Fatigue resistance during a voluntary performance task is associated with lower levels of mobility in cerebral palsy

Effectiveness of whole-body vibration in patients with cerebral palsy: A systematic review and meta-analysis

BACKGROUND

This study examined the effects of systemic vibration exercises on cerebral palsy patients.

METHODS

Literature published in Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane library, Embase, Physiotherapy Evidence Database (PEDro), and PubMed was reviewed. A total of 2978 studies were initially retrieved. After further reading of the full texts 17 articles were finally included. A quality assessment of the included studies was conducted using the risk of bias (RoB) 2.0, and the Funnel plot and the Egger test were conducted to confirm the publication bias. Subgroup analysis was carried out according to the dependent variables, the international classification of functioning, disability, and health (ICF), frequency, treatment period and age.

RESULTS

The overall effect size of homogeneity was 0.474 (CI = 0.148-0.801). The analysis of the dependent variables showed the following order of the effect size: balance, muscle strength, spasticity, bone density, range of motion of the joint, gait function, and motor function. In the ICF classification, the effect size was observed to follow the order of body structure and function, activity, and participation. The effect size in the intervention according to the treatment period showed the following order: 7 to 12 weeks, 1 to 6 weeks, and 14 to 24 weeks. The age-dependent classification showed the following order in the effect size: school age, adolescent and adult, and infant and school age.

CONCLUSIONS

Systemic vibration is the most effective intervention to improve the balance and gait in patients with cerebral palsy and improve the body structure and function according to the ICF.

Age-Related Differences in Muscle Size and Strength between Individuals with Cerebral Palsy and Individuals with Typical Development

AIM

Examine age-related differences in muscle size and strength of the knee extensors in individuals with cerebral palsy (CP) and individuals with typical development (TD).

METHODS

54 individuals with CP (14.5 ± 4.5 years, GMFCS I-V) and 33 individuals with TD (16.2 ± 5.5 years) were included. Relationships between rectus femoris (RF) and vastus lateralis (VL) muscle volume and isokinetic knee extensor strength with age were examined with linear regression and ANCOVA to test age-related differences between groups.

RESULTS

Linear regression for muscle volume with age was statistically significant in TD (VL: r2 = 0.48, RF: r2 = 0.56, p < .05) and those with CP (VL: r = 0.36, RF: r2 = 0.27, p < .05) with no differences in regression slopes between groups (p > .05). Age-related strength differences were observed in TD (r2 = 0.66, p < .001) and those with CP (r2 = 0.096, p = .024), but the slopes were significantly different between CP and TD (p < .001).

CONCLUSION

Age-related linear differences in muscle volume and strength were observed in both groups. The linear slope of the age-related differences in knee extensor muscle strength and strength-to-body mass ratio were significantly lower in individuals with CP compared to individuals with TD, suggesting that strength is insufficient to keep up with gains in body mass during growth.

Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy

Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischaemic (HI) injury in utero (at 70%-83% gestation) are born with muscle stiffness, hyperreflexia and, as recently discovered, increased 5-HT in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to the application of α-methyl 5-HT (a 5-HT1 /5-HT2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with increased amplitude and hyperpolarization of persistent inward currents and hyperpolarized threshold voltage for action potentials, whereas control MNs did not exhibit any of these responses. Although 5-HT similarly modulated MN properties of HI motor-unaffected and motor-affected kits, it affected sag/hyperpolarization-activated cation current (Ih ) and spike frequency adaptation only in HI motor-affected MNs. To further explore the differential sensitivity of MNs to 5-HT, we performed immunostaining for inhibitory 5-HT1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT1A receptor compared to age-matched control MNs. This suggests that HI MNs may lack a normal mechanism of central fatigue, mediated by 5-HT1A receptors. Altered expression of other 5-HT receptors (including 5-HT2 ) likely also contributes to the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI-affected rabbits can cause MN hyperexcitability, muscle stiffness and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP. KEY POINTS: We used whole cell patch clamp electrophysiology to test the responsivity of spinal motoneurons (MNs) from neonatal control and hypoxia-ischaemia (HI) rabbits to 5-HT, which is elevated in the spinal cord after prenatal HI injury. HI rabbit MNs showed a more robust excitatory response to 5-HT than control rabbit MNs, including hyperpolarization of the persistent inward current and threshold voltage for action potentials. Although most MN properties of HI motor-unaffected and motor-affected kits responded similarly to 5-HT, 5-HT caused larger sag/hyperpolarization-activated cation current (Ih ) and altered repetitive firing patterns only in HI motor-affected MNs. Immunostaining revealed that fewer lumbar MNs expressed inhibitory 5-HT1A receptors in HI rabbits compared to controls, which could account for the more robust excitatory response of HI MNs to 5-HT. These results suggest that elevated 5-HT after prenatal HI injury could trigger a cascade of events that lead to muscle stiffness and altered motor unit development.

Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy

Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischemic (HI) injury in utero (at 70-80% gestation) are born with muscle stiffness, hyperreflexia, and, as recently discovered, increased serotonin (5-HT) in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to application of α-methyl 5-HT (a 5-HT 1 /5-HT 2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with hyperpolarization of persistent inward currents and threshold voltage for action potentials, reduced maximum firing rate, and an altered pattern of spike frequency adaptation while control MNs did not exhibit any of these responses. To further explore the differential sensitivity of MNs to 5-HT, we performed immunohistochemistry for inhibitory 5-HT 1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT 1A receptor compared to age-matched controls. This suggests many HI MNs lack a normal mechanism of central fatigue mediated by 5-HT 1A receptors. Other 5-HT receptors (including 5-HT 2 ) are likely responsible for the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI rabbits can cause MN hyperexcitability, muscle stiffness, and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP.

Key points

After prenatal hypoxia-ischemia (HI), neonatal rabbits that show hypertonia are known to have higher levels of spinal serotoninWe tested responsivity of spinal motoneurons (MNs) in neonatal control and HI rabbits to serotonin using whole cell patch clampMNs from HI rabbits showed a more robust excitatory response to serotonin than control MNs, including hyperpolarization of the persistent inward current and threshold for action potentials, larger post-inhibitory rebound, and less spike frequency adaptation Based on immunohistochemistry of lumbar MNs, fewer HI MNs express inhibitory 5HT 1A receptors than control MNs, which could account for the more robust excitatory response of HI MNs. These results suggest that after HI injury, the increased serotonin could trigger a cascade of events leading to muscle stiffness and altered motor unit development.

Effects of voluntary exercise on muscle structure and function in cerebral palsy

Skeletal muscles are required for functional movement and force production. While it is clear that cerebral palsy (CP) results in loss of muscle strength and bodily function, and that much of this loss is caused by injury to the central nervous system, muscle is a very plastic tissue that is also dramatically affected. In many studies, it is assumed that voluntary exercise will cause the muscle to respond in the same way that typically developing muscle does, but there are scarce data demonstrating that this is true. The purpose of this review is to briefly describe muscle architectural adaptation to various forms of exercise with specific reference to voluntary exercise performed in children with CP. Exercise itself is not generic but can vary by intensity, duration, and the exact nature of the muscle length change and velocity imposed during the exercise. Our goal is to stimulate discussion in this area by pointing out salient experimental variables and, ultimately, to improve activity and participation in children with CP.

Glycine receptor subunit-ß -deficiency in a mouse model of spasticity results in attenuated physical performance, growth and muscle strength

Spasticity is the most common neurological disorder associated with increased muscle contraction causing impaired movement and gait. The aim of this study was to characterize the physical performance, skeletal muscle function, and phenotype of mice with a hereditary spastic mutation (B6.Cg-Glrb^spa/J). Motor function, gait, and physical activity of juvenile and adult spastic mice and the morphological, histological, and mechanical characteristics of their soleus and gastrocnemius medialis muscles were compared with those of their wild-type (WT) littermates. Spastic mice showed attenuated growth, impaired motor function, and low physical activity. Gait of spastic mice was characterized by a typical hopping pattern. Spastic mice showed lower muscle forces, which were related to the smaller physiological cross-sectional area of spastic muscles. The muscle-tendon complex length-force relationship of adult gastrocnemius medialis was shifted toward shorter lengths, which was explained by attenuated longitudinal tibia growth. Spastic gastrocnemius medialis was more fatigue resistant than WT gastrocnemius medialis. This was largely explained by a higher mitochondrial content in muscle fibers and relatively higher percentage of slow-type muscle fibers. Muscles of juvenile spastic mice showed similar differences compared with WT juvenile mice, but these were less pronounced than between adult mice. This study shows that in spastic mice, disturbed motor function and gait is likely to be the result of hyperactivity of skeletal muscle and impaired skeletal muscle growth, which progress with age.

Psychological, Cardiometabolic, and Musculoskeletal Morbidity and Multimorbidity Among Adults With Cerebral Palsy and Spina Bifida: A Retrospective Cross-sectional Study

BACKGROUND

Individuals living with cerebral palsy or spina bifida are at heightened risk for a number of chronic health conditions, such as secondary comorbidities, that may develop or be influenced by the disability, the presence of impairment, and/or the process of aging. However, very little is known about the prevalence and/or risk of developing secondary comorbidities among individuals living with cerebral palsy or spina bifida throughout adulthood. The objective of this study was to compare the prevalence of psychological, cardiometabolic, and musculoskeletal morbidity and multimorbidity among adults with and without cerebral palsy or spina bifida.

METHODS

Privately insured beneficiaries were included if they had an International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic code for cerebral palsy or spina bifida (n = 29,841). Adults without cerebral palsy or spina bifida were also included (n = 5,384,849). Prevalence estimates of common psychological, cardiometabolic, and musculoskeletal morbidity and multimorbidity (≥2 conditions) were compared.

RESULTS

Adults living with cerebral palsy or spina bifida had a higher prevalence of all psychological disorders and psychological multimorbidity (14.6% vs. 5.4%), all cardiometabolic disorders and cardiometabolic multimorbidity (22.4% vs. 15.0%), and all musculoskeletal disorders and musculoskeletal multimorbidity (12.2% vs. 5.4%), as compared with adults without cerebral palsy or spina bifida, and differences were to a clinically meaningful extent.

CONCLUSIONS

Adults with cerebral palsy or spina bifida have a significantly higher prevalence of common psychological, cardiometabolic, and musculoskeletal morbidity and multimorbidity, as compared with adults without cerebral palsy or spina bifida. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of disease onset/progression in these higher risk populations.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

CME OBJECTIVES

Upon completion of this article, the reader should be able to: (1) List the main categories of morbidity that present with higher risk in adults with cerebral palsy and spina bifida; (2) Discuss the potential impact of multimorbidity on 'early aging' in adults living with cerebral palsy and spina bifida; and (3) Describe challenges that adults with cerebral palsy and spina bifida have in obtaining appropriate health care to address prevention and treatment of multimorbidity.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Pain phenotypes among adults living with cerebral palsy and spina bifida

ABSTRACT

Chronic pain is the most commonly reported physical symptomology of cerebral palsy (CP) and spina bifida (SB) throughout the lifespan, and yet, pain is perhaps the least understood comorbidity in these populations. The objective of this study was to compare the prevalence and types of pain diagnosed among adults living with and without CP or SB. In this retrospective cohort study, we analyzed data from a nationwide commercial insurance claims database. Beneficiaries were included if they had an International Classification of Diseases, Ninth revision, Clinical Modification diagnosis code for CP or SB (n = 22,648). Adults without CP or SB were also included as controls (n = 931,623). Pain phenotypes (nociceptive, nociplastic, and neuropathic pain) and pain multimorbidity (≥2 conditions) were compared. We found that adults living with CP or SB had a higher prevalence of any pain disorders (55.9% vs 35.2%), nociceptive pain (44.0% vs 26.7%), nociplastic pain (26.1% vs 11.9%), neuropathic pain (9.6% vs 5.6%), and pain multimorbidity (21.1% vs 8.4%), as compared to adults without CP or SB, and differences were to a clinically meaningful extent. Adjusted odds ratios of nociceptive pain (odds ratio [OR]: 2.20; 95% confidence interval [CI]: 2.15-2.24), nociplastic pain (OR: 2.47; 95% CI: 2.41-2.53), neuropathic pain (OR: 2.71; 95% CI: 2.54-2.89), and other pain (OR: 3.92; 95% CI: 3.67-4.19) were significantly higher for adults living with CP or SB. In conclusion, adults with CP or SB have a significantly higher prevalence and odds of common peripheral, central, and neuropathic pain disorders and pain multimorbidity, as compared to adults without CP or SB.

Skeletal muscle maximal mitochondrial activity in ambulatory children with cerebral palsy

AIM

To compare skeletal muscle mitochondrial enzyme activity and mitochondrial content between independently ambulatory children with cerebral palsy (CP) and typically developing children.

METHOD

Gracilis biopsies were obtained from 12 children during surgery (n=6/group, children with CP: one female, five males, mean age 13y 4mo, SD 5y 1mo, 4y 1mo-17y 10mo; typically developing children: three females, three males, mean age 16y 5mo, SD 1y 4mo, 14y 6mo-18y 2mo). Spectrophotometric enzymatic assays were used to evaluate the activity of mitochondrial electron transport chain complexes. Mitochondrial content was evaluated using citrate synthase assay, mitochondrial DNA copy number, and immunoblots for specific respiratory chain proteins.

RESULTS

Maximal enzyme activity was significantly (50-80%) lower in children with CP versus typically developing children, for complex I (11nmol/min/mg protein, standard error of the mean [SEM] 1.7 vs 20.7nmol/min/mg protein, SEM 4), complex II (6.9nmol/min/mg protein, SEM 1.2 vs 21nmol/min/mg protein, SEM 2.7), complex III (31.9nmol/min/mg protein, SEM 7.4 vs 72.7nmol/min/mg protein, SEM 7.2), and complex I+III (7.4nmol/min/mg protein, SEM 2.5 vs 31.8nmol/min/mg protein, SEM 9.3). Decreased electron transport chain activity was not the result of lower mitochondrial content.

INTERPRETATION

Skeletal muscle mitochondrial electron transport chain enzymatic activity but not mitochondrial content is reduced in independently ambulatory children with CP. Decreased mitochondrial oxidative capacity might explain reported increased energetics of movement and fatigue in ambulatory children with CP. What this paper adds Skeletal muscle mitochondrial electron transport chain enzymatic activity is reduced in independently ambulatory children with cerebral palsy (CP). Mitochondrial content appears to be similar between children with CP and typically developing children.

Systematic Review of Fatigue in Individuals With Cerebral Palsy

In this systematic review, we collected and analyzed literature works comparing self-reported fatigue and objectively-measured fatigue in individuals with cerebral palsy (CP) and in age-matched typically developing/typically developed (TD) controls (Healthy). The search was conducted on four electronic databases/platforms (PubMed, Web of Science, Cochrane Library, and Scopus) using the key words “cerebral palsy” combined with “fatig^*,” where the asterisk was used as a wildcard. As a critical appraisal tool, the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies (2017) was used. A total of 22 studies passed the critical appraisal rating and were included in both narrative and quantitative analyses. The overall evidence quality of the findings was considered very good. Data of objectively-measured fatigue in performing maximal fatiguing tasks indicated lower fatigue levels in participants with CP, possibly due to their pathological inability to recruit highly fatigable muscle fibers. Highly trained individuals with CP and TD controls performing maximal fatiguing tasks seem to be an exception to this, as they exhibited similar levels of fatigue. In submaximal fatiguing tasks, including daily physical activities, either objectively-measured or self-reported fatigue was higher in participants with CP than in TD controls, indicating a lower ability for development of neurophysiological compensation for fatigue among participants with CP. Further studies on fatigue are needed to gain an insight into the multifold mechanisms of fatigue in individuals with CP. Understanding fatigue mechanisms could help in setting up strategies for effective intervention programs, with benefits in healthcare and improved quality of life of individuals with CP.

Systematic Review Registration: [PROSPERO 2019], identifier [CRD42019143524].

Psychological morbidity among adults with cerebral palsy and spina bifida

BACKGROUND

Very little is known about the risk of developing psychological morbidities among adults living with cerebral palsy (CP) or spina bifida (SB). The objective of this study was to compare the incidence of and adjusted hazards for psychological morbidities among adults with and without CP or SB.

METHODS

Privately insured beneficiaries were included if they had an International Classification of Diseases, Ninth revision, Clinical Modification diagnostic code for CP or SB (n = 15 302). Adults without CP or SB were also included (n = 1 935 480). Incidence estimates of common psychological morbidities were compared at 4-years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios for incident psychological morbidities.

RESULTS

Adults living with CP or SB had a higher 4-year incidence of any psychological morbidity (38.8% v. 24.2%) as compared to adults without CP or SB, and differences were to a clinically meaningful extent. Fully adjusted survival models demonstrated that adults with CP or SB had a greater hazard for any psychological morbidity [hazard ratio (HR): 1.60; 95% CI 1.55-1.65], and all but one psychological disorder (alcohol-related disorders), and ranged from HR: 1.32 (1.23, 1.42) for substance disorders, to HR: 4.12 (3.24, 5.25) for impulse control disorders.

CONCLUSIONS

Adults with CP or SB have a significantly higher incidence of and risk for common psychological morbidities, as compared to adults without CP or SB. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce the risk of disease onset/progression in these higher-risk populations.

Post-stroke fatigue: how it relates to motor fatigability and other modifiable factors in people with chronic stroke

Post-stroke fatigue (PSF) is a common symptom associated with disability and decreased quality of life. Distinction can be made between perceived fatigue and fatigability. The first aim of this study was to evaluate the prevalence of perceived fatigue and fatigability amongst patients with chronic stroke and to explore how these two parameters relate. The second aim was to study the relationship between modifiable factors (sleep disorders, anxiety, depression and activities of daily living) and fatigue in this population. Sixty-two patients with chronic stroke (> 6 months) were included. Perceived fatigue was evaluated using the Fatigue Severity Scale (FSS). Motor fatigability was assessed with the percent change in meters walked from first to last minute of the 6-min Walk Test and an isometric muscular fatigability test. Subjects also completed self-report questionnaires assessing anxiety and depression (Hospital Anxiety and Depression Scale-HADS), sleep quality (Pittsburgh Sleep Quality Index-PSQI) and activity limitations (ACTIVLIM-stroke). Seventy-one percent of participants presented PSF. There was no correlation between the FSS and motor fatigability. FSS significantly correlated with HADS-Anxiety (ρ = 0.53, P < 0.001), HADS-depression (ρ = 0.63, P < 0.001), PSQI (ρ = 0.51, P < 0.001) and ACTIVLIM (ρ = - 0.30, P < 0.05). A linear regression model showed that the HADS-Depression, the PSQI and the ACTIVLIM explained 46% of the variance of the FSS. A high proportion of chronic stroke patients presents PSF, with no relation between their fatigue and fatigability. Perceived fatigue is associated with potentially modifiable factors: anxious and depressive symptoms, poor sleep quality and activity limitations. Registered at ClinicalTrials.gov (NCT04277234) (21/02/2019).

Cardiometabolic Morbidity in Adults With Cerebral Palsy and Spina Bifida

PURPOSE

The purpose of this study was to compare the incidence of, and adjusted hazards for, cardiometabolic morbidities among adults with and without cerebral palsy or spina bifida.

METHODS

Privately insured beneficiaries were included if they had an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic code for cerebral palsy or spina bifida (n = 15,302). Adults without cerebral palsy or spina bifida were also included (n = 1,935,480). Incidence estimates of common cardiometabolic morbidities were compared at 4 years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios (HRs) for incident cardiometabolic morbidities.

RESULTS

Adults living with cerebral palsy or spina bifida had a higher 4-year incidence of any cardiometabolic morbidity (41.5% vs 30.6%) as compared to adults without cerebral palsy or spina bifida, and differences were to a clinically meaningful extent. Fully adjusted survival models demonstrated that adults with cerebral palsy or spina bifida had a greater hazard for any cardiometabolic morbidity (HR: 1.52; 95% confidence interval [CI]: 1.47, 1.57), and all but 1 cardiometabolic disorder (nonalcoholic fatty liver disease) and ranged from HR: 1.20 (1.15, 1.25) for hypercholesterolemia to HR: 1.86 (1.74, 1.98) for heart failure.

CONCLUSIONS

Adults with cerebral palsy or spina bifida have a significantly higher incidence of, and risk for, common cardiometabolic morbidities, as compared to adults without cerebral palsy or spina bifida. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of cardiometabolic disease onset and progression in these higher-risk populations.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

The immediate influence of various whole-body vibration frequency on balance and walking ability in children with cerebral palsy: a pilot study

The purpose of this pilot study is to examine the immediate effect of interventions based on the frequency of whole-body vibration on children with cerebral palsy’s balance and walking abilities. A total of 12 were selected as subjects. All subjects measured 10-m walking test (10MWT), Timed Up and Go (TUG) test and measured sway length (SL) and limit of stability (LOS) by bio-rescue. And those were performed again after the frequencies of the 12, 18, and 26 Hz were applied respectively. To check the immediate effect, all subjects performed only one frequency of interventions per day and no other treatment was performed in parallel to control the foreign variables. After intervention, 10MWT were significantly increased in the 12 and 18 Hz groups (P<0.05). TUG test and LOS were significantly increased in the 18 Hz group (P<0.05). There were no significant differences on TUG, SL, and LOS in the 12 Hz group. There were no significant differences on 10MWT, TUG, SL, and LOS in the 26 Hz group. Looking at the results of this study, the immediate effect of whole-body vibration shows that the frequency of the 18 Hz group is the most effective interventions in promoting walking and balancing abilities in children with cerebral palsy than frequencies of the 12 and 26 Hz groups.

Lentivirus-mediated microRNA-26a-modified neural stem cells improve brain injury in rats with cerebral palsy

This study is launched to investigate the effect of lentivirus-mediated microRNA-26a (miR-26a)-modified neural stem cells (NSCs) in brain injury in rats with cerebral palsy (CP). The successfully constructed miR-26a lentivirus expression vector and empty vector virus were used to modify NSCs. The model of CP with ischemia and anoxia was established in rats. NSCs and miR-26a-NSCs were stereoscopically injected into the cerebral cortex of the modeled rats, respectively. The survival and migration of NSCs infected with recombinant lentivirus expressing green fluorescence in vivo was observed under a light microscope. The neurobehavioral functions, morphology, and ultrastructure of cerebral cortex and hippocampus, apoptosis of brain cells, expression of apoptosis-related protein caspase-3 and Bax, together with the expression of the glial fibrillary acidic protein (GFAP) in cerebral cortex and hippocampus were determined. Expression of miR-26a in NSCs infected with plVTHM-miR-26a increased significantly. After NSCs transplantation, the neurobehavioral status of CP rats was improved, the degree of brain pathological injury was alleviated, the apoptotic index of cells in cerebral cortex and hippocampus and the expression of the apoptotic protein (caspase-3 and Bax) were decreased, the expression of GFAP were significantly decreased. After miR-26a-NSCs transplantation, these aforementioned results further improved or decreased. Our study suggests that miR-26a-modified NSCs mediated by lentivirus can improve brain injury, inhibit apoptosis of brain cells and activation of astrocytes in CP rats.

Age-related trends in cardiometabolic disease among adults with cerebral palsy

AIM

To examine the longitudinal trends of cardiometabolic diseases in a large sample of adults with cerebral palsy (CP).

METHOD

The Optum Clinformatics Data Mart is a de-identified nationwide claims database of beneficiaries from a single private payer. Beneficiaries were included if they had an International Classification of Diseases, Ninth Revision, Clinical Modification code for a diagnosis of CP. Adults with at least 3 years of continuous enrollment on a single plan between 2002 and 2009 were included in the final analyses (n=2659). We examined the longitudinal trends of incident diabetes mellitus, hypercholesterolemia, hypertension, cardiac dysrhythmias, and atherosclerosis, stratified by age categories: 18 to 39 years, 40 to 59 years, and 60 years and over. Kaplan-Meier product-limit survival curves were compared across age categories for each of the cardiometabolic outcomes, and a Cox proportional hazards regression was run to determine adjusted hazard ratios.

RESULTS

The cumulative incidence of each of the cardiometabolic diseases ranged from 6.0% for atherosclerosis to 34.4% for hypercholesterolemia at 3 years and over. Risk-adjusted Cox proportional hazard models revealed that age was a robust predictor of survival for each outcome, with higher hazard ratio ranges in middle age (hazard ratio 1.41-2.72) and older adults (hazard ratio 2.20-5.93) compared with young adults.

INTERPRETATION

Adults with CP have high rates of cardiometabolic diseases; and disease-free survival shortens significantly with higher ages.

WHAT THIS PAPER ADDS

Adults with cerebral palsy have high rates of cardiometabolic diseases. Disease-free survival of all cardiometabolic diseases shortens significantly with higher ages. The highest rates were for hypercholesterolemia and hypertension.

Short-burst interval treadmill training walking capacity and performance in cerebral palsy: a pilot study

PURPOSE

To examine the effect of short-burst interval locomotor treadmill training (SBLTT) on walking capacity and performance in cerebral palsy (CP).

METHODS

Twelve children with spastic diplegic CP (average 8.6 years) across Gross Motor Function Classification System levels II (8) and III (4) were randomized to 20 SBLTT sessions over 4 or 10 weeks. SBLTT consisted of alternating 30 seconds of slow and fast walking for 30 minutes/session. Outcomes included the 10 m walk test, one-minute walk test (1MWT), and timed-up-and go (TUG) (capacity) and StepWatch (performance) collected at baseline, post, and 6 weeks post.

RESULTS

Fast speed (+.11, p = .04; +.11 m/s, p = .006), 1MWT (+11.2; +11.7 m, p = .006) and TUG (-1.7; -1.9 seconds, p = .006) improved post SBLTT and 6 weeks, respectively. Walking performance increased: average strides/day (+948; +1712, p < .001) and percent time in high strides rates (+0.4, p = 0.07; +0.2, p = .008).

CONCLUSIONS

Pilot study suggests SBLTT may improve short-term walking capacity and performance.

Athletes with Brain Injury: Pathophysiologic and Medical Challenges

Participation in elite sporting activities is becoming increasingly popular for individuals with brain injury. This article outlines the types of brain injury and the associated movement dysfunctions. In addition, specific pathophysiologic and medical challenges facing athletes with brain injury are discussed. Further research conducted using athletes with brain injury will add to the existing literature indicating the benefits of athletic training in this population. Increased scientific study within this area stands to further improve understanding of the complex interaction between neuromuscular impairment and athletic performance.

Effects of Two Fatigue Protocols on Impact Forces and Lower Extremity Kinematics during Drop Landings: Implications for Noncontact Anterior Cruciate Ligament Injury

The purpose of the study was to determine the effects of fatigue on the impact forces and sagittal plane kinematics of the lower extremities in a drop landing task. 15 male collegiate athletes were recruited. Five successful trials of a drop landing task were obtained during prefatigue and postfatigue in two fatigue protocols (constant speed running fatigue protocol [R-FP] and shuttle running + vertical jumping fatigue protocol [SV-FP]). Duration time, maximal heart rate, and RPE of each protocol were measured separately. Kinematic measures of the hip, knee, and ankle joints at different times coupled with peak impact force and loading rate were acquired. Our results showed a more flexed landing posture due to an increase in hip and knee flexion angles in the postfatigue condition. However, no differences in peak impact force and loading rate were found between pre- and postfatigue conditions. The changes were similar between protocols, but the SV-FP showed a significantly shorter exercise duration time than the R-FP. Fatigued athletes in this study demonstrated altered motor control strategies during a drop landing task, which may be an intentional or unintentional protective strategy for preventing themselves from potential ACL injury.

Multimorbidity in Middle-Aged Adults with Cerebral Palsy

OBJECTIVE

Individuals with cerebral palsy have less lean body mass, greater relative adiposity, and lower fitness and physical activity participation, and yet the prevalence of age-related multimorbidity in this population has yet to be established. The study objective was to examine the prevalence of lifestyle-related chronic conditions and multimorbidity in a sample of middle-aged adults with cerebral palsy.

METHODS

A clinic-based sample of middle-aged adults with cerebral palsy was examined using Electronic Medical Records Search Engine software. Our cohort included 435 individuals aged 40 to 60 years, with an International Classification of Diseases, Clinical Modification, 9th and 10th Revisions Diagnosis Code for cerebral palsy. Prevalence of 12 chronic conditions was evaluated, including existing diagnoses or historical record of osteopenia/osteoporosis, myocardial infarction, stroke, coronary artery disease, impaired glucose tolerance/type 2 diabetes, other cardiovascular conditions, rheumatoid arthritis, osteoarthritis, asthma, emphysema, prehypertension/hypertension, and hyperlipidemia. Multivariate logistic models were used to estimate multimorbidity (ie, ≥2 chronic conditions), adjusting for age, sex, smoking status, obesity, and Gross Motor Function Classification System (GMFCS).

RESULTS

There were 137 unique multimorbidity combinations. Multimorbidity was significantly more prevalent among obese versus nonobese individuals for both GMFCS I-III (75.8% vs 53.6%) and GMFCS IV-V (79.0% vs 64.2%), but was also significantly higher in nonobese individuals with GMFCS IV-V (64.2%) compared with nonobese individuals with GMFCS I-III (53.6%). Both the obesity status (odds ratio, 2.20; 95% confidence interval, 1.32-2.79) and the GMFCS IV-V category (odds ratio, 1.81; 95% confidence interval, 1.32-3.68) were independently associated with multimorbidity.

CONCLUSIONS

Middle-aged adults with cerebral palsy have high estimates of multimorbidity; both obesity and higher GMFCS levels are independently associated with greater risk.

Plantar flexor muscle weakness and fatigue in spastic cerebral palsy patients

BACKGROUND

Patients with cerebral palsy develop an important muscle weakness which might affect the aetiology and extent of exercise-induced neuromuscular fatigue.

AIM

This study evaluated the aetiology and extent of plantar flexor neuromuscular fatigue in patients with cerebral palsy.

METHODS

Ten patients with cerebral palsy and 10 age- and sex-matched healthy individuals (∼20 years old, 6 females) performed four 30-s maximal isometric plantar flexions interspaced by a resting period of 2-3s to elicit a resting twitch. Maximal voluntary contraction force, voluntary activation level and peak twitch were quantified before and immediately after the fatiguing task.

RESULTS

Before fatigue, patients with cerebral palsy were weaker than healthy individuals (341±134N vs. 858±151N, p<0.05) and presented lower voluntary activation (73±19% vs. 90±9%, p<0.05) and peak twitch (100±28N vs. 199±33N, p<0.05). Maximal voluntary contraction force was not significantly reduced in patients with cerebral palsy following the fatiguing task (-10±23%, p>0.05), whereas it decreased by 30±12% (p<0.05) in healthy individuals.

CONCLUSIONS

Plantar flexor muscles of patients with cerebral palsy were weaker than their healthy peers but showed greater fatigue resistance.

WHAT THIS PAPER ADDS

Cerebral palsy is a widely defined pathology that is known to result in muscle weakness. The extent and origin of muscle weakness were the topic of several previous investigations; however some discrepant results were reported in the literature regarding how it might affect the development of exercise-induced neuromuscular fatigue. Importantly, most of the studies interested in the assessment of fatigue in patients with cerebral palsy did so with general questionnaires and reported increased levels of fatigue. Yet, exercise-induced neuromuscular fatigue was quantified in just a few studies and it was found that young patients with cerebral palsy might be more fatigue resistant that their peers. Thus, it appears that (i) conflicting results exist regarding objectively-evaluated fatigue in patients with cerebral palsy and (ii) the mechanisms underlying this muscle fatigue - in comparison to those of healthy peers - remain poorly understood. The present study adds important knowledge to the field as it shows that when young adults with cerebral palsy perform sustained maximal isometric plantar flexions, they appear less fatigable than healthy peers. This difference can be ascribed to a better preservation of the neural drive to the muscle. We suggest that the inability to drive their muscles maximally accounts for the lower extent of exercise-induced neuromuscular fatigue in patients with cerebral palsy.

Relations between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy

AIM

To investigate the relation between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy (CP) and peers with typical development.

METHOD

In this case-control study, knee extensor muscle endurance was estimated from individual load-endurance curves as the load corresponding to a 15-repetition maximum in 17 adolescents with spastic CP (six males, 11 females; age 12-19y) and 18 adolescents with typical development (eight males, 10 females; age 13-19y). Questionnaires were used to assess subjectively reported fatigue (Pediatric Quality of Life Inventory Multidimensional Fatigue Scale) and participation (Life-Habits questionnaire). Walking capacity was assessed using the 6-minute walk test. Relations were determined using multiple regression analyses.

RESULTS

Muscle endurance related significantly to subjectively reported fatigue and walking capacity in adolescents with CP, while no relations were found for adolescents with typical development (subjectively reported fatigue: regression coefficient β [95% confidence intervals] for CP=23.72 [6.26 to 41.18], for controls=2.72 [-10.26 to 15.69]; walking capacity β for CP=125m [-87 to 337], for controls=2m [-86 to 89]). The 15-repetition maximum did not relate to participation in adolescents with CP.

INTERPRETATION

Subjectively reported fatigue and reduced walking capacity in adolescents with CP are partly caused by lower muscle endurance of knee extensors. Training of muscle endurance might contribute to reducing the experience of fatigue and improving walking capacity. Reduced muscle endurance seems to have no effect on participation.

Addressing muscle performance impairments in cerebral palsy: Implications for upper extremity resistance training

STUDY DESIGN

Case study and literature review.

INTRODUCTION

Muscle performance consists of not only strength but also muscle power, rate of force development, and endurance. Therefore, resistance training programs should address not only the force-generating capacity of the muscle but also the ability to produce force quickly.

PURPOSE

To discuss the National Strength and Conditioning Association's resistance training guidelines for youth as specifically related to optimal dosing for muscle strength versus muscle power. Dosing parameters of frequency, volume, intensity, duration, and velocity are discussed independently for strength and power.

METHODS

We describe how resistance training principles can be applied to the upper extremity in CP through a case study. The case describes an individual with spastic CP, who has a severe motor disability and is non-ambulatory, but has been able to perform resistance training focused on speed, power, and strength.

DISCUSSION

Recommendations to optimize the dosing of this individual's resistance training program are made.

Cerebral palsy

Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging.

A potential mechanism by which torque output is preserved in cerebral palsy during fatiguing contractions of the knee extensors

INTRODUCTION

The purpose of this study was to compare agonist and antagonist electromyography (EMG) during an isokinetic fatigue protocol in subjects with cerebral palsy (CP) and typical development (TD).

METHODS

Nine individuals with CP and 11 with TD completed 50 repetitions of maximum concentric knee extensions (KE) and flexions (KF) at 60°/second.

RESULTS

Rate of decline in peak torque for KE was significantly less in CP compared with TD. Rate of decline in agonist EMG was not significantly different between groups, but the rate of decline in antagonist EMG was significantly greater in CP. There were no differences between groups for KF.

CONCLUSIONS

Declining agonist EMG occurred in parallel with declining antagonist hamstring activity in CP, decreasing the relative opposing force and resulting in a lesser decline in net torque. This finding illustrates a potential mechanism by which net torque is preserved in those with CP who are inherently weaker.

Paralympic athletes with cerebral palsy display altered pacing strategies in distance-deceived shuttle running trials

This study investigated performance and physiology to understand pacing strategies in elite Paralympic athletes with cerebral palsy (CP). Six Paralympic athletes with CP and 13 able-bodied (AB) athletes performed two trials of eight sets of 10 shuttles (total 1600m). One trial was distance-deceived (DEC, 1000 m + 600 m) one trial was nondeceived (N-DEC, 1600 m). Time (s), heart rate (HR, bpm), ratings of perceived exertion (RPE, units), and electromyography of five bilateral muscles (EMG) were recorded for each set of both trials. The CP group ran slower than the AB group, and pacing differences were seen in the CP DEC trial, presenting as a flat pacing profile over the trial (P < 0.05). HR was higher and RPE was lower in the CP group in both trials (P < 0.05). EMG showed small differences between groups, sides, and trials. The present study provides evidence for a possible pacing strategy underlying exercise performance and fatigue in CP. The results of this study show (1) underperformance of the CP group, and (2) altered pacing strategy utilization in the CP group. We proposed that even at high levels of performance, the residual effects of CP may negatively affect performance through selection of conservative pacing strategies during exercise.

Wide-pulse-high-frequency neuromuscular electrical stimulation in cerebral palsy

OBJECTIVE

The present study assesses whether wide-pulse-high-frequency (WPHF) neuromuscular electrical stimulation (NMES) could result in extra-force production in cerebral palsy (CP) patients as previously observed in healthy individuals.

METHODS

Ten CP and 10 age- and sex-matched control participants underwent plantar flexors NMES. Two to three 10-s WPHF (frequency: 100 Hz, pulse duration: 1 ms) and conventional (CONV, frequency 25 Hz, pulse duration: 50 μs) trains as well as two to three burst-like stimulation trains (2s at 25 Hz, 2s at 100 Hz, 2s at 25 Hz; pulse duration: 1 ms) were evoked. Resting soleus and gastrocnemii maximal H-reflex amplitude (Hmax) was normalized by maximal M-wave amplitude (Mmax) to quantify α-motoneuron modulation.

RESULTS

Similar Hmax/Mmax ratio was found in CP and control participants. Extra-force generation was observed both in CP (+18 ± 74%) and control individuals (+94 ± 124%) during WPHF (p<0.05). Similar extra-forces were found during burst-like stimulations in both groups (+108 ± 110% in CP and +65 ± 85% in controls, p>0.05).

CONCLUSION

Although the mechanisms underlying extra-force production may differ between WPHF and burst-like NMES, similar increases were observed in patients with CP and healthy controls.

SIGNIFICANCE

Development of extra-forces in response to WPHF NMES evoked at low stimulation intensity might open new possibilities in neuromuscular rehabilitation.

Altered corticomuscular coherence elicited by paced isotonic contractions in individuals with cerebral palsy: a case-control study

The purpose of the study was to analyze corticomuscular coherence during planning and execution of simple hand movements in individuals with cerebral palsy (CP) and healthy controls (HC). Fourteen individuals with CP and 15 HC performed voluntary paced movements (opening and closing the fist) in response to a warning signal. Simultaneous scalp EEG and surface EMG of extensor carpi radialis brevis were recorded during 15 isotonic contractions. Time-frequency corticomuscular coherence (EMG-C3/C4) before and during muscular contraction, as well as EMG intensity, onset latency and duration were analyzed. Although EMG intensity was similar in both groups, individuals with CP exhibited longer onset latency and increased duration of the muscular contraction than HC. CP also showed higher corticomuscular coherence in beta EEG band during both planning and execution of muscular contraction, as well as lower corticomuscular coherence in gamma EEG band at the beginning of the contraction as compared with HC. In conclusion, our results suggest that individuals with CP are characterized by an altered functional coupling between primary motor cortex and effector muscles during planning and execution of isotonic contractions. In addition, the usefulness of corticomuscular coherence as a research tool for exploring deficits in motor central processing in persons with early brain damage is discussed.

Effects of quadriceps muscle fatigue on stiff-knee gait in patients with hemiparesis

The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG). Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest). Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF) and vastus lateralis (VL) kinematics and electromyographic (EMG) activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i) an increase of sagittal hip and knee flexion during the swing phase, ii) an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii) a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients.

Postural orientation during standing in children with bilateral cerebral palsy

PURPOSE

To investigate postural orientation and maintenance of joint position during standing in children with bilateral spastic cerebral palsy (BSCP).

METHODS

Standing was examined with 3-D motion analysis in 26 children with BSCP, and 19 children typically developing (TD). Two groups of children with cerebral palsy (CP) were analyzed: 15 who were able to maintain standing without support and 11 who needed support.

RESULTS

Children with CP stood with more flexion than children TD. In the CP groups, children standing without support stood more asymmetrically with less hip and knee flexion and less movement than those who required support.

CONCLUSION

Children with CP had varying abilities to stand and maintain standing posture with or without support. Both CP groups stood with more flexion than their potential passive joint angle, more obvious in children requiring support. Investigations on how muscle strength and spatial perception influence posture remains to be explored.

Muscle fatigue during repetitive voluntary contractions: a comparison between children with cerebral palsy, typically developing children and young healthy adults

AIM

To combine peak torque and EMG analyses to investigate the hypothesis that 1) children with cerebral palsy (CP) have lower muscle fatigability than typically developing children (TD) and whether 2) muscle fatigue correlates with muscle strength.

METHODS

Seven CP children, eight TD children and ten young healthy adults (YHA) performed an all-out fatigue test of 35 maximal concentric knee extension and flexion contractions on an isokinetic dynamometer. Angular velocity was set at 60°/s. Peak torque (PT) was determined per repetition and either normalized to bodyweight or maximum voluntary torque. Surface-EMG of quadriceps and hamstring muscles was measured to obtain changes in median frequency (EMG-mf) and smooth rectified EMG amplitude per contraction.

RESULTS

Decline in PT differed between all groups for extensors and flexors, where YHA showed the largest decline and CP children the smallest decline over the course of the test. YHA showed a larger decline in EMG-mf of all quadriceps and hamstrings than TD and CP children, while TD children showed a larger decline in EMG-mf of m.rectus femoris and m.vastus lateralis than CP children.

INTERPRETATION

Results confirm that children with CP show lower fatigability than TD children and that the lower fatigability coincides with lower maximal muscle strength.

Secondary muscle pathology and metabolic dysregulation in adults with cerebral palsy

Cerebral palsy (CP) is caused by an insult to or malformation of the developing brain which affects motor control centers and causes alterations in growth, development, and overall health throughout the life span. In addition to the disruption in development caused by the primary neurological insult, CP is associated with exaggerated sedentary behaviors and a hallmark accelerated progression of muscle pathology compared with typically developing children and adults. Factors such as excess adipose tissue deposition and altered partitioning, insulin resistance, and chronic inflammation may increase the severity of muscle pathology throughout adulthood and lead to cardiometabolic disease risk and/or early mortality. We describe a model of exaggerated health risk represented in adults with CP and discuss the mechanisms and secondary consequences associated with chronic sedentary behavior, obesity, aging, and muscle spasticity. Moreover, we highlight novel evidence that implicates aberrant inflammation in CP as a potential mechanism linking both metabolic and cognitive dysregulation in a cyclical pattern.

Recumbent cross-training is a feasible and safe mode of physical activity for significantly motor-impaired adults with cerebral palsy

OBJECTIVE

To examine the feasibility and potential benefits of using recumbent cross-training for nonambulatory adults with cerebral palsy (CP).

DESIGN

Observational.

SETTING

Clinical center for CP treatment and rehabilitation.

PARTICIPANTS

Significantly motor-impaired adults with CP (N=11) with a mean age ± SD of 36.3±13.2 years and Gross Motor Function Classification System (GMFCS) levels III and IV.

INTERVENTIONS

Participants completed a 40-minute session of aerobic exercise using the NuStep Recumbent Cross Trainer, in which resistance was progressively increased at 5-minute intervals.

MAIN OUTCOME MEASURES

Every 5 minutes during the exercise session, heart rate, blood pressure, oxygen consumption (VO(2)), energy expenditure, and respiratory exchange ratios (RERs) were recorded along with rating of perceived exertion. Immediately after, and 24 hours postexercise, participants received a standard survey to assess levels of pain and discomfort.

RESULTS

All participants were able to complete the 40-minute exercise protocol. Five of the 11 participants achieved a heart rate of at least 60% maximum throughout the duration, 10 participants had a significant elevation in VO(2) from baseline, and all participants had elevated RER values. Six participants reported pain during exercise, but only 2 reported pain after exercise was over.

CONCLUSIONS

The NuStep Recumbent Cross Trainer is a feasible exercise modality for significantly motor-impaired adults with CP, GMFCS III and IV. Moreover, this mode was sufficient to stimulate a significant cardiorespiratory response in all participants, and thus it and similar devices may serve as a viable option for aerobic exercise interventions in this population, to prevent obesity and related cardiometabolic consequences.

Fatigue in cerebral palsy: a critical review

OBJECTIVE

Fatigue contributes to the deterioration or cessation of walking ability in adults with cerebral palsy (CP). However, conflict exists as to its role. Studies involving functional tasks reported increased, and earlier onset of, fatigue in CP, whereas laboratory studies have reported individuals with CP to be more fatigue-resistant than their peers.

METHODS

A critical review of the literature related to fatigue in CP was conducted.

RESULTS

This review describes factors that contribute to the observed fatigue resistance in laboratory tasks and how a decreased force-production in CP can result in higher energy expenditure to perform the same amount of work as their peers.

CONCLUSION

More research regarding the process of fatigue and recovery for individuals with CP is needed; specifically studies that focus on functional movements requiring the integration of the whole body, thereby stressing the neuromuscular system in a different way than previously explored.

Análise isocinética da articulação do cotovelo em crianças com paralisia cerebral

A quantidade de torque aplicado na articulação é uma medida de aptidão física importante para crianças com paralisia cerebral. O presente estudo analisou parâmetros cinéticos na articulação do cotovelo em crianças saudáveis e com paralisia cerebral. Participaram 10 crianças com paralisia cerebral e 10 crianças sem comprometimento neurológico. Avaliou-se a média do pico de torque, média do ângulo do pico de torque, coeficiente de variação do torque e aceleração angular do movimento de flexo-extensão do cotovelo nas velocidades com um dinamômetro isocinético. A média de pico de torque (extensão), aceleração (flexão) e coeficiente de variação (flexão e extensão) são diferentes entre grupos. Conclui-se que o torque e aceleração sofreram interferências no movimento de flexo-extensão; as principais diferenças encontradas foram entre os extremos das velocidades; não houve diferenças no ângulo do pico de torque. A espasticidade não interferiu na força dos músculos agonistas do movimento de flexão da articulação do cotovelo.

Rapid force generation is impaired in cerebral palsy and is related to decreased muscle size and functional mobility

Limb movements involving contraction times of 50-200 ms occur in many everyday activities, such as gait, which is faster than the time required to generate maximal force. Therefore, the ability to rapidly produce force may be even more important for the performance of functional activities. In this study rate of force development (RFD) and impulse of the knee extensors were examined in 12 ambulatory children with cerebral palsy (CP) (age: 11.9 ± 2.9 years) and 11 with typical development (TD) (Age: 11.3 ± 3.0 years). The relationship with muscle architecture and functional mobility was also determined. RFD and impulse were calculated during a maximal isometric knee extension contraction. Rectus femoris (RF) cross-sectional area and RF and vastus lateralis (VL) muscle thickness (MT), fascicle length (FL), and fascicle angle (FA) were measured using ultrasound imaging. Gait temporal-spatial parameters, Pediatric Outcomes Data Collection Instrument (PODCI), and Activities Scale for Kids performance version (ASKp) were collected. Although VL MT was the primary determinant of RFD and impulse in CP, FA and FL were also significant predictors in the TD group. RFD and impulse were significantly lower in CP compared to TD (70% decrease) in addition to maximal strength (50% decrease). RFD and impulse were predictive of measures of functional mobility, including gait, transfers, and sports and higher level activities but not temporal-spatial gait measures. Results suggest that the ability to rapidly generate torque may be of greater importance than maximal strength during certain tasks, such as transfers and sports and higher level activities.

Fatigue in children with neurologic impairments

Children with neuromuscular illness are at high risk for fatigue. This symptom, although difficult to decipher, can contribute significantly to the child's disability. It is, therefore, imperative to consider fatigue in the management of children with special health care needs. Currently, the literature on chronic fatigue in children is sparse and so more investigative work must be done to understand and manage this condition.

Contributors to fatigue resistance of the hamstrings and quadriceps in cerebral palsy

BACKGROUND

The purpose of this study was to elucidate relationships between quadriceps and hamstrings voluntary muscle fatigue and upper motor lesion impairments in cerebral palsy in order to gain a better understanding of their contribution to the observed fatigue resistance.

METHODS

Seventeen ambulatory subjects with cerebral palsy (mean age: 17.0, SD=4.8 years) were recruited. Quantitative measures of strength, spasticity, cocontraction, and stiffness for both muscle groups were collected on an isokinetic dynamometer and entered in a factor analysis. The resulting factors were used as independent variables in a multiple regression analysis with quadriceps and hamstrings fatigue as dependent variables.

FINDINGS

Five independent factors explained 90% of the variance. In order of loadings, higher hamstring cocontraction and spasticity and lower hamstring strength were associated with lower levels of hamstring fatigue. Higher quadriceps cocontraction and lower quadriceps strength were the most predictive of lower levels of quadriceps fatigue.

INTERPRETATION

Greater motor impairments of the agonist muscle, particularly cocontraction, spasticity, and weakness, were associated with lower rates of muscle fatigue of the same muscle during performance of a voluntary fatigue protocol for the hamstrings and quadriceps. Muscles are highly adaptable; therefore, the results of this study suggest that the observed fatigue resistance may be due to the effect of the primary neural insult on motor unit recruitment and rate modulation or the result of secondary adaptations to spasticity, weakness, or excessive cocontraction.