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Abstract Background Cerebral palsy (CP) is an upper motor neuron disease that results in a progressive movement disorder. Secondary to the neurological insult, muscles from CP patients often become spastic. Spastic muscle is characterized by an increased resistance to stretch, but often develops the further complication of contracture which represents a prominent disability in children with CP. This study's purpose is to characterize alterations of spastic muscle on the transcriptional level. Increased knowledge of spastic muscle may lead to novel therapies to improve the quality of life for children with CP. Method The transcriptional profile of spastic muscles were defined in children with cerebral palsy and compared to control patients using Affymetrix U133A chips. Expression data were verified using quantitative-PCR (QPCR) and validated with SDS-PAGE for select genes. Significant genes were determined using a 2 × 2 ANOVA and results required congruence between 3 preprocessing algorithms. Results CP patients clustered independently and 205 genes were significantly altered, covering a range of cellular processes. Placing gene expression in the context of physiological pathways, the results demonstrated that spastic muscle in CP adapts transcriptionally by altering extracellular matrix, fiber type, and myogenic potential. Extracellular matrix adaptations occur primarily in the basal lamina although there is increase in fibrillar collagen components. Fiber type is predominately fast compared to normal muscle as evidenced by contractile gene isoforms and decrease in oxidative metabolic gene transcription, despite a paradoxical increased transcription of slow fiber pathway genes. We also found competing pathways of fiber hypertrophy with an increase in the anabolic IGF1 gene in parallel with a paradoxical increase in myostatin, a gene responsible for stopping muscle growth. We found evidence that excitation-contraction coupling genes are altered in muscles from patients with CP and may be a significant component of disease. Conclusion This is the first transcriptional profile performed on spastic muscle of CP patients and these adaptations were not characteristic of those observed in other disease states such as Duchenne muscular dystrophy and immobilization-induced muscle atrophy. Further research is required to understand the mechanism of muscle adaptation to this upper motor neuron lesion that could lead to the development of innovative therapies.

In the last decade there has been incredible interest and advancement in the surgical care of adult patients with upper motor neuron (UMN) injuries. Spasticity represents a prevalent and debilitating feature of UMN syndrome, which can result from cerebral palsy, spinal cord injury, cerebrovascular accident and traumatic or anoxic brain injury. While several diagnostic tools and management strategies have been described for upper limb spasticity, evidence-based practice guidelines do not currently exist due to low patient volume and a paucity of surgeons routinely performing surgeries in UMN syndrome patients. As such, expert consensus may help provide guidance for patients, therapists and clinicians alike. In this article an expert panel was assembled, and the Delphi method was utilized to present diagnostic considerations, define operative indications, discuss surgical treatment modalities and encourage a standard set of outcome measures for patients with upper extremity spasticity. [ABSTRACT FROM AUTHOR]

PURPOSE: This study aimed to explore the feasibility of using time-matched uniaxial accelerometers for measuring movement in daily life in children with cerebral palsy (CP) before and after botulinum toxin injections. METHODS: This observational study of clinical care with a pre-post design was set in the home and school environment. Participants included eleven children (4–13 years of age) with CP (GMFCS I-III). The children wore uniaxial accelerometers (ActiGraph, model GT1M) for 4 days on both wrists, the right ankle and around the waist before, 3 weeks and 3 months after BoNT-A injections in the legs. Five children also got BoNT-A in the most affected arm. All injections were given according to clinical indications and routine. The accelerometers were all time-matched to define ambulation, arm swing, voluntary activity of arms, and bimanual activity. The feasibility of wearing accelerometers with this setup was evaluated. A linear mixed model was used for analysis of the percentage time and at which intensity the different activities were performed. The confidence interval demonstrated any difference between the dominant and non-dominant arm. RESULTS: Time-matching of accelerometers placed on both wrists, the waist, and one ankle is a feasible method of registering ambulation, arm swing during gait, and arm movements while not ambulating. Before injections, the children spent 5.6% of their time ambulating. This value declined to 3.9% at 3 months. Contrary to clinical goals, arm movement did not increase after injecting the most affected arm with BoNT-A, however, injections may have decreased mirror movements, which are often bothersome for the child. CONCLUSION: A time-matched 4-accelerometer set-up is feasible in children with cerebral palsy. A future study including time-matched multi-axial accelerometers on all four limbs, could provide important information on the effect of BoNT-A in daily life. [ABSTRACT FROM AUTHOR]

Due to a highly variable distribution of intramuscular collagen content within muscle, the amount collagen content itself does not relate to the actual passive muscle properties during mechanical testing as was shown in mouse hind limb muscles (Binder-Markey et al.). Keywords: muscle mechanics; extracellular matrix; connective tissue; neuromusculoskeletal interaction; adaptation; pathology; force production - transmission phenomena EN muscle mechanics extracellular matrix connective tissue neuromusculoskeletal interaction adaptation pathology force production - transmission phenomena 1 6 6 12/08/21 20211206 NES 211206 There is a growing emphasis on the importance of muscle extracellular matrix on muscular mechanics and specifically on the effects of the interaction of the extracellular matrix (ECM) and the contractile apparatus. An experimental assessment using multi-photon excitation microscopy in mouse tibialis anterior muscle surgically dissected from the tibia and surrounding muscles showed that in isometrically activated muscle the sarcomeres re-organize their lengths into a more uniform pattern over time, whereas in the passive state their length non-uniformity remained the same (Moo and Herzog). They demonstrate how a passively lengthened muscle can also have shortened parts and how an isometric contracting muscle can also have lengthened parts along the muscle fascicles. [Extracted from the article]

Skeletal muscle in individuals with CP also contains lower amounts of mtDNA, potentially indicating fewer mitochondria in CP skeletal muscle compared with typically developing muscle. We compared skeletal muscle samples from children with cerebral palsy (CP) and typically developing children and observed evidence of reduced mtDNA and OXPHOS protein content in CP skeletal muscle, indicating reduced mitochondrial abundance. Cerebral palsy (CP) muscle contains fewer energy-generating organelles than typically developing muscle. [Extracted from the article]

Abstract Background Cerebral palsy (CP) is an upper motor neuron disease that results in a progressive movement disorder. Secondary to the neurological insult, muscles from CP patients often become spastic. Spastic muscle is characterized by an increased resistance to stretch, but often develops the further complication of contracture which represents a prominent disability in children with CP. This study's purpose is to characterize alterations of spastic muscle on the transcriptional level. Increased knowledge of spastic muscle may lead to novel therapies to improve the quality of life for children with CP. Method The transcriptional profile of spastic muscles were defined in children with cerebral palsy and compared to control patients using Affymetrix U133A chips. Expression data were verified using quantitative-PCR (QPCR) and validated with SDS-PAGE for select genes. Significant genes were determined using a 2 × 2 ANOVA and results required congruence between 3 preprocessing algorithms. Results CP patients clustered independently and 205 genes were significantly altered, covering a range of cellular processes. Placing gene expression in the context of physiological pathways, the results demonstrated that spastic muscle in CP adapts transcriptionally by altering extracellular matrix, fiber type, and myogenic potential. Extracellular matrix adaptations occur primarily in the basal lamina although there is increase in fibrillar collagen components. Fiber type is predominately fast compared to normal muscle as evidenced by contractile gene isoforms and decrease in oxidative metabolic gene transcription, despite a paradoxical increased transcription of slow fiber pathway genes. We also found competing pathways of fiber hypertrophy with an increase in the anabolic IGF1 gene in parallel with a paradoxical increase in myostatin, a gene responsible for stopping muscle growth. We found evidence that excitation-contraction coupling genes are altered in muscles from patients with CP and may be a significant component of disease. Conclusion This is the first transcriptional profile performed on spastic muscle of CP patients and these adaptations were not characteristic of those observed in other disease states such as Duchenne muscular dystrophy and immobilization-induced muscle atrophy. Further research is required to understand the mechanism of muscle adaptation to this upper motor neuron lesion that could lead to the development of innovative therapies.

Peripheral nerve injuries (PNI) of the upper limb are a common event in the paediatric population, following both fractures and soft tissues injuries. Open injuries should in theory be easier to identify and the repair of injured structures performed as soon as possible in order to obtain a satisfying outcome. Conversely, due to the reduced compliance of younger children during clinical assessment, the diagnosis of a closed nerve injury may sometimes be delayed. As the compliance of patients is influenced by pain, anxiety and stress, the execution of the clinical manoeuvres intended to identify a loss of motor function or sensibility, can be impaired. Although the majority of PNI are neuroapraxias resulting in spontaneous recovery, there are open questions regarding certain aspects of closed PNI, e.g. when to ask for electrophysiological exams, when and how long to wait for a spontaneous recovery and when a surgical approach becomes mandatory. The aim of the article is therefore to analyse the main aspects of the different closed PNI of the upper limb in order to provide recommendations for timely and correct management, and to determine differences in the PNI treatment between children and adults. [ABSTRACT FROM AUTHOR]

Introduction: Children with cerebral palsy (CP) and acquired brain injury (ABI) commonly develop muscle contractures with advancing age. An underlying growth defect contributing to skeletal muscle contracture formation in CP/ABI has been suggested.Methods: The biceps muscles of children and adolescents with CP/ABI (n = 20) and typically developing controls (n = 10) were investigated. We used immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blotting to assess gene expression relevant to growth and size homeostasis.Results: Classical pro-inflammatory cytokines and genes involved in extracellular matrix (ECM) production were elevated in skeletal muscle of children with CP/ABI. Intramuscular collagen content was increased and satellite cell number decreased and this was associated with reduced levels of RNA polymerase I transcription factors, 45s pre-rRNA and 28S rRNA.Discussion: The present study provides novel data suggesting a role for pro-inflammatory cytokines and reduced ribosomal production in the development/maintenance of muscle contractures, possibly underlying stunted growth and perimysial ECM expansion. Muscle Nerve 58: 277-285, 2018. [ABSTRACT FROM AUTHOR]

Children with cerebral palsy (CP) often develop reduced passive range of motion with age. The determining factor underlying this process is believed to be progressive development of contracture in skeletal muscle that likely changes the biomechanics of the joints. Consequently, to identify the underlying mechanisms, we modeled the mechanical characteristics of the forearm flexors acting across the wrist joint. We investigated skeletal muscle strength (Grippit®) and passive stiffness and viscosity of the forearm flexors in 15 typically developing (TD) children (10 boys/5 girls, mean age 12 years, range 8-18 yrs) and nine children with CP Nine children (6 boys/3 girls, mean age 11 ± 3 years (yrs), range 7-15 yrs) using the NeuroFlexor® apparatus. The muscle stiffness we estimate and report is the instantaneous mechanical response of the tissue that is independent of reflex activity. Furthermore, we assessed cross-sectional area of the flexor carpi radialis (FCR) muscle using ultrasound. Age and body weight did not differ significantly between the two groups. Children with CP had a significantly weaker (-65%, p < 0.01) grip and had smaller cross-sectional area (-43%, p < 0.01) of the FCR muscle. Passive stiffness of the forearm muscles in children with CP was increased 2-fold (p < 0.05) whereas viscosity did not differ significantly between CP and TD children. FCR cross-sectional area correlated to age (R² = 0.58, p < 0.01), body weight (R² = 0.92, p < 0.0001) and grip strength (R² = 0.82, p < 0.0001) in TD children but only to grip strength (R² = 0.60, p < 0.05) in children with CP. We conclude that children with CP have weaker, thinner, and stiffer forearm flexors as compared to typically developing children. [ABSTRACT FROM AUTHOR]

The objective of the study was to investigate the feasibility of modified constraint-induced (CI) therapy provided in a 2-week day-camp model with and without intramuscular botulinum toxin type A (BoNT-A) injections for children with congenital cerebral palsy. Sixteen children with congenital hemiplegia, Manual Ability Classification System (MACS) level I and II, aged 8-17 years, participated in a CI therapy day camp; of whom five participants (aged 11-16 years) received intramuscular BoNT-A prior to CI therapy. Assessments were conducted 4 months and 2 weeks before (baselines 1 and 2), immediately after, and 6 months after the day camp. For the children who received BoNT-A, no statistical analyses were conducted due to the small size of the sample. In this group, consistent improvement was only found according to the Melbourne Unilateral Limb Assessment. The children who received only the CI therapy demonstrated improvements in the Jebsen-Taylor Hand Function Test ( p =. 04) at posttest, but improvements were not sustained at 6-month follow-up. No significant improvement was obtained for the Melbourne Assessment or the Assisting Hand Assessment. Children in both groups improved on specially trained tasks: frisbee golf, stacking blocks, and in-hand manipulation. Feedback from the participants suggests that the day-camp model is a feasible intervention following intramuscular BoNT-A injections. The results suggest that children with congenital hemiplegia with varying severity of impairment in hand function may benefit from CI therapy, but not every child demonstrates improvements in hand function. The characteristics of children who respond the best to CI therapy are not clear. [ABSTRACT FROM AUTHOR]

Morphological properties of skeletal muscle were compared between wrist flexors and extensors within the same children (n = 8, six females, two males; age range 4 to 9y, median age 7 y) with wrist muscle imbalance secondary to spastic cerebral palsy (CP). Five patients had hemiplegic CP, two diplegic CP, and one patient had tetraplegic CP. Muscle biopsies were taken during either tendon transfer or tendon lengthening procedures. Analyses included distribution of muscle fibre types, fibre sizes, and expression of developmental myosins. Extensor fibre area was significantly greater than flexor fibre area for type 2A fibres and type 2B fibres but not for type 1 fibres. Coefficient of variation (CV) of fibre size for all three fibre types was greater for flexors compared with extensors. The greatest CV was observed for the type 2A fibres in flexors (39.5 [3.6%]). A wide variation was observed for expression of developmental myosin with the magnitude of the expression being greater, but not statistically significant, in flexors compared with extensors (5.4/mm2 vs 0.53/mm2). These data demonstrate that significant secondary myopathy of wrist flexor muscles results from CP. [ABSTRACT FROM AUTHOR]

Enormous progress has been made in understanding the etiology and therapies for arthrogryposis (multiple congenital contractures). A 2nd International Symposium on Arthrogryposis was sponsored by the Turner Institute in St. Petersburg, Russia. Olga Agranovich, Head of the Arthrogryposis Department of the Turner Institute, organized this special meeting. Care providers from multiple disciplines from all over the world representing 18 nations attended. Participants included: Pediatric orthopedic specialists, rehabilitation physicians, occupational therapists, physical therapists, medical geneticists, neurologists, craniofacial physicians, psychologists, developmental biologists, as well as representatives from parent support groups. The 1st symposium established the need for a collaborative and interdisciplinary approach to the treatment of arthrogryposis, engagement of parent support organizations, and the aim for more research. The Second Symposium highlighted the continuing need for more research on various therapies, identification of different types of arthrogryposis, standardized descriptions of severity, development of new orthotics, improved prenatal diagnosis, and studying adult outcome. Major progress has been made on both upper and lower limb treatments. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

This commentary is on the original article by Hedberg‐Graff et al. on pages 204–211 of this issue. [ABSTRACT FROM AUTHOR]

Background: Arthrogryposis Multiplex Congenita (AMC) is a heterogeneous condition characterized by multiple joint contractures at birth. Greater movements in the trunk and pelvis during walking have been observed in children with AMC using orthoses compared to those wearing only shoes. This study investigated gait dynamics in children with AMC and identified compensatory mechanisms that accommodate walking.Methods: Twenty-six children with AMC who walked with orthoses or shoes and a control group consisting of 37 typically-developing children were evaluated in 3D gait analysis. Children with AMC were divided into subgroups based on which joints needed to be stabilized in the sagittal plane; AMC1 used knee-ankle-foot orthoses (KAFOs) with locked knee joints, AMC2 used KAFOs with open knee joints or ankle-foot orthoses, and AMC3 used shoes.Results: The Gait Deviation Index was lower in AMC groups than in the control group, with the lowest in AMC1. Excessive trunk movements in frontal and transverse planes were observed in AMC2 and especially in AMC1. Lower hip flexion moment was found in AMC1, while AMC2 and AMC3 showed similar hip flexion moments as the control group. Knee extension moments were similar between the groups. In the frontal plane there were only small differences between the groups in hip abduction moment. A joint work analysis indicated greater contribution from the hip muscles to overall positive work in AMC groups, particularly in AMC1, than in the control group.Conclusion: All AMC groups showed less hip extension than the control group, but hip flexion moment was significantly lower only in AMC1, which can be attributed to their gait strategy with bilateral locked KAFOs. AMC1, who had weak knee extensors, were helped by their locked KAFOs and therefore showed similar knee extension moment as the other groups. This finding, together with their gait patterns, demonstrates the children's high reliance on hip muscles and presumably trunk muscles to provide propulsion. Our study shows that with adequate orthotic support, children with AMC and even with severe weakness and contractures can achieve walking. [ABSTRACT FROM AUTHOR]

In this study, the properties of circulating extracellular vesicles (EVs) were examined in cerebral palsy (CP) and typically developed (TD) individuals at rest and after aerobic exercise, focusing on the size, concentration, and microRNA cargo of EVs. Nine adult individuals with CP performed a single exercise bout consisting of 45 min of Frame Running, and TD participants completed either 45 min of cycling ( n = 10; TD EX) or were enrolled as controls with no exercise ( n = 10; TD CON). Blood was drawn before and 30 min after exercise and analyzed for EV concentration, size, and microRNA content. The size of EVs was similar in CP vs. TD, and exercise had no effect. Individuals with CP had an overall lower concentration (∼25%, p < 0.05) of EVs. At baseline, let-7a, let-7b and let-7e were downregulated in individuals with CP compared to TD ( p < 0.05), while miR-100 expression was higher, and miR-877 and miR-4433 lower in CP compared to TD after exercise ( p < 0.05). Interestingly, miR-486 was upregulated ∼2-fold in the EVs of CP vs. TD both at baseline and after exercise. We then performed an in silico analysis of miR-486 targets and identified the satellite cell stemness factor Pax7 as a target of miR-486. C2C12 myoblasts were cultured with a miR-486 mimetic and RNA-sequencing was performed. Gene enrichment analysis revealed that several genes involved in sarcomerogenesis and extracellular matrix (ECM) were downregulated. Our data suggest that circulating miR-486 transported by EVs is elevated in individuals with CP and that miR-486 alters the transcriptome of myoblasts affecting both ECM- and sarcomerogenesis-related genes, providing a link to the skeletal muscle alterations observed in individuals with CP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Vechetti, Norrbom, Alkner, Hjalmarsson, Palmcrantz, Pontén, Pingel, von Walden and Fernandez-Gonzalo.)

Introduction: Cerebral palsy (CP) is the most common motor impairment in children. Skeletal muscles in individuals with CP are typically weak, thin, and stiff. Whether epigenetic changes at the ribosomal DNA (rDNA) promoter are involved in this dysregulation remains unknown. Methods: Skeletal muscle samples were collected from 19 children with CP and 10 typically developed (TD) control children. Methylation of the rDNA promoter was analyzed using the Agena Epityper Mass array and gene expression by qRT-PCR. Results: Biceps brachii muscle ribosome biogenesis was suppressed in CP as compared to TD. Average methylation of the rDNA promoter was not different between CP and TD but negatively correlated to elbow flexor contracture in the CP group. Discussions: We observed a negative correlation between rDNA promoter methylation and degree of muscle contracture in the CP group. Children with CP with more severe motor impairment had less methylation of the rDNA promoter compared to less affected children. This finding suggests the importance of neural input and voluntary muscle movements for promoter methylation to occur in the biceps muscle., (Copyright © 2020 von Walden, Fernandez-Gonzalo, Pingel, McCarthy, Stål and Pontén.)

Objective: To investigate the potential of an acute bout of transcranial electrical stimulation to induce anabolic signalling., Design: Experimental intervention on healthy subjects., Subjects: Ten healthy subjects, 5 women and 5 men (mean age (standard deviation (SD) 32 years (SD 4))., Methods: The quadriceps muscle was stimulated at a frequency of 10 Hz for 10 s, followed by 20 s of rest, repeated 40 times over 20 min. Electromyography and force data were collected for all transcranial electrical stimulation sequences. Muscle biopsies were obtained from the vastus lateralis muscle before and 1 and 3 h after stimulation., Results: One bout of transcranial electrical stimulation decreased phosphorylation of AKT at Thr308 (1 h: -29%, 3 h: -38%; p < 0.05) and mTOR phosphorylation at Ser2448 (1 h: -10%; ns, 3 h: -21%; p < 0.05), both in the anabolic pathway. Phosphorylation of AMPK, ACC and ULK1 were not affected. c-MYC gene expression was unchanged following transcranial electrical stimulation, but rDNA transcription decreased (1 h: -28%, 3 h: -19%; p < 0.05). PGC1α-ex1b mRNA increased (1 h: 2.3-fold, 3 h: 2.6-fold; p < 0.05), which also correlated with vastus lateralis electromyography activity, while other PGC-1α variants were unchanged., Conclusion: Acute transcranial electrical stimulation of skeletal muscle in weight-bearing healthy individuals did not induce anabolic signalling, and some signs of impaired muscle anabolism were detected, suggesting limited potential in preventing muscle wasting.

The aim of this study was to evaluate whether short-term positive effects on bimanual function after surgery of the paretic arm in cerebral palsy are maintained long term. Assisting Hand Assessment (AHA) and active range of motion was tested before surgery and at 7 month and 9-year follow-up (n=18). AHA improved significantly from 50 to 52 U at 7 months, but was not different from before surgery at the 9-year follow-up, 49 U. Surgery of wrist and elbow flexors significantly improved active extension. Improvement in wrist and elbow extension was maintained at the 9-year follow-up, but usefulness of the hand measured with AHA had returned to the same level as before surgery.

Arthrogryposis multiplex congenital is a relatively uncommon condition, with little consensus on treatment. In 2007, the 1st International Symposium on Arthrogryposis was held in Birmingham, United Kingdom, to bring together patients, their families, and a multinational group of health care experts in the field of arthrogryposis, to discuss various aspects of the care of patients with arthrogryposis multiplex congenital. From that meeting, there was a coalescence of thought on diagnosis and classification, a sharing of practices on treatments and their outcomes, and an agreement on future directions. At the beginning of the 2nd International Symposium on Arthrogryposis held in Saint Petersburg in September 2014, Russia, these "lessons learnt" were synopsized to set the tone for the new meeting.

Lower extremity deformities of patients with arthrogryposis multiplex congenita present a wide spectrum of severity and deformity combinations. Treatment goals range from merely ensuring comfortable seating and shoe wear, to fully independent and active ambulation, but the overarching intention is to help realize the patient's greatest potential for independence and function. Treatment of hip and knee contractures and dislocations has become more interventional, whereas treatment of foot deformities has paradoxically become much less surgical. This article synopsizes the treatment strategies presented in September 2014 in Saint Petersburg, Russia at the second international symposium on arthrogryposis.