RhoG facilitates a conformational transition in the guanine nucleotide exchange factor complex DOCK5/ELMO1 to an open state.

The dedicator of cytokinesis (DOCK)/engulfment and cell motility (ELMO) complex serves as a guanine nucleotide exchange factor (GEF) for the GTPase Rac. RhoG, another GTPase, activates the ELMO-DOCK-Rac pathway during engulfment and migration. Recent cryo-EM structures of the DOCK2/ELMO1 and DOCK2/ELMO1/Rac1 complexes have identified closed and open conformations that are key to understanding the autoinhibition mechanism. Nevertheless, the structural details of RhoG-mediated activation of the DOCK/ELMO complex remain elusive. Herein, we present cryo-EM structures of DOCK5/ELMO1 alone and in complex with RhoG and Rac1. The DOCK5/ELMO1 structure exhibits a closed conformation similar to that of DOCK2/ELMO1, suggesting a shared regulatory mechanism of the autoinhibitory state across DOCK-A/B subfamilies (DOCK1-5). Conversely, the RhoG/DOCK5/ELMO1/Rac1 complex adopts an open conformation that differs from that of the DOCK2/ELMO1/Rac1 complex, with RhoG binding to both ELMO1 and DOCK5. The alignment of the DOCK5 phosphatidylinositol (3,4,5)-trisphosphate binding site with the RhoG C-terminal lipidation site suggests simultaneous binding of RhoG and DOCK5/ELMO1 to the plasma membrane. Structural comparison of the apo and RhoG-bound states revealed that RhoG facilitates a closed-to-open state conformational change of DOCK5/ELMO1. Biochemical and surface plasmon resonance (SPR) assays confirm that RhoG enhances the Rac GEF activity of DOCK5/ELMO1 and increases its binding affinity for Rac1. Further analysis of structural variability underscored the conformational flexibility of the DOCK5/ELMO1/Rac1 complex core, potentially facilitating the proximity of the DOCK5 GEF domain to the plasma membrane. These findings elucidate the structural mechanism underlying the RhoG-induced allosteric activation and membrane binding of the DOCK/ELMO complex.

Botulinum toxin type a blocks aquaporin 5 trafficking by decreasing synaptosomal-associated protein 23 in submandibular acinar cells.

The trafficking of aquaporin 5 (AQP5) is critical for salivary secretion. Synaptosomal-associated protein 23 (SNAP23) is an important regulator in the process of membrane fusion. However, the role of SNAP23 on AQP5 trafficking has not been explored. Botulinum toxin type A (BoNT/A) is a bacterial toxin that effectively treats sialorrhea. We previously reported that BoNT/A induced AQP5 redistribution in cultured acinar cells, but the mechanism remained unclear. In this study, SNAP23 was predominantly localized to the plasma membrane of acinar cells in the rat submandibular gland (SMG) and colocalized with AQP5 at the apical membrane of acinar cells. In stable GFP-AQP5-transfected SMG-C6 cells, the acetylcholine receptor agonist carbachol (CCh) induced trafficking of AQP5 from intracellular vesicles to the apical membrane. Furthermore, SNAP23 knockdown by siRNA significantly inhibited CCh-induced AQP5 trafficking, whereas this inhibitory effect was reversed by SNAP23 re-expression, indicating that SNAP23 was essential in AQP5 trafficking. More importantly, BoNT/A inhibited salivary secretion from SMGs, and the underlying mechanism involved that BoNT/A blocked CCh-triggered AQP5 trafficking by decreasing SNAP23 in acinar cells. Taken together, these results identified a crucial role for SNAP23 in AQP5 trafficking and provided new insights into the mechanism of BoNT/A in treating sialorrhea and thereby a theoretical basis for clinical applications.

Palmitoylation-dependent regulation of cardiomyocyte Rac1 signaling activity and minor effects on cardiac hypertrophy.

S-palmitoylation is a reversible lipid modification catalyzed by 23 S-acyltransferases with a conserved zinc finger aspartate-histidine-histidine-cysteine (zDHHC) domain that facilitates targeting of proteins to specific intracellular membranes. Here we performed a gain-of-function screen in the mouse and identified the Golgi-localized enzymes zDHHC3 and zDHHC7 as regulators of cardiac hypertrophy. Cardiomyocyte-specific transgenic mice overexpressing zDHHC3 show cardiac disease, and S-acyl proteomics identified the small GTPase Rac1 as a novel substrate of zDHHC3. Notably, cardiomyopathy and congestive heart failure in zDHHC3 transgenic mice is preceded by enhanced Rac1 S-palmitoylation, membrane localization, activity, downstream hypertrophic signaling, and concomitant induction of all Rho family small GTPases whereas mice overexpressing an enzymatically dead zDHHC3 mutant show no discernible effect. However, loss of Rac1 or other identified zDHHC3 targets Gαq/11 or galectin-1 does not diminish zDHHC3-induced cardiomyopathy, suggesting multiple effectors and pathways promoting decompensation with sustained zDHHC3 activity. Genetic deletion of Zdhhc3 in combination with Zdhhc7 reduces cardiac hypertrophy during the early response to pressure overload stimulation but not over longer time periods. Indeed, cardiac hypertrophy in response to 2 weeks of angiotensin-II infusion is not diminished by Zdhhc3/7 deletion, again suggesting other S-acyltransferases or signaling mechanisms compensate to promote hypertrophic signaling. Taken together, these data indicate that the activity of zDHHC3 and zDHHC7 at the cardiomyocyte Golgi promote Rac1 signaling and maladaptive cardiac remodeling, but redundant signaling effectors compensate to maintain cardiac hypertrophy with sustained pathological stimulation in the absence of zDHHC3/7.

GTPase splice variants RAC1 and RAC1B display isoform-specific differences in localization, prenylation, and interaction with the chaperone protein SmgGDS.

Identifying events that regulate the prenylation and localization of small GTPases will help define new strategies for therapeutic targeting of these proteins in disorders such as cancer, cardiovascular disease, and neurological deficits. Splice variants of the chaperone protein SmgGDS (encoded by RAP1GDS1) are known to regulate prenylation and trafficking of small GTPases. The SmgGDS-607 splice variant regulates prenylation by binding preprenylated small GTPases but the effects of SmgGDS binding to the small GTPase RAC1 versus the splice variant RAC1B are not well defined. Here we report unexpected differences in the prenylation and localization of RAC1 and RAC1B and their binding to SmgGDS. Compared to RAC1, RAC1B more stably associates with SmgGDS-607, is less prenylated, and accumulates more in the nucleus. We show that the small GTPase DIRAS1 inhibits binding of RAC1 and RAC1B to SmgGDS and reduces their prenylation. These results suggest that prenylation of RAC1 and RAC1B is facilitated by binding to SmgGDS-607 but the greater retention of RAC1B by SmgGDS-607 slows RAC1B prenylation. We show that inhibiting RAC1 prenylation by mutating the CAAX motif promotes RAC1 nuclear accumulation, suggesting that differences in prenylation contribute to the different nuclear localization of RAC1 versus RAC1B. Finally, we demonstrate RAC1 and RAC1B that cannot be prenylated bind GTP in cells, indicating that prenylation is not a prerequisite for activation. We report differential expression of RAC1 and RAC1B transcripts in tissues, consistent with these two splice variants having unique functions that might arise in part from their differences in prenylation and localization.

Comparative Efficacy and Side Effect Profiles of Interventions for Pediatric Saliva Control: A Cohort Study.

OBJECTIVE: To compare efficacy and side effect profile data on conservative, behavioral, pharmacological, and surgical treatments used for pediatric saliva control. STUDY DESIGN: A cohort study of children (n = 483) referred to a specialty Saliva Control service between May 2014 and November 2019 was performed, using quantitative data from pretreatment and post-treatment questionnaires (the Drooling Impact Scale [DIS], Drooling Rating Scale [DRS]) and recording of side effects. Overall, 483 children were included; treatment choices were based on published international guidelines. RESULTS: The greatest improvement was seen after intraglandular botulinum toxin A (BTX-A) injections (n = 207; 551 courses; mean DIS change, 34.7; 95% CI = 29.2-35.7) or duct transpositional surgery (n = 31; mean change in DIS, 29.0; 95% CI, 22.3-35.7). Oral anticholinergics were associated with good outcomes, with no significant statistical difference between glycopyrronium bromide (n = 150; mean DIS change, 21.5; 95% CI, 19.1-24.0) or trihexyphenidyl (n = 87; mean DIS change, 22.4; 95% CI, 18.9-25.8). Inhaled ipratropium bromide was not as efficacious (n = 80; mean DIS change, 11.1; 95% CI, 8.9-13.3). Oromotor programs were used in a selected group with reliable outcomes (n = 9; mean DIS change, 13.0). Side effects were consistent with previous studies. Overall, in cases of milder severity, enterally administered therapies provided a good first-line option. With more severe problems, BTX-A injections or saliva duct transpositional surgery were more effective and well tolerated. CONCLUSIONS: We describe a large, single-center pediatric saliva control cohort, providing direct comparison of the efficacy and side effect profiles for all available interventions and inform clinical practice for specialists when considering different options. BTX-A injections or saliva duct transpositional surgery seem to be more effective for saliva control that is more severe.

The 3D muscle morphology and intramuscular innervation of the digital bellies of flexor digitorum profundus: Clinical implications for botulinum toxin injection sites.

Spasticity of flexor digitorum profundus is frequently managed with botulinum toxin injections. Knowledge of the 3D morphology and intramuscular innervation of the digital bellies of flexor digitorum profundus is necessary to optimize the injections. The purpose of this study was to digitize and model in 3D the contractile and connective tissue elements of flexor digitorum profundus to determine muscle morphology, model and map the intramuscular innervation and propose sites for botulinum toxin injection. Fiber bundles (FBs)/aponeuroses and intramuscular nerve branches were dissected and digitized in 12 formalin embalmed cadaveric specimens. Cartesian coordinate data were reconstructed into 3D models as in situ to visualize and compare the muscle morphology and intramuscular innervation patterns of the bellies of flexor digitorum profundus. The 3rd, 4th and 5th digital bellies were superficial to the 2nd digital belly and located adjacent to each other in all specimens. Each digital belly had distinct intramuscular innervation patterns. The 2nd digital belly received intramuscular branches from the anterior interosseus nerve (AIN). The superior half of the 3rd digital belly was innervated intramuscularly by the ulnar nerve (n = 4) or by both the anterior interosseus and ulnar nerves (n = 1). The inferior half of the belly received dual innervation from the anterior interosseus and ulnar nerves in 2 specimens, or exclusively from the AIN (n = 2) or the ulnar nerve (n = 1). The 4th digital belly was innervated by intramuscular branches of the ulnar nerve. One main branch, after coursing through the 4th digital belly, entered the lateral aspect of the 5th digital belly and arborized intramuscularly. The morphology of the FBs, aponeuroses and intramuscular innervation of the digital bellies of FDP were mapped and modelled volumetrically in 3D as in situ. Previous studies were not volumetric nor identified the course of the intramuscular nerve branches within each digital belly. Based on the intramuscular innervation of each of the digital bellies, one possible optimized botulinum toxin injection location was proposed. This injection location, at the junction of the superior and middle thirds of the forearm, would be located in dense nerve terminal zones of the anterior interosseus and ulnar nerves. Future anatomical and clinical investigations are necessary to evaluate the efficacy of these anatomical findings in the management of spasticity.

Subclinical effects of botulinum toxin A and microwave thermolysis for axillary hyperhidrosis: A descriptive study with line-field confocal optical coherence tomography and histology.

Botulinum toxin A (BTX) and microwave thermolysis (MWT) are standard axillary hyperhidrosis treatments, but comparison of their subclinical effects is lacking. Line-field confocal optical coherence tomography (LC-OCT) is a promising non-invasive imaging tool for visualizing tissue-interactions. This study aimed to describe subclinical effects of BTX and MWT for axillary hyperhidrosis with LC-OCT-imaging compared to histology. This study derived from an intra-individual, randomized, controlled trial, treating axillary hyperhidrosis with BTX versus MWT. Subclinical effects based on LC-OCT images from baseline and 6-month follow-up (n = 8 patients) were evaluated and compared to corresponding histological samples. At baseline, LC-OCT visualized eccrine pores at the skin surface and ducts in the upper dermis (500 µm), but not deeper-lying sweat glands. Histology identified entire sweat glands. Six months post-treatment, LC-OCT revealed no detectable morphology changes in any BTX-treated axillae (100%), while recognizing obstructed eccrine pores and atrophy of eccrine ducts in most MWT-treated axillae (75%). Histology corroborated LC-OCT findings, while also showing substantial changes to entire sweat glands. LC-OCT enabled visualization of subclinical alterations of superficial eccrine ducts after MWT and unchanged morphology after BTX. LC-OCT is a promising tool for non-invasive assessment of treatment-specific tissue-interactions that can be complementary to histology.

Botulinum toxin injections for the treatment of neurogenic thoracic outlet syndrome: A systematic review.

Botulinum toxin (BTX) injections into the musculature surrounding the brachial plexus have been examined as a potential treatment for neurogenic thoracic outlet syndrome (nTOS). This systematic review identified 15 publications, of which one was a randomized controlled trial. BTX injections performed with ultrasound or electromyographic guidance, and with the inclusion of the pectoralis minor muscle, in addition to the anterior and/or middle scalenes, tended to provide greater symptom improvement and may predict response to first rib resection. Importantly, most studies were of low quality; thus, the results should be interpreted with caution. Further high-quality studies are needed to confirm these findings.

Botulinum toxin treatment for hemifacial spasm: harmonising neurological and aesthetic outcomes.

Hemifacial spasm (HFS) represents a challenging cranial movement disorder primarily affecting the facial nerve innervated muscles, with significant prevalence among Asians. Botulinum toxin type A (BoNT/A) injections, established as a primary therapeutic intervention since FDA approval, offer considerable effectiveness in alleviating spasms, albeit accompanied by challenges such as temporary effects and potential adverse events including facial asymmetry. This comprehensive review underscores the crucial need for harmonising neurological benefits and aesthetic outcomes in HFS management. The discussion delves into the interplay between facial aesthetics and neurological objectives in BoNT/A injections, emphasising precise techniques, dosages, and site considerations. Distinct aspects in neurological and aesthetic domains are also examined, including detailing the targeted muscles and injection methodologies for optimal therapeutic and aesthetic results. Importantly, evidence regarding various BoNT/A formulations, recommendations, and reconstitution guidelines in both neurology and aesthetics contexts are provided, along with a schematic approach outlining the stepwise process for BoNT/A injection in HFS treatment, addressing critical areas such as orbicularis oculi muscle sites, eyebrow correction strategies, mid- and lower-face considerations, contralateral injection sites, and post-injection follow-up and complication management. By highlighting the culmination of neurological efficacy and facial esthetics in BoNT/A treatment for HFS patients, this review proposes a holistic paradigm to achieve balanced symptomatic relief and natural aesthetic expression, ultimately enhancing quality of life for individuals grappling with HFS.

Does botulinum toxin affect psycho-social aspects in dystonia?

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

Open label experience of repeated OnabotulinumtoxinA injections towards the sphenopalatine ganglion in patients with chronic cluster headache and chronic migraine.

BACKGROUND: A novel technique for injection of OnabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) has shown promise in refractory chronic migraine (CM) and chronic cluster headache (CCH). Open label safety and efficacy data are presented here. METHODS: Patients with refractory CM or CCH who had received at least one injection and completed headache diaries were included. Efficacy was defined as ≥50% reduction in moderate-to-severe headache days for CM, or ≥50% reduction in attack frequency for CCH, at weeks five to eight. RESULTS: Over 261 injections, there were 123 adverse events (AE), of which one was serious. Most (93%) AEs were mild and all were transient. The 50% response to one injection was 81% for CM and 69% for CCH. The response gradually reduced over subsequent months for CM but stayed between 55% and 67% for CCH. Repeated injections were beneficial. CONCLUSIONS: Injections resulted in improvement for both groups and was maintained with repeated injections. Repeat injection after three months may be beneficial in CM. Adverse events were not uncommon, but universally transient, presumably as a result of the mechanism of action of BTA. Repeated BTA injection towards the SPG could be an effective treatment for refractory CM and CCH. Larger, randomised, placebo-controlled trials are required.

Comparative retention and effectiveness of migraine preventive treatments: A nationwide registry-based cohort study.

BACKGROUND AND PURPOSE: Little is known about the comparative effects of migraine preventive drugs. We aimed to estimate treatment retention and effectiveness of migraine preventive drugs in a nationwide registry-based cohort study in Norway between 2010 and 2020. METHODS: We assessed retention, defined as the number of uninterrupted treatment days, and effectiveness, defined as the reduction in filled triptan prescriptions during four 90-day periods after the first preventive prescription, compared to a 90-day baseline period. We compared retention and efficacy for different drugs against beta blockers. Comparative retention was estimated with hazard ratios (HRs), adjusted for covariates, using Cox regression, and effectiveness as odds ratios (ORs) using logistic regression, with propensity-weighted adjustment for covariates. RESULTS: We identified 104,072 migraine patients, 81,890 of whom were female (78.69%) and whose mean (standard deviation) age was 44.60 (15.61) years. Compared to beta blockers, botulinum toxin (HR 0.43, 95% confidence interval [CI] 0.42-0.44) and calcitonin gene-related peptide pathway antibodies (CGRPabs; HR 0.63, 95% CI 0.59-0.66) were the least likely to be discontinued, while clonidine (HR 2.95, 95% CI 2.88-3.02) and topiramate (HR 1.34, 95% CI 1.31-1.37) were the most likely to be discontinued. Patients on simvastatin, CGRPabs, and amitriptyline were more likely to achieve a clinically significant reduction in triptan use during the first 90 days of treatment, with propensity score-adjusted ORs of 1.28 (95% CI 1.19-1.38), 1.23 (95% CI 0.79-1.90), and 1.13 (95% CI 1.08-1.17), respectively. CONCLUSIONS: We found a favorable effect of CGRPabs, amitriptyline, and simvastatin compared with beta blockers, while topiramate and clonidine were associated with poorer outcomes.

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.

Is chemodenervation with incobotulinumtoxinA an alternative to invasive chronic anal fissure treatments?

BACKGROUND: Botulinum toxin type A is currently strongly recommended for the treatment of anal fissures (AFs). However, there is still no consensus on dosage or injection technique. This study provides further efficacy and safety evidence in a 2-year follow-up. METHOD: Prospective, open-label, single-arm, single-center study carried out in adult patients with AFs non-responsive to previous treatments. Patients were treated with incobotulinumtoxinA (incoBoNT/A) injected in both laterals and posterior intersphincteric groove. Healing rate at 2 years was the primary endpoint. Secondary endpoints included internal anal sphincter pressures, incontinence, and safety. RESULTS: A total of 49 patients were treated with a mean incoBoNT/A dose of 40.5 U (spread across three locations). Healing rate at 2 years was 83.9% with a 24.5% of recurrence throughout the study. Only 7 patients (14.3%) reported adverse events (AEs) that were mild and temporary. Mean reduction in anal resting pressure was -9.1 mmHg at 3 months (p = 0.001). Mean reduction in voluntary squeeze pressure was -27.5 mmHg at 3 months (p < 0.001). Mean pain perception measured with a visual analog scale decreased by -6.5 points at 2 years (p < 0.001). There was an incontinence increase at 1 month of 1.3 points (p = 0.006), but baseline values were restored at 6 months. CONCLUSION: We present results that support the use of incoBoNT/A as a second line for AFs that do not respond to ointment therapy. IncoBoNT/A injection is a less invasive treatment that should be considered before surgery due to its efficacy and its safety which includes no permanent impairment. TRIAL REGISTRATION: ISRCTN90354265; Registered on 16th February 2024. Retrospectively registered.

The safety and efficacy of onabotulinumtoxinA injections for children and adolescents with chronic migraine: A systematic review and meta-analysis.

OBJECTIVE: To qualitatively and quantitatively summarize the evidence for the use of onabotulinumtoxinA injections in children and adolescents with migraine. BACKGROUND: There are limited evidence-based treatment options for youth with migraine, especially youth with chronic migraine (CM). OnabotulinumtoxinA injections are an established evidence-based treatment for adults with CM. While several studies have assessed their safety and efficacy among adolescents with CM, there are no published systematic reviews summarizing the pediatric evidence. METHODS: We carried out a systematic review, reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis, aiming to identify studies that included five or more children and adolescents aged ≤18 years with a diagnosis of migraine, who were treated with ≥50 units (U) of onabotulinumtoxinA and had outcomes assessed ≥4 weeks after one or more injection cycle. Both observational studies and randomized controlled trials (RCTs) were eligible for inclusion. Two investigators independently carried out the first (titles and abstracts) and second (full text) screening stages, as well as data extraction and quality appraisal. The American Academy of Neurology risk of bias grading scheme was used to assess study risk of bias. Studies with adequate data were pooled using random effects meta-analyses, and Hedge's g standardized mean differences with 95% confidence intervals (CIs) were generated to estimate the effect sizes of the continuous outcomes included. Studies lacking data required for meta-analysis were summarized qualitatively. RESULTS: We screened 634 studies and included 14 studies comprising 491 participants, of whom 489 had CM. Two studies were RCTs, 12 were observational uncontrolled studies, and all but one study included only youth with CM. Five Class IV observational uncontrolled studies were amenable to pooling in meta-analyses. After a mean of 2-2.6 injection cycles, headache frequency was shown to decrease significantly after treatment with onabotulinumtoxinA (Hedge's g = 0.97, 95% CI 0.58-1.35; p < 0.0001), as did severity (Hedge's g = 1.24, 95% CI 0.55-1.94; p = 0.0005), with both estimates having a large effect size magnitude. A Class I parallel-group RCT of one injection series (155 U, 74 U, or placebo), powered to detect a change in 4 headache days per month, did not find outcome differences between the active and placebo treatment arms. A Class IV crossover RCT showed superiority of active (155 U) versus placebo injections. The remaining Class IV observational studies that were excluded from the meta-analyses all showed improved outcomes with onabotulinumtoxinA injections over time. No serious adverse events related to treatment occurred. CONCLUSION: OnabotulinumtoxinA injections have established safety for use in children and adolescents with CM and are likely effective in reducing headache frequency and severity over time. However, in the absence of an adequately powered parallel-group RCT assessing the efficacy of multiple injection cycles, it remains unclear if this intervention is superior to placebo.

Sustained benefits of onabotulinumtoxinA treatment in chronic migraine: An analysis of the pooled Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) randomized controlled trials.

OBJECTIVE: To characterize the long-term (56-week) benefits of continuous onabotulinumtoxinA treatment response in individuals with chronic migraine (CM) who achieved reduction to <15 headache days/month with treatment. BACKGROUND: There are limited data exploring reductions in monthly headache days to levels consistent with episodic migraine among those experiencing CM. Understanding the impact of sustained preventive treatment response in CM can provide important information about the impact of successful therapy. METHODS: The two Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy trials of onabotulinumtoxinA in adults included a 24-week, randomized, double-blind, placebo-controlled phase and a 32-week open-label phase. Data were pooled to determine proportions of individuals with <15 headache days/month while on treatment during several time periods in the double-blind phase (Weeks 21-24; any 12 consecutive weeks; Weeks 13-24) and the entire study (Weeks 53-56; any 12 consecutive weeks; any 4-week period). We assessed the long-term impact on mean monthly headache days and changes from baseline on the six-item Headache Impact Test (HIT-6) and Migraine-Specific Quality of Life questionnaire version 2.1 (MSQv2.1). RESULTS: We analyzed 1384 participants with chronic migraine (double-blind: onabotulinumtoxinA, n = 688; placebo, n = 696; open-label: n = 688 [onabotulinumtoxinA]). The discontinuation rates prior to the completion of the full 56-week treatment period for onabotulinumtoxinA and placebo were 25.4% (n = 175) and 29.3% (n = 204), respectively. During Weeks 13-24 of the double-blind phase, significantly more onabotulinumtoxinA-treated (386/688 [56.1%]) than placebo-treated (342/696 [49.1%]) individuals had <15 headache days/month (p = 0.010), with fewer monthly headache days for onabotulinumtoxinA versus placebo responders. The proportions of participants achieving <15 monthly headache days with onabotulinumtoxinA were 60.9% (419/688) at Weeks 25-56, 81.1% (558/688) at Weeks 53-56, and 79.4% (546/688) during any consecutive 12-week period. Mean changes from baseline on the HIT-6 and MSQv2.1 questionnaire surpassed within-group minimal important difference thresholds in all periods. At Week 24, onabotulinumtoxinA-treated participants who achieved <15 monthly headache days during Weeks 21-24 had a greater mean HIT-6 score reduction (-6.5 vs. -1.4) and greater mean MSQv2.1 Role-Function Restrictive score improvements (21.3 vs. 6.4) than those who did not achieve <15 monthly headache days during the same period. CONCLUSIONS: Participants who achieved <15 monthly headache days with onabotulinumtoxinA treatment achieved meaningful benefits in headache-related disability and migraine-specific quality of life compared with those who remained at or above the 15-monthly headache days threshold. Sustained benefits observed over 56 weeks support long-term onabotulinumtoxinA use for the prevention of CM.

Treatment of Neuropsychiatric Symptoms in Parkinson's Disease With Botulinum Toxin A: A 12 week Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: The study aimed to evaluate the impact of Botulinum toxin A (BoNT/A) on neuropsychiatric symptoms in Parkinson's disease (PD) patients. METHODS: A total of 125 PD patients and an equal number of age- and gender-matched healthy controls were involved. Mental health status was assessed using the Cornell Medical Index (CMI) self-assessment questionnaire. Sixty-four PD patients exhibiting neuropsychiatric symptoms were selected for the controlled study and randomly grouped into treatment and control groups. The treatment group received BoNT/A injections, while the control group received a placebo. The primary outcome measures included depression scores from the CMI and the proportion of patients displaying improvement in neuropsychiatric symptoms at 8 weeks post-treatment. The secondary outcome was other CMI scores at 4, 8, and 12 weeks post-treatment. RESULTS: The outcomes revealed that PD patients had significantly higher scores in various neuropsychiatric factors compared to healthy controls. At 4 weeks post-treatment, the treatment group displayed improvements in depression and tension. At 8 weeks post-treatment, they exhibited significant reductions in depression, anxiety, sensitivity, and tension compared to the control group. Moreover, a notably higher percentage of patients in the treatment group showed improvement in neuropsychiatric symptoms compared to the control group. At 12 weeks post-treatment, the treatment group exhibited significant improvements in somatization, depression, sensitivity, and tension. CONCLUSION: PD patients commonly experience multiple neuropsychiatric symptoms, and BoNT/A has demonstrated efficacy in alleviating these symptoms. Specifically, BoNT/A was found to effectively alleviate somatization, tension, anxiety, depression, and sensitivity in PD patients.

How to define failure of intradetrusor injections of botulinum toxin A for neurogenic detrusor overactivity.

INTRODUCTION: Neurogenic detrusor overactivity (NDO) has a major impact on patients' quality of life and can lead to upper urinary tract complications. Intradetrusor botulinum toxin type A injections are administered as second-line treatment to these patients following the failure of anticholinergic agents. The aim of the DETOX 2 study is to propose a consensus definition of the failure of intradetrusor botulinum toxin injections for NDO in patients presenting spinal cord injury, spina bifida, or multiple sclerosis (MS) with self-catheterization. METHOD: This study followed the method adopted by the French National Authority for Health for recommendations by consensus. Based on a review of the literature and a preliminary survey, a steering committee compiled a questionnaire and selected a rating group comprising 16 experts from the Neuro-Urology Committee of the French Urology Association (cnuAFU) and Genulf. The experts were asked to complete the online questionnaire. At the end of the first round, all participants came together to discuss any disagreements and a second-round online questionnaire was completed to reach a consensus. RESULTS: Thirteen of the 16 experts approached completed both rounds of questionnaires. A strong consensus was reached for two proposals (median score = 9/10) which were therefore included in the definition from the first round: at least one repeat injection of the same botulinum toxin at the same dose must be given to rule out failure on technical grounds and a duration of efficacy <3 months must be considered a failure. At the end of round 2, a relative consensus was reached regarding the clinical criterion defining failure (median score = 7/10) and the urodynamic criterion of failure (median score = 8/10). An additional proposal was selected during this second round on the need for a voiding diary (median score = 8/10). CONCLUSION: The first consensus definition of failure of an intradetrusor injection of TB-A for NDO has been achieved with this study: persistence of detrusor overactivity with maximum detrusor pressures >40 cm H2O and/or a compliance issue and/or persistence of urinary incontinence and/or urgency and/or a number of daily self-catheterizations >8/day and/or efficacy <3 months. This study will help to standardize research on the failure of the intradetrusor botulinum toxin for NDO in clinical practice and clinical research.

Improvement of neurogenic urinary dysfunctions in female rats treated with an injection of botulinum toxin A at the epicenter of the spinal cord injured site.

OBJECTIVE: To assess the effect of an injection of botulinum toxin A (BoNT/A) at the epicenter of the spinal cord injury (SCI) site on the recovery of lower urinary tract function in female rats with thoracic SCI. MATERIALS AND METHODS: Twenty-four female Wistar rats with Sham (laminectomy at T8/T9 level) or SCI (at T8/T9; 30 g compression for 5 s) were assigned into Sham-SS (injected with 5 µL of saline solution), Sham-BoNT/A (injected with 15 pg/rat, equivalent to 7.5 Units/kg of BoNT/A in 5 µL volume), SCI-SS (injured and injected with saline), SCI-BoNT/A (injured and injected with BoNT/A), N = 6 per group. Weekly evaluation of stereotyped micturition behavior, hind-limb nociception, and locomotor activity was performed 1 week before and during 6 weeks after surgery. Subsequently, all groups underwent simultaneous electromyography of the external urethral sphincter (EUS-EMG) and cystometric (CMG) studies. RESULTS: A compression SCI at the T8/T9 thoracic level significantly impairs sensory and locomotive functions, as well as stereotyped micturition behavior. However, these impairments were improved by BoNT/A injection after SCI. Neither injections of saline solution nor BoNT/A had an appreciable effect on the same parameters evaluated in the Sham groups. The combined EUS-EMG and CMG evaluations revealed important improvements of lower urinary tract physiology, particularly a reduction in the frequency of non-voiding contractions and the properties of EUS bursting activity indicated as the amplitude of the EUS-EMG signal and duration of burst electrical activity during effective voiding. CONCLUSION: The severe impairments on sensory and locomotive functions as well stereotyped micturition caused by an SCI could be potentially attenuated by an injection of a small amount of BoNT/A directly into the epicenter of the SCI region. A reduction in the release of neurotoxic neurotransmitters requiring the SNARE complex may be the mechanism triggered by BoNT/A to reduce neurotoxicity and hyperexcitability created in the SCI area to improve the survival of spinal cord cells involved in micturition.

Efficacy and safety of an alternative onabotulinumtoxinA injection paradigm for refractory overactive bladder.

AIMS: In studies utilizing a 20-injection-site paradigm of onabotulinumtoxinA treatment for overactive bladder (OAB), some patients performed clean intermittent catheterization (CIC). An alternative injection paradigm of fewer injections targeting the lower bladder may reduce the need for CIC by maintaining upper bladder function. This study evaluated the efficacy and safety of an unapproved alternative 10-injection-site paradigm targeting the lower bladder. METHODS: In this phase 4, double-blind, parallel-group study, patients with OAB and urinary incontinence (UI) for ≥6 months with ≥3 episodes of urinary urgency incontinence (no more than 1 UI-free day) and ≥8 micturitions per day over 3 days during screening were randomized 2:1 to onabotulinumtoxinA 100 U or placebo injected at 10 sites in the lower bladder. RESULTS: Of 120 patients, 78 in the onabotulinumtoxinA group and 39 in the placebo group had efficacy assessments. In the double-blind phase, mean change from baseline at week 12 in daily frequency of UI episodes was greater with onabotulinumtoxinA (-2.9) versus placebo (-0.3) (least squares mean difference [LSMD]: -2.99, p < 0.0001). Achievement of 100% (odds ratio [OR]: 6.15 [95% confidence interval, CI: 0.75-50.37]), ≥75% (OR: 7.25 [2.00-26.29]), and ≥50% improvement (OR: 4.79 [1.87-12.28]) from baseline in UI episodes was greater with onabotulinumtoxinA versus placebo. Reductions from baseline in the daily average number of micturitions (LSMD: -2.24, p < 0.0001), nocturia (LSMD: -0.71, p = 0.0004), and urgency (LSMD: -2.56, p < 0.0001) were greater with onabotulinumtoxinA than with placebo. Treatment benefit was improved or greatly improved in the onabotulinumtoxinA group (74.0% of patients) versus placebo (17.6%) (OR: 13.03 [95% CI: 3.23-52.57]). Mean change from baseline in Incontinence Quality of Life score was greater with onabotulinumtoxinA versus placebo (LSMD: 24.2, p = 0.0012). Two of 78 (2.6%) patients in the onabotulinumtoxinA group used CIC during the double-blind period; no females used CIC during the double-blind period. Commonly reported adverse events (≥5%) were urinary tract infection (UTI), dysuria, and productive cough for both groups; rate of UTI was higher with onabotulinumtoxinA versus placebo. CONCLUSION: In patients treated with onabotulinumtoxinA for OAB with UI, an unapproved alternative injection paradigm targeting the lower bladder demonstrated efficacy over placebo, with a low incidence of CIC.