Real-world analysis of botulinum toxin (BoNT) injections in post-stroke spasticity: Higher doses of BoNT and longer intervals in the early-start group

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.

Safety and Real-World Dosing of OnabotulinumtoxinA for the Treatment of Adult Spasticity: Post Hoc Analysis of the Adult Spasticity International Registry Study

OBJECTIVE

The aim of the study is to evaluate the safety of onabotulinumtoxinA treatment for spasticity across dose ranges in real-world practice.

DESIGN

Adult Spasticity International Registry was a multicenter, prospective, observational study (NCT01930786) of onabotulinumtoxinA treatment for adult spasticity over 2 yrs. Adverse events, serious adverse events, treatment-related adverse events, and serious treatment-related adverse events were sorted into five categories (≤200, 201-400, 401-600, 601-800, ≥801 U) based on cumulative dose per session.

RESULTS

In 3103 treatment sessions ( T ), 730 patients received ≥1 dose of onabotulinumtoxinA. Dose categories included the following: ≤200 U ( n = 312, T = 811), 201-400 U ( n = 446, T = 1366), 401-600 U ( n = 244, T = 716), 601-800 U ( n = 69, T = 149), and ≥801 U ( n = 29, T = 61). Of these patients, 261 reported 827 adverse events, 94 reported 195 serious adverse events, 20 reported 23 treatment-related adverse events, and 2 patients treated with 201-400 U onabotulinumtoxinA reported 3 serious treatment-related adverse events. Treatment-related adverse events reported included ≤200 U (8/811, 0.9%), 201-400 U (7/1366, 0.5%), 401-600 U (6/716, 0.8%), 601-800 U (1/149, 0.7%), and ≥801 U (1/61, 1.6%).

CONCLUSIONS

In this post hoc analysis, most treatment sessions were performed with 201-400 U onabotulinumtoxinA. Patients treated with 201-400 U onabotulinumtoxinA had an adverse event profile consistent with onabotulinumtoxinA package inserts globally (e.g., United States, European Union, United Kingdom, Canada). No new safety signals were identified.

Real-world differences in dosing and clinical utilization of OnabotulinumtoxinA and AbobotulinumtoxinA in the treatment of upper limb spasticity

According to prescribing information, potency units are not interchangeable between botulinum toxin A products. This exploratory study compared real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA in adults with upper limb spasticity. In this retrospective study, 101 clinicians provided chart data via online surveys for 215 US post-stroke patients treated for upper limb spasticity with ≥3 onabotulinumtoxinA or abobotulinumtoxinA doses (phase 1: 9/18/2020-12/10/2020; phase 2: 9/30/2021-12/7/2021). Most participating clinicians were physicians (70.3%) specializing in neurology (71.3%) or physiatry (20.8%). In the onabotulinumtoxinA (n = 107) and abobotulinumtoxinA (n = 108) groups, ∼75% of patients had moderate-to-severe spasticity. A range of onabotulinumtoxinA:abobotulinumtoxinA dose ratios (1:2.2 [95%CI: 1.8-2.6] to 1:4.1 [95%CI: 3.0-6.0]) was observed across muscles. For the most recent dose, mean number of muscles injected was greater for onabotulinumtoxinA (4.3) versus abobotulinumtoxinA (3.1; P = 0.0003). For onabotulinumtoxinA versus abobotulinumtoxinA, the proportion of injections was 81.3% versus 63.9% (P = 0.0067) in forearm muscles and 23.4% versus 3.7% (P = 0.0001) in hand muscles. Mean injection intervals were similar (onabotulinumtoxinA: 102.0 days; abobotulinumtoxinA: 99.1 days). Differences in real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA for upper limb spasticity were observed. There was no standard dose-conversion ratio, consistent with each product's prescribing information.

Evidence of treating spasticity before it develops: a systematic review of spasticity outcomes in acute spinal cord injury interventional trials

Introduction: Spasticity is a common consequence of spinal cord injury (SCI), estimated to affect up to 93% of people living with SCI in the community. Problematic spasticity affects around 35% people with SCI spasticity. The early period after injury is believed to be the most opportune time for neural plasticity after SCI. We hypothesize that clinical interventions in the early period could reduce the incidence of spasticity. To address this, we evaluated the spasticity outcomes of clinical trials with interventions early after SCI.Methods: We performed a systematic review of the literature between January 2000 and May 2021 to identify control trials, in humans and animals, that were performed early after SCI that included measures of spasticity in accordance with PRISMA guidelines.Results: Our search yielded 1,463 records of which we reviewed 852 abstracts and included 8 human trial peer-reviewed publications and 9 animal studies. The 9 animal trials largely supported the hypothesis that early intervention can reduce spasticity, including evidence from electrophysiological, behavioral, and histologic measures. Of the 8 human trials, only one study measured spasticity as a primary outcome with a sample size sufficient to test the hypothesis. In this study, neuromodulation of the spinal cord using electric stimulation of the common peroneal nerve reduced spasticity in the lower extremities compared to controls.Conclusion: Given the prevalence of problematic spasticity, there is surprisingly little research being performed in the early period of SCI that includes spasticity measures, and even fewer studies that directly address spasticity. More research on the potential for early interventions to mitigate spasticity is needed.

Early Use of Phenol Neurolysis Likely Reduces the Total Amount of Botulinum Toxin in Management of Post-Stroke Spasticity

The main objective was to examine practice patterns of phenol neurolysis for post-stroke spasticity management in the early stage. We performed a chart review of patients who were admitted for inpatient rehabilitation within 6 months after first-ever stroke and received phenol neurolysis within 15 months post-stroke. Out of 2,367 stroke admissions from January 2014 and December 2018, 68 patients met the criteria. 52.9% of these patients received phenol neurolysis within 12 weeks, i.e., early stage. The earliest phenol neurolysis procedure was at 19 days after stroke. On average, patients received first phenol injections at 16.3 weeks after stroke with an average dose of 7.3 ml. Most commonly injected nerves were tibial nerve motor branches (41/68), sciatic nerve motor branches (37/68), lateral pectoral nerve (16/68), medial pectoral nerve (15/68), obturator nerve (15/68) and musculocutaneous nerve (15/68). Among 68 patients, 24 received phenol only; 17 received phenol neurolysis first followed by botulinum toxin (BoNT) injections; 19 received BoNT injections first followed by phenol neurolysis; 8 received both phenol and BoNT injections at the same time. The interval from stroke to first procedure was similar between the Phenol-First group (13.3 weeks) and the BoNT-First group (12.6 weeks). The total amount of BoNT was significantly lower in the Phenol-First group (361.3 units) than in the BoNT-First group (515.8 units) (p = 0.005). The total amount of phenol was not statistically different between the Phenol-First group (5.9 ml) and the BoNT-First group (8.3 ml). The interval between the first procedure and its subsequent procedure was not statistically different between the Phenol-First group (18.3 weeks) and the BoNT-First group (10.7 weeks). These long intervals suggest that the subsequent injection (type and dose) was not planned during the first procedure. The general patterns of target areas were similar between BoNT injections and phenol neurolysis, except that phenol neurolysis rarely targeted the upper extremity distal muscles. No side effects after phenol or BoNT injections in the early stage after stroke were observed in the chart review. In summary, phenol neurolysis was started as early as 19 days after stroke. On average, patients received first phenol about 4 months after stroke with an average of 7.3 ml of phenol. Early use of phenol neurolysis likely decreases the total amount of BoNT for management of post-stroke spasticity without increased side effects.