Botulinum toxin and spasticity

The application and therapeutic effect of botulinum toxin type a (BTX-A) in the treatment of patients with pain after cancer treatment: a systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTX-A) is a potential treatment for cancer pain. This study aimed to analyze the effectiveness and safety of BTX-A in the treatment of pain after cancer treatment.

PATIENTS AND METHODS

Systematic searches of PubMed, Cochrane Library, and Embase databases were conducted. Randomized controlled trials evaluating the efficacy and safety of BTX-A compared with either placebo or active treatment in patients with pain after cancer treatment were included. The outcomes included pain intensity, quality of life, and adverse events.

RESULTS

This systematic review included four studies of which two were included in the meta-analysis. Compared with a placebo, BTX-A injection in patients with pain after cancer treatment had a clinically meaningful reduction in self-reported pain post-treatment [mean difference=-1.79 (95% CI: -2.14--1.43), P <0.00001, I ²=0%].

CONCLUSION

This systematic review and meta-analysis demonstrated that BTX-A is safe and effective for pain relief in patients with pain after cancer treatment.

Examining the role of intrinsic and reflexive contributions to ankle joint hyper-resistance treated with botulinum toxin-A

BACKGROUND

Spasticity, i.e. stretch hyperreflexia, increases joint resistance similar to symptoms like hypertonia and contractures. Botulinum neurotoxin-A (BoNT-A) injections are a widely used intervention to reduce spasticity. BoNT-A effects on spasticity are poorly understood, because clinical measures, e.g. modified Ashworth scale (MAS), cannot differentiate between the symptoms affecting joint resistance. This paper distinguishes the contributions of the reflexive and intrinsic pathways to ankle joint hyper-resistance for participants treated with BoNT-A injections. We hypothesized that the overall joint resistance and reflexive contribution decrease 6 weeks after injection, while returning close to baseline after 12 weeks.

METHODS

Nine participants with spasticity after spinal cord injury or after stroke were evaluated across three sessions: 0, 6 and 12 weeks after BoNT-A injection in the calf muscles. Evaluation included clinical measures (MAS, Tardieu Scale) and motorized instrumented assessment using the instrumented spasticity test (SPAT) and parallel-cascade (PC) system identification. Assessments included measures for: (1) overall resistance from MAS and fast velocity SPAT; (2) reflexive resistance contribution from Tardieu Scale, difference between fast and slow velocity SPAT and PC reflexive gain; and (3) intrinsic resistance contribution from slow velocity SPAT and PC intrinsic stiffness/damping.

RESULTS

Individually, the hypothesized BoNT-A effect, the combination of a reduced resistance (week 6) and return towards baseline (week 12), was observed in the MAS (5 participants), fast velocity SPAT (2 participants), Tardieu Scale (2 participants), SPAT (1 participant) and reflexive gain (4 participants). On group-level, the hypothesis was only confirmed for the MAS, which showed a significant resistance reduction at week 6. All instrumented measures were strongly correlated when quantifying the same resistance contribution.

CONCLUSION

At group-level, the expected joint resistance reduction due to BoNT-A injections was only observed in the MAS (overall resistance). This observed reduction could not be attributed to an unambiguous group-level reduction of the reflexive resistance contribution, as no instrumented measure confirmed the hypothesis. Validity of the instrumented measures was supported through a strong association between different assessment methods. Therefore, further quantification of the individual contributions to joint resistance changes using instrumented measures across a large sample size are essential to understand the heterogeneous response to BoNT-A injections.

Do gait parameters improve after botulinum toxin injections in post stroke patients? A prospective study

The intramuscular injection of botulinum toxin is one of the most efficient ways to treat localized spasticity in patients suffering from Central Nervous System lesions like stroke, cerebral palsy and multiple sclerosis. The gait analysis based on kinetics and kinematics is a recognized way of measurement of the effect of intramuscular injection of botulinum toxin in spastic patients suffering from chronic stroke. The aim of this study is to provide evidence of the beneficial effect of botulinum toxin on characteristics of gait pattern on patients suffering from chronic stroke. So, thirteen patients with spasticity due to chronic stroke were included in the protocol and were treated by botulinum toxin injections in the lower extremity. All patients were evaluated before the injection as well as one month after the botulinum injection on a foot pressure sensitive walkway with a power plate and by the readings of seven inertial measurements units which recorded spatio-temporal specific parameters during walking, and the spasticity was measured according to modified Ashworth Scale. While all spatio-temporal parameters of motion analysis and balance improved for most of the patients after botulinum toxin injection, only one parameter, the normal to hemiplegic step length, reached statistical significant improvement (p < 0.03). Moreover the modified Ashworth score was statistically improved post injection (p < 0.001). In conclusion the use of botulinum toxin injections is beneficial in post stroke patients as this is depicted in gait parameters improvement which accompanies the spasticity reduction.

Botulinum toxin for chronic rhinitis: A systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTX-A) is a potential treatment for chronic rhinitis. This study aimed to assess the effectiveness and safety of BTX-A in treating patients with chronic rhinitis.

METHODS

Systematic searches of MEDLINE, Scopus, and EMBASE databases were performed. Randomized controlled trials (RCTs) that assessed the efficacy of BTX-A in allergic rhinitis and/or nonallergic rhinitis patients, compared with either placebo or active treatment, were included. The outcomes were total nasal symptom (TNSS), disease-specific quality of life (QOL), and adverse events.

RESULTS

Nine RCTs (340 patients) met the eligibility criteria. Compared with placebo, the ≤ 12-week effects favored BTX-A injection on TNSS (standardized mean difference [SMD] -2.22, 95% confidence interval [CI] -3.27 to -1.17, p < 0.01, four RCTs). Beneficial effects > 12 weeks over placebo (MD -9.69, 95% CI -11.29 to -8.09, p < 0.01, one RCT) were demonstrated up to 24 weeks. However, the benefits were not shown on nasal congestion and individual nasal symptoms. Compared with active comparators (triamcinolone injection, ipratropium bromide, and cetirizine), there was no difference in the < 12-week effect between groups on TNSS. There was no difference between BTX-A and cetirizine on QOL (one RCT). The > 12-week effects on TNSS and individual nasal symptoms favored BTX-A over triamcinolone injection (one RCT). The risk ratio of adverse events favored BTX-A over cetirizine (one RCT).

CONCLUSIONS

BTX-A improved TNSS and QOL in patients with chronic rhinitis. These effects were demonstrated up to 24 weeks post treatment. BTX-A was safe, well tolerated, and may be considered in patients who are refractory to current standard-of-care therapies.

Electrical Stimulation of Injected Muscles to Boost Botulinum Toxin Effect on Spasticity: Rationale, Systematic Review and State of the Art

Botulinum toxin type A (BoNT-A) represents a first-line treatment for spasticity, a common disabling consequence of many neurological diseases. Electrical stimulation of motor nerve endings has been reported to boost the effect of BoNT-A. To date, a wide range of stimulation protocols has been proposed in the literature. We conducted a systematic review of current literature on the protocols of electrical stimulation to boost the effect of BoNT-A injection in patients with spasticity. A systematic search using the MeSH terms “electric stimulation”, “muscle spasticity” and “botulinum toxins” and strings “electric stimulation [mh] OR electrical stimulation AND muscle spasticity [mh] OR spasticity AND botulinum toxins [mh] OR botulinum toxin type A” was conducted on PubMed, Scopus, PEDro and Cochrane library electronic databases. Full-text articles written in English and published from database inception to March 2021 were included. Data on patient characteristics, electrical stimulation protocols and outcome measures were collected. This systematic review provides a complete overview of current literature on the role of electrical stimulation to boost the effect of BoNT-A injection for spasticity, together with a critical discussion on its rationale based on the neurobiology of BoNT-A uptake.

Neurophysiological validation of simultaneous intrinsic and reflexive joint impedance estimates

BACKGROUND

People with brain or neural injuries, such as cerebral palsy or spinal cord injury, commonly have joint hyper-resistance. Diagnosis and treatment of joint hyper-resistance is challenging due to a mix of tonic and phasic contributions. The parallel-cascade (PC) system identification technique offers a potential solution to disentangle the intrinsic (tonic) and reflexive (phasic) contributions to joint impedance, i.e. resistance. However, a simultaneous neurophysiological validation of both intrinsic and reflexive joint impedances is lacking. This simultaneous validation is important given the mix of tonic and phasic contributions to joint hyper-resistance. Therefore, the main goal of this paper is to perform a group-level neurophysiological validation of the PC system identification technique using electromyography (EMG) measurements.

METHODS

Ten healthy people participated in the study. Perturbations were applied to the ankle joint to elicit reflexes and allow for system identification. Participants completed 20 hold periods of 60 seconds, assumed to have constant joint impedance, with varying magnitudes of intrinsic and reflexive joint impedances across periods. Each hold period provided a paired data point between the PC-based estimates and neurophysiological measures, i.e. between intrinsic stiffness and background EMG, and between reflexive gain and reflex EMG.

RESULTS

The intrinsic paired data points, with all subjects combined, were strongly correlated, with a range of [Formula: see text] in both ankle plantarflexors and dorsiflexors. The reflexive paired data points were moderately correlated, with [Formula: see text] in the ankle plantarflexors only.

CONCLUSION

An agreement with the neurophysiological basis on which PC algorithms are built is necessary to support its clinical application in people with joint hyper-resistance. Our results show this agreement for the PC system identification technique on group-level. Consequently, these results show the validity of the use of the technique for the integrated assessment and training of people with joint hyper-resistance in clinical practice.

Effect of combined rehabilitation program with botulinum toxin type A injections on gross motor function scores in children with spastic cerebral palsy

[Purpose] To examine whether combining botulinum toxin type A with physiotherapy is better than botulinum toxin type A alone in reducing muscle tone and improving gross motor function in spastic diplegia. [Subjects and Methods] Forty-six ambulatory children with spastic diplegia (age: 25–154 months) were recruited. Patients were assigned to Groups 1 (n=18) and 2 (n=28). After baseline assessment, all children received botulinum toxin type A injections (6 units/kg) into the lower limb muscles. A second botulinum toxin type A injection was given 6 months later. The ankles were placed in plaster casts for 2 weeks after the first injection and an orthosis was prescribed after cast removal. Group 2 received 2 weeks of intensive physiotherapy. The gross motor function scores for the 2 groups were recorded at baseline, 4, 6, and 52 weeks. [Results] The improvement in gross motor function scores was significant for Group 2 and non-significant for Group 1. After 4, 6, and 52 weeks, Groups 1 and 2 showed 2.6% and 6.3% improvement, 4.8% and 12% improvement, and 5.5% and 19.4% improvement, respectively. [Conclusion] The addition of a 2-week physiotherapy programme after the initial botulinum toxin type A injections produced significantly greater improvements in gross motor function scores.

Goals Set by Patients Using the ICF Model before Receiving Botulinum Injections and Their Relation to Spasticity Distribution

Purpose: Goal Attainment Scaling (GAS) is used to assess functional gains in response to treatment. Specific characteristics of the functional goals set by individuals receiving botulinum toxin type A (BoNTA) injections for spasticity management are unknown. The primary objectives of this study were to describe the characteristics of the goals set by patients before receiving BoNTA injections using the International Classification of Functioning, Disability and Health (ICF) and to determine whether the pattern of spasticity distribution affected the goals set. Methods: A cross-sectional retrospective chart review was carried out in an outpatient spasticity-management clinic in Toronto. A total of 176 patients with a variety of neurological lesions attended the clinic to receive BoNTA injections and completed GAS from December 2012 to December 2013. The main outcome measures were the characteristics of the goals set by the participants on the basis of ICF categories (body functions and structures, activity and participation) and the spasticity distribution using Modified Ashworth Scale scores. Results: Of the patients, 73% set activity and participation goals, and 27% set body functions and structures goals (p<0.05). In the activity and participation category, 30% of patients set moving and walking goals, 28% set self-care and dressing goals, and 12% set changing and maintaining body position goals. In the body functions and structures category, 18% set neuromuscular and movement-related goals, and 8% set pain goals. The ICF goal categories were not related to the patterns of spasticity (upper limb vs. lower limb or unilateral vs. bilateral spasticity) or type of upper motor neuron (UMN) lesion (p>0.05). Conclusion: Our results show that patients receiving BoNTA treatment set a higher percentage of activity and participation goals than body functions and structures goals. Goal classification was not affected by type of spasticity distribution or type of UMN disorder.

Treatment for dysphagia (swallowing difficulties) in hereditary ataxia

BACKGROUND

Hereditary ataxias are a heterogeneous group of disorders resulting in progressive inco-ordination. Swallowing impairment, also known as dysphagia, is a common and potentially life threatening sequel of disease progression. The incidence and nature of dysphagia in these conditions is largely unknown. The loss of an effective and safe swallow can dramatically affect the health and well-being of an individual. Remediation of difficulties of eating and drinking is an important goal in the clinical care of people with hereditary ataxia.

OBJECTIVES

To assess the effects of interventions for swallowing impairment (dysphagia) in people with hereditary ataxias.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL Plus, PsycINFO, and the Education Resources Information Center (ERIC) on 14 September 2015. We also searched Linguistics and Language Behavior Abstracts (LLBA), Dissertation Abstracts, and Trials Registries on 24 September 2015.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) and quasi-RCTs that compared treatments for hereditary ataxia with placebo or no treatment. We only included studies measuring dysphagia.

DATA COLLECTION AND ANALYSIS

Three review authors (ES, KJ, MK) independently screened all titles and abstracts. In the event of any disagreement or uncertainty over the inclusion of a particular paper, the review authors planned to meet and reach consensus.

MAIN RESULTS

We identified no RCTs from the 519 titles and abstracts screened. We excluded papers primarily for not including participants with a hereditary ataxia (that is, being focused on other neurological conditions), being theoretical reviews rather than intervention studies, or being neither randomised nor quasi-randomised trials.We identified five papers of various design that described treatment for dysphagia, or improvement to swallow as a by-product of treatment, in people with hereditary ataxia. None of these studies were RCTs or quasi-RCTs.

AUTHORS' CONCLUSIONS

There is an absence of any significant evidence supporting the use of any dysphagia intervention in hereditary ataxia. The lack of evidence highlights the critical need for well-controlled treatment trials in the field.

Botulinum toxin type A injections for the management of muscle tightness following total hip arthroplasty: a case series

BACKGROUND

Development of hip adductor, tensor fascia lata, and rectus femoris muscle contractures following total hip arthroplasties are quite common, with some patients failing to improve despite treatment with a variety of non-operative modalities. The purpose of the present study was to describe the use of and patient outcomes of botulinum toxin injections as an adjunctive treatment for muscle tightness following total hip arthroplasty.

METHODS

Ten patients (14 hips) who had hip adductor, abductor, and/or flexor muscle contractures following total arthroplasty and had been refractory to physical therapeutic efforts were treated with injection of botulinum toxin A. Eight limbs received injections into the adductor muscle, 8 limbs received injections into the tensor fascia lata muscle, and 2 limbs received injection into the rectus femoris muscle, followed by intensive physical therapy for 6 weeks.

RESULTS

At a mean final follow-up of 20 months, all 14 hips had increased range in the affected arc of motion, with a mean improvement of 23 degrees (range, 10 to 45 degrees). Additionally all hips had an improvement in hip scores, with a significant increase in mean score from 74 points (range, 57 to 91 points) prior to injection to a mean of 96 points (range, 93 to 98) at final follow-up. There were no serious treatment-related adverse events.

CONCLUSION

Botulinum toxin A injections combined with intensive physical therapy may be considered as a potential treatment modality, especially in difficult cases of muscle tightness that are refractory to standard therapy.

BOTULINUM TOXIN: FROM SPASTICITY RELIEVER TO A NEUROMOTOR RE-LEARNING TOOL

Botulinum toxin is becoming increasingly popular as the drug of choice for relief of spasticity in a wide range of conditions, from stroke to strabismus to vaginismus. Besides this role as spasticity reliever, several recent clinical reports claim that in stroke, cerebral palsy, spinal cord injury (SCI), and dystonias, BoTx brings about significant improvement in function--attributed to synaptic plasticity of the muscular afferents. The authors' research had shown that BoTx also generates synaptic plasticity in spinal alpha-motoneurons-interneurons. The article describes how BoTx facilitates relearning by Hebbian and Contrastive Hebbian modes and how it can be used as a neuro-relearning tool to enhance and hasten motor recovery in the aforementioned disorders.

Upper-limb botulinum toxin A injection and occupational therapy in children with hemiplegic cerebral palsy identified from a population register: a single-blind, randomized, controlled trial

OBJECTIVES

The purpose of this work was to assess the effect of botulinum toxin A and occupational therapy compared with occupational therapy alone on body structure, activities participation, and self-perception in a sample of children (aged 3-16 years) with hemiplegic cerebral palsy recruited from a statewide register.

PATIENTS AND METHODS

Participants of this single-blind, randomized, controlled trial identified from a population-based cerebral palsy register received either an individually prescribed and localized injection of botulinum toxin A with 4 sessions of occupational therapy over 4 weeks (intervention) or occupational therapy alone (control). Outcomes were assessed from 2 domains of the World Health Organization International Classification of Functioning, Disability, and Health: body structure (Modified Ashworth Scale and Tardieu Scale) and activities participation (Assessment of Motor and Process Skills, Goal Attainment Scale, Pediatric Evaluation of Disability Inventory, and Pediatric Quality of Life Inventory). Self-perception was also measured.

RESULTS

All of the participants (intervention: n = 21; control: n = 22) provided data at baseline and 3 and 6 months. Mean age was 8.6 years; 23 were boys and 20 were girls. At 3 months, children allocated to receive the intervention performed significantly better in terms of body structure and activities participation. They reported improvements in self-perception for the global self-worth domain. At 6 months, the differences between the intervention and control groups persisted for the measures of body structure but not for activities participation or self-perception.

CONCLUSION

Botulinum toxin A injection combined with a low-intensity occupational therapy program achieves significant improvements in body structure, activity participation, and self-perception.

Motor Points for the Neuromuscular Blockade of the Subscapularis Muscle

OBJECTIVE

To locate the motor points of the subscapularis muscle in relation to palpable anatomic landmarks and hence suggest a technique for botulinum toxin injection into subscapularis applicable to patients of all ages.

DESIGN

Anatomic dissection of the innervation of 20 subscapular muscles.

SETTING

University dissecting room.

CADAVERS

Ten formalin-preserved cadavers.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The location of motor points in relation to anatomic landmarks.

RESULTS

The median number of motor points for the subscapularis was 5 (range, 3-6). All motor point measurements were related to surface points and converted into proportional values along reference lines. Motor points from the 20 dissections showed clustering in a band. A line of best fit was calculated (y=1.48x-0.743).

CONCLUSIONS

We describe an injection technique that would deliver botulinum toxin close to the motor points of the subscapularis, a surrogate marker of the motor endplate zones. By using proportional distances, this technique is applicable to an adult and pediatric population. This should lead to an increased efficacy and decreased side-effect profile in clinical practice, although clinical trials will need to confirm this.

The Use of a Portable Muscle Tone Measurement Device to Measure the Effects of Botulinum Toxin Type A on Elbow Flexor Spasticity

OBJECTIVE

To use a portable muscle tone assessment device to measure spasticity after a botulinum toxin type A (BTX-A) injection.

DESIGN

Before-after trial.

SETTING

Hospital.

PARTICIPANTS

Ten chronic stroke patients with upper-limb spasticity.

INTERVENTION

BTX-A was injected in the biceps brachii.

MAIN OUTCOME MEASURES

The biomechanic parameters, viscous component, and averaged viscosity derived from the acquired reactive resistance and angular displacements, as well as the reflex electromyographic threshold of biceps brachii, were used for spasticity evaluation.

RESULTS

A statistically significant decrease in averaged viscosity and a significant increase in reflex electromyographic threshold (P<.05) both indicated reduction in spasticity owing to BTX-A intervention. There was no clear reflex electromyographic activity detected at lower stretch frequencies.

CONCLUSIONS

Our portable design allows for the convenient use of the device for quantifying spasticity in clinics. All quantitative measurements suggest that BTX-A decreases spasticity within 2 weeks of injection. Our portable muscle tone measurement device may be useful for the clinical assessment of elbow flexor spasticity.

Treatment of recurrent posterior dislocation of the shoulder in cerebral palsy by injection with botulinum toxin A into the M. subscapularis

SUBJECTS

A 20-year-old woman, known to have cerebral palsy and a spastic hemiparesis, suffered from frequent (up to 20 times a day) and painful posterior dislocation of the affected shoulder.

INTERVENTIONS

For the last two years we have treated her with injections with botulinum toxin A (100 U Botox) in the M. subscapularis.

RESULTS

Pain and dislocation rate have improved substantially.

The effect of combined use of botulinum toxin type A and functional electric stimulation in the treatment of spastic drop foot after stroke: a preliminary investigation

OBJECTIVE

To investigate the effect of combined botulinum toxin type A (BTX) and functional electric stimulation (FES) treatment on spastic drop foot in stroke.

DESIGN

Nonblinded randomized controlled trial.

SETTING

Hospitals.

PARTICIPANTS

Consecutive sample of 21 ambulant adults within 1 year after stroke with a spastic drop foot, of whom 18 completed the study.

INTERVENTIONS

The treatment group received BTX injections (Dysport) on 1 occasion into the medial and lateral heads of the gastrocnemius (200U each) and tibialis posterior (400U each) muscles and FES, used on a daily basis for 16 weeks to assist walking. Both groups continued with physiotherapy at the same rate.

MAIN OUTCOME MEASURES

Walking speed, Physiological Cost Index, Modified Ashworth Scale, Rivermead Motor Assessment, and Medical Outcomes Study 36-Item Short-Form Health Survey.

RESULTS

Walking speed increased over 12 weeks in both control (P=.020) and treatment groups (nonstimulated, P=.004; stimulated, P=.042). The baseline corrected (analysis of covariance) increase in mean walking speed at 12 weeks, relative to controls, was.04m/s (95% confidence interval [CI],.003-.090) without stimulation, and.09m/s (95% CI,.031-.150) with stimulation.

CONCLUSIONS

Combined treatment effectively improved walking and function. A larger study is needed to quantify the treatment effect and to investigate its impact on quality of life.

Botulinum toxin in motor disorders: practical considerations with emphasis on interventional neurophysiology

After a brief review of the pharmacological properties of the botulinum toxin (BT), its mechanism of action on the nerve endings of the neuromuscular junctions, and the general therapeutic principles and adverse side effects, we discuss the advantages of interventional neurophysiology for the treatment of focal motor disorders by means of botulinum toxin A (BTA) muscle infiltration. Electromyography (EMG) provides a valuable objective information in the diagnosis of many motor disturbances and enables the precise identification of the muscles that contribute to the abnormal movement or posture. The use of EMG guidance for BTA injection seems advisable in every muscle but it become indispensable in those difficult to access, deeply located or partially atrophied by previous toxin infiltrations. The EMG study also serves to localise the areas with the highest abnormal activity and the motor point of the muscle, where the injection of toxin exerts its maximal effect. Consequently, lower doses of BTA can be employed without decreasing the efficacy of treatment but reducing the potential risk of side effects, antibody production and the cost of treatment. Electrophysiological diagnosis and BTA treatment may be performed during the same exploration. Considerations on the particular aspects and lines of action are given referring to the main focal muscular hyperactivity motor disorders such as cervical, oromandibular and laryngeal dystonias, blepharospasm, writer's cramp, hemifacial and hemimasticatory spasms, infantile and adult forms of spasticity and some other focal disturbances such as strabismus, detrusor-sphincter dyssynergia and anismus.