatognathic system. It is often misdiagnosed as craniomandibular dysfunction or psychiatric disease. According to clinical features, the oromandibular dystonia is classified into 6 subtypes (jaw closing-, jaw opening-, tongue-, jaw deviation-, jaw protrusion-, and lip dystonia). There are several treatment methods like botulinum toxin injection, muscle afferent block (injection of lidocaine and alcohol into the masticatory or tongue muscles for blocking muscle afferents from muscle spindle), occlusal splint, and oral surgery (coronoidotomy). Most of patients can be treated successfully according to subtype by combination of these treatments. Special treatment recommendations for each subtype were described in this focus article. Accurate diagnosis and treatment of oral dystonia requires comprehensive knowledge and skills of both oral and maxillofacial surgery and neurology. Therefore, collaboration among these departments is very important.

Preoperative botulinum toxin A injection in complex abdominal wall reconstruction- a propensity-scored matched study

INTRODUCTION

Fascial closure during complex abdominal wall reconstruction (AWR) improves recurrence and wound infection rates. To facilitate fascial closure in massive ventral hernias preoperative Botulinum Toxin A (BTA) injection can be used.

METHODS

2:1 propensity-scored matching of patients undergoing AWR with and without BTA was performed based on BMI, defect width, and loss of domain using CT-volumetric analysis.

RESULTS

145 patients without BTA and 75 with BTA were comparable on hernia size (240vs251cm², p = 0.589) and hernia volume (1405vs1672cm³, p = 0.243). Patients with BTA had higher wound class (CDC≥3 37%vs13%, p < 0.001). Patients with BTA had a higher fascial closure rate (92%vs81%, p = 0.036), received more components separation (61%vs47%, p = 0.042), lower wound infection rate (12%vs26%,p = 0.019) and comparable recurrence rates (9%vs12%, p = 0.589). Recurrences occurred more often without complete fascial closure compared to patients with (33%vs7%, p < 0.001).

CONCLUSION

In patients with massive ventral hernias and severe loss of domain, preoperative BTA-injection improves fascial closure rates during AWR.

A Monoclonal Antibody Combination against both Serotypes A and B Botulinum Toxin Prevents Inhalational Botulism in a Guinea Pig Model

Botulinum neurotoxins (BoNT) are extremely potent and can induce respiratory failure, requiring long-term intensive care to prevent death. Recombinant monoclonal antibodies (mAbs) hold considerable promise as BoNT therapeutics and prophylactics. In contrast, equine antitoxin cannot be used prophylactically and has a short half-life. Two three-mAb combinations are in development that specifically neutralize BoNT serotype A (BoNT/A) and B (BoNT/B). The three-mAb combinations addressing a single serotype provided pre-exposure prophylaxis in the guinea pig inhalation model. A lyophilized co-formulation of six mAbs, designated G03-52-01, that addresses both A and B serotypes is in development. Here, we investigated the efficacy of G03-52-01 to protect guinea pigs against an aerosol exposure challenge of BoNT/A1 or BoNT/B1. Previously, it was found that each antibody demonstrated a dose-dependent exposure and reached maximum circulating concentrations within 48 h after intramuscular (IM) or intravenous (IV) injection. Here we show that G03-52-01, in a single IM injection of G03-52-01 administered 48 h pre-exposure, protected guinea pigs against an aerosol challenge of up to 238 LD₅₀s of BoNT/A1 and 191 LD₅₀s of BoNT/B1. These data suggest that a single IM administration of G03-52-01 provides pre-exposure prophylaxis against botulism from an aerosol exposure of BoNT/A1 or BoNT/B1.

Image-guided botulinum toxin injection in the lateral abdominal wall prior to abdominal wall reconstruction surgery: review of techniques and results

Ventral hernias represent the most common complication after abdominal surgery. Loss of domain and/or large ventral hernias in patients are especially challenging for surgeons to manage, but preoperative image-guided botulinum toxin injection has emerged as an effective adjunct to abdominal wall surgery. Loss of domain is caused by chronic muscle retraction of the lateral abdominal wall and leads to an irreducible protrusion of abdominal viscera into the hernia sac. Botulinum toxin can be used in the oblique muscles as a chemical component relaxation technique to aid abdominal wall reconstruction. Intramuscular botulinum toxin injection causes functional denervation by blocking neurotransmitter acetylcholine release resulting in flaccid paralysis and elongation of lateral abdominal wall muscles, increasing the rate of fascial closure during abdominal wall reconstruction, and decreasing recurrence rates. In total, 200-300 units of onabotulinumtoxinA (Botox®) or 500 units of abobotulinumtoxinA (Dypsort®) in a 2:1 dilution with normal saline is most commonly used. Botulinum toxin can be injected with ultrasonographic, EMG, or CT guidance. Injection should be performed at least 2 weeks prior to abdominal wall reconstruction, for maximal effect during surgery. At minimum, botulinum toxin should be injected into the external and internal oblique muscles at three separate sites bilaterally for a total of six injections. Although botulinum toxin use for abdominal wall reconstruction is currently not indicated by the Food and Drug Administration, it is safe with only minor complications reported in literature.

The Effect of Botulinum Toxin Type A Injections on Stricture Formation, Leakage Rates, Esophageal Elongation, and Anastomotic Healing Following Primary Anastomosis in a Long- and Short-Gap Esophageal Atresia Model - A Protocol for a Randomized, Controlled, Blinded Trial in Pigs

BACKGROUND

Esophageal atresia (EA) is a congenital malformation affecting 1:3000-4500 newborns. Approximately 15% have a long-gap EA (LGEA), in which case a primary anastomosis is often impossible to achieve. To create continuity of the esophagus patients instead have to undergo lengthening procedures or organ interpositions; methods associated with high morbidity and poor functional outcomes. Esophageal injections of Botulinum Toxin Type A (BTX-A) could enable primary anastomosis and mitigate stricture formation through decreased tissue tension.

METHODS AND ANALYSIS

In this randomized controlled blinded animal trial, 24 pigs are divided into a long- or short-gap EA group (LGEA and SGEA, respectively) and randomized to receive BTX-A or isotonic saline injections. In the LGEA group, injections are given endoscopically in the esophageal musculature. After seven days, a 3 cm esophageal resection and primary anastomosis is performed. In the SGEA group, a 1 cm esophageal resection and primary anastomosis is performed, followed by intraoperative injections of BTX-A or isotonic saline. After 14 days, stricture formation, presence of leakage, and esophageal compliance is assessed using endoscopic and manometric techniques, and in vivo and ex vivo contrast radiography. Tissue elongation is evaluated in a stretch-tension test, and the esophagus is assessed histologically to evaluate anastomotic healing.

ETHICS AND DISSEMINATION

The study complies with the ARRIVE guidelines for animal studies and has been approved by the Danish Animal Experimentation Council. Results will be published in peer-reviewed journals and presented at national and international conferences.

HIGHLIGHTS

The optimal management of long-gap esophageal atresia remains controversialPrimary anastomosis could improve functional outcomes and reduce complicationsBotulinum Toxin Type A decreases tissue tension and could facilitate anastomosisReduced tension could further abate the risk for anastomotic stricture and leakageWe present a model to evaluate the method in long- and short-gap esophageal atresia.

The Effects of Preoperative Botulinum Toxin A Injection on Abdominal Wall Reconstruction

BACKGROUND

Fascial closure significantly reduces postoperative complications and hernia recurrence after abdominal wall reconstruction (AWR), but can be challenging in massive ventral hernias.

METHODS

A prospective single-institution cohort study was performed to examine the effects of preoperative injection of botulinum toxin A (BTA) in patients undergoing AWR for midline or flank hernias.

RESULTS

A total of 108 patients underwent BTA injection with average 243 units, mean 32.5 days before AWR, without complications. Comorbidities included diabetes (31%), history of smoking (27%), and obesity (mean body mass index 30.5 ± 7.7). Hernias were recurrent in 57%, massive (mean defect width 15.3 ± 5.5 cm; hernia sac volume 2154 ± 3251 cm³) and had significant loss of domain (mean 46% visceral volume outside abdominal cavity). Contamination was present in 38% of patients. Fascial closure was achieved in 91%, with 57% requiring component separation techniques (CSTs). Subxiphoidal hernias needed a form of CST in 88% compared with 50% for hernia not extending subxiphoidal (P < 0.001). Mesh augmentation was used in 98%. Postoperative complications occurred in 40%: 19% surgical site occurrences, 12% surgical site infections, and 7% respiratory failure requiring intubation, 2% mesh infection and no fascial dehiscence. Recurrence was identified in seven patients after mean 14 months of follow-up. Patients undergoing AWR with CST had more surgical site occurrences (29 versus 7%, p0.003) and respiratory failures (18 versus 0%, P = 0.002) than patients who did not require CST.

CONCLUSIONS

In patients with massive ventral hernias, the use of preoperative BTA injections for AWR is safe and is associated with high fascial closure rates and excellent recurrence rates.

[Piriformis syndrome. Treatment under control of CT fluoroscopy]

OBJECTIVE

To demonstrate one of the effective methods of treatment of the piriformis syndrome under the control of a highly technological visualization method.

MATERIAL AND METHODS

Eight patients (7 women and 1 man), aged 44 to 63 years, with piriformis syndrome, were studied from 2016 to 2018. The main complaints of the patients were pain in the lumbosacral spine with irradiation to the gluteal region and/or legs. All patients underwent MRI and/or MSCT of the lumbosacral spine, the pelvic ultrasound, according to the results of which 1 patient was diagnosed with uterine myoma, 5 with lesions of intervertebral discs in the L4-L5 and L5-S1 segments of varying severity in combination with changes in posture. For therapeutic purposes, all patients under the control of CT fluoroscopy were administered to xeomin (n=3), dexamethasone (n=1) or betamethasone (n=4).

RESULTS

In all patients, a positive therapeutic effect was observed after 4-12 months for xeomin injections, 2-3 weeks for dexamethasone and up to 3 months for betamethasone. No complications during the manipulations were observed. The authors present a clinical case to describe the botulinum therapy technique under the control of CT fluoroscopy, which allows effective treatment of the piriformis syndrome.

CONCLUSION

In the treatment of the piriformis syndrome it is necessary to apply an integrated approach, the leading of which are methods of local impaction on the suffering muscle. Only a methodologically correct injection can increase the effectiveness of treatment in these patients and reduce the risk of complications.

Management of solitary rectal ulcer syndome: Results of a french national survey: Société Nationale Française de Coloproctologie SNFCP, France

There is no consensus on the treatment for solitary rectal ulcer syndrome (SRUS). This study aimed to obtain information from physicians treating patients with SRUS in a French medical surgical society to facilitate management plans and to develop a support algorithm. Members of the French National Society of Coloproctology (SNFCP) were invited to complete a survey that included twenty items about therapeutic management and healing criteria. Overall, 91 practitioners (median age: 52 [42-59] years) responded to the questionnaire; 64/91 (70.3%) were proctologists, and 27/91 (29.7%) were colorectal surgeons. Only 15 members (16.5%) followed more than 5 patients with SRUS per year. The therapeutic objectives were to improve both patient symptoms (100%) and quality of life (98.9%). Laxative treatment and first-line rehabilitation were agreed upon by 83.5% and 73% of the respondents, respectively. Surgery, mainly rectopexy, was offered after failed medical treatment by 81.1% of the practitioners (79.1%). The first-line strategy preferred by the professionals included laxatives and biofeedback rehabilitation. Surgical treatment, preferably rectopexy, was proposed as a second intervention. No consensus was reached regarding other therapeutic alternatives, and additional studies are required to clarify their indications.

Progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a neurodegenerative disease characterized pathologically by 4 repeat tau deposition in various cell types and anatomical regions. Richardson's syndrome (RS) is the initially described and one of the clinical phenotypes associated with PSP pathology, characterized by vertical supranuclear gaze paly in particular downwards, postural instability with early falls and subcortical frontal dementia. PSP can manifest as several other clinical phenotypes, including PSP-parkinsonism, -pure akinesia with gait freezing, -frontotemporal dementia, - corticobasal syndrome, - speech/language impairment. RS can also have a pathologic diagnosis other than PSP, including corticobasal degeneration, FTD-TDP-43 and others. New clinical diagnostic criteria take into account this phenotypic variability in an attempt to diagnose the disease earlier, given the current lack of a validated biomarker. At present, therapeutic options for PSP are symptomatic and insufficient. Recent large neuroprotective trials have failed to provide a positive clinical outcome, however, have led to the design of better studies that are ongoing and hold promise for a neuroprotective treatment for PSP.

Validation of the Hemifacial Spasm Grading Scale: a clinical tool for hemifacial spasm

BACKGROUND

To create an objective rating tool for hemifacial spasm (HFS) and validate it on a cohort of patients.

METHODS

A panel of movement disorders specialists elaborated, through the Delphi method, the Hemifacial Spasm Grading Scale (HSGS). The validity of the scale was tested in a longitudinal, prospective observational study, with standardized video recording protocol before and after botulinum neurotoxin (BoNT) treatment. The video recordings obtained from each patient were then independently assessed with HSGS by three blinded raters. The scale was compared to patient-reported HFS-7 scale and to the clinical grading of spasm intensity scale.

RESULTS

Intra-rater reproducibility ranged between ICC 0.73 (95% CI = 0.54-0.86) and 0.83 (0.68-0.92) and inter-rater reproducibility between 0.62 (95% CI = 0.44-0.77) and 0.82 (0.69-0.90). HSGS scores correlated with clinical grading of spasm intensity scale scores, but not with HFS-7. HSGS confirmed BoNT efficacy, with scores lowering at 1 month from treatment.

CONCLUSIONS

HSGS represents an objective, quick and reliable scale for the assessment of HFS, and might be useful to monitor BoNT treatment efficacy over time.

Bruxismo durante o Sono

Bruxismo durante o sono (BS) é uma parassonia caracterizada por movimentos involuntários e estereotipados com ranger dos dentes durante o sono. A prevalência do BS é igual nos dois sexos, variando de 3% a 20% na população geral, sendo mais comum nos jovens. O BS secundário é causado por transtornos neurológicos ou pode estar associado a transtornos primários do sono e antidepressivos inibidores seletivos da recaptação da serotonina. Já o BS primário apresenta fatores de predisposição genética ou psicológica, má oclusão dentária, disfunção leve dos gânglios da base e combinações desses fatores. Os principais sinais e sintomas do BS incluem o ruído característico de ranger dos dentes, desgaste dentário, dor local, hipertrofia dos músculos masseteres e temporais, cefaléias, disfunção da articulação temporomandibular, sono de má qualidade e sonolência diurna. O diagnóstico clínico de BS é feito por meio da história do paciente, do cônjuge e do exame odontológico. A polissonografia documenta a presença de episódios de ranger dos dentes, permitindo identificar alterações da arquitetura do sono, presença de microdespertares, abalos mioclônicos de membros inferiores, roncos e distúrbios respiratórios sonodependentes. O tratamento deve ser direcionado para os fatores etiológicos com base no BS secundário. Não existe tratamento-padrão para o BS primário, devendo este ser individualizado ao paciente. O tratamento odontológico do BS primário e secundário com placas de repouso tem como objetivo prevenir danos das estruturas orofaciais e aliviar dor craniofacial. O tratamento comportamental inclui técnicas de relaxamento, abstinência de cafeína e tabaco. O tratamento farmacológico do BS primário e secundário emprega drogas agonistas dopaminérgicas, benzodiazepínicos ansiolíticos, buspirona, hipnóticos não-benzodiazepínicos, como o zolpidem, relaxantes musculares, certos antidepressivos, como mirtazapina, nefazodona, trazodona, bupopriona e drogas antiepilépticas, como a gabapentina. Aplicações locais de toxina botulínica nos músculos masseteres e temporais podem ser utilizadas em casos de bruxismo intenso não-responsivo à terapêutica convencional.

Botulinum Neurotoxin Therapy for Lingual Dystonia Using an Individualized Injection Method Based on Clinical Features

Lingual dystonia is a debilitating type of oromandibular dystonia characterized by involuntary, often task-specific, contractions of the tongue muscle activated by speaking or eating. Botulinum neurotoxin (BoNT) has been used to treat lingual dystonia; however, it is known to cause serious complications, such as dysphasia and aspiration. The purpose of this study was to evaluate the efficacy and adverse effects of individualized BoNT therapy for lingual dystonia. One-hundred-and-seventy-two patients (102 females and 70 males, mean age: 46.2 years) with lingual dystonia were classified into four subtypes based on symptoms of involuntary tongue movements: protrusion (68.6%), retraction (16.9%), curling (7.6%), and laterotrusion (7.0%). Patients were treated with BoNT injection into the genioglossus and/or intrinsic muscles via individualized submandibular and/or intraoral routes. Results were compared before and after BoNT therapy. Botulinum neurotoxin was injected in 136 patients (mean: 4.8 injections). Clinical sub-scores (mastication, speech, pain, and discomfort) in a disease-specific rating scale were reduced significantly (p < 0.001) after administration. Comprehensive improvement after BoNT injection, assessed using the rating scale, was 77.6%. The curling type (81.9%) showed the greatest improvement, while the retraction type showed the least improvement (67.9%). Mild and transient dysphasia occurred in 12.5% of patients (3.7% of total injections) but disappeared spontaneously within several days to two weeks. No serious side effects were observed. With careful diagnosis of subtypes and a detailed understanding of lingual muscle anatomy, individualized BoNT injection into dystonic lingual muscles can be effective and safe.

Masticatory hypofunction effects induced by BTXA injection of hippocampal neurons in developing rats

BACKGROUND AND OBJECTIVE

In clinical practice, malocclusion is often encountered during the period of growth and development of individuals. In addition to nutritional imbalance, some studies have found that mastication affects learning and memory ability. Tooth loss and masticatory hypofunction have been suggested as risk factors of Alzheimer disease. However, relatively little research has been done in developing animals. The present study evaluated the relationship between masticatory hypofunction and neuropathological changes of the hippocampus in developing rats.

DESIGN

Four-week-old Wistar rats were randomly divided into saline-injected and botulinum toxin type A (BTXA)-injected groups. After an experiment period of 4 weeks, the rats were sacrificed for evaluation of neuropathological changes in the hippocampus through Nissl staining and phosphorylated cyclic AMP (cAMP) response element binding protein (CREB) immunohistochemistry.

RESULTS

Nissl staining revealed a significant reduction in the density of neurons in the BTXA-injected rats. The BTXA-injected rats exhibited a decreased level of CREB phosphorylation. The degree of p-CREB immunoreactivity differed significantly between the two groups.

CONCLUSION

The BTXA-injected rats exhibited a reduction in neuron density and phosphorylated CREB, indicating that mastication might influence the learning and memory ability during the growth period. Therefore, it is strongly suggested that malocclusion be corrected as soon as possible during growth and development.

Temporary autonomic modulation with botulinum toxin type A to reduce atrial fibrillation after cardiac surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) frequently complicates cardiac surgery and is associated with worse outcomes. The cardiac autonomic nervous system is implicated in the pathogenesis of POAF.

OBJECTIVE

The purpose of this study was to determine the efficacy and safety of selective cardiac autonomic modulation in preventing POAF.

METHODS

In this randomized, double-blind, placebo-controlled trial, adults undergoing cardiac surgery were randomized 1:1 to intraoperative injection of 250 units onabotulinumtoxinA (botulinum toxin type A [BoNTA]) or placebo into epicardial fat pads. The study was powered to detect a 40% reduction in relative risk of POAF. Time to first episode of in-hospital POAF was the primary outcome, evaluated in patients receiving injection. Additionally, incidence of POAF, length of stay (LOS), and adverse events were examined.

RESULTS

The trial assigned 145 patients to injection, 15 of whom were dropped before treatment, leaving 130 patients for analysis. Overall, 36.5% (23/63) of BoNTA-treated patients developed POAF compared with 47.8% (32/67) of placebo-treated patients. The time-to-event analysis revealed a hazard ratio of 0.69 (95% confidence interval 0.41-1.19; P = .18) for the BoNTA vs placebo arm. There were no significant differences in postoperative hospital LOS (median [interquartile range] 6.0 [3.4] vs 6.2 [3.7] days; P = .51) or adverse events prolonging LOS (27/63 [42.9%] vs 30/67 [44.8%]; P = .83) in patients receiving BoNTA vs placebo.

CONCLUSION

Epicardial injection of onabotulinumtoxinA was without discernible adverse effects, but we failed to detect a significant difference in risk of POAF. Future large-scale studies of epicardial onabotulinumtoxinA injection as a potential POAF prevention strategy should be designed to study smaller, but clinically meaningful, treatment effects.

The Role of Botox in Colorectal Disorders

PURPOSE OF REVIEW

To overview the current medical literature on the efficacy of botulism toxin treatment (BTX-A) for lower gastrointestinal disorders (GIT).

RECENT FINDINGS

BTX-A was found to have a short-term efficacy for the treatment of dyssynergic defecation. Surgical treatment was found to be more effective than BTX-A for the healing of chronic anal fissures, and BTX-A can be considered when surgery is undesirable. Data regarding the effects of BTX-A injection for the treatment of chronic anal pain is limited. Beneficial effects were observed only in a minority of patients. BTX-A treatment was found to be effective for the treatment of obstructive symptoms after surgery for Hirsprung's disease as well as for the treatment of internal anal sphincter achalasia. BTX-A treatment has a short-term efficacy and is safe. Further research is still needed in order to establish the exact place of BTX-A treatment of lower GIT disorders.

The Investigation and Treatment of Diabetic Gastroparesis

PURPOSE

This review provides an update on the investigations and treatment options for gastroparesis.

METHODS

A comprehensive literature search of Medline, PubMed, Embase and OVID was conducted which included all systematic reviews and research articles that focused on the diagnosis, investigations and management diabetic gastroparesis.

FINDINGS

Dietary modifications and pharmacologic treatment with prokinetics to increase gastric motility form the mainstay of treatment. However, the use of prokinetics is limited by adverse effects and serious adverse effects, leaving metoclopramide as the only drug approved by the US Food and Drug Administration for the treatment of gastroparesis. Newer therapies, including motilin receptor agonists, ghrelin receptor agonists, and neurokinin receptor antagonists, are currently being investigated. Transpyloric stenting, gastric electrical stimulation, and gastric per-oral endoscopic myotomy provide mechanical options for intervention, and surgical interventions in severe intractable gastroparesis include laparoscopic pyloroplasty or gastrectomy.

IMPLICATIONS

Advances to better understand the pathophysiology and management of diabetic gastroparesis have been limited, especially with discordance between symptoms and severity of delay in gastric emptying. Established treatment options are limited; however, recent pharmacologic and surgical interventions show promise.

Botulinum Neurotoxin Injection for the Treatment of Recurrent Temporomandibular Joint Dislocation with and without Neurogenic Muscular Hyperactivity

The aim of this study was to compare treatment outcomes following intramuscular injection of botulinum neurotoxin (BoNT) in patients with recurrent temporomandibular joint dislocation, with and without muscle hyperactivity due to neurological diseases. Thirty-two patients (19 women and 13 men, mean age: 62.3 years) with recurrent temporomandibular joint dislocation were divided into two groups: neurogenic (8 women and 12 men) and habitual (11 women and 1 man). The neurogenic group included patients having neurological disorders, such as Parkinson’s disease or oromandibular dystonia, that are accompanied by muscle hyperactivity. BoNT was administered via intraoral injection to the inferior head of the lateral pterygoid muscle. In total, BoNT injection was administered 102 times (mean 3.2 times/patient). The mean follow-up duration was 29.5 months. The neurogenic group was significantly (p < 0.001) younger (47.3 years) than the habitual group (84.8 years) and required significantly (p < 0.01) more injections (4.1 versus 1.7 times) to achieve a positive outcome. No significant immediate or delayed complications occurred. Thus, intramuscular injection of BoNT into the lateral pterygoid muscle is an effective and safe treatment for habitual temporomandibular joint dislocation. More injections are required in cases of neurogenic temporomandibular joint dislocation than in those of habitual dislocation without muscle hyperactivity.

Multilingual website and cyberconsultations for oromandibular dystonia

Oromandibular dystonia is a focal dystonia that manifests as involuntary masticatory and/or tongue muscle contractions. This movement disorder is frequently misdiagnosed as a temporomandibular disorder. Hence, it would be useful to establish a method that makes it possible for patients with the condition to find appropriate medical institutions by themselves. The author produced a website Involuntary movements of the stomatognathic region (https://sites. google.com/site/oromandibulardystoniaenglish/) for patients with oromandibular dystonia, which is available in twenty languages. It has been viewed more than 1,000,000 times by individuals from all over the world. The visitors to the site have completed questionnaires and/or sent images or videos of their involuntary movements over the internet. Cyberconsultations (remote diagnosis) were also performed via Skype^™. Approximately 1000 patients with involuntary stomatognathic movements visited our department. Only 12.5% of the patients had previously been diagnosed with or were suspected to have dystonia. The findings of this study suggest that the multilingual website has contributed to increasing awareness of oromandibular dystonia and that the provision of basic telemedicine via the internet can aid the diagnosis and treatment of oromandibular dystonia.

Does Botulinum Toxin Injection into Masseter Muscles Affect Subcutaneous Thickness?

BACKGROUND

Botulinum toxin (BoNT) is widely used to treat masseter muscle hypertrophy. Changes in the muscle thickness have been found in many studies, but there has been no report on changes in the thickness from the skin surface to the masseter muscle.

OBJECTIVES

We aimed to use ultrasonography to measure not only changes in the muscle thickness but also changes in subcutaneous thickness.

METHODS

This study enrolled 20 volunteer patients: 10 were assigned to an experimental group (injected with each side 25 U of botulinum toxin into both masseter muscles) and 10 to a control group (injected with normal saline). The thicknesses were measured before the injection and at 4, 8, and 12 weeks after the injection both at rest and during maximum muscle contraction.

RESULTS

The subcutaneous thickness did not differ significantly over time either at rest (P = 0.063) or during maximal contraction (P = 0.392), or between the experimental and control groups at rest (P = 0.392) or during maximum contraction (P = 0.259). The muscle thickness in the experimental group differed significantly over time.

CONCLUSIONS

Botulinum toxin injection only changes the muscle thickness and does not affect the subcutaneous thickness from the skin surface to the masseter muscle.