Clinical efficacy and safety analysis of type A botulinum toxin in the treatment of adolescents with refractory overactive bladder.

The objective of this study was to assess the clinical effectiveness and safety of type A botulinum toxin in the treatment of refractory overactive bladder in adolescents. We conducted a retrospective analysis of 37 adolescent patients with refractory overactive bladder who were treated at the Urology Department of Hangzhou Third People's Hospital between January 2018 and August 2023. These patients received intravesical injections of type A botulinum toxin at a concentration of 10 U/mL, with an average of 20 injection points. We recorded changes in urination diaries and urodynamic parameters both before and 1 month after treatment. After 1 month of treatment, significant improvements were observed in several parameters, when compared to the pretreatment values. These included daytime frequency of urination (11.13 ±â€…6.45), average single void volume (173.24 ±â€…36.48) mL, nighttime frequency of urination (2.43 ±â€…0.31), urgency episodes (3.12 ±â€…0.27), initial bladder capacity (149.82 ±â€…41.34) mL, and maximum bladder capacity (340.25 ±â€…57.12) mL (all P < .001). After the first treatment, 5 patients had mild hematuria, 4 patients had urinary tract infection, and 1 patient had urinary retention, which was relieved after catheterization. No serious complications or adverse reactions were observed in other patients. The follow-up period ranged from 6 to 18 months, and the duration of efficacy varied from 2 to 8 months. Eight patients who initially had treatment failure achieved symptom relief after reinjection. In adolescents with refractory overactive bladder who do not respond well to conventional drug therapy, type A botulinum toxin can be administered safely and effectively. It significantly improves lower urinary tract symptoms and enhances the quality of life for these patients.

[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 However, in the opinion of Lobbezoo et al., some outdated views on bruxism are used, and botulinum toxin is incorrectly classified as safe, according to them.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!

Comprehensive Observational and Longitudinal study on the Outbreak of Stroke-related Spasticity focusing on the Early Onset management with Botulinum NeuroToxin (COLOSSEO-BoNT): protocol for a real-world prospective observational study on upper limb spasticity.

INTRODUCTION: Poststroke spasticity (PSS) affects up to 40% of patients who had a stroke. Botulinum neurotoxin type A (BoNT-A) has been shown to improve spasticity, but the optimal timing of its application remains unclear. While several predictors of upper limb PSS are known, their utility in clinical practice in relation to BoNT-A treatment has yet to be fully elucidated. The COLOSSEO-BoNT study aims to investigate predictors of PSS and the effects of BoNT-A timing on spasticity-related metrics in a real-world setting. METHODS AND ANALYSIS: The recruitment will involve approximately 960 patients who have recently experienced an ischaemic stroke (within 10 days, V0) and will follow them up for 24 months. Parameters will be gathered at specific intervals: (V1) 4, (V2) 8, (V3) 12, (V4) 18 months and (V5) 24 months following enrolment. Patients will be monitored throughout their rehabilitation and outpatient clinic journeys and will be compared based on their BoNT-A treatment status-distinguishing between patients receiving treatment at different timings and those who undergo rehabilitation without treatment. Potential predictors will encompass the Fugl-Meyer assessment, the National Institute of Health Stroke Scale (NIHSS), stroke radiological characteristics, performance status, therapies and access to patient care pathways. Outcomes will evaluate muscle stiffness using the modified Ashworth scale and passive range of motion, along with measures of quality of life, pain, and functionality. ETHICS AND DISSEMINATION: This study underwent review and approval by the Ethics Committee of the Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy. Regardless of the outcome, the findings will be disseminated through publication in peer-reviewed journals and presentations at national and international conferences. TRIAL REGISTRATION NUMBER: NCT05379413.

Incobotulinum Toxin-A in Professional Musicians with Focal Task-Specific Dystonia: A Double Blind, Placebo Controlled, Cross-Over Study.

Background: Musician's focal task-specific dystonia is a complex disorder of fine motor control, with incomplete understanding of its etiology. There have been relatively few trials of botulinum toxin in upper limb task-specific dystonia, and prior studies have yielded variable results, leading to skepticism regarding the utility of this approach in elite performers. Methods: We conducted a double-blind, placebo-controlled, randomized, cross-over study of incobotulinum toxin-A in 21 professional musicians with focal upper extremity task-specific dystonia affecting performance on their instrument, using a novel paradigm of initial injections followed by booster injections at two- and four-week intervals. The primary outcome measure was the change in blinded dystonia rating of the active arm by two expert raters using a Clinical Global Impression numeric scale at week 8 compared to enrollment. Findings: 19 men and 2 women with musicians' dystonia were enrolled over a six-year period. Nineteen patients completed the study. Analysis of the primary outcome measure in comparison to baseline revealed a change in dystonia severity of P = 0.04 and an improvement in overall musical performance of P = 0.027. No clinically significant weakness was observed, and neutralizing antibodies to toxin were not found. Interpretation: Despite its small sample size, our study demonstrated a statistically significant benefit of incobotulinum toxin-A injections as a treatment for musicians' task-specific dystonia. Tailoring the use of toxin with booster injections allowed refinement of dosing strategy and outcomes, with benefits that were meaningful to patients clearly visible on videotaped evaluations. In addition to its application to musicians' dystonia, this approach may have relevance to optimize application of botulinum toxin in other forms of focal dystonia such as blepharospasm, cervical dystonia, writer's cramp, and spasmodic dysphonia.

Effect of ultrasound-guided injection of botulinum toxin type A into shoulder joint cavity on shoulder pain in poststroke patients: study protocol for a randomized controlled trial.

BACKGROUND: Hemiplegic shoulder pain (HSP) is a common complication after stroke. It severely affects the recovery of upper limb motor function. Early shoulder pain in hemiplegic patients is mainly neuropathic caused by central nerve injury or neuroplasticity. Commonly used corticosteroid injections in the shoulder joint can reduce shoulder pain; however, the side effects also include soft tissue degeneration or increased tendon fragility, and the long-term effects remain controversial. Botulinum toxin injections are relatively new and are thought to block the transmission of pain receptors in the shoulder joint cavity and inhibit the production of neuropathogenic substances to reduce neurogenic inflammation. Some studies suggest that the shoulder pain of hemiplegia after stroke is caused by changes in the central system related to shoulder joint pain, and persistent pain may induce the reorganization of the cortical sensory center or motor center. However, there is no conclusive evidence as to whether or not the amelioration of pain by botulinum toxin affects brain function. In previous studies of botulinum toxin versus glucocorticoids (triamcinolone acetonide injection) in the treatment of shoulder pain, there is a lack of observation of differences in changes in brain function. As the content of previous assessments of pain improvement was predominantly subjective, objective quantitative assessment indicators were lacking. Functional near-infrared imaging (fNIRS) can remedy this problem. METHODS: This study protocol is designed for a double-blind, randomized controlled clinical trial of patients with post-stroke HSP without biceps longus tenosynovitis or acromion bursitis. Seventy-eight patients will be randomly assigned to either the botulinum toxin type A or glucocorticoid group. At baseline, patients in each group will receive shoulder cavity injections of either botulinum toxin or glucocorticoids and will be followed for 1 and 4 weeks. The primary outcome is change in shoulder pain on the visual analog scale (VAS). The secondary outcome is the assessment of changes in oxyhemoglobin levels in the corresponding brain regions by fNIRS imaging, shoulder flexion, external rotation range of motion, upper extremity Fugl-Meyer, and modified Ashworth score. DISCUSSION: Ultrasound-guided botulinum toxin type A shoulder joint cavity injections may provide evidence of pain improvement in patients with HSP. The results of this trial are also help to analyze the correlation between changes in shoulder pain and changes in cerebral hemodynamics and shoulder joint motor function. TRIAL REGISTRATION: Chinese clinical Trial Registry, ChiCTR2300070132. Registered 03 April 2023, https://www.chictr.org.cn/showproj.html?proj=193722 .

Concomitant Botulinum Toxin Injections for Neurogenic Detrusor Overactivity and Spasticity-A Retrospective Analysis of Practice and Safety.

As multiple indications for botulinum toxin injections (BTIs) can coexist for neurological patients, there are to date no description of concomitant injections (CIs) to treat both spasticity and neurogenic detrusor overactivity incontinence (NDOI) in patients with spinal cord injuries (SCIs) and multiple sclerosis (MS). We therefore identified patients followed at our institution by health data hub digging, using a specific procedure coding system in use in France, who have been treated at least once with detrusor and skeletal muscle BTIs within the same 1-month period, over the past 5 years (2017-2021). We analyzed 72 patients representing 319 CIs. Fifty (69%) were male, and the patients were mostly SCI (76%) and MS (18%) patients and were treated by a mean number of CIs of 4.4 ± 3.6 [1-14]. The mean cumulative dose was 442.1 ± 98.8 U, and 95% of CIs were performed within a 72 h timeframe. Among all CIs, five patients had symptoms evocative of distant spread but only one had a confirmed pathological jitter in single-fiber EMG. Eleven discontinued CIs for surgical alternatives: enterocystoplasty (five), tenotomy (three), intrathecal baclofen (two) and neurotomy (one). Concomitant BTIs for treating both spasticity and NDOI at the same time appeared safe when performed within a short delay and in compliance with actual knowledge for maximum doses.

Long-Term Enhancement of Botulinum Toxin Injections for Post-Stroke Spasticity by Use of Stretching Exercises-A Randomized Controlled Trial.

Botulinum toxin A (BONT/A) injections play a central role in the treatment of upper limb spasticity in stroke patients. We proposed structured stretching exercises to enhance the effect of post-stroke spasticity relief of the upper limbs following BONT/A injections. A total of 43 patients who had a stroke with grade 2 spasticity or higher on the Modified Ashworth Scale (MAS) in their upper-limb muscles were randomly assigned to the intervention (n = 21) or control group (n = 22). The former received structured stretching exercises after their BONT/A injections for 20 min, 5 days per week, for 6 months at a hospital, while the others conducted self-stretching exercises at home. The outcome measures were assessed before the intervention (T0) and after three (T1) and six months (T2). Significantly greater improvements in the MAS scores of the elbows, wrists, and fingers were found in the intervention group's patients at T1 and T2. The behavioral outcome measures, including shoulder pain, activities of daily living, and quality of life, and our electrophysiological studies also showed a significantly higher enhancement in this patient group. In conclusion, the structured stretching exercises plus BONT/A injections for six months showed a superior effect in relieving post-stroke upper-limb spasticity compared to self-stretching exercises.

Effectiveness of repeated injections of botulinum toxin A on gait and fatigue in adults with spastic paraparesis secondary to multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is the most common neurologic disease in young adults. Spasticity is one of its most disabling symptoms, with botulinum toxin A type A (BoNT-A) being one of the treatments of choice for this symptom. OBJECTIVE: We assessed the response to abobotulinumtoxinA in improving walking ability and fatigue in patients with spastic paraparesis caused by MS. METHODS: We performed a real-world, multicenter, prospective, open-label low-intervention trial in 84 patients with MS and spastic paraparesis of the lower limbs infiltrated with abobotulinumtoxinA (LINITOX study). The response of spasticity, walking ability and fatigue is analyzed in 4 cycles of ultrasound-guided injection in the lower limbs. RESULTS: The patients improved their walking ability by an average of 11.34% meters measured with 6-Minute Walk Test (6MWT), and decreased the percentage of fatigue by 6.86% (4.66 percentage points less), in the 12-Item Multiple Sclerosis Walking Scale (MSWS-12) 4 weeks after abobotulinumtoxinA injection, both values are statistically significant. This improvement seems to persist over time, throughout the cycles. CONCLUSION: We found improved walking ability and less fatigue in patients with MS-related spastic paresis of the lower limbs after injection of abobotulinumtoxinA.

Exploring botulinum toxin's impact on masseter hypertrophy: a randomized, triple-blinded clinical trial.

The present study aimed to assess the effectiveness and functional adverse effects of a single and multiple injections of botulinum toxin A (BoNT-A) for masseter hypertrophy (MH). Twenty-six women complaining about lower third facial enlargement due to MH, received 75 U of BoNT-A (abobotulinum toxin) in each masseter muscles. After 3 months, patients were randomly assigned to receive a second treatment session of Saline Solution: (G1; n = 11) or BoNT-A: (G2; n = 12). Muscle thickness (ultrasound), electrical activity (electromyography; EMG), masticatory performance, and subjective perception of MH were evaluated. Follow-up was performed at 1, 3 and 6 months. Muscle thickness, EMG activity, and masticatory performance were analyzed using ANOVA two-way and Sidak test as post-hoc. Masticatory performance was analyzed by the Friedman's test and Mann-Whitney test. Regarding inter-groups comparisons, there was a significant decrease in the left masseter muscle thickness in the G2 group at the 6 month follow-up (p < 0.02). For EMG, significant differences were evident at the 6 month assessment, with higher masseter activity for G1 (p < 0.05). For masticatory performance, no significant differences were observed throughout the study (p > 0.05) and a higher improvement in subjective perception of MH was observed in the 1 month follow-up for G2 (p < 0.05). In conclusion, BoNT-A is effective for MH, however multiple injections cause functional adverse effects in masseter muscle.

[Botulinum toxin A for idiopathic overactive bladder in women]. / Botulinumtoxin A bei idiopathischer Blasenüberaktivität (iOAB) der Frau.

Following a description of the historic evolution of botulinum toxin A detrusor injections for neurogenic and nonneurogenic bladder overactivity, which was mainly driven by German-speaking countries, the terminological revolution of 2002 and the influence on design and outcomes of upcoming approval studies for the indication overactive bladder (OAB) are examined. OnabotulinumtoxinA (100 IU) for second-line treatment of OAB received European approval in 2013. Phase IV observational studies concerning therapeutic persistence and adherence with onabotulinumtoxinA are analyzed and compared with therapeutic alternatives. Predictors of treatment success and complications are identified and compared to the required preinterventional diagnostic effort. Since onabotulinumtoxinA and sacral neuromodulation (SNM) are competing for second-line OAB treatment, both options are compared with regard to differential indications, effectivity, durability and patient adherence. Gender-specific causes of urgency and urge incontinence in women are differentiated from the diagnosis of OAB and require priority treatment. On the basis of diagnostic examination results, an algorithm for invasive second-line treatment of OAB is presented, since overly liberal utilization of onabotulinumtoxinA in therapy-naive OAB patients has not proven superiority over oral antimuscarinergic standard therapy, which can only be explained by improper patient selection.

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 multicenter, double-blind, randomized, parallel-group, active-controlled, phase 3 clinical trial to compare the effectiveness and safety of two botulinum toxin type A formulations for improving moderate to severe glabellar wrinkles in Asians.

Botulinum toxin type A (BoNT-A) was first isolated in 1946, and since then, several formulations have been developed and widely used to treat wrinkles by inducing muscle paralysis. This multicenter, double-blind, randomized, parallel-group, active-controlled phase 3 clinical trial was designed to evaluate the efficacy and safety of a newly developed BoNT-A formulation, BMI2006, in improving moderate to severe glabellar wrinkles and to compare with existing onabotulinumtoxin A (OBoNT) injections. A total of 276 subjects were enrolled and received 20 units of the randomized material, which was intramuscularly injected into five different locations on the forehead. The primary endpoint, assessed at 4 weeks, showed no statistically significant difference in the improvement rate of glabellar wrinkles between the two groups, with BMI2006 demonstrating non-inferiority to comparator BoNT-A. Secondary endpoints, evaluated by both treating investigators and independent investigators, also exhibited similar improvement rates throughout the study period. Both groups reported high levels of satisfaction with no statistical difference between the two groups. Safety evaluations indicated mild and transient adverse events, with no serious reactions observed. In conclusion, BMI2006 is an effective and safe BoNT-A for treating glabellar wrinkles with an expected duration of action between 8 and 12 weeks.

Positive effect of self-exercise following Botulinum toxin injection on the permanence of the recovery among the patients with HFS and BFS: A clinical trial.

BACKGROUND: Botulinum toxin (BoNT) injection serves as the primary modality for addressing hemifacial spasm (HFS) and blepharospasm (BFS), which are prevalent movement disorders affecting the craniofacial region. However, even though the short-term effectiveness of the botulinum injection may reach over 80%, the long-term effectiveness is still a debatable point Herein, we aim to investigate whether facial self-exercise following the BoNT injection can extend the time period of effectiveness. METHODS: In this study, 51 volunteers who received Onabotilinumtoxin A (BoNTA) treatment for the diagnosis of HFS or BFS, were randomized into 2 groups. A detailed instruction about the self-exercise was given by an experienced physician to the subjects in Group 1. Volunteers were asked to repeat the exercise program afterward and continue to each movement for 5 seconds, to repeat each movement 10 times with a 10-second break, every day, 3 times a week for 1 week. hemifacial spasm grating scale (HSGS) and Jankovic scales were used to assess the efficacy of the treatment. RESULTS: Both groups are similar to each other based on demographic features and the severity of the diseases. According to HSGS and Jankovic scales, at the end of the first month, there was no significant difference between the groups. At the end of the third month, the improvement achieved in the first month remained the same in each parameter in Group 1. On the other hand, in Group 2, most of the values returned to the baseline. CONCLUSION: Facial self-exercise following the botulinum toxin application may extend the period of effectiveness of botulinum toxin treatment the subjects with HFS and BFS.

Assessment of pain relief after four botulinum toxin A injection cycles in patients with post-stroke lower limb spasticity: A prospective, observational study.

INTRODUCTION: Spasticity is common after a stroke and is an independent risk factor for developing pain. BotulinumtoxinA injection is the treatment of choice for focal spasticity. We examined the effect of intramuscular botulinumtoxinA on pain relief in patients in routine clinical practice who were experiencing pain as a primary complaint associated with post-stroke lower limb spasticity. METHODS: Prospective, multicentre, post-marketing observational study. The study period was 16 months. The primary effectiveness variable was the mean change from baseline on the pain 0-10 Numerical Rating Scale after four botulinumtoxinA injection cycles. Secondary endpoints included changes from baseline on the pain 0-100 Visual Analogue Scale, Goal Attainment Scale, modified Ashworth Scale, 10-Meter Walk Test, Penn Spasm Frequency Scale, and 36-item Short-Form Health Survey. RESULTS: Of 186 enrolled patients, 180 (96.8%) received botulinumtoxinA at least once. The mean (standard deviation) pain 0-10 Numerical Rating Scale score decreased significantly (p<0.0001) from 4.9 (2.2) at baseline to 2.5 (2.1) at study end, representing a 50% decrease in pain severity. Relief of pain due to spasticity was supported by improvement from baseline in all secondary variables except the 10-Meter Walk Test. Two adverse events (erysipelas and phlebitis) in one patient were considered likely to be related to botulinumtoxinA injection. CONCLUSION: BotulinumtoxinA appears to provide pain relief as an additional benefit of local treatment in patients with post-stroke lower limb spasticity for whom pain relief is a primary therapeutic goal (a Lay Abstract has been provided as Appendix A).

Outcomes of sequential third-line therapies in patients with refractory overactive bladder.

INTRODUCTION: Sacral neuromodulation (SNM) and onabotulinumtoxinA (BoNTA) injection are third-line therapies for overactive bladder (OAB). Although the efficacy of each third-line treatment has been well established in clinical trials, there is far less information about performing one third-line therapy after the other. Our aim is thus to investigate the outcomes of post-SNM BoNTA and post-BoNTA SNM as "second" third-line treatments. METHODS: We retrospectively reviewed all OAB patients who had both SNM and BoNTA between 2013 and 2022. The primary endpoint was the response rates (>50% improvements) of the second third-line treatments. Secondary endpoints were the proportion of the patients who achieved total dry, the duration of treatments of patients who had significant responses, and risk factors that are associated with treatment response or duration of treatments. RESULTS: A total of 172 patients had two third-line therapies. There were 104 patients who had post-SNM BoNTA and 68 patients who had post-BoNTA SNM. In the post-SNM BoNTA group, 62.5% (65/104) had significant responses after BoNTA treatment. In the post-BoNTA SNM group, 61.8% (44/68) had significant responses after SNM treatment. The proportions of patients who became dry were 21.2% and 23.5%, respectively. In the post-SNM BoNTA group, spinal pathology is associated with a lower probability of a significant response (48.9% vs. 73.7%, p-value = 0.0105). CONCLUSIONS: BoNTA or SNM remains a viable option for refractory OAB after patients fail from one another. Spinal pathology is associated with a poorer response of post-SNM BoNTA.

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.