[Treatment of bruxism with botulinum toxin: think twice!] / Behandeling van bruxisme met botulinetoxine: bezint eer ge begint!

A recent publication in the Nederlands Tijdschrift Voor Tandheelkunde (Dutch Journal of Dentistry) suggests botulinum toxin as a primary treatment for bruxism, especially for severe complaints of teeth grinding or jaw clenching. However, in the opinion of Lobbezoo et al., some outdated views on bruxism are used, and botulinum toxin is incorrectly classified as safe, according to them. In this Vision article, the authors describe the current insights into bruxism; they indicate how the presence of bruxism can be assessed in the clinic; when and how bruxism is treated; and finally, what the role of botulinum toxin is: an ultimum refugium. Therefore, regarding the use of botulinum toxin within the discipline of orofacial pain and dysfunction Lobbezoo et al. recommend: think twice!

Update on Non-Interchangeability of Botulinum Neurotoxin Products.

The growing use of botulinum neurotoxins (BoNTs) for medical and aesthetic purposes has led to the development and marketing of an increasing number of BoNT products. Given that BoNTs are biological medications, their characteristics are heavily influenced by their manufacturing methods, leading to unique products with distinct clinical characteristics. The manufacturing and formulation processes for each BoNT are proprietary, including the potency determination of reference standards and other features of the assays used to measure unit potency. As a result of these differences, units of BoNT products are not interchangeable or convertible using dose ratios. The intrinsic, product-level differences among BoNTs are compounded by differences in the injected tissues, which are innervated by different nerve fiber types (e.g., motor, sensory, and/or autonomic nerves) and require unique dosing and injection sites that are particularly evident when treating complex therapeutic and aesthetic conditions. It is also difficult to compare across studies due to inherent differences in patient populations and trial methods, necessitating attention to study details underlying each outcome reported. Ultimately, each BoNT possesses a unique clinical profile for which unit doses and injection paradigms must be determined individually for each indication. This practice will help minimize unexpected adverse events and maximize efficacy, duration, and patient satisfaction. With this approach, BoNT is poised to continue as a unique tool for achieving individual goals for an increasing number of medical and aesthetic indications.

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.

Botulinum Toxin and Deep Brain Stimulation in Dystonia.

Deep Brain Stimulation (DBS) is a recognized treatment for different dystonia subtypes and has been approved by the Food and Drug Administration (FDA) since 2003. The European Federation of Neurological Societies (EFNS) and the International Parkinson and Movement Disorders Society (MDS) recommend DBS for dystonia after failure of botulinum toxin (BoNT) and other oral medications for dystonia treatment. In addition, several long-term studies have demonstrated the continuous efficacy of DBS on motor and quality of life (QoL) scores. However, there are only a few reports comparing the overall impact of surgical treatment in BoNT protocols (e.g., dosage and number of selected muscles before and after surgery). This retrospective multicenter chart-review study analyzed botulinum toxin total dosage and dosage per muscle in 23 dystonic patients before and after DBS surgery. The study's primary outcome was to analyze whether there was a reduction in BoNT dosage after DBS surgery. The mean BoNT dosages difference between baseline and post-surgery was 293.4 units for 6 months, 292.6 units for 12 months, and 295.2 units at the last visit. The median total dose of BoNT in the preoperative period was 800 units (N = 23). At the last visit, the median was 700 units (p = 0.05). This represents a 12.5% reduction in BoNT median dosage. In conclusion, despite the limitations of this retrospective study, there was a significant reduction in BoNT doses after DBS surgery in patients with generalized dystonia.

Mobile digital gait analysis captures effects of botulinum toxin in hereditary spastic paraplegia.

BACKGROUND AND PURPOSE: Hereditary spastic paraplegias (HSPs) comprise a group of inherited neurodegenerative disorders characterized by progressive spasticity and weakness. Botulinum toxin has been approved for lower limb spasticity following stroke and cerebral palsy, but its effects in HSPs remain underexplored. We aimed to characterize the effects of botulinum toxin on clinical, gait, and patient-reported outcomes in HSP patients and explore the potential of mobile digital gait analysis to monitor treatment effects and predict treatment response. METHODS: We conducted a prospective, observational, multicenter study involving ambulatory HSP patients treated with botulinum toxin tailored to individual goals. Comparing data at baseline, after 1 month, and after 3 months, treatment response was assessed using clinical parameters, goal attainment scaling, and mobile digital gait analysis. Machine learning algorithms were used for predicting individual goal attainment based on baseline parameters. RESULTS: A total of 56 patients were enrolled. Despite the heterogeneity of treatment goals and targeted muscles, botulinum toxin led to a significant improvement in specific clinical parameters and an improvement in specific gait characteristics, peaking at the 1-month and declining by the 3-month follow-up. Significant correlations were identified between gait parameters and clinical scores. With a mean balanced accuracy of 66%, machine learning algorithms identified important denominators to predict treatment response. CONCLUSIONS: Our study provides evidence supporting the beneficial effects of botulinum toxin in HSP when applied according to individual treatment goals. The use of mobile digital gait analysis and machine learning represents a novel approach for monitoring treatment effects and predicting treatment response.

A systematic review of the perspectives of botulinum toxin use on the quality of life of neurological patients with drooling.

OBJECTIVE: To investigate the effectiveness of botulinum toxin in the salivary glands of patients with neurological impairment and drooling and its impact on the quality of life. MATERIALS AND METHODS: This systematic review was registered with the International Prospective Register of Systematic Reviews (CRD 42,023,435,242) and conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. An electronic search was performed in the PubMed/MEDLINE, Embase, Scopus, Cochrane Library, and clinical trial databases until August 2023, no language restriction. Cohort studies and randomized clinical trials of patients diagnosed with drooling and neurological impairment who used botulinum toxin on the salivary gland were included, which evaluated subjective quality of life parameters. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist and Risk of Bias 2 tools. The certainty of the evidence was analyzed using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: Eight studies involving 317 patients were included. All studies, through subjective parameters, suggested the effectiveness of botulinum toxin in reducing drooling, resulting in an improvement in the quality of life. Three studies demonstrated improvements in swallowing and four in cases of respiratory diseases. Two clinical trials had a high risk of bias, whereas one had low risk. The five cohort studies that were evaluated had a high risk of bias. The certainty of the evidence was considered low. CONCLUSIONS: Based on the patient/caregivers' perception of improvement in drooling, dysphagia, and respiratory symptoms, it can be inferred that botulinum toxin application reduces subjective drooling in neurologically compromised patients. Its impact contributes to the general well-being and quality of life. CLINICAL RELEVANCE: Injection of botulinum toxin into the salivary glands can be considered an alternative technique to surgical or medicinal approaches in reducing drooling. It is effective, less invasive and without significant side effects. It promotes a positive impact on the well-being and quality of life of neurological patients.

Botulinum Toxin for Axial Postural Abnormalities in Parkinson's Disease: A Systematic Review.

Axial postural abnormalities (APAs), characterized by their frequency, disabling nature, and resistance to pharmacological treatments, significantly impact Parkinson's disease and atypical Parkinsonism patients. Despite advancements in diagnosing, assessing, and understanding their pathophysiology, managing these complications remains a significant challenge. Often underestimated by healthcare professionals, these disturbances can exacerbate disability. This systematic review assesses botulinum toxin treatments' effectiveness, alone and with rehabilitation, in addressing APAs in Parkinson's disease, utilizing MEDLINE (PubMed), Web of Science, and SCOPUS databases for source material. Of the 1087 records retrieved, 16 met the selection criteria. Most research has focused on botulinum toxin (BoNT) as the primary treatment for camptocormia and Pisa syndrome, utilizing mostly observational methods. Despite dose and injection site variations, a common strategy was using electromyography-guided injections, occasionally enhanced with ultrasound. Patients with Pisa syndrome notably saw consistent improvements in APAs and pain. However, studies on the combined effects of botulinum toxin and rehabilitation are limited, and antecollis is significantly under-researched. These findings recommend precise BoNT injections into hyperactive muscles in well-selected patients by skilled clinicians, avoiding compensatory muscles, and underscore the necessity of early rehabilitation. Rehabilitation is crucial in a multidisciplinary approach to managing APAs, highlighting the importance of a multidisciplinary team of experts.

Systematic review of the utilization of botulinum toxin in Mohs micrographic surgery.

The use of botulinum toxin for off-label indications has become more prevalent, but the specific benefits in Mohs micrographic surgery (MMS) have not yet been fully elucidated. A systematic review was performed of PubMed, Cochrane, EMBASE, and Scopus databases to identify all articles describing the use of botulinum toxin in MMS. Analysis was subdivided into scar minimization, parotid injury, and pain management. A total of nine articles were included. Scar minimization and treatment of parotid injury were the most reported uses. One case reported the use of botulinum toxin for pain management. Off label uses of botulinum toxin are being explored. Additional research is warranted to determine the efficacy and utility of botulinum toxin in MMS.

[Botulinum toxin in male lower urinary tract symptoms (LUTS): What can we expect?] / Botulinumtoxin bei Symptomen des unteren Harntraktes beim Mann ("male LUTS"): Was darf man erwarten?

During the last two decades botulinum toxin has also conquered urology. Botulinum toxin reduces the contractility and sensitivity of the detrusor muscle and relieves pain. It is therefore a promising drug whose use in men also appears promising. The following article highlights the practical relevance of botulinum toxin for male lower urinary tract symptoms (LUTS). But first of all, a distinction must be made between use in male LUTS due to benign prostate syndrome (BPS) and use in cases of overactive bladder (OAB) alone. A differentiated diagnosis and treatment of male LUTS is therefore essential.

A systematic review of procedural modalities in the treatment of notalgia paresthetica.

BACKGROUND: Notalgia paresthetica (NP) is a rare condition characterized by localized pain and pruritus of the upper back, associated with a distinct area of hyperpigmentation. Given the lack of standardized treatment and the uncertain efficacy of available options, applying procedural methods is of growing interest in treating NP. AIMS: We sought to comprehensively evaluate the role of procedural treatments for NP. METHODS: We systematically searched PubMed/Medline, Ovid Embase, and Web of Science until November 14th, 2023. We also performed a citation search to detect all relevant studies. Original clinical studies published in the English language were included. RESULTS: Out of 243 articles, sixteen studies have reported various procedural modalities, with or without pharmacological components, in treating NP. Pharmacological procedures, including injections of botulinum toxin, lidocaine, and corticosteroids, led to a level of improvement in case reports and case series. However, botulinum toxin did not show acceptable results in a clinical trial. Moreover, non-pharmacological procedures were as follows: physical therapy, exercise therapy, kinesiotherapy, acupuncture and dry needling, electrical muscle stimulation, surgical decompression, and phototherapy. These treatments result in significant symptom control in refractory cases. Physical therapy can be considered a first-line choice or an alternative in refractory cases. CONCLUSION: Procedural modalities are critical in the multidisciplinary approach to NP, especially for patients who are refractory to topical and oral treatments. Procedural modalities include a spectrum of options that can be applied based on the disease's symptoms and severity.

Nonpharmacologic Treatment of Chronic Constipation.

Functional constipation is a common clinical diagnosis that affects approximately 14% of the world's population. Non-pharmacological therapies often represent the initial steps in management and may include lifestyle adjustments or changes such as physical activity and diet. Pharmacological options have been used when the non-pharmacological approach has been ineffective. Biofeedback therapy, surgery, sacral nerve stimulation, botulinum toxin injection, and vibrating capsules can be considered in scenarios where the laxatives are ineffective. Biofeedback therapy is highly effective and safe in treating dyssynergic defecation, which affects more than half of patients with chronic constipation. This paper overviews non-pharmacological therapies for functional constipation.

Transition of endochondral bone formation at the normal and botulinum-treated mandibular condyle of growing juvenile rat.

OBJECTIVE: The aim of this study was to understand the temporal and spatial distribution of canonical endochondral ossification (CEO) and non-canonical endochondral ossification (NCEO) of the normal growing rat condyle, and to evaluate their histomorphological changes following the simultaneous hypotrophy of the unilateral masticatory closing muscles with botulinum toxin (BTX). DESIGN: 46 rats at postnatal 4 weeks were used for the experiment and euthanized at postnatal 4, 8, and 16 weeks. The right masticatory muscles of rats in experimental group were injected with BTX, the left being injected with saline as a control. The samples were evaluated using 3D morphometric, histological, and immunohistochemical analysis with three-dimensional regional mapping of endochondral ossifications. RESULTS: The results showed that condylar endochondral ossification changed from CEO to NCEO at the main articulating surface during the experimental period and that the BTX-treated condyle presented a retroclined smaller condyle with an anteriorly-shifted narrower articulating surface. This articulating region showed a thinner layer of the endochondral cells, and a compact distribution of flattened cells. These were related to the load concentration, decreased cellular proliferation with thin cellular layers, reduced extracellular matrix, increased cellular differentiation toward the osteoblastic bone formation, and accelerated transition of the ossification types from CEO to NCEO. CONCLUSION: The results suggest that endochondral ossification under loading tended to show more NCEO, and that masticatory muscular hypofunction by BTX had deleterious effects on endochondral bone formation and changed the condylar growth vector, resulting in a retroclined, smaller, asymmetrical, and deformed condyle with thin cartilage.

Combined rehabilitation therapy with botulinum toxin to the upper limbs for acute spinal cord injury: A case report.

INTRODUCTION: Patients with spinal cord injury (SCI) and incomplete paralysis may experience muscle immobilization due to functional impairment of agonist and antagonist muscles. This can induce spasticity and pain, with the risk of contracture increasing as the period of immobilization increases. This could be aggravated by pain, which interferes with rehabilitation. There is no established treatment for pain and joint contractures caused by acute SCI. Botulinum therapy plays a role in relieving muscle tension. Here, we report a case of acute SCI in which botulinum therapy was administered. CASE PRESENTATION: The patient experienced a C5-cervical SCI due to a road traffic accident, with marked paralysis in the upper and lower limbs below the C5 level. The patient had persistent elbow flexion since the SCI and complained of excruciating pain, making adequate rehabilitation difficult. Botulinum toxin was administered to the biceps and brachialis muscles 15 days after the SCI. After administration, the patient experienced a reduction in pain with relaxation of the elbow flexor muscles, and rehabilitation treatment was resumed. This patient's contracture did not worsen, his pain decreased, and he was able to initiate self-feeding training. DISCUSSION: In this case, occupational and physical therapy was administered with botulinum therapy. Together, they successfully reduced pain. Botulinum therapy provides analgesia and muscle relaxation and may lead to functional recovery, and we believe that treatment can be considered even in the acute phase.

Therapeutic Uses and Efficacy of Botulinum Toxin in Orofacial Medicine: A Dental Perspective.

Botulinum neurotoxin (BoNT) is the exotoxin of Clostridium botulinum, a Gram-positive, spore-forming bacterium [...].

Mindfulness in Facilitating Pelvic Floor Botulinum Toxin Injection in Women with Chronic Pelvic Pain.

Botulinum toxin (BoNT) injection can safely be done as an office-based procedure, but can be painful itself, especially when injecting pelvic floor muscles to treat chronic pelvic pain (CPP). Mindfulness interventions may reduce procedure-associated acute anxiety and pain. We applied mindfulness techniques to increase the tolerability of office-based pelvic floor BoNT injections in women with CPP. Women enrolled in a clinical trial of BoNT for endometriosis-associated CPP were offered a brief, guided mindfulness session before and/or after transvaginal injection. Anxiety, pain, and dysphoria were rated on a 0-10 numerical rating scale (NRS) before and after each mindfulness session. Eight women underwent mindfulness sessions. Five participants had a session before and two after the transvaginal injection. One participant had two sessions: one before and one after separate injections. All six women completing a session prior to injection had at least moderate anxiety, which lessened after the mindfulness session (median NRS change: -3.3/10). All three women reporting injection-associated pain experienced less intense pain following the post-injection session (median NRS change: -3/10). Three women experiencing dysphoria improved after the session (median NRS change: -3/10). A brief, guided mindfulness session may lessen acute pain, anxiety, and dysphoria associated with office-based transvaginal BoNT injection.

Intramuscular Botulinum Neurotoxin Serotypes E and A Elicit Distinct Effects on SNAP25 Protein Fragments, Muscular Histology, Spread and Neuronal Transport: An Integrated Histology-Based Study in the Rat.

Botulinum neurotoxins E (BoNT/E) and A (BoNT/A) act by cleaving Synaptosome-Associated Protein 25 (SNAP25) at two different C-terminal sites, but they display very distinct durations of action, BoNT/E being short acting and BoNT/A long acting. We investigated the duration of action, spread and neuronal transport of BoNT/E (6.5 ng/kg) and BoNT/A (125 pg/kg) after single intramuscular administrations of high equivalent efficacious doses, in rats, over a 30- or 75-day periods, respectively. To achieve this, we used (i) digit abduction score assay, (ii) immunohistochemistry for SNAP25 (N-ter part; SNAP25N-ter and C-ter part; SNAP25C-ter) and its cleavage sites (cleaved SNAP25; c-SNAP25E and c-SNAP25A) and (iii) muscular changes in histopathology evaluation. Combined in vivo observation and immunohistochemistry analysis revealed that, compared to BoNT/A, BoNT/E induces minimal muscular changes, possesses a lower duration of action, a reduced ability to spread and a decreased capacity to be transported to the lumbar spinal cord. Interestingly, SNAP25C-ter completely disappeared for both toxins during the peak of efficacy, suggesting that the persistence of toxin effects is driven by the persistence of proteases in tissues. These data unveil some new molecular mechanisms of action of the short-acting BoNT/E and long-acting BoNT/A, and reinforce their overall safety profiles.

Pangenome analyses of Clostridium butyricum provide insights into its genetic characteristics and industrial application.

Clostridium butyricum is a Gram-positive anaerobic bacterium known for its ability to produce butyate. In this study, we conducted whole-genome sequencing and assembly of 14C. butyricum industrial strains collected from various parts of China. We performed a pan-genome comparative analysis of the 14 assembled strains and 139 strains downloaded from NCBI. We found that the genes related to critical industrial production pathways were primarily present in the core and soft-core gene categories. The phylogenetic analysis revealed that strains from the same clade of the phylogenetic tree possessed similar antibiotic resistance and virulence factors, with most of these genes present in the shell and cloud gene categories. Finally, we predicted the genes producing bacteriocins and botulinum toxins as well as CRISPR systems responsible for host defense. In conclusion, our research provides a desirable pan-genome database for the industrial production, food application, and genetic research of C. butyricum.

Neurobiological mechanisms of botulinum neurotoxin-induced analgesia for neuropathic pain.

Botulinum neurotoxins (BoNTs) are a family of neurotoxins produced by Clostridia and other bacteria that induce botulism. BoNTs are internalized into nerve terminals at the site of injection and cleave soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins to inhibit the vesicular release of neurotransmitters. BoNTs have been approved for multiple therapeutic applications, including the treatment of migraines. They have also shown efficacies for treating neuropathic pain, such as diabetic neuropathy, and postherpetic and trigeminal neuralgia. However, the mechanisms underlying BoNT-induced analgesia are not well understood. Peripherally administered BoNT is taken up by the nerve terminals and reduces the release of glutamate, calcitonin gene-related peptide, and substance P, which decreases neurogenic inflammation in the periphery. BoNT is retrogradely transported to sensory ganglia and central terminals in a microtubule-dependent manner. BoNTs decrease the expression of pronociceptive genes (ion channels or cytokines) from sensory ganglia and the release of neurotransmitters and neuropeptides from primary afferent central terminals, which likely leads to decreased central sensitization in the dorsal horn of the spinal cord or trigeminal nucleus. BoNT-induced analgesia is abolished after capsaicin-induced denervation of transient receptor potential vanilloid 1 (TRPV1)-expressing afferents or the knockout of substance P or the neurokinin-1 receptor. Although peripheral administration of BoNT leads to changes in the central nervous system (e.g., decreased phosphorylation of glutamate receptors in second-order neurons, reduced activation of microglia, contralateral localization, and cortical reorganization), whether such changes are secondary to changes in primary afferents or directly mediated by trans-synaptic, transcytotic, or the hematogenous transport of BoNT is controversial. To enhance their therapeutic potential, BoNTs engineered for specific targeting of nociceptive pathways have been developed to treat chronic pain. Further mechanistic studies on BoNT-induced analgesia can enhance the application of native or engineered BoNTs for neuropathic pain treatment with improved safety and efficacy.

Intramuscular nerve distribution of the sternocleidomastoid muscle for the botulinum toxin injection.

PURPOSE: The aim of this study is to define the intramuscular nerve distribution of the sternocleidomastoid muscle (SCM) and the innervation zones (IZ) to describe the optimal botulinum toxin injection sites. METHODS: The cricoid cartilage (CC), laryngeal prominence (LP) and hyoid bone (HB) and angle of mandible (AM) were determined as landmarks. The length of the muscles were measured between the sternoclavicular joint and tip of the mastoid process. SCM was evaluated in two parts as anterior and posterior divided by the line where the length of the muscle was measured. Measurements were made to define the relationships of the SCM with common carotid artery, internal and external jugular veins. IZ were described according to these vessels. Afterwards, Modified Sihler's staining technique was applied to expose the intramuscular nerve distribution. RESULTS: The average length of SCM was 160,1 mm. Motor entry point of the accessory nerve fibers were between the AM-HB lines, in the range of 30-40% of the muscle length, and in the posterior part of the muscles. IZ were between the HB-CC lines in the anterior and posterior part. When this interval was examined according to the vessels, the optimal injection sites were between the LP-CC lines. CONCLUSIONS: This study shows the position of the intramuscular nerve fibers endings of the SCM according to the chosen landmarks and the relationship of the IZ with the vessels to prevent complications. These results can be used as a guide for safe and effective botulinum toxin injections with optimal quantities.