OnabotulinumtoxinA Improves Pain in Patients With Post-Stroke Spasticity: Findings From a Randomized, Double-Blind, Placebo-Controlled Trial

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).

Pain, disability, and quality of life in participants after concurrent onabotulinumtoxinA treatment of upper and lower limb spasticity: Observational results from the ASPIRE study

INTRODUCTION

Upper and lower limb spasticity is commonly associated with central nervous system disorders including stroke, traumatic brain injury, multiple sclerosis, cerebral palsy, and spinal cord injury, but little is known about the concurrent treatment of upper and lower limb spasticity with botulinum toxins.

OBJECTIVE

To evaluate onabotulinumtoxinA (onabotA) utilization and to determine if concurrent onabotA treatment of the upper and lower limbs has supported improvements in participants with spasticity.

DESIGN

Sub-analysis of a 2-year, international, prospective, observational registry (ASPIRE, NCT01930786).

SETTING

International clinic sites (54).

PARTICIPANTS

Adult spasticity participants across etiologies, who received ≥1 concurrent onabotA treatment of the upper and lower limbs during the study.

INTERVENTION

Participants were treated with onabotA at the clinician's discretion.

OUTCOMES

Baseline characteristics and outcomes of disability (Disability Assessment Scale [DAS]), pain (Numeric Pain Rating Scale [NPRS]), participant satisfaction, physician satisfaction, and quality of life (QoL; Spasticity Impact Assessment [SIA]) were evaluated. Adverse events were monitored throughout the study.

RESULTS

Of 744 participants enrolled, 730 received ≥1 dose of onabotA; 275 participants received treatment with onabotA in both upper and lower limbs during ≥1 session; 39.3% of participants were naïve to onabotA for spasticity. The mean (SD) total dose per treatment session ranged from 421.2 (195.3) to 499.6 (188.6) U. The most common baseline upper limb presentation was clenched fist (n = 194, 70.5%); lower limb was equinovarus foot (n = 219, 66.9%). High physician and participant satisfaction and improvements in pain, disability and QoL were reported after most treatments. Nine participants (3.3%) reported nine treatment-related adverse events; two participants (0.7%) reported three serious treatment-related severe adverse events. No new safety signals were identified.

CONCLUSION

More than a third of enrolled participants received at least one concurrent onabotA treatment of the upper and lower limbs, with reduced pain, disability, and improved QoL after treatment, consistent with the established safety profile of onabotA for the treatment of spasticity.

Botulinum toxin in the rehabilitation of painful syndromes: multiperspective literature analysis, lexical analysis and systematic review of randomized controlled trials

Pain represents a common symptom of several diseases and is often associated with a reduction in rehabilitation outcomes and recovery. The effectiveness of pain alleviation by botulinum toxin has been recently demonstrated. We searched in PubMed the papers about this topic published in the last ten years, and we selected clinical trials, guidelines, meta-analyses, reviews, and systematic reviews. We used different approaches: multiperspective presentation, lexical evaluation, and systematic review. The systematic review was only performed for the randomized controlled trials. We predominantly found reviews and trials about the rehabilitation of stroke/brain injury and epicondylitis. The most common outcome measures were pain, function, and spasticity. Among the common words, pain was the most frequent and the terms were grouped into different families, especially concerning the outcomes. Rehabilitation showed a relatively low frequency. Finally, the systematic review showed moderate-low levels of bias which confirms the effectiveness of botulinum toxin for pain treatment. The current literature about botulinum toxin is wide and globally diffuse but with some limitations in study strategies and clearness in the formal presentation. The evidence justifies the use of botulinum toxin in treating pain in different diseases.

Pericranial Muscle Stiffness, Pain Thresholds, and Tenderness during a Treatment Cycle of OnabotulinumtoxinA for Chronic Migraine Prevention

BACKGROUND

Treatment with OnabotulinumtoxinA (BoNT-A) is effective as a preventive treatment for chronic migraine (CM). Preclinical studies suggest that the mechanism of action of BoNT-A in migraine is based on blocking unmyelinated C fibers. We aimed to investigate whether the muscle-relaxing effect of BoNT-A is associated with the preventive mechanism in patients with chronic migraine by measuring the stiffness, pain thresholds, and tenderness of the BoNT-A-applied muscles.

METHODS

A total of 22 patients with CM who were already in BoNT-A treatment participated in this longitudinal prospective study. Pericranial muscle stiffness was measured using ultrasound shear wave elastography, which measures the speed of shear waves propagating through the muscle. Pressure pain thresholds (PPT) were obtained via algometry, and muscle tenderness was measured via manual palpation. Measurements were made before BoNT-A injections and six weeks after the treatment. The measurements were performed while the muscles were maximally relaxed. The patients also completed daily diaries on headache and neck pain.

RESULTS

No change was observed in muscle stiffness (p = 0.737) or pericranial muscle tenderness (p = 0.400). The PPT over the trapezius muscles increased from 250 kPa before treatment to 304 kPa six weeks after treatment (p = 0.027). No change was observed on the temporalis muscles (p = 0.200) nor the non-dominant index finger (p = 0.067). BoNT-A decreased neck pain (p = 0.008) and headache (p = 0.007).

CONCLUSIONS

The findings suggest that BoNT-A leads to the desensitization of cutaneous and muscle nociceptors in the head and neck regions, whereas muscle relaxation might not be an important part of the anti-migraine effect.

Changes in serum levels of pain mediators in hemiplegic shoulder pain

OBJECTIVE

To provide a new insight into the diagnosis and treatment of hemiplegic shoulder pain (HSP) by investigating changes in serum pain mediators.

DESIGN

Cross-sectional study.

SUBJECTS/PATIENTS

Shoulder pain group (n = 34) and control group (n = 21).

METHODS

Pain-free shoulder mobility, anxiety status, depression status, and shoulder pain were measured by passive range of motion (PROM), self-rating anxiety scale, self-rating depression scale (SDS), and visual analog scale, respectively. The enzyme-linked immunosorbent assay was used to test the serum pain mediators, including interleukin (IL)-1β, IL-2, IL-6, IL-10, nerve growth factor (NGF), tumor necrosis factor-α (TNF-α), substance P (SP), calcitonin gene-related peptide (CGRP), bradykinin (BK), 5-hydroxytryptamine (5-HT), prostaglandin E2 (PGE2), and lysophosphatidic acid (LPA).

RESULTS

Shoulder pain group pain-free PROM significantly lower than control (p < .01), and SDS index score of shoulder pain group was significantly higher than control (p < .05). The rate of spasticity in the flexor elbow muscles is higher in shoulder pain group (p < .01). CGRP, IL-10, and IL-2 were significantly upregulated in shoulder pain group compared with control (p < .01), whereas NGF, TNF-α, IL-6, 5-HT, PGE2, SP, LPA, BK, and IL-1β were significantly decreased (p < .01).

CONCLUSION

Patients with HSP have a higher risk of joint mobility disorders and depression; spasticity may be an important factor in the development of shoulder pain; CGRP is thought to be the major pain mediator in HSP, and HSP may not be inflammatory.

Treatment of chronic migraine with Botox (onabotulinumtoxinA): Development, insights, and impact

Chronic migraine (CM) is a neurological disease characterized by frequent migraine attacks that prevent affected individuals from performing daily activities of living, significantly diminish quality of life, and increase familial burden. Before onabotulinumtoxinA was approved for CM, there were few treatment options for these seriously disabled patients and none had regulatory approval. The terminology and recognition of CM evolved in parallel with the onabotulinumtoxinA clinical development program. Because there were no globally accepted classification criteria for CM when onabotulinumtoxinA was in development, the patient populations for the trials conducted by Allergan were determined by the Allergan migraine team in collaboration with headache scientists and clinicians. These trials and collaborations ultimately led to improvements in CM classifications. In 2010, onabotulinumtoxinA became the first medication and first biologic approved specifically to prevent headaches in patients with CM. Approval was based on 2 similarly designed phase 3, double-blind, randomized, placebo-controlled, multicenter clinical studies. Both studies showed significantly greater improvements in mean change from baseline in headache-day frequency in patients with CM receiving onabotulinumtoxinA compared with those receiving placebo. The safety and effectiveness of onabotulinumtoxinA have been established globally in >5000 patients with CM with or without medication overuse treated in clinical and observational studies. Benefits also include improvements in quality of life, fewer psychiatric comorbidities, and reduced healthcare resource utilization. Across studies, onabotulinumtoxinA was well tolerated; adverse events tended to be mild or moderate in severity and to decline over subsequent treatment cycles.

The pluripotential evolution and journey of Botox (onabotulinumtoxinA)

Clinical use of onabotulinumtoxinA evolved based on strategic, hypothesis-driven applications, as well as serendipitous observations by physicians and patients. The success of onabotulinumtoxinA in blepharospasm and strabismus led to its study in other head and neck dystonias, followed by limb dystonia, tremor, and spasticity. The aesthetic use of onabotulinumtoxinA followed initial reports from patients of improved facial lines after injections for facial dystonias and hemifacial spasm. Although patients with dystonias and spasticity regularly reported that their local pain improved after injections, onabotulinumtoxinA was not systematically explored for chronic migraine until patients began reporting headache improvements following aesthetic injections. Clinicians began assessing onabotulinumtoxinA for facial sweating and hyperhidrosis based on its inhibition of acetylcholine from sympathetic cholinergic nerves. Yet another line of research grew out of injections for laryngeal dystonia, whereby clinicians began to explore other sphincters in the gastrointestinal tract and eventually to treatment of pelvic sphincters; many of these sphincters are innervated by autonomic nerves. Additional investigations in other autonomically mediated conditions were conducted, including overactive bladder and neurogenic detrusor overactivity, achalasia, obesity, and postoperative atrial fibrillation. The study of onabotulinumtoxinA for depression also grew out of the cosmetic experience and the observation that relaxing facial muscle contractions associated with negative emotions may improve mood. For approved indications, the safety profile of onabotulinumtoxinA has been demonstrated in the formal development programs and post-marketing reports. Over time, evidence has accumulated suggesting clinical manifestations of systemic effects, albeit uncommon, particularly with high doses and in vulnerable populations. Although onabotulinumtoxinA is approved for approximately 26 indications across multiple local regions, there are 15 primary indication uses that have been approved in most regions, including the United States, Europe, South America, and Asia. This review describes many uses for which AbbVie has not sought and/or received regulatory approval and are mentioned for historical context only.

Treatment of adult spasticity with Botox (onabotulinumtoxinA): Development, insights, and impact

Upper and lower limb spasticity (ULS, LLS) often occur following a stroke or in patients with other neurological disorders, leading to difficulties in mobility and daily living and decreased quality of life. Prior to the use of onabotulinumtoxinA, antispastic medications had limited efficacy and often caused sedation. Phenol injections were difficult for physicians to perform, painful, and led to tissue destruction. The success of onabotulinumtoxinA in treating cervical dystonia led to its use in spasticity. However, many challenges characterized the development of onabotulinumtoxinA for adult spasticity. The wide variability in the presentation of spasticity among patients rendered it difficult to determine which muscles to inject and how to measure improvement. Another challenge was the initial refusal of the Food and Drug Administration to accept the Ashworth Scale as a primary endpoint. Additional scales were designed to incorporate a goal-oriented, patient-centered approach that also accounted for the variability of spasticity presentations. Several randomized, double-blind, placebo-controlled trials of post-stroke spasticity of the elbow, wrist, and/or fingers showed significantly greater improvements in the modified Ashworth Scale and patient treatment goals and led to the approval of onabotulinumtoxinA for the treatment of ULS in adult patients. Lessons learned from the successful ULS trials were applied to design an LLS trial that led to approval for the latter indication. Additional observational trials mimicking real-world treatment have shown continued effectiveness and patient satisfaction. The use of onabotulinumtoxinA for spasticity has ushered in a more patient-centered treatment approach that has vastly improved patients' quality of life.

Botulinum toxin for motor disorders

Botulinum neurotoxins are a group of biological toxins produced by the gram-negative bacteria Clostridium botulinum. After intramuscular injection, they produce dose-related muscle relaxation, which has proven useful in the treatment of a large number of motor and movement disorders. In this chapter, we discuss the utility of botulinum toxin treatment in three major and common medical conditions related to the dysfunction of the motor system, namely dystonia, tremor, and spasticity. A summary of the existing literature is provided along with different techniques of injection including those recommended by the authors.

Effectiveness of Botulinum Toxin on Pain in Stroke Patients Suffering from Upper Limb Spastic Dystonia

This observational study aimed at investigating pain in stroke patients with upper limb spastic dystonia. Forty-one consecutive patients were enrolled. A 0–10 numeric rating scale was used to evaluate pain at rest and during muscle tone assessment. Patients were asked to indicate the most painful joint at passive mobilization (shoulder, elbow, wrist-fingers). The DN4 questionnaire was administered to disclose neuropathic pain. All patients were assessed just before and 1 month after incobotulinumtoxin-A treatment. Pain was present in 22 patients, worsened or triggered by passive muscle stretching. DN4 scored < 4 in 20 patients. The most painful joints were wrist–fingers in 12 patients, elbow in 5 patients and shoulder in the remaining 5 patients. Both elbow and wrist–fingers pain correlated with muscle tone. BoNT-A treatment reduced pain in all the joints, including the shoulder. We discussed that nociceptive pain is present in a vast proportion of patients with upper limb spastic dystonia. BoNT-A treatment reduced both spastic dystonia and pain in all the joints but the shoulder, where the effect on pain could be mediated by the reduction of pathological postures involving the other joints.

Assessment, goal setting, and botulinum neurotoxin a therapy in the management of post-stroke spastic movement disorder: updated perspectives on best practice

INTRODUCTION

Post-stroke spastic movement disorder (PS-SMD) appears up to 20% in the first week following stroke and 40% in the chronic phase. It may create major hurdles to overcome in early stroke rehabilitation and as one relevant factor that reduces quality of life to a major degree in the chronic phase.

AREAS COVERED

In this review, we discuss predictors,early identification, clinical assessments, goal setting, and management in multiprofessional team, including Botulinum neurotoxin A (BoNT-A) injection for early and chronic management of PS-SMD.

EXPERT OPINION

The earlier PS-SMD is recognized and managed, the better the outcome will be. The comprehensive management in the subacute or chronic phase of PS-SMD with BoNT-A injections requires detailed assessment, patient-centered goal setting, technical-guided injection, effective dosing of BoNT-A per site, muscle, and session and timed adjunctive treatment, delivered in a multi-professional team approach in conjunction with physical treatment. Evidence-based data showed BoNT-A injections are safe and effective in managing focal, multifocal, segmental PS-SMD and its complications. If indicated, BoNT-A therapy should be accompanied with adjunctive treatment in adequate time slots. BoNT-A could be added to oral, intrathecal, and surgical treatment in severe multisegmental or generalized PS-SMD to reach patient/caregiver's goals, especially in chronic PS-SMD.

Pain Reduction in Adults with Limb Spasticity Following Treatment with IncobotulinumtoxinA: A Pooled Analysis

Some studies have shown that incobotulinumtoxinA reduces spasticity-associated pain, but further evidence is needed. This exploratory analysis pooled pain-relief data from six Phase 2 or 3 studies of incobotulinumtoxinA (four placebo-controlled studies) for treating upper limb spasticity in adults. Spasticity-associated pain was assessed at baseline and 4 weeks post incobotulinumtoxinA injection using the disability assessment scale (DAS) for pain. Only data for patients with pain at baseline were analysed. Overall, 544 (incobotulinumtoxinA, N = 415; placebo, N = 129) of 937 patients (58.1%) experienced pain at baseline. At Week 4, a significantly greater proportion of incobotulinumtoxinA- (52.1%) than placebo-treated patients (28.7%; Chi-square p < 0.0001) showed a response (≥1-point improvement in DAS pain score). In logistic regression analysis, incobotulinumtoxinA-treated patients were 2.6 times more likely to achieve this endpoint than placebo-treated patients. A significant difference between incobotulinumtoxinA and placebo was observed regardless of baseline pain severity. Additionally, 27.1% of incobotulinumtoxinA- versus 12.4% of placebo-treated patients reported complete pain relief at Week 4 (p = 0.0006). Pain relief increased with multiple injection cycles. To achieve patient-centred care, pain relief may be considered a treatment goal in adults with spasticity-associated pain regardless of pain severity. This study contributes to understanding the benefits of incobotulinumtoxinA in treating limb spasticity-associated pain.

Ultrasonographic Evaluation of Three Approaches for Botulinum Toxin Injection into Tibialis Posterior Muscle in Chronic Stroke Patients with Equinovarus Foot: An Observational Study

Spastic equinovarus (SEV) foot deformity is commonly observed in patients with post-stroke spasticity. Tibialis posterior (TP) is a common target for botulinum toxin type-A (BoNT-A) injection, as a first-line treatment in non-fixed SEV deformity. For this deep muscle, ultrasonographic guidance is crucial to achieving maximum accuracy for the BoNT-A injection. In current clinical practice, there are three approaches to target the TP: an anterior, a posteromedial, and a posterior. To date, previous studies have failed to identify the best approach for needle insertion into TP. To explore the ultrasonographic characteristics of these approaches, we investigated affected and unaffected legs of 25 stroke patients with SEV treated with BoNT-A. We evaluated the qualitative (echo intensity) and quantitative (muscle depth, muscle thickness, overlying muscle, subcutaneous tissue, cross-sectional area) ultrasound characteristics of the three approaches for TP injection. In our sample, we observed significant differences among almost all the parameters of the three approaches, except for the safety window. Moreover, our analysis showed significant differences in cross-sectional area between treated and untreated. Advantages and disadvantages of each approach were investigated. Our findings can thus provide a suitable reference for clinical settings, especially for novice operators.

Efficacy of rehabilitative techniques in reducing hemiplegic shoulder pain in stroke: Systematic review and meta-analysis

BACKGROUND

Hemiplegic shoulder pain (HSP) is a disabling complication affecting stroke survivors. In this context, rehabilitation might play a key role in its clinical management. Recent systematic reviews of the impact of rehabilitative approaches on pain reduction in patients with HSP are lacking.

OBJECTIVE

This systematic review of randomized controlled trials (RCTs) with meta-analysis aimed to investigate the efficacy of rehabilitative techniques in reducing HSP in stroke survivors.

METHODS

PubMed, Scopus, and Web of Science were searched from inception to March 8, 2021 to identify RCTs of stroke survivors with HSP undergoing specific rehabilitative techniques combined with conventional therapy to reduce pain intensity. A network meta-analysis and meta-analysis of the Bayesian network of random effects were performed. The risk of bias of studies was assessed with Version 2 of the Cochrane Risk of Bias tool for randomized trials.

RESULTS

Of 1139 articles identified, 12 were included in the final synthesis. We analyzed data for 723 stroke survivors, reporting a significant overall decrease in pain intensity after a rehabilitative approach by the Bayesian meta-analysis (standardized mean difference 2.78, 95% confidence interval 0.89;-4.59; p = 0.003). We report a significant reduction in HSP with botulinum toxin type A injection (p = 0.001), suprascapular nerve pulsed radiofrequency (p = 0.030), suprascapular nerve block (p = 0.020), and trigger-point dry needling (p = 0.005) as compared with conventional rehabilitation. Concerning the effect size, we identified a Bayesian factor₁₀ of 97.2, with very strong evidence of superiority of rehabilitative techniques.

CONCLUSIONS

The present systematic review and meta-analysis showed that adding other rehabilitative techniques to conventional rehabilitation was significantly more effective than conventional rehabilitation alone in the complex management of patients affected by HSP.

The Safety and Effect of Local Botulinumtoxin A Injections for Long-Term Management of Chronic Pain in Post-Herpetic Neuralgia: Literature Review and Cases Report Treated with Incobotulinumtoxin A

There are few reports on the safety and effectiveness of long-term botulinumtoxin A (BoNT A) therapy in severe chronic pain of post-herpetic neuralgia (PHN). The literature was searched with the term "neuropathic pain" and "botulinum" on PubMed (up to 29 February 2020). Pain was assessed with the Visual Analogue Scale (VAS) before and after BoNT A therapy. A total of 10 clinical trials and six case reports including 251 patients with PHN were presented. They showed that BoNT A therapy had significant pain reduction (up to 30-50%) and improvement in quality of life. The effect duration seems to be correlated with BoNT A doses injected per injection site. Intervals between BoNT A injections were 10-14 weeks. No adverse events were reported in cases and clinical studies, even in the two pregnant women, whose babies were healthy. The repeated (≥6 times) intra/subcutaneous injections of incobotulinumtoxin A (Xeomin®, Merz Pharmaceuticals, Germany) over the two years of our three cases showed marked pain reduction and no adverse events. Adjunctive local BoNT A injection is a promising option for severe PHN, as a safe and effective therapy in long-term management for chronic neuropathic pain. Its effect size and -duration seem to be depended on the dose of BoNT A injected per each point.

Real-World Adherence to OnabotulinumtoxinA Treatment for Spasticity: Insights From the ASPIRE Study

OBJECTIVE

To identify baseline characteristics and treatment-related variables that affect adherence to onabotulinumtoxinA treatment from the Adult Spasticity International Registry (ASPIRE) study.

DESIGN

Prospective, observational registry (NCT01930786).

SETTING

International clinical sites.

PARTICIPANTS

Adults with spasticity (N=730).

INTERVENTIONS

OnabotulinumtoxinA at clinician's discretion.

MAIN OUTCOME MEASURES

Clinically meaningful thresholds used for treatment adherent (≥3 treatment sessions during 2-year study) and nonadherent (≤2 sessions). Data analyzed using logistic regression and presented as odds ratios (ORs) with 95% confidence intervals (CIs). Treatment-related variables assessed at sessions 1 and 2 only.

RESULTS

Of the total population, 523 patients (71.6%) were treatment adherent with 5.3±1.6 sessions and 207 (28.4%) were nonadherent with 1.5±0.5 sessions. In the final model (n=626/730), 522 patients (83.4%) were treatment adherent and 104 (16.6%) were nonadherent. Baseline characteristics associated with adherence: treated in Europe (OR=1.84; CI, 1.06-3.21; P=.030) and use of orthotics (OR=1.88; CI, 1.15-3.08; P=.012). Baseline characteristics associated with nonadherence: history of diplopia (OR=0.28; CI, 0.09-0.89; P=.031) and use of assistive devices (OR=0.51; CI, 0.29-0.90; P=.021). Treatment-related variables associated with nonadherence: treatment interval ≥15 weeks (OR=0.43; CI, 0.26-0.72; P=.001) and clinician dissatisfaction with onabotulinumtoxinA to manage pain (OR=0.18; CI, 0.05-0.69; P=.012). Of the population with stroke (n=411), 288 patients (70.1%) were treatment adherent with 5.3±1.6 sessions and 123 (29.9%) were nonadherent with 1.5±0.5 session. In the final stroke model (n=346/411), 288 patients (83.2%) were treatment adherent and 58 (16.8%) were nonadherent. Baseline characteristics associated with adherence: treated in Europe (OR=2.99; CI, 1.39-6.44; P=.005) and use of orthotics (OR=3.18; CI, 1.57-6.45; P=.001). Treatment-related variables associated with nonadherence: treatment interval ≥15 weeks (OR=0.42; CI, 0.21-0.83; P=.013) and moderate/severe disability on upper limb Disability Assessment Scale pain subscale (OR=0.40; CI, 0.19-0.83; P=.015).

CONCLUSIONS

These ASPIRE analyses demonstrate real-world patient and clinical variables that affect adherence to onabotulinumtoxinA and provide insights to help optimize management strategies to improve patient care.

Botulinum Neurotoxin for the Treatment of Neuropathic Pain

Botulinum neurotoxin is widely used for the treatment of central and peripherical neurological conditions. Initially used to treat strabismus, over the years its use has been expanded also to spasticity and other neurological disorders. This review summarizes the evidence from the published literature regarding its effect on neuropathic pain. Almost all investigations were performed using onabotulinum toxin type A (BoNT/A). Most studies provided positive results, even though toxin formulation, dose, dilution, injection techniques, and sites are heterogeneous across studies. Future larger, high-quality, specifically designed clinical trials are warranted to confirm botulinum neurotoxin efficacy in neuropathic pain.

Feasibility and potential effects of using the electro-dress Mollii on spasticity and functioning in chronic stroke

Background

Spasticity after lesions of central motor pathways may be disabling and there is a need for new, cost-effective treatment methods. One novel approach is offered by the electro-dress Mollii®, primarily designed to enhance reciprocal inhibition of spastic muscles by multifocal, transcutaneous antagonist stimulation.

Methods

The Mollii® suit was set individually for 20 participants living with spasticity and hemiplegia after stroke and used in the home setting for 6 weeks. Usability and perceived effects were monitored by weekly telephone interviews. Outcome was assessed by use of the NeuroFlexor™ method for quantification of the neural component (NC) of resistance to passive stretch (spasticity), and the modified Ashworth scale (MAS) for total resistance, Fugl-Meyer Assessment of motor recovery for sensorimotor function in upper (FM-UE) and lower extremities (FM-LE), activity performance with the Action Research Arm Test (ARAT), Berg balance scale, 10 m and 6 min walk tests, and perceived functioning with the Stroke Impact Scale.

Results

Compliance was high (mean 19.25 of 21 sessions). Perceived positive effects were reported by 60% and most commonly related to decreased muscle tone (n = 9), improved gait pattern function (n = 7) and voluntary movement in the upper extremity (n = 6). On a group level, the NC decreased significantly in the wrist flexors of the affected hand (p = 0.023) and significant improvements according to FM-UE (p = 0.000) and FM-LE (p = 0.003) were seen after the intervention. No significant difference was detected with MAS or assessed activity performance, except for the ARAT (p = 0.000). FM-UE score change correlated significantly and fairly with the perceived effect in the upper extremity (r 0.498 p = 0.025) and in the corresponding analysis for the FM-LE and perceived effect in the lower extremity (r = 0.469 p = 0.037).

Conclusion

This study indicates that the Mollii® method is feasible when used in the home setting to decrease spasticity and improve sensorimotor function. The results may guide a larger controlled study combined with rehabilitation interventions to enhance effects on activity and participation domains.

Trial registration

NCT04076878. Registered 2 September 2019 - Retrospectively registered

Mechanism of Action of OnabotulinumtoxinA in Chronic Migraine: A Narrative Review

Objective

To review the literature on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Background

OnabotulinumtoxinA is a chronic migraine preventive treatment that significantly reduces headache frequency. The traditional mechanism described for onabotulinumtoxinA – reducing muscle contractions – is insufficient to explain its efficacy in migraine, which is primarily a sensory neurological disease.

Methods

A narrative literature review on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Results

Following injection into tissues, onabotulinumtoxinA inhibits soluble N‐ethylmaleimide‐sensitive fusion attachment protein receptor (SNARE)‐mediated vesicle trafficking by cleaving one of its essential proteins, soluble N‐ethylmaleimide‐sensitive fusion attachment protein (SNAP‐25), which occurs in both motor and sensory nerves. OnabotulinumtoxinA inhibits regulated exocytosis of motor and sensory neurochemicals and proteins, as well as membrane insertion of peripheral receptors that convey pain from the periphery to the brain, because both processes are SNARE dependent. OnabotulinumtoxinA can decrease exocytosis of pro‐inflammatory and excitatory neurotransmitters and neuropeptides such as substance P, calcitonin gene‐related peptide, and glutamate from primary afferent fibers that transmit nociceptive pain and participate in the development of peripheral and central sensitization. OnabotulinumtoxinA also decreases the insertion of pain‐sensitive ion channels such as transient receptor potential cation channel subfamily V member 1 (TRPV1) into the membranes of nociceptive neurons; this is likely enhanced in the sensitized neuron. For chronic migraine prevention, onabotulinumtoxinA is injected into 31‐39 sites in 7 muscles of the head and neck. Sensory nerve endings of neurons whose cell bodies are located in trigeminal and cervical ganglia are distributed throughout the injected muscles, and are overactive in people with migraine. Through inhibition of these sensory nerve endings, onabotulinumtoxinA reduces the number of pain signals that reach the brain and consequently prevents activation and sensitization of central neurons postulated to be involved in migraine chronification.

Conclusion

OnabotulinumtoxinA likely acts via sensory mechanisms to treat chronic migraine.

Effectiveness of AbobotulinumtoxinA in Post-stroke Upper Limb Spasticity in Relation to Timing of Treatment

Background: Recent studies of botulinum toxin for post-stroke spasticity indicate potential benefits of early treatment (i. e., first 6 months) in terms of developing hypertonicity, pain and passive function limitations. This non-interventional, longitudinal study aimed to assess the impact of disease duration on the effectiveness of abobotulinumtoxinA treatment for upper limb spasticity. Methods: The early-BIRD study (NCT01840475) was conducted between February 2013 and 2018 in 43 centers across Germany, France, Austria, Netherlands and Switzerland. Adult patients with post-stroke upper limb spasticity undergoing routine abobotulinumtoxinA treatment were followed for up to four treatment cycles. Patients were categorized by time from stroke event to first botulinum toxin-A treatment in the study (as defined by the 1st and 3rd quartiles time distribution) into early-, medium- and late- start groups. We hypothesized that the early-start group would show a larger benefit (decrease) as assessed by the modified Ashworth scale (MAS, primary endpoint) on elbow plus wrist flexors compared with the late-start group. Results: Of the 303 patients enrolled, 292 (96.4%) received ≥1 treatment and 186 (61.4%) received 4 injection cycles and completed the study. Patients in all groups showed a reduction in MAS scores from baseline over the consecutive injection visits (i.e., at end of each cycle). Although reductions in MAS scores descriptively favored the early treatment group, the difference compared to the late group did not reach statistical significance at the last study visit (ANCOVA: difference in adjusted means of 0.15, p = 0.546). Conclusions: In this observational, routine-practice study, patients in all groups displayed a benefit from abobotulinumtoxinA treatment, supporting the effectiveness of treatment for patients at various disease stages. Although the data revealed some trends in favor of early vs. late treatment, we did not find strong evidence for a significant benefit of early vs. late start of treatment in terms of reduction in MAS scores.

Canadian Stroke Best Practice Recommendations: Rehabilitation, Recovery, and Community Participation following Stroke. Part One: Rehabilitation and Recovery Following Stroke; 6th Edition Update 2019

The sixth update of the Canadian Stroke Best Practice Recommendations: Rehabilitation, Recovery, and Reintegration following Stroke. Part one: Rehabilitation and Recovery Following Stroke is a comprehensive set of evidence-based guidelines addressing issues surrounding impairments, activity limitations, and participation restrictions following stroke. Rehabilitation is a critical component of recovery, essential for helping patients to regain lost skills, relearn tasks, and regain independence. Following a stroke, many people typically require rehabilitation for persisting deficits related to hemiparesis, upper-limb dysfunction, pain, impaired balance, swallowing, and vision, neglect, and limitations with mobility, activities of daily living, and communication. This module addresses interventions related to these issues as well as the structure in which they are provided, since rehabilitation can be provided on an inpatient, outpatient, or community basis. These guidelines also recognize that rehabilitation needs of people with stroke may change over time and therefore intermittent reassessment is important. Recommendations are appropriate for use by all healthcare providers and system planners who organize and provide care to patients following stroke across a broad range of settings. Unlike the previous set of recommendations, in which pediatric stroke was included, this set of recommendations includes primarily adult rehabilitation, recognizing many of these therapies may be applicable in children. Recommendations related to community reintegration, which were previously included within this rehabilitation module, can now be found in the companion module, Rehabilitation, Recovery, and Community Participation following Stroke. Part Two: Transitions and Community Participation Following Stroke.

Safety of OnabotulinumtoxinA with Concomitant Antithrombotic Therapy in Patients with Muscle Spasticity: A Retrospective Pooled Analysis of Randomized Double-Blind Studies

BACKGROUND

OnabotulinumtoxinA is approved as a treatment across multiple indications. For the treatment of spasticity, onabotulinumtoxinA is injected directly into affected muscles. Intramuscular injections may result in local bleeding and related complications, especially in patients receiving anticoagulant therapy. Despite anticoagulants being commonly used, there is limited information in the medical literature regarding the safety of intramuscular medications in patients receiving oral anticoagulants. This retrospective analysis included pooled safety data from Allergan-sponsored studies evaluating onabotulinumtoxinA for the treatment of patients with muscle spasticity.

OBJECTIVE

The objective of this study was to determine the risk of bleeding complications in patients with post-stroke spasticity receiving antithrombotic therapy and intramuscular onabotulinumtoxinA.

METHODS

We conducted a retrospective analysis of pooled safety data from 16 randomized, double-blind, placebo-controlled Allergan-sponsored studies of onabotulinumtoxinA for the treatment of post-stroke upper or lower limb muscle spasticity, including adult patients with at least moderate upper or lower limb spasticity and receiving at least one dose of the study drug. Bleeding-related adverse events starting within 4 weeks of study treatment were assessed. The incidence rates of bleeding complications were compared for patients receiving classes of antithrombotic therapy vs those not receiving antithrombotic therapy and for those receiving onabotulinumtoxinA vs placebo (with or without antithrombotic therapy).

RESULTS

Of 1877 patients, 1182 received antithrombotic therapy. The overall incidence of bleeding complications was < 2%. In those receiving any antithrombotic therapy, the incidence of bleeding was 1.0% vs 1.4% (no antithrombotic therapy); after onabotulinumtoxinA, it was 0.9% for those receiving antithrombotic therapy vs 1.4% (no antithrombotic therapy), and for placebo 1.2% vs 1.4%, respectively. Subgroup results were similar.

CONCLUSIONS

No apparent increased risk of bleeding complications was observed following administration of onabotulinumtoxinA to patients receiving antithrombotic therapy. Nonetheless, patient education and careful observation of the injection site in patients receiving antithrombotic therapy remains warranted.

Budget impact of botulinum toxin treatment for spasticity after stroke — a German perspective

Aim

Botulinum toxin agents can improve the quality of life of patients with post-stroke upper limb spasticity (ULS) and are recommended by international and German guidelines. However, health-services research indicates an underuse of botulinum toxin agents in this patient group. The study aims to clarify the budget impact of treatment with botulinum toxin agents according to the guidelines for all eligible patients with ULS in Germany compared to usual care.

Methods

The budgetary impact for the statutory health insurance system was estimated by calculating a Markov cohort model with a timeframe of 5 years comparing three treatment options. Four health states were included. The base-case analysis compares standard doses of two botulinum toxin agents to usual care. The model accounts for direct medical costs. Sensitivity analyses vary doses of botulinum toxin agents and prevalence of spasticity after stroke.

Results

In the base case, both botulinum toxin agents lead to increased costs compared to usual care. Treatment with Dysport® (cumulative costs for the 5-year period: €280,321,317) is less expensive than the treatment with Xeomin® (€377,511,529). Cumulative costs over 5 years in usual care are €61,306,062.

Conclusion

The botulinum toxin therapy is associated with additional costs, but an increased use of botulinum toxin would be consistent with guideline-based therapy. In particular, it has to be considered that spasticity as a chronic condition is accompanied by a relevant loss of quality of life. Thus, considering only the therapy costs may not be sufficient for making final therapeutic decisions.

Effect of Intrathecal Baclofen on Pain and Quality of Life in Poststroke Spasticity

Background and Purpose- Intrathecal baclofen (ITB) is an effective treatment for managing patients with severe poststroke spasticity, who can experience continued pain and decline in their quality of life (QoL). SISTERS (Spasticity In Stroke-Randomized Study) was a randomized, controlled, open-label, multicenter, phase 4 study to evaluate ITB therapy versus conventional medical management (CMM) with oral antispastic medications for treatment of poststroke spasticity. Methods- Poststroke patients with spasticity in ≥2 extremities and an Ashworth Scale score of ≥3 in ≥2 affected lower extremity muscle groups were randomized (1:1) to ITB (N=31) or CMM (N=29). Both treatment arms received physiotherapy throughout. The primary outcome was the change in average Ashworth Scale score in the lower extremities of the affected side from baseline to month 6. Here, we report results for secondary outcomes: pain via the Numeric Pain Rating Scale, health-related QoL by the EuroQol-5 dimensional 3 level utility score and health status visual analog scale score, stroke-specific QoL, and patient satisfaction. Analyses were performed on an intention-to-treat basis. Results- We observed significant treatment effects in favor of ITB over CMM for changes from baseline to month 6 in Numeric Pain Rating Scale scores for actual pain (ITB versus CMM: mean, -1.17 [SD, 3.17] versus 0.00 [3.29]; median, -1.00 versus 0.00; P=0.0380) and least pain (mean, -1.61 [2.29] versus 0.24 [3.07]; median, -1.00 versus 0.00; P=0.0136), and EuroQol-5 dimensional 3 level utility scores (mean, +0.09 [0.26] versus +0.01 [0.16]; median, +0.07 versus 0.00; P=0.0197). Between-group differences were not statistically significant for EuroQol-5 dimensional 3 level visual analog scale, stroke-specific QoL summary, or Numeric Pain Rating Scale worst pain scores, although ITB patients showed greater numeric improvements from baseline during follow-up. More ITB patients than CMM patients (73% versus 48%) were satisfied with the spasticity reduction at month 6. Conclusions- These data support that ITB therapy is associated with improvements in pain and QoL in poststroke patients. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01032239.

OnabotulinumtoxinA Reduces Temporal Pain Processing at Spinal Level in Patients with Lower Limb Spasticity

Spasticity is a muscle tone disorder associated with different neurological conditions. Spasticity could be associated with pain, high disability, poor functional recovery, and reduced quality of life. Botulinum neurotoxin type A (BoNT-A) is considered a first-line treatment for spasticity and, more recently, it also represents a therapeutic option for various chronic pain conditions. In this open label study, we aim to evaluate the effect of the BoNT-A on the spinal nociception in patients affected by spasticity of the lower limbs with associated pain with predominantly neuropathic features. Ten patients with stroke, 10 with multiple sclerosis and 5 with spinal cord injury were enrolled in the study. They were tested with clinical scales (neuropathic pain scale inventory (NPSI), numerical rating scale (NRS), modified Ashworth scale (MAS) and with the nociceptive withdrawal reflex at lower limbs to explore the spinal temporal summation threshold at baseline and 30 day after BoNT-A injection. OnabotulinumtoxinA (50 to 200 units per site) was injected in the lower limb muscles according to the distribution of spasticity. No significant differences were found at baseline for neurophysiological features across groups. After the BoNT-A injection, we recorded a significant reduction in MAS and NRS scores. Regarding the neurophysiological parameters, we described a significant increase in the temporal summation threshold after the BoNT-A injection. Our data supports the hypothesis that peripherally injected OnabotulinumtoxinA modulates the excitability of spinal cord nociceptive pathways. This activity may take place irrespective of the effect of the drug on spasticity.

Analgesic Effects of Botulinum Toxin in Children with CP

Experiencing pain is the greatest contributor to a reduced quality of life in children with cerebral palsy (CP). The presence of pain is quite common (~60%) and increases with age. This leads to missed school days, less participation, and reduced ambulation. Despite these alarming consequences, strategies to relieve the pain are absent and poorly studied. Moreover, it is difficult to evaluate pain in this group of children, especially in cases of children with cognitive deficits, and tools for pain evaluation are often inadequate. Botulinum toxin has been shown to alleviate pain in a variety of disorders and could potentially have an analgesic effect in children with CP as well. Even though most of the studies presented here show promising results, many also have limitations in their methodology as it is unlikely to capture all dimensions of pain in this heterogeneous group using only one assessment tool. In this review, we present a new way of examining the analgesic effect of botulinum toxin in children with CP using a variety of pain scores.

Botulinum Toxin for the Treatment of Neuropathic Pain

Botulinum toxin (BoNT) has been used as a treatment for excessive muscle stiffness, spasticity, and dystonia. BoNT for approximately 40 years, and has recently been used to treat various types of neuropathic pain. The mechanism by which BoNT acts on neuropathic pain involves inhibiting the release of inflammatory mediators and peripheral neurotransmitters from sensory nerves. Recent journals have demonstrated that BoNT is effective for neuropathic pain, such as postherpetic neuralgia, trigeminal neuralgia, and peripheral neuralgia. The purpose of this review is to summarize the experimental and clinical evidence of the mechanism by which BoNT acts on various types of neuropathic pain and describe why BoNT can be applied as treatment. The PubMed database was searched from 1988 to May 2017. Recent studies have demonstrated that BoNT injections are effective treatments for post-herpetic neuralgia, diabetic neuropathy, trigeminal neuralgia, and intractable neuropathic pain, such as poststroke pain and spinal cord injury.