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.

Adverse Effects of Intravesical OnabotulinumtoxinA Injection in Patients with Idiopathic Overactive Bladder or Neurogenic Detrusor Overactivity: A Systematic Review and Meta-Analysis of Randomized Controlled Studies.

Despite the efficacy of onabotulinumtoxinA, its safety profile remains a concern. This meta-analysis reviewed the major adverse events (AEs) associated with intravesical onabotulinumtoxinA treatment in patients with neurogenic detrusor overactivity (NDO) and idiopathic overactive bladder (iOAB). Randomized controlled trials (RCTs) conducted between January 2000 and December 2022 were searched for adult patients administered different onabotulinumtoxinA dosages or onabotulinumtoxinA vs. placebo. Quality assessment was performed using the Cochrane Collaboration tool, and statistical analysis was performed using Review Manager version 5.3. A total of 26 RCTs were included in the analysis, including 8 on NDO and 18 on iOAB. OnabotulinumtoxinA vs. placebo significantly increased the urinary tract infection (UTI) incidence in patients with NDO (relative risk, or RR, 1.54) and iOAB (RR, 2.53). No difference in the RR with different onabotulinumtoxinA dosages was noted. Urinary retention was frequent with onabotulinumtoxinA use in the NDO (RR, 6.56) and iOAB (RR, 7.32) groups. Similar observations were made regarding the risks of de novo clean intermittent catheterization (CIC). The risk of voiding difficulty increased with onabotulinumtoxinA use in patients with iOAB. Systemic AEs of onabotulinumtoxinA, including muscle weakness (RR, 2.79) and nausea (RR, 3.15), were noted in patients with NDO; most systemic AEs had a low incidence and were sporadic.

Onabotulinumtoxina in the Prevention of Migraine in Pediatric Population: A Systematic Review.

Migraine is a leading cause of disability worldwide, yet it remains underrecognized and undertreated, especially in the pediatric and adolescent population. Chronic migraine occurs approximately in 1% of children and adolescents requiring preventive treatment. Topiramate is the only FDA-approved preventative treatment for children older than 12 years of age, but there is conflicting evidence regarding its efficacy. OnabotulinumtoxinA is a known and approved treatment for the management of chronic migraine in people older than 18 years. Several studies examine its role in the pediatric population with positive results; however, the clear-cut benefit is still unclear. OnabotulinumtoxinA seems not only to improve disability scores (PedMIDAS) but also to improve the quality, characteristics, and frequency of migraines in the said population. This systematic review aims to summarize the evidence on the efficacy, dosing, administration, long-term outcomes, and safety of onabotulinumtoxinA in pediatric and adolescent migraine. Eighteen studies met the eligibility criteria and were included in this review. The mean monthly migraine days (MMDs), decreased from of 21.2 days per month to 10.7 after treatment. The reported treatment-related adverse effects were mild and primarily injection site related and ranged from 0% to 47.0%. Thus, this review provides compelling evidence suggesting that OnabotulinumtoxinA may represent a safe and effective preventive treatment option for pediatric migraine.

Clinical Conditions Targeted by OnabotulinumtoxinA in Different Ways in Medicine.

OnabotulinumtoxinA (BT-A) is used in different medical fields for its beneficial effects. BT-A, a toxin originally produced by the bacterium Clostridium botulinum, is widely known for its ability to temporarily paralyze muscles by blocking the release of acetylcholine, a neurotransmitter involved in muscle contraction. The literature continually reports new hypotheses regarding potential applications that do not consider blockade of acetylcholine release at the neuromuscular junction as a common pathway. In this opinion article, it is our aim to investigate the different pathway targets of BT-A in different medical applications. First of all, the acetylcholine effect of BT-A is used to reduce wrinkles for cosmetic purposes, in the treatment of urological problems, excessive sweating, temporomandibular joint disorders, obesity, migraine, spasticity in neurological diseases, and in various cases of muscle overactivity such as cervical dystonia, blepharospasm, and essential head tremor. In another potential pathway, glutamate A, CGRP, and substance P are targeted for pain inhibition with BT-A application in conditions such as migraine, trigeminal neuralgia, neuropathic pain, and myofascial pain syndrome. On the other hand, as a mechanism different from acetylcholine and pain mediators, BT-A is used in the treatment of hair loss by increasing oxygenation and targeting transforming growth factor-beta 1 cells. In addition, the effect of BT-A on the apoptosis of cancer cells is also known and is being developed. The benefits of BT-A applied in different doses to different regions for different medical purposes are shown in literature studies, and it is also emphasized in those studies that repeating the applications increases the benefits in the long term. The use of BT-A continues to expand as researchers discover new potential therapeutic uses for this versatile toxin.

Treatment response to onabotulinumtoxinA in cervical dystonia patients with anterocollis and retrocollis.

Anterocollis (AC) and retrocollis (RC) are less common cervical dystonia (CD) subtypes that are often under-represented in CD clinical trials. Herein we describe real-world demographics, disease characteristics, and treatment response to onabotulinumtoxinA (onabotA) in AC or RC patients from an observational, multicenter, prospective registry, CD PROBE. After three onabotA treatments, outcomes (CDIP-58, PGIC, CGIC, CD severity, TWSTRS) in patients with predominant AC or RC were compared to torticollis (TC) and all CD subtypes combined. The mean dosages at each treatment ranged from 153.5 to 195.4 U (AC) to 184.0-213.4 U (RC). After treatment, AC and RC patients reported improvements in the CDIP-58. "Much" or "very much improved" on PGIC and CGIC was reported by AC patients (n = 11/23, 48%) and clinicians (n = 14/23, 61%); and by RC patients (n = 14/24, 58%) and clinicians (n = 19/24, 83%). The mean total TWSTRS decreased from 45.7 (n = 59) to 36.1 (n = 23, 21.0% improvement) for AC patients and from 40.1 (n = 55) to 31.6 (n = 23, 21.2% improvement) for RC patients; the proportion of AC and RC patients with severe CD decreased. Outcomes for AC and RC were generally consistent with those for TC and all subtypes combined. Dysphagia was reported in 4/59 (6.8%) of AC patients (one serious), 7/55 (12.7%) of RC patients (none serious), 29/494 (5.9%) of TC patients (none serious), and 64/1012 (6.3%) of all CD patients (two serious). No new safety signals were identified. In conclusion, treatment with onabotA may relieve CD symptoms in some patients with AC and RC, consistent with results for other CD subtypes and the known safety profile of onabotA for the treatment of CD.

The effectiveness and predictors influencing the outcome of onabotulinumtoxinA treatment in chronic migraine: understanding from diverse patient profiles in a single session.

Objective: This real-world study aimed to investigate how onabotulinumtoxinA affects the outcome of migraine, along with accompanying anxiety, depression, and bruxism among a group of patients with chronic migraine (CM) and define predictors of good response. Methods: Patients diagnosed with CM who received onabotulinumtoxinA were included in this single-center, real-world retrospective cohort study. Monthly headache days (MHDs), monthly migraine days (MMDs), headache intensity (numeric rating scale-NRS) and headache characteristics were evaluated at baseline and 12 weeks post-treatment. Patient-reported outcome measures (PROMs) included Migraine Disability Assessment Scale (MIDAS), Headache Impact Test-6 (HIT-6) scores, 12-item Allodynia Symptom Checklist (ASC-12), Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI). Response to onabotulinumtoxinA (% reduction in MHDs) and treatment-related adverse events (TRAEs) were also evaluated. OnabotulinumA was applied to the masseter muscles in patients complaining of bruxism. Results: A total of 72 patients (mean ± SD age: 36.3 ± 8.5 years; 91.7% were female) diagnosed with CM were included. OnabotulinumtoxinA revealed significant decrease in median (IQR) MHDs [from 20(15-25) at baseline to 6(4-10), p < 0.001], MMDs [from 9(6-12) to 3(1-6), p < 0.001] and NRS [from 9(8-10) to 7(6-8), p < 0.001], and the MIDAS [from 54(30-81) to 16(7-24), p < 0.001], HIT-6 [from 67(65-69) to 58(54-64), p < 0.001], ASC-12 [from 6(1.5-9) to 2(0-9), p = 0.002], BAI [from 12(6.5-19) to 9(3-17), p < 0.001] and BDI [from 11(6.5-17) to 3(2-7) p < 0.001] scores at 12 weeks post-treatment. Patients complaining of bruxism received onabotulinumtoxinA injections in the first n = 27 (37.5%) and 12. week post-treatment n = 19 (70.4%) periods. Overall, 70.8% of patients responded (≥50% reduction in MHDs), while 29.2% did not (<50% reduction). Both groups showed similar characteristics in demographics, migraine history, baseline PROMs scores, comorbidities, and prior treatments. Conclusion: OnabotulinumtoxinA is an effective treatment option that rapidly improves migraine outcomes, disability, and impact while also alleviating comorbid depression and/or anxiety. This study's noteworthy finding is that onabotulinumtoxinA is effective in a majority of CM patients, irrespective of their prior treatment history, migraine characteristics, or concurrent comorbidities. Furthermore, we identified no specific predictors for a favorable response to onabotulinumtoxinA. Applying onabotulinumtoxinA to the masseter muscles can relieve discomfort associated with concurrent bruxism; however, it does not impact migraine outcomes.

A Risk-Difference Meta-Analysis for the Prophylactic Treatments of Chronic Migraine.

Chronic migraine (CM) imposes significant personal, societal, and financial burdens, historically lacking specific prophylactic treatments. Monoclonal antibodies (mAbs) targeting calcitonin gene-related peptide (CGRP) represent a novel, mechanism-based, and migraine-specific prophylactic approach. Four mAbs, namely, erenumab, fremanezumab, galcanezumab, and eptinezumab, have been marketed, although head-to-head trials with standard anti-migraine treatments are absent. This study aimed to compare the efficacy and safety of anti-CGRP mAbs with standard anti-migraine treatments using a cross-trial indirect model of the absolute risk difference (ARD) of a 50% responder rate, in order to express the final results in terms of the number needed to treat (NNT) and number needed to harm (NNH). Phase 3 and 2b randomized controlled trials (RCTs) for CM prophylaxis were searched in the MEDLINE and CENTRAL databases with specific inclusion and exclusion criteria. The ARD between groups for the percentage of trial participants who reported a 50% reduction in monthly migraine days and the differences in the number of adverse events (AEs), serious adverse events (SAEs), and participants who withdrew from each RCT were calculated, and subsequently, the NNT and NNH were calculated for each one of the outcome measures. In total, eight RCTs were considered eligible. A similar efficacy and safety have been demonstrated among CGRP mAbs and all standard CM treatments. The results of the ARD for the total number of studies concerning efficacy, total adverse events, serious adverse events, and dropout from the RCTs ranged from -0.688 (95% confidence interval (CI): -0.821-(-0.513)) to -0.018 (95% CI: -0.044-(0.007)), from 0.032 (95% CI: -0.041, 0.104) to -0.380 (95% CI: -0.589, -0.126), from -0.025 (95% CI: -0.046, -0.006) to 0.014 (95% CI: -0.015, 0.42), from 0.048 (95% CI: -0.112, 0.014) to 0.232 (95% CI: -0.016, 0.458) correspondingly. All anti-CGRP mAbs showed a roughly equal statistically significant ARD and similar NNTs, ranging from 5 to 8, while the ARD of onbotulinum toxin A (oBTA) was not significant with an NNT 56. The two studies of topiramate showed contradictory results, the one significant while the other not, with NNTs 2 and 22, respectively. All four anti-CGRP mAbs showed an invariably high efficacy among their studies, in terms of the ARD and its derivative measure of NNT, in contrast to oBTA, while in topiramate, the results are contradictory between the two studies.

Long-term safety of OnabotulinumtoxinA treatment in chronic migraine patients: a five-year retrospective study.

Background: Real-world studies have shown the sustained therapeutic effect and favourable safety profile of OnabotulinumtoxinA (BoNTA) in the long term and up to 4 years of treatment in chronic migraine (CM). This study aims to assess the safety profile and efficacy of BoNTA in CM after 5 years of treatment in a real-life setting. Methods: We performed a retrospective chart review of patients with CM in relation to BoNTA treatment for more than 5 years in 19 Spanish headache clinics. We excluded patients who discontinued treatment due to lack of efficacy or poor tolerability. Results: 489 patients were included [mean age 49, 82.8% women]. The mean age of onset of migraine was 21.8 years; patients had CM with a mean of 6.4 years (20.8% fulfilled the aura criteria). At baseline, patients reported a mean of 24.7 monthly headache days (MHDs) and 15.7 monthly migraine days (MMDs). In relation to effectiveness, the responder rate was 59.1% and the mean reduction in MMDs was 9.4 days (15.7 to 6.3 days; p < 0.001). The MHDs were also reduced by 14.9 days (24.7 to 9.8 days; p < 0.001). Regarding the side effects, 17.5% experienced neck pain, 17.3% headache, 8.5% eyelid ptosis, 7.5% temporal muscle atrophy and 3.2% trapezius muscle atrophy. Furthermore, after longer-term exposure exceeding 5 years, there were no serious adverse events (AE) or treatment discontinuation because of safety or tolerability issues. Conclusion: Treatment with BoNTA led to sustained reductions in migraine frequency, even after long-term exposure exceeding 5 years, with no evidence of new safety concerns.

Comparative effectiveness and tolerability of calcitonin gene-related peptide (CGRP) monoclonal antibodies and onabotulinumtoxinA in chronic migraine: A multicenter, real-world study in Taiwan.

OBJECTIVE: To compare the real-world effectiveness and tolerability of calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) and onabotulinumtoxinA in chronic migraine (CM) patients. METHODS: This multicenter study involved retrospective analysis of prospectively collected data of CM patients treated with CGRP mAbs or onabotulinumtoxinA, including difficult-to-treat (DTT) patients (i.e., ≥3 preventive failures). Treatment outcomes were determined at 6 months based on prospective headache diaries and Migraine Disability Assessment (MIDAS). RESULTS: The study included 316 (55 M/261F, mean age 44.4 ± 13.5 years) and 333 (61 M/272F, mean age 47.9 ± 13.4 years) CM patients treated with CGRP mAbs or onabotulinbumtoxinA, respectively. At 6 months, CGRP mAb treatment was associated with a greater decrease in monthly migraine days (MMDs) (-13.0 vs. -8.7 days/month, p < 0.001) and a higher ≥50% responder rate (RR) (74.7% vs. 50.7%, p < 0.001) compared with onabotulinumtoxinA injections. The findings were consistent in DTT patients (-13.0 vs. -9.1 MMDs, p < 0.001; ≥50% RR: 73.9% vs. 50.3%, p < 0.001) or those with medication-overuse headache (MOH) (-13.3 vs. -9.0 MMDs, p < 0.001; ≥50% RR: 79.0% vs. 51.6%, p < 0.001). Besides, patients receiving CGRP mAbs had greater improvement (-42.2 vs. -11.8, p < 0.001) and a higher ≥50% RR (62.0% vs. 40.0%, p = 0.001) in MIDAS scores and a lower rate of adverse events (AEs) (6.0% vs. 21.0%, p < 0.001). However, none of the patients discontinued treatment due to AEs. CONCLUSIONS: In this multicenter, real-world study, CGRP mAbs were more effective than onabotulinumtoxinA in CM patients, even in DTT or MOH patients. All of these injectables were well tolerated. Further prospective studies are needed to verify these findings.

Early effect of onabotulinumtoxinA on EEG-based functional connectivity in patients with chronic migraine: A pilot study.

OBJECTIVE: In this pilot prospective cohort study, we aimed to evaluate, using high-density electroencephalography (HD-EEG), the longitudinal changes in functional connectivity (FC) in patients with chronic migraine (CM) treated with onabotulinumtoxinA (OBTA). BACKGROUND: OBTA is a treatment for CM. Several studies have shown the modulatory action of OBTA on the central nervous system; however, research on migraine is limited. METHODS: This study was conducted at the Neurology Unit of "Policlinico Tor Vergata," Rome, Italy, and included 12 adult patients with CM treated with OBTA and 15 healthy controls (HC). Patients underwent clinical scales at enrollment (T0) and 3 months (T1) from the start of treatment. HD-EEG was recorded using a 64-channel system in patients with CM at T0 and T1. A source reconstruction method was used to identify brain activity. FC in δ-θ-α-ß-low-γ bands was analyzed using the weighted phase-lag index. FC changes between HCs and CM at T0 and T1 were assessed using cross-validation methods to estimate the results' reliability. RESULTS: Compared to HCs at T0, patients with CM showed hyperconnected networks in δ (p = 0.046, area under the receiver operating characteristic curve [AUC: 0.76-0.98], Cohen's κ [0.65-0.93]) and ß (p = 0.031, AUC [0.68-0.95], Cohen's κ [0.51-0.84]), mainly involving orbitofrontal, occipital, temporal pole and orbitofrontal, superior temporal, occipital, cingulate areas, and hypoconnected networks in α band (p = 0.029, AUC [0.80-0.99], Cohen's κ [0.42-0.77]), predominantly involving cingulate, temporal pole, and precuneus. Patients with CM at T1, compared to T0, showed hypoconnected networks in δ band (p = 0.032, AUC [0.73-0.99], Cohen's κ [0.53-0.90]) and hyperconnected networks in α band (p = 0.048, AUC [0.58-0.93], Cohen's κ [0.37-0.78]), involving the sensorimotor, orbitofrontal, cingulate, and temporal cortex. CONCLUSION: These preliminary results showed that patients with CM presented disrupted EEG-FC compared to controls restored by a single session of OBTA treatment, suggesting a primary central modulatory action of OBTA.

Cost Analysis of Oral Phenazopyridine vs Intravesical Lidocaine for Preprocedural Analgesia for Intradetrusor OnabotulinumtoxinA Injections.

INTRODUCTION: Office administration of intradetrusor onabotulinumtoxinA is commonly used to treat overactive bladder. For preprocedure analgesia, either 50 mL 2% intravesical lidocaine instillation for 20 to 30 minutes or 200 mg oral phenazopyridine can be used. Phenazopyridine is associated with shorter appointment times and is noninferior to lidocaine for pain control in this setting. We performed a cost analysis of phenazopyridine vs lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. METHODS: A health care sector-perspective cost analysis was performed. The following assumptions were made: (1) similar efficacy of each medication in providing adequate analgesia, (2) similar physician ease of performing the procedure with either analgesic, and (3) similar patient satisfaction with either analgesic. Average cost of medications, adverse reactions, nursing tasks, and office visit time were found in publicly available data. Sensitivity analyses were performed using TreeAge Pro 2021, R1 software. RESULTS: Phenazopyridine is less costly compared to lidocaine per visit for office intradetrusor onabotulinumtoxinA injection ($827 vs $925). A difference of $98 per procedure provides a total annual cost savings of over $24 million if all procedures are performed with phenazopyridine instead of lidocaine. Sensitivity analysis showed that phenazopyridine remained less costly under most circumstances, and threshold analysis provided exact circumstances under which phenazopyridine is no longer cost saving. CONCLUSIONS: Phenazopyridine provides cost savings compared to lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. If adopted by providers nationwide, phenazopyridine may reduce health care spending and minimize office visit time while maintaining patient pain control and satisfaction.

A Validation of the Equivalence of the Cell-Based Potency Assay Method with a Mouse LD50 Bioassay for the Potency Testing of OnabotulinumtoxinA.

(1) Background: At present, the only potency assay approved in China for the in-country testing of botulinum toxin type A for injection products is the mouse bioassay (MBA). The Chinese market for neurotoxin products is rapidly expanding, but MBAs are subject to high variability due to individual variations in mice, as well as variations in injection sites, in addition to the limited number of batches tested for one MBA. Compared with the mLD50 method, the cell-based potency assay (CBPA) developed for the potency testing of onabotulinumtoxinA (BOTOX) by AbbVie not only does not use any experimental animals but also allows for significant time and cost savings. Due to the significant benefits conferred by the replacement of the mLD50 assay with CBPA in China, the CBPA method has been transferred, validated, and cross-validated to demonstrate the equivalence of the two potency methods. (2) Methods: The differentiated SiMa cells were treated with both BOTOX samples and the reference standard, and the cleaved SNAP25197 in the cell lysates was quantified using Chemi-ECL ELISA. A 4-PL model was used for the data fit and sample relative potency calculation. The method accuracy, linearity, repeatability, and intermediate precision were determined within the range of 50% to 200% of the labeled claim. A statistical equivalence of the two potency methods (CBPA and mLD50) was initially demonstrated by comparing the AbbVie CBPA data with NIFDC mLD50 data on a total of 167 commercial BOTOX lots (85 50U lots and 82 100U lots). In addition, six lots of onabotulinumtoxinA (three 50U and three 100U) were re-tested as cross-validation by these two methods for equivalence. (3) Results: The overall assay's accuracy and intermediate precision were determined as 104% and 9.2%, and the slope, R-square, and Y-intercept for linearity were determined as 1.071, 0.998, and 0.036, respectively. The repeatability was determined as 6.9%. The range with the acceptable criteria of accuracy, linearity, and precision was demonstrated as 50% to 200% of the labeled claim. The 95% equivalence statistic test using margins [80%, 125%] indicates that CBPA and mLD50 methods are equivalent for both BOTOX strengths (i.e., 50U and 100U). The relative potency data from cross-validation were within the range of ≥80% to ≤120%. (4) Conclusions: The CBPA meets all acceptance criteria and is equivalent to mLD50. The replacement of mLD50 with CBPA is well justified in terms of ensuring safety and efficacy, as well as for animal benefits.

OnabotulinumtoxinA is now an important tool for managing pediatric neurogenic lower urinary tract dysfunction.

Initial urologic management of pediatric neurogenic lower urinary tract dysfunction (NLUTD) includes clean intermittent catheterization (CIC) regimen and use of anticholinergic or beta3 agonist medications. Historically, NLUTD that did not respond to these initial management strategies received open surgical procedures such as augmentation cystoplasty (AC) to increase bladder capacity and create a lower-pressure reservoir. Since its first reported use in 2002, intradetrusor onabotulinumtoxinA (BTX-A) injections has developed an emerging role in management of pediatric NLUTD, culminating in its recent FDA-approval in 2021. In this review, the current evidence regarding the safety, tolerability, and efficacy of BTX-A use in pediatric NLUTD will be summarized. Additionally, we will attempt to define the current role of BTX-A in the management of patients with NLUTD, discuss limitations to the current body of literature, and suggest future avenues of study.

Onabotulinumtoxina (craniotomy scar combined with cranial suture line injections) for persistent post craniotomy headache: Case series with long-term follow-up.

BACKGROUND: There is no defined preventive treatment protocol for persistent post-craniotomy headache. In several small case series and individual case reports onabotulinumtoxinA injected into the craniotomy scar has shown possible efficacy. What is lacking is long term follow-up and if focusing on the cranial suture lines along with the craniotomy scar can enhance improvement and provide more sustained benefit. METHODS: Retrospective chart review with case series. RESULTS: Four patients (three women, one man) with ICHD-3 defined persistent post craniotomy headache were treated using a novel onabotulinumtoxinA injection protocol. All the patients presented with continuous head pain of moderate to severe intensity. All had severe allodynia on the side of their craniotomy. All had significant reduction in quality of life. Our application of onabotulinumtoxinA involved injection into both the surgical scar and the transected/irritated cranial suture lines noted on neuroimaging and physical examination. With treatment all patients demonstrated significant benefit including a reduction in daily pain intensity (75%-100%), developing periods of pain freedom (2-7 days per week) and having a dramatic improvement in quality of life (close to 100% in all). The benefit was sustained for at least five years of follow-up. CONCLUSION: From our case series it appears that injection not only along the painful craniotomy scar but into the involved cranial suture lines provides positive efficacy and sustained improvement in patients with persistent post craniotomy headache.

The impact of the migraine treatment onabotulinumtoxinA on inflammatory and pain responses: Insights from an animal model.

OBJECTIVE: Migraine, a prevalent and debilitating disease, involves complex pathophysiology possibly including inflammation and heightened pain sensitivity. The current study utilized the complete Freund's adjuvant (CFA) model of inflammation, with onabotulinumtoxinA (BoNT/A) as a treatment of interest due to its use in clinical migraine management. Using an animal model, the study sought to investigate the role of BoNT/A in modulating CFA-induced inflammation, alterations in pain sensitivity, and the regulation of calcitonin gene-related peptide (CGRP) release. Further, we aimed to assess the changes in SNAP-25 through western blot analysis to gain insights into the mechanistic action of BoNT/A. METHODS: BoNT/A or control was administered subcutaneously at the periorbital region of rats 3 days before the induction of inflammation using CFA. Periorbital mechanical sensitivity was assessed post-inflammation, and alterations in CGRP release were evaluated. Changes in SNAP-25 levels were determined using western blot analysis. RESULTS: Upon CFA-induced inflammation, there was a marked increase in periorbital mechanical sensitivity, with the inflammation side showing increased sensitivity compared to other periorbital areas. BoNT/A did decrease the withdrawal thresholds in the electronic von Frey test. Despite not being able to observe differences in pain thresholds or CGRP release, BoNT/A reduced baseline release under CFA inflamed conditions. Analysis of SNAP-25 levels in the trigeminal ganglion revealed both intact and cleaved forms that were notably elevated in BoNT/A-treated animals. These findings, derived from western blot analysis, suggest an effect on neurotransmitter release. CONCLUSION: Our investigation highlights the role of BoNT/A in reducing baseline CGRP in the context of inflammation and its involvement in SNAP-25 cleavage. In contrast, BoNT/A did not appear to alter facial pain sensitivity induced by inflammation, suggesting that mechanisms other than baseline CGRP could be implicated in the elevated thresholds in the CFA model.

Sequential administration of peripheral nerve blocks and onabotulinumtoxinA for the treatment of chronic migraine and other headache disorders-A retrospective tolerability and safety study.

OBJECTIVE: To determine the tolerability and safety of concurrent peripheral nerve blocks and onabotulinumtoxinA treatment during a single outpatient clinic procedure visit. BACKGROUND: Procedural interventions are available for the treatment of headache disorders. OnabotulinumtoxinA and peripheral nerve blocks are used as alternatives or in addition to oral therapies to reduce the frequency and intensity of migraine attacks. There is currently a lack of safety data focusing on the sequential administration of local anesthetic via peripheral nerve blocks and onabotulinumtoxinA during a single clinical encounter for the treatment of headache. The primary aim of the study was to determine the safety and tolerability of concurrent peripheral nerve blockade and onabotulinumtoxinA injections during a single outpatient clinic procedure visit. We hypothesized that the dual intervention would be safe and well tolerated by patients with chronic migraine and other headache disorders. METHODS: A retrospective chart review was performed using clinical data from patients seen by multiple providers over a 16-month timeframe at one outpatient headache clinic. Patients were identified by procedure codes and those receiving peripheral nerve block(s) and onabotulinumtoxinA injections during a single encounter within the study period were eligible for inclusion. Inclusion criteria were (1) patients 18 years and older who were (2) receiving both peripheral nerve blocks and onabotulinumtoxinA injections for the treatment of chronic migraine. Patients were excluded if they were under age 18, received their procedure outside of the clinic (emergency room, inpatient ward), or were receiving sphenopalatine ganglion blocks. Age- and sex-matched patients who received one procedure, either peripheral nerve blocks or onabotulinumtoxinA, were used for control. The primary outcome of this safety study was the number of adverse events that occurred in the dual intervention group compared to the single intervention control arms. Information regarding adverse events was gathered via retrospective chart review. If an adverse event was recorded, it was then graded by the reviewer utilizing the Common Terminology Criteria for Adverse Events ranging from Grade 1 Mild Event to Grade 5 Death. Additionally, it was noted whether the adverse event led to treatment discontinuation. RESULTS: In total, 375 patients were considered eligible for inclusion in the study. After age and sex matching of controls, 131 patients receiving dual intervention were able to be compared to 131 patients receiving onabotulinumtoxinA alone and 104 patients receiving dual intervention were able to be compared to 104 patients receiving peripheral nerve block(s) alone. The primary endpoint analysis showed no significant difference in total adverse events between dual intervention compared to nerve blocks alone or onabotulinumtoxinA alone. The number of adverse events that led to treatment discontinuation approached but did not reach statistical significance for those receiving dual intervention versus onabotulinumtoxinA alone in the number of adverse events that led to treatment termination (4.6%, 6/131 vs. 0.8%, 1/131, p = 0.065); however, the number of patients who discontinued therapy was not significantly different between those groups (2.3%, 3/131 vs. 0.8%, 1/131; p = 0.314; odds ratio 0.3 [0-3.2]; p = 0.338). CONCLUSIONS: In this retrospective chart review, there was no significant difference in adverse events or therapy discontinuation between patients receiving sequential peripheral nerve block(s) and onabotulinumtoxinA injections versus those receiving either peripheral nerve block(s) or onabotulinumtoxinA injections alone. As a result, we concluded that the combination procedure is likely safe and well tolerated in routine clinical practice.