Botulinum Toxin Treatment for Limb Spasticity in Childhood Cerebral Palsy

Methods of muscle spasticity assessment in children with cerebral palsy: a scoping review

BACKGROUND

Evaluating muscle spasticity in children with cerebral palsy (CP) is essential for determining the most effective treatment strategies. This scoping review assesses the current methods used to evaluate muscle spasticity, highlighting both traditional and innovative technologies, and their respective advantages and limitations.

METHODS

A search (to April 2024) used keywords such as muscle spasticity, cerebral palsy, and assessment methods. Selection criteria included articles involving CP children, assessing spasticity objectively/subjectively, comparing methods, or evaluating method effectiveness.

RESULTS

From an initial pool of 1971 articles, 30 met our inclusion criteria. These studies collectively appraised a variety of techniques ranging from well-established clinical scales like the modified Ashworth Scale and Tardieu Scale, to cutting-edge technologies such as real-time sonoelastography and inertial sensors. Notably, innovative methods such as the dynamic evaluation of range of motion scale and the stiffness tool were highlighted for their potential to provide more nuanced and precise assessments of spasticity. The review unveiled a critical insight: while traditional methods are convenient and widely used, they often fall short in reliability and objectivity.

CONCLUSION

The review discussed the strengths and limitations of each method and concluded that more reliable methods are needed to measure the level of muscle spasticity more accurately.

Understanding Clinical Effectiveness and Safety Implications of Botulinum Toxin in Children: A Narrative Review of the Literature

Since its first approval by the Food and Drug Administration in 1989 for strabismus, botulinum toxin indications of use have been widely expanded. Due to its anticholinergic properties, this toxin is currently approved in adult patients for the treatment of a wide range of neuromuscular, otolaryngologic, orthopedic, gastrointestinal, and urologic disorders. Approved pediatric indications of use include the treatment of blepharospasm associated with dystonia, strabismus, lower-limb spasticity, focal spasticity in patients with cerebral palsy, and neurogenic detrusor overactivity. Alongside these approved indications, botulinum toxin is extensively used off-label. Although several clinical studies have shown that botulinum toxin is effective and well-tolerated in children, uncertainties persist regarding its long-term effects on growth and appropriate dosing in this population. As such, further research is needed to better define the botulinum toxin risk-benefit profile and expand approved uses in pediatrics. This narrative review aimed to provide a broad overview of the evidence concerning the clinical effectiveness and safety of BoNT with respect to its principal authorized and non-authorized pediatric therapeutic indications, as well as to describe perspectives on its future use in children.

An Integrated Approach for Real-Time Monitoring of Knee Dynamics with IMUs and Multichannel EMG

Measuring human joint dynamics is crucial for understanding how our bodies move and function, providing valuable insights into biomechanics and motor control. Cerebral palsy (CP) is a neurological disorder affecting motor control and posture, leading to diverse gait abnormalities, including altered knee angles. The accurate measurement and analysis of knee angles in individuals with CP are crucial for understanding their gait patterns, assessing treatment outcomes, and guiding interventions. This paper presents a novel multimodal approach that combines inertial measurement unit (IMU) sensors and electromyography (EMG) to measure knee angles in individuals with CP during gait and other daily activities. We discuss the performance of this integrated approach, highlighting the accuracy of IMU sensors in capturing knee joint movements when compared with an optical motion-tracking system and the complementary insights offered by EMG in assessing muscle activation patterns. Moreover, we delve into the technical aspects of the developed device. The presented results show that the angle measurement error falls within the reported values of the state-of-the-art IMU-based knee joint angle measurement devices while enabling a high-quality EMG recording over prolonged periods of time. While the device was designed and developed primarily for measuring knee activity in individuals with CP, its usability extends beyond this specific use-case scenario, making it suitable for applications that involve human joint evaluation.

Botulinum Toxin-A High-Dosage Effect on Functional Outcome and Spasticity-Related Pain in Subjects with Stroke

Stroke patients can develop spasticity and spasticity-related pain (SRP). These disorders are frequent and can contribute to functional limitations and disabling conditions. Many reports have suggested that higher doses than initially recommended of BTX-A can be used effectively and safely, especially in the case of severe spasticity; however, whether the treatment produces any benefit on the functional outcome and SRP is unclear. Studies published between January 1989 and December 2022 were retrieved from MEDLINE/PubMed, Embase, and Cochrane Central Register. Only obabotulinumtoxinA (obaBTX-A), onabotulinumtoxinA, (onaBTX-A), and incobotulinumtoxinA (incoBTX-A) were considered. The term "high dosage" indicates ≥600 U. Nine studies met the inclusion criteria. Globally, 460 subjects were treated with BTX-A high dose, and 301 suffered from stroke. Studies had variable method designs, sample sizes, and aims. Only five (55.5%) reported data about the functional outcome after BTX-A injection. Functional measures were also variable, and the improvement was observed predominantly in the disability assessment scale (DAS). SRP pain was quantified by visual analog scale (VAS) and only three studies reported the BTX-A effect. There is no scientific evidence that this therapeutic strategy unequivocally improves the functionality of the limbs. Although no clear-cut evidence emerges, certain patients with spasticity might obtain goal-oriented improvement from high-dose BTX-A. Likewise, data are insufficient to recommend high BTX dosage in SRP.

Safety and Efficacy of Botulinum Toxin Type A in Children With Spastic Cerebral Palsy Aged <2 Years: A Systematic Review

In this study, we reviewed the safety and efficacy of botulinum toxin type A (BoNT-A) injection with respect to motor development in children with spastic cerebral palsy aged <2 years. Randomized controlled trials of BoNT-A published between July 1993 and May 2021 were searched in PubMed, WANFANG, CNKI (Chinese National Knowledge Infrastructure), and Cochrane Library Central Register of Controlled Trials using keywords "Botulinum Toxin," "cerebral palsy," "nao xing tan huan," "nao tan," and "rou du du su." The 11-item PEDro Scale was used to rate the quality of all the identified studies. Twelve studies, involving 656 subjects, met the inclusion criteria, and of these, 2 involved patients aged <2 years. Treatment safety was assessed based on adverse event (AE) number and frequency, and efficacy was assessed based on spasticity, range of movement, and motor development. We observed that 3 self-limiting adverse events that were frequently reported included weakness, dysesthesia of the skin, and pain at the injection site. Moreover, there was a significant decrease in the incidence of spasticity and a notable improvement in the range of movement of BoNT-A-treated patients. Therefore, BoNT-A injection shows great safety and efficacy in the treatment of children with cerebral palsy aged <2 years.

Recent developments in muscle synergy analysis in young people with neurodevelopmental diseases: A Systematic Review

The central nervous system simplifies motor control by sending motor commands activating groups of muscles, known as synergies. Physiological locomotion can be described as a coordinated recruitment of four to five muscle synergies. The first studies on muscle synergies in patients affected by neurological diseases were on stroke survivors. They showed that synergies can be used as biomarkers for motor impairment as they vary in patients with respect to healthy people. Likewise, muscle synergy analysis has been applied to developmental diseases (DD). The need for a comprehensive view of the present findings is crucial for comparing results achieved so far and promote future directions in the field. In the present review, we screened three scientific databases and selected thirty-six papers investigating muscle synergies extracted from locomotion in children affected by DD. Thirty-one articles investigate how cerebral palsy (CP) influences motor control, the currently exploited method in studying motor control in CP and finally the effects of treatments in these patients in terms of synergies and biomechanics; two articles investigate how muscle synergies vary in Duchenne muscular dystrophy (DMD), and three other articles assess other developmental pathologies, such as chronic and acute neuropathic pain. For CP, most of the studies demonstrate that the number of synergies is lower and that the synergy composition varies in the affected children with respect to normal controls. Still, the predictability of treatment's effects and the etiology of muscle synergy variation are open questions, as it has been reported that treatments minimally modify synergies, even if they improve biomechanics. The application of different algorithms in extracting synergies might bring about more subtle differences. Considering DMD, no correlation was found between non-neural muscle weakness and muscle modules' variation, while in chronic pain a decreased number of synergies was observed as a possible consequence of plastic adaptations. Even if the potential of the synergistic approach for clinical and rehabilitation practices is recognized, there is not full consensus on protocols nor widely accepted guidelines for the systematic clinical adoption of the method in DD. We critically commented on the current findings, on the methodological issues and the relative open points, and on the clinical impact of muscle synergies in neurodevelopmental diseases to fill the gap for applying the method in clinical practice.

IncobotulinumtoxinA for the treatment of lower-limb spasticity in children and adolescents with cerebral palsy: A phase 3 study

PURPOSE

Investigate the efficacy and safety of multipattern incobotulinumtoxinA injections in children/adolescents with lower-limb cerebral palsy (CP)-related spasticity.

METHODS

Phase 3 double-blind study in children/adolescents (Gross Motor Function Classification System - Expanded and Revised I-V) with unilateral or bilateral spastic CP and Ashworth Scale (AS) plantar flexor (PF) scores ⩾ 2 randomized (1:1:2) to incobotulinumtoxinA (4, 12, 16 U/kg, maximum 100, 300, 400 U, respectively) for two 12- to 36-week injection cycles. Two clinical patterns were treated. Pes equinus (bilateral or unilateral) was mandatory; if unilateral, treatment included flexed knee or adducted thigh.

ENDPOINTS

Primary: AS-PF change from baseline to 4 weeks; Coprimary: investigator-rated Global Impression of Change Scale (GICS)-PF at 4 weeks; Secondary: investigator's, patient's, and parent's/caregiver's GICS, Gross Motor Function Measure-66 (GMFM-66).

RESULTS

Among 311 patients, AS-PF and AS scores in all treated clinical patterns improved from baseline to 4-weeks post-injection and cumulatively across injection cycles. GICS-PF and GICS scores confirmed global spasticity improvements. GMFM-66 scores indicated better motor function. No significant differences between doses were evident. Treatment was well-tolerated, with no unexpected treatment-related adverse events or neutralising antibody development.

CONCLUSION

Children/adolescents with lower-limb spasticity experienced multipattern benefits from incobotulinumtoxinA, which was safe and well-tolerated in doses up to 16 U/kg, maximum 400 U.

Botulinum Toxin A Injection in Treatment of Upper Limb Spasticity in Children with Cerebral Palsy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Cerebral palsy (CP) is the most common cause of childhood disability globally. Botulinum toxin A injections are widely used to manage limb spasticity in children with CP. Intramuscular botulinum toxin A has been used in the upper limbs of children with CP to manage preoperative and postoperative pain, facilitate nursing, and achieve functional and/or cosmetic improvement of hand position. These goals are achieved primarily through reduction of spasticity. The aim of this review was to assess the evidence for the effect of botulinum toxin A injections used to manage upper limb spasticity in children with spastic CP. Specifically, we examined the role of botulinum toxin A as an adjunctive treatment to other physical therapy modalities. Additionally, we analyzed the associated complications.

METHODS

The literature extraction process involved 4 phases: identification, screening, eligibility, and inclusion. We used a combination of Google Scholar, PubMed, and ScienceDirect. The choice of the search terms was based on the Medical Subject Headings. We extracted the relevant studies using a combination of words or terms related to (1) patient population, (2) pathology, (3) clinical intervention, and (4) anatomical distribution of pathology. Studies were included if they were randomized controlled trials conducted on children and/or adolescents with CP targeting the upper extremities in which botulinum toxin A was used as an adjunctive treatment to a primary intervention.

RESULTS

The literature extraction process yielded 15 randomized controlled trials for inclusion in this review. The total number of participants enrolled in the included studies was 499, with 255 in the intervention group (51%) and 244 controls (49%). All participants in the eligible studies had unilateral spastic CP except for those in 4 studies (27%) with 198 participants (40%) that included a heterogeneous sample of unilateral and bilateral spastic CP. The mean age of participants in the intervention group ranged from 2.6 to 10.7 years among the individual studies. The mean age of participants in the control group ranged from 3.1 to 10.55 years among the individual studies. This review indicated that botulinum toxin A had a positive effect on the degree of spasticity and cosmetic appearance of the injected upper limb. The results with respect to functional gains and quality of life were either conflicting or not significant.

CONCLUSIONS

Randomized controlled trials of botulinum toxin A injection in the treatment of upper limb spasticity in children with CP used variable outcome measures and yielded mixed results. Overall, there is some evidence to support the use of botulinum toxin A as an adjuvant treatment to other physical therapy regimens or placebo to reduce spasticity in the short term. There is insufficient evidence to support its use as an adjunctive treatment to improve upper limb function or quality of life. The complications were acceptable and did not outweigh the clinical gains incurred.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

A prospective study on transfer of pronator teres to extensor carpi radialis brevis for forearm and wrist deformity in children with cerebral palsy

We prospectively evaluated the clinical and functional outcomes of pronator teres to extensor carpi radialis brevis transfer in children with cerebral palsy. Patients were followed-up at 6 months postoperatively, and functionally assessed using the House classification, Manual Ability Classification System (MACS) and Upper Extremity Functional Index (UEFI). Fifteen children with a mean age of 8.1 years underwent tendon transfers. All patients were of Gschwind and Tonkin Grade 2 for pronation deformity; eight patients were of Zancolli's classification Group 1 and seven, Group 2 for wrist flexion deformity. The average gain in active supination was 67°, and wrist extension 15°. An increase of 7.0 in the UEFI score was recorded, although no significant improvement in MACS and House classification was observed. We conclude that the pronator teres to extensor carpi radialis brevis transfer improves upper limb function through effective correction of forearm pronation and wrist flexion deformities.Level of evidence: II.

Differences between Two Methods to Stabilize Supramalleolar Osteotomies in Children-A Retrospective Case Series

Supramalleolar osteotomy (SMO) in pediatric patients can be fixed in various ways. We analyzed the records of 77 pediatric patients (124 SMOs) aged ≤16 years. In 56 patients (96 SMOs), K-wires were used to stabilize SMOs (WF group), while 21 patients (28 SMOs) were treated with locking compression plates (LCPs; PF group). We recorded time to radiographic consolidation, rate of complications, length of hospital stay (LOS), and time to implant removal. Mean time to radiographic consolidation of SMOs was 7.2 weeks in the WF group and 11.1 weeks in the PF group. Complication rate in the WF group was 10.7%. LOS was similar in the two groups (7.0 days in the WF group vs. 7.3 days in the PF group). K-wire stabilization resulted in a shortened interval until consolidation of osteotomies, but children were required to use a cast. Stabilization of SMOs with LCPs facilitated early mobilization and functional rehabilitation with no need to apply a cast. In conclusion, both methods provided safe fixation of SMOs with a low rate of complications. K-wire stabilization combined with a cast achieves fast consolidation of SMOs. We recommend SMO stabilization with angular stable LCPs in patients with muscular weakness or spasticity in whom early mobilization and physiotherapy are necessary to prevent loss of muscle power, muscle function, and bone mass.

Single Residue Variation in Skeletal Muscle Myosin Enables Direct and Selective Drug Targeting for Spasticity and Muscle Stiffness

Muscle spasticity after nervous system injuries and painful low back spasm affect more than 10% of global population. Current medications are of limited efficacy and cause neurological and cardiovascular side effects because they target upstream regulators of muscle contraction. Direct myosin inhibition could provide optimal muscle relaxation; however, targeting skeletal myosin is particularly challenging because of its similarity to the cardiac isoform. We identified a key residue difference between these myosin isoforms, located in the communication center of the functional regions, which allowed us to design a selective inhibitor, MPH-220. Mutagenic analysis and the atomic structure of MPH-220-bound skeletal muscle myosin confirmed the mechanism of specificity. Targeting skeletal muscle myosin by MPH-220 enabled muscle relaxation, in human and model systems, without cardiovascular side effects and improved spastic gait disorders after brain injury in a disease model. MPH-220 provides a potential nervous-system-independent option to treat spasticity and muscle stiffness.

Medical Updates in Management of Hypertonia

Identifying the subtypes of hypertonia is becoming increasingly important. Treatment strategies, including tone-modulating surgical interventions, medication type and dosing, and chemodenervation, may differ depending on the type of hypertonia present. It is important to delineate how hypertonia interferes with function and quality of life so that the appropriate intervention can be selected at the right time. Outcomes of treatment depend heavily on clear communication of goals. Botulinum toxin should not be used in isolation but as an adjunct to rehabilitation modalities.

IncobotulinumtoxinA for the treatment of spasticity in children with cerebral palsy - a retrospective case series focusing on dosing and tolerability

BACKGROUND

IncobotulinumtoxinA (Xeomin®) is a botulinum neurotoxin type A with established efficacy in the treatment of upper-limb spasticity in adults. This retrospective case series in a university hospital setting aimed to elucidate the safety and tolerability of incobotulinumtoxinA for treatment of spasticity in children with cerebral palsy.

METHODS

Participants received incobotulinumtoxinA injections up to a maximum total dose of 600 U, 24 U/kg body weight. Medical records were reviewed for key demographic information, incobotulinumtoxinA exposure, and adverse effects (AEs).

RESULTS

Sixty-nine children were included (mean age [SD], 8.3 [3.9] years; 44/69 [63.8%] male). One-hundred-and-ninety-one injections were administered, with mean (SD) of 2.8 (1.5) treatment cycles/participant and dosing interval of 6.0 (1.7) months. The number of muscles injected increased from 2.4 (1.2) at cycle 1 to 4.2 (1.9) at cycle 6. The mean (SD) total incobotulinumtoxinA dose increased from 191.7 (126.2) U, (8.5 [5.4] U/kg body weight) at cycle 1 to 368.0 (170.1) U, (9.9 [5.5] U/kg body weight) at cycle 6. Seventy four adverse effects (37.5% of injections) were reported, the most frequent was injection pain (93.2% of AEs). Only three AEs were considered directly treatment-related by injectors: muscle weakness, generalized weakness, and fever.

CONCLUSIONS

Our clinical experience indicates that incobotulinumtoxinA is a well-tolerated treatment option for focal spasticity in children with cerebral palsy.

TRIAL REGISTRATION

As the study was observational and retrospective, no EudraCT registration number was requested. The internal code assigned to the study in the administrative resolution was: 1143-N-15.

Botulinum toxin type A for the treatment of muscle contractures secondary to acute spinal cord injury in a young cat

Case summary

A 4-month-old male entire domestic shorthair cat presented for sudden onset of right thoracic monoparesis following a fall; within 18 h, the clinical signs progressed to non-ambulatory right hemiplegia with absent sensation in the distal right thoracic limb and left hemiparesis. MRI revealed changes consistent with a C6-C7 acute non-compressive nucleus pulposus extrusion with suspected secondary C5-C7 spinal cord haemorrhage. Rehabilitation exercises were started immediately after the diagnosis of acute spinal cord trauma. Sensation in the right thoracic limb improved and, with the help of a splint applied to that limb, the cat was ambulatory on all four limbs. Unfortunately, clinical signs started to progress over the course of 10 days. The cat developed progressive discomfort on manipulation of the right elbow and carpus, and a hyperflexion of the right carpus. Radiographs revealed no skeletal abnormalities. Muscle contractures were suspected. Under general anaesthesia the triceps and flexor muscles of the carpus and digits were injected with a total of 100 U of botulinum toxin type A (BTX-A). No complications were associated with the procedure and 24 h after the injection the carpal hyperflexion resolved.

Relevance and novel information

The use of BTX-A to treat muscle contractures in human medicine is an established and increasingly used technique. For example, in subacute stroke patients with a non-functional arm, BTX-A forearm injection appears to prevent disabling finger stiffness, likely by minimising the development of contractures. Here, we demonstrate that intramuscular BTX-A is an effective treatment for acquired muscle contractures in a cat.

Sedation and analgesia in children with cerebral palsy: a narrative review

BACKGROUND

Patients with cognitive impairment due to cerebral palsy experience pain more often than healthy peers and frequently require diagnostic and therapeutic painful procedures. Analgesia and procedural sedation outside the operating room are often required, but they may not adequately be provided because of the inability to accurately recognize and classify the state of pain and for the perceived higher risk of complications.

DATA SOURCES

We reviewed the available literature to highlight the specific risk factors and area of criticism, that should be further improved. We searched the Cochrane Library, Medline, Pubmed from 1987 to September 2018 using key words such as 'cerebral palsy and children and pain' or 'sedation and cerebral palsy and children'.

RESULTS

While different pain scales are useful in recognizing pain expressions, anxiety scales are not available. Moreover, studies on non-pharmacological techniques do not always have comparable results. Several risk factors, from anatomic abnormalities to liver and kidney functioning, should be kept in mind before proceeding with sedation.

CONCLUSIONS

Large trials are needed to assess the impact of non-pharmacological techniques and to evaluate which pain control strategy (pharmacological and non-pharmacological) should be used in different settings.

Botulinum Toxin A for Improving Lack of Ankle Dorsiflexion Range of Motion After Major Burns-A Retrospective Chart Review

OBJECTIVE

To review the effectiveness of botulinum toxin A (BTX-A) for treating the loss of maximum ankle dorsiflexion range of motion after burn injury.

DESIGN

Retrospective chart review.

SETTING

Large urban burn center.

PARTICIPANTS

Patients (3-51 y) with major burn injury and loss of ankle dorsiflexion range while hospitalized (N=5).

INTERVENTION

BTX-A treatment in addition to standard care.

MAIN OUTCOME MEASURES

Maximum ankle dorsiflexion range of motion at time of treatment, 1 month and 3 months posttreatment.

RESULTS

Patients' total burn area ranged from 18% to 95%, and time from injury to BTX-A injection (80-125 units) was 19-93 days. Ankle range at the time of injection was -10 to -50 degrees, and all patients had improved ankle range at 1 month postinjection (-30 to +10 degrees). At 3 months postinjection, 3 participants had neutral ranges of motion that were relatively improved compared to preinjection ranges. Patients with additional complications or severe injury showed regression toward preinjection maximum ankle dorsiflexion range of motion.

CONCLUSION

This retrospective study examines BTX-A as a potential tool for treating ankle plantar flexion contractures post major burn injury after failed conservative treatment. Initial review shows some patients may benefit from these injections, but more systematically designed studies are required to assess effectiveness. If effective, further investigation will be needed to validate and standardize treatment protocols, establish dosing, and assess long-term effectiveness in those with burn injury or severe complications.

Novel ATL1 mutation in a Chinese family with hereditary spastic paraplegia: A case report and review of literature

BACKGROUND

Hereditary spastic paraplegias (HSPs) refer to a group of heterogeneous neurodegenerative diseases characterized by lower limbs spasticity and weakness. So far, over 72 genes have been found to cause HSP (SPG1-SPG72). Among autosomal dominant HSP patients, spastic paraplegia 4 (SPG4/SPAST) gene is the most common pathogenic gene, and atlastin-1 (ATL1) is the second most common one. Here we reported a novel ATL1 mutation in a Chinese spastic paraplegia 3A (SPG3A) family, which expands the clinical and genetic spectrum of ATL1 mutations.

CASE SUMMARY

A 9-year-old boy with progressive spastic paraplegia accompanied by right hearing loss and mental retardation for five years was admitted to our hospital. Past history was unremarkable. The family history was positive, and his grandfather and mother had similar symptoms. Neurological examinations revealed hypermyotonia in his lower limbs, hyperreflexia in knee reflex, bilateral positive Babinski signs and scissors gait. The results of blood routine test, liver function test, blood glucose test, ceruloplasmin test and vitamin test were all normal. The serum lactic acid level was significantly increased. The testing for brainstem auditory evoked potential demonstrated that the right side hearing was impaired while the left was normal. Magnetic resonance imaging showed mild atrophy of the spinal cord. The gene panel test revealed that the proband carried an ATL1 c.752A>G p.Gln251Arg (p.Q251R) mutation, and Sanger sequencing confirmed the existence of family co-segregation.

CONCLUSION

We reported a novel ATL1 Q251R mutation and a novel clinical phenotype of hearing loss in a Chinese SPG3A family.

[Sedation-analgesia protocol for the injection of botulinum toxin A in cerebral palsy]

OBJECTIVE

To evaluate the impact of the sedation-analgesia technique on the pain experienced by the patient.

METHODS

This cross-sectional study was conducted on consecutive patients with cerebral palsy (CP) who underwent infiltration with botulinum toxin A (BoTNA). The patients were divided into 4 different groups according to the analgesic strategy assigned: Group I, without sedation or topical anaesthetic cream; Group II, inhalation of nitrous oxide; Group III, deep intravenous sedation; and Group IV, light sedation with benzodiazepines. Pain was assessed with different scales depending on patient age. Parents were asked to rate their satisfaction with their child's comfort by using a 5-point Likert-type scale. The primary end-point was the proportion of patients that experienced a pain level equal or lower than 2, according to pain scales, in the different study groups.

RESULTS

Of the 124 patients included in the study, 56 (45.2%) experienced a pain level ≤2. In the Group III a significantly greater proportion of patients were classified with a pain level score ≤2, P<.001, as compared with all the study groups, respectively. The BoTNA injection was guided by ultrasonography in 109 (87.9%) patients, and by palpation in 15 (12.1%).

CONCLUSION

The results of this study suggested that, in patients with CP treated with BoTNA injections, the sedation-analgesic strategy had a significant impact on the pain experienced by the subject. Selecting an appropriate analgesic strategy is crucial for reducing the stress associated with the administration of BoTNA injections in children with CP.

Loss of myogenic potential and fusion capacity of muscle stem cells isolated from contractured muscle in children with cerebral palsy

Cerebral palsy (CP) is the most common cause of pediatric neurodevelopmental and physical disability in the United States. It is defined as a group of motor disorders caused by a nonprogressive perinatal insult to the brain. Although the brain lesion is nonprogressive, there is a progressive, lifelong impact on skeletal muscles, which are shorter, spastic, and may develop debilitating contractures. Satellite cells are resident muscle stem cells that are indispensable for postnatal growth and regeneration of skeletal muscles. Here we measured the myogenic potential of satellite cells isolated from contractured muscles in children with CP. When compared with typically developing (TD) children, satellite cell-derived myoblasts from CP differentiated more slowly (slope: 0.013 (SD 0.013) CP vs. 0.091 (SD 0.024) TD over 24 h, P < 0.001) and fused less (fusion index: 21.3 (SD 8.6) CP vs. 81.3 (SD 7.7) TD after 48 h, P < 0.001) after exposure to low-serum conditions that stimulated myotube formation. This impairment was associated with downregulation of several markers important for myoblast fusion and myotube formation, including DNA methylation-dependent inhibition of promyogenic integrin-β 1D (ITGB1D) protein expression levels (-50% at 42 h), and ~25% loss of integrin-mediated focal adhesion kinase phosphorylation. The cytidine analog 5-Azacytidine (5-AZA), a demethylating agent, restored ITGB1D levels and promoted myogenesis in CP cultures. Our data demonstrate that muscle contractures in CP are associated with loss of satellite cell myogenic potential that is dependent on DNA methylation patterns affecting expression of genetic programs associated with muscle stem cell differentiation and muscle fiber formation.

Effectiveness of Botulinum Toxin A for Persistent Upper Limb Pain After Breast Cancer Treatment: A Double-Blinded Randomized Controlled Trial

OBJECTIVE

To investigate the effect of a single botulinum toxin A (BTX-A) infiltration in the pectoralis major muscle in addition to a standard physical therapy program for treatment of persistent upper limb pain in breast cancer survivors.

DESIGN

Double-blinded (patient and assessor) randomized controlled trial.

SETTING

A university hospital.

PARTICIPANTS

Breast cancer patients (N=50) with pain.

INTERVENTION

The intervention group received a single BTX-A infiltration. The control group received a placebo (saline) infiltration. Within 1 week after the infiltration, all patients attended an individual physical therapy program (12 sessions) during the first 3 months and a home exercise program up to 6 months after infiltration.

MAIN OUTCOME MEASURES

The primary outcome was change in pain intensity at the upper limb (visual analog scale, 0-100) after 3 months. Secondary outcomes were prevalence rate of pain, pressure hypersensitivity, pain quality, shoulder function, and quality of life. Measures were taken before the intervention and at 1, 3, and 6 months' follow-up.

RESULTS

No significant difference in change in pain intensity after 3 months was found (mean difference in change, 3/100; 95% confidence interval [CI], -13 to 19). From baseline up to 6 months, a significantly different change in upper limb pain intensity was found between groups in favor of the intervention group (mean difference in change, 16/100; 95% CI, 1-31).

CONCLUSIONS

A single BTX-A infiltration in combination with an individual physical therapy program significantly decreased pain intensity at the upper limb in breast cancer survivors up to 6 months. However, the effect size was not clinically relevant, and no other beneficial effects were found.

Muscle disuse caused by botulinum toxin injection leads to increased central gain of the stretch reflex in the rat

Botulinum toxin (Btx) is used in children with cerebral palsy and in other neurological patients to diminish spasticity and reduce the risk of development of contractures. We investigated changes in the central gain of the stretch reflex circuitry in response to Btx injection in the triceps surae muscle in rats. Experiments were performed in 21 rats. Eight rats were a control group, and 13 rats were injected with 6 IU of Btx in the left triceps surae muscle. Two weeks after Btx injection, larger monosynaptic reflexes (MSR) were recorded from the left (injected) than the right (noninjected) L4 + L5 ventral roots following stimulation of the corresponding dorsal roots. A similar increase on the left side was observed in response to stimulation of descending motor tracts, suggesting that increased excitability of spinal motor neurons may at least partly explain the increased reflexes. However, significant changes were also observed in postactivation depression of the MSR, suggesting that plastic changes in transmission from Ia afferent to the motor neurons also may be involved. The data demonstrate that muscle paralysis induced by Btx injection is accompanied by plastic adaptations in the central stretch reflex circuitry, which counteract the antispastic effect of Btx.NEW & NOTEWORTHY Injection of botulinum toxin into ankle muscles causes increased gain of stretch reflex. This is caused by adaptive changes in regulation of transmitter release from Ia afferents and increased excitability of spinal motor neurons.

Classification of upper limb disability levels of children with spastic unilateral cerebral palsy using K-means algorithm

Treatment for cerebral palsy depends upon the severity of the child's condition and requires knowledge about upper limb disability. The aim of this study was to develop a systematic quantitative classification method of the upper limb disability levels for children with spastic unilateral cerebral palsy based on upper limb movements and muscle activation. Thirteen children with spastic unilateral cerebral palsy and six typically developing children participated in this study. Patients were matched on age and manual ability classification system levels I to III. Twenty-three kinematic and electromyographic variables were collected from two tasks. Discriminative analysis and K-means clustering algorithm were applied using 23 kinematic and EMG variables of each participant. Among the 23 kinematic and electromyographic variables, only two variables containing the most relevant information for the prediction of the four levels of severity of spastic unilateral cerebral palsy, which are fixed by manual ability classification system, were identified by discriminant analysis: (1) the Falconer index (CAI _E ) which represents the ratio of biceps to triceps brachii activity during extension and (2) the maximal angle extension (θ _{Extension,max}). A good correlation (Kendall Rank correlation coefficient = -0.53, p = 0.01) was found between levels fixed by manual ability classification system and the obtained classes. These findings suggest that the cost and effort needed to assess and characterize the disability level of a child can be further reduced.

Reducing severe spasticity in cerebral palsy following meningoencephalitis by botulinum toxin

A 3-year-old boy diagnosed with diplegic cerebral palsy had received Botulinum toxin injection to reduce severe spasticity. There was an improvement of muscles tone and motor function including better ability of limb flexion of the knees and hip, adduction of the hip, flexion of the toes, and plantar flexion of the foot. No side effect was observed after the procedure.

[Facial palsy in children]

Facial palsy (FP) in children is congenital or acquired. When present at birth (congenital), etiologies are mostly traumatic and rarely developmental. Acquired FP needs investigation. Research on the etiology helps to determine prognostic and treatment. At most times, no specific cause is found. Treatment of idiopathic FP consists of early oral corticosteroid therapy and ocular protection. Treating the sequelae is essential and the physician has to consider the dynamic balance of both sides of the face. Dynamic rehabilitation should mainly concern the inferior facial third. We recommend the lengthening temporalis myoplasty (LTM). This relevant technique ensures replicable and reliable results with a harmonious smile. Facial dynamic rehabilitation after surgical procedure (muscle tranfer or free muscle flap) must be directed toward control of voluntary movement, to move from a mandibular smile to a spontaneous and voluntary smile, thanks to brain plasticity. Furthermore, botulinum toxin is well tolerated and remains a great tool to treat a child who can support injections.