Relationship between brain lesion characteristics and communication in preschool children with cerebral palsy

BackgroundMRI shows promise as a prognostic tool for clinical findings such as gross motor function in children with cerebral palsy(CP), however the relationship with communication skills requires exploration.AimsTo examine the relationship between the type and severity of brain lesion on MRI and communication skills in children with CP.Methods and procedures131 children with CP (73 males(56%)), mean corrected age(SD) 28(5) months, Gross Motor Functional Classification System distribution: I = 57(44%), II = 14(11%), III = 19(14%), IV = 17(13%), V = 24(18%). Children were assessed on the Communication and Symbolic Behavioral Scales Developmental Profile (CSBS-DP) Infant-Toddler Checklist. Structural MRI was analysed with reference to type and semi-quantitative assessment of the severity of brain lesion. Children were classified for motor type, distribution and GMFCS. The relationships between type/severity of brain lesion and communication ability were analysed using multivariable tobit regression.Outcomes and resultsChildren with periventricular white matter lesions had better speech than children with cortical/deep grey matter lesions (β = −2.6, 95%CI = −5.0, −0.2, p = 0.04). Brain lesion severity on the semi-quantitative scale was related to overall communication skills (β = −0.9, 95%CI = −1.4, −0.5, p < 0.001). Motor impairment better accounted for impairment in overall communication skills than brain lesion severity.ImplicationsStructural MRI has potential prognostic value for communication impairment in children with CP.What this paper adds?This is the first paper to explore important aspects of communication in relation to the type and severity of brain lesion on MRI in a representative cohort of preschool-aged children with CP. We found a relationship between the type of brain lesion and communication skills, children who had cortical and deep grey matter lesions had overall communication skills > 1 SD below children with periventricular white matter lesions. Children with more severe brain lesions on MRI had poorer overall communication skills. Children with CP born at term had poorer communication than those born prematurely and were more likely to have cortical and deep grey matter lesions. Gross motor function better accounted for overall communication skills than the type of brain lesion or brain lesion severity.     

Does early communication mediate the relationship between motor ability and social function in children with cerebral palsy?

BackgroundChildren diagnosed with neurodevelopmental conditions such as cerebral palsy (CP) are at risk of experiencing restrictions in social activities negatively impacting their subsequent social functioning. Research has identified motor and communication ability as being unique determinants of social function capabilities in children with CP, to date, no research has investigated whether communication is a mediator of the relationship between motor ability and social functioning.AimsTo investigate whether early communication ability at 24 months corrected age (ca.) mediates the relationship between early motor ability at 24 months ca. and later social development at 60 months ca. in a cohort of children diagnosed with cerebral palsy (CP).MethodA cohort of 71 children (43 male) diagnosed with CP (GMFCS I = 24, 33.8%, II = 9, 12.7%, III = 12, 16.9%, IV = 10, 14.1%, V = 16, 22.5%) were assessed at 24 and 60 months ca. Assessments included the Gross Motor Function Measure (GMFM), the Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS-DP) Infant-Toddler Checklist and the Paediatric Evaluation of Disability Inventory (PEDI). A mediation model was examined using bootstrapping.ResultsEarly communication skills mediated the relationship between early motor abilities and later social functioning, b = 0.24 (95% CI = 0.08–0.43 and the mediation model was significant, F (2, 68) = 32.77, p < 0.001, R² = 0.49.Conclusions and implicationEarly communication ability partially mediates the relationship between early motor ability and later social function in children with CP. This demonstrates the important role of early communication in ongoing social development. Early identification of communication delay and enriched language exposure is crucial in this population.     

Children with cerebral palsy and periventricular white matter injury: Does gestational age affect functional outcome?

This study aimed to determine differences in functional profiles and movement disorder patterns in children aged 4–12 years with cerebral palsy (CP) and periventricular white matter injury (PWMI) born >34 weeks gestation compared with those born earlier. Eligible children born between 1999 and 2006 were recruited through the Victorian CP register. Functional profiles were determined using the Gross Motor Function Classification System (GMFCS), Manual Abilities Classification System (MACS), Communication Function Classification System (CFCS), Functional Mobility Scale (FMS) and Bimanual Fine Motor Function (BFMF). Movement disorder and topography were classified using the Surveillance of Cerebral Palsy in Europe (SCPE) classification. 49 children born >34 weeks (65% males, mean age 8y 9mo [standard deviation (SD) 2y 2mo]) and 60 children born ≤34 weeks (62% males, mean age 8y 2mo [SD 2y 2mo]) were recruited. There was evidence of differences between the groups for the GMFCS (p = 0.003), FMS 5, 50 and 500 (p = 0.003, 0.002 and 0.012), MACS (p = 0.04) and CFCS (p = 0.035), with a greater number of children born ≤34 weeks more severely impaired compared with children born later. Children with CP and PWMI born >34 weeks gestation had milder limitations in gross motor function, mobility, manual ability and communication compared with those born earlier.     

The relationship between motor abilities and early social development in a preschool cohort of children with cerebral palsy

AimTo investigate the relationship between motor ability and early social development in a cohort of preschool children with cerebral palsy (CP).DesignPopulation-based cohort study.MethodsParticipants were 122 children with CP assessed at 18, 24 and 30 months, corrected age (ca). Motor ability was measured by the Gross Motor Function Classification System (GMFCS) with classification assigned by physiotherapists. The sample was representative of a population-based cohort (I = 48, 38.4%, II = 19, 15.2%, III = 17, 13.6%, IV = 22, 17.6% and V = 19, 15.2%). Social development was measured by the Paediatric Evaluation of Disability Inventory (PEDI) and included capabilities in social interaction, social communication, interactive play and household/community tasks.ResultsCross-sectional analyses indicated a significant relationship between motor ability and social development at 18 months, F(4, 56) = 11.44, p < .0001, η² = .45, at 24 months, F(4, 79) = 15.66, p < .0001, η² = .44 and at 30 months, F(4, 76) = 16.06, p < .0001, η² = .49. A longitudinal analysis with a subset of children (N = 24) indicated a significant interaction between age at assessment and GMFCS, F(2, 21) = 7.02, p = .005, η² = .40. Comparison with community norms indicated that at 18 months corrected age, 44.3% of the cohort was greater than two standard deviations below the mean (>2SD) for social development and a further 27.9% of the cohort was greater than one standard deviation below the mean (>1SD).InterpretationThere is a relationship between motor ability and social development in preschool children with CP. Children with CP may require support for social development in additional to physical interventions, from as early as 18 months.     

Development of social functioning and communication in school-aged (5–9 years) children with cerebral palsy

The aim of this study was to examine determinants of the course and level of social functioning and communication in school-aged children with cerebral palsy (CP) over a 2-year period. A clinic-based sample of 5 and 7 years old children with CP (n = 108; 72 males; mean age 6 y 3 mo, SD 12 mo; Gross Motor Function Classification System (GFMCS) level I–V) was followed longitudinally in three yearly assessments. Social functioning and communication were measured with the Vineland Adaptive Behavior Scales (VABS). Data were analyzed with generalized estimated equations. The results showed that social function followed a course of progressive restrictions over time in non-ambulatory children with CP aged 5–9 compared to children who could walk with or without walking aids. Overall lower levels of social functioning were found in children with GMFCS V, epilepsy, speech problems, lower intellectual capacity and older age at baseline. For communication more restrictions over time were found in children with lower intellectual capacity. Children with GMFCS V, speech problems and older age at baseline had overall greater restrictions in communication. It was concluded that motor functioning and intellectual ability can be used to identify children at risk for progressive restrictions in social functioning and communication. For children with CP and social and communicative restrictions, multidisciplinary assessment and treatment may be indicated to counteract an unfavorable development.     

Sleep disorders in children with cerebral palsy: neurodevelopmental and behavioral correlates

ObjectivesWe aimed to estimate the frequency of sleep disorders in children with cerebral palsy (CP) using the Sleep Disturbance Scale for Children (SDSC) and to evaluate the relations between sleep disorders and motor, cognitive, and behavioral problems.MethodsOne hundred and sixty-five children with CP ages 6–16 years (mean age, 11 years) were assessed using the SDSC, the Gross Motor Function Classification System (GMFCS), the Wechsler Intelligence Scale for Children and the Child Behavior Check List (CBCL) to assess sleep, motor, cognitive, and behavioral problems, respectively.ResultsAn abnormal total sleep score was found in 19% of children with CP; more than 40% of children had an abnormal score on at least one SDSC factor. The SDSC total score was significantly associated (P < .01) with mental retardation, epilepsy, CBCL scores, and level 5 on the GMFCS.ConclusionsOur results confirm that sleep disorders are common in children with cerebral palsy. The relationship between motor and cognitive behavior and epilepsy should be further explored to better understand how these factors influence one another to identify effective treatments and to improve the well-being of the child.     

A prospective study of cognitive fluency and originality in children exposed in utero to carbamazepine,lamotrigine, or valproate monotherapy

ObjectiveTo investigate the differential effects of fetal exposure to antiepileptic drugs (AEDs) on cognitive fluency and flexibility in a prospective sample of children.MethodsThis substudy of the Neurodevelopmental Effects of Antiepileptic Drugs investigation enrolled pregnant women with epilepsy on AED monotherapy (carbamazepine, lamotrigine, and valproate). Blinded to drug exposure, 54 children were tested for ability to generate ideas in terms of quantity (fluency/flexibility) and quality (originality). Forty-two children met inclusion criteria (mean age = 4.2 years, SD = 0.5) for statistical analyses of drug exposure group differences.ResultsFluency was lower in the valproate group (mean = 76.3, SD = 7.53) versus the lamotrigine (mean = 93.76, SD = 13.5, ANOVA P < 0.0015) and carbamazepine (mean = 95.5, SD = 18.1, ANOVA P < 0.003) groups. Originality was lower in the valproate group (mean = 84.2, SD = 3.23) versus the lamotrigine (mean = 103.1, SD = 14.8, ANOVA P < 0.002) and carbamazepine (mean = 99.4, SD = 17.1, ANOVA P < 0.01) groups. These results were not explained by factors other than AED exposure.ConclusionChildren prenatally exposed to valproate demonstrate impaired fluency and originality compared with children exposed to lamotrigine and carbamazepine.     

Motor control of the lower extremity musculature in children with cerebral palsy

The aim of this investigation was to quantify the differences in torque steadiness and variability of the muscular control in children with cerebral palsy (CP) and typically developing (TD) children. Fifteen children with CP (age = 14.2 ± 0.7 years) that had a Gross Motor Function Classification System (GMFCS) score of I-III and 15 age and gender matched TD children (age = 14.1 ± 0.7 years) participated in this investigation. The participants performed submaximal steady-state isometric contractions with the ankle, knee, and hip while surface electromyography (sEMG) was recorded. An isokinetic dynamometer was used to measure the steady-state isometric torques while the participants matched a target torque of 20% of the subject's maximum voluntary torque value. The coefficient of variation was used to assess the amount of variability in the steady-state torque, while approximate entropy was used to assess the regularity of the steady-state torque over time. Lastly, the distribution of the power spectrum of the respective sEMG was evaluated. The results of this investigation were: 1) children with CP had a greater amount of variability in their torque steadiness at the ankle than TD children, 2) children with CP had a greater amount of variability at the ankle joint than at the knee and hip joint, 3) the children with CP had a more regular steady-state torque pattern than TD children for all the joints, 4) the ankle sEMG of children with CP was composed of higher harmonics than that of the TD children.     

Inattention and hyperactivity in association with autism spectrum disorders in the CHARGE study

BackgroundAttention deficits in young children with autism spectrum disorder (ASD) are not well understood. This study sought to determine: 1) the prevalence of ADHD symptoms in young children with ASD, typical development (TD), and developmental delay (DD) and 2) the association between ADHD symptoms and cognitive and behavioral functioning in children with ASD.MethodADHD symptoms, defined according to Aberrant Behavior Checklist (ABC) hyperactivity subscale scores, were compared across children aged 2–5 from a large case-control study with ASD (n = 548), TD (n = 423), and DD (n = 180). Inattention and hyperactivity items within this subscale were also explored. Within the ASD group, linear and logistic regression were used to examine how ADHD symptoms were associated with cognition as assessed by the Mullen Scales of Early Learning and adaptive functioning as assessed by the Vineland Adaptive Behavior Scales.ResultsMean hyperactivity subscale scores were lowest in children with TD (mean = 3.19), higher in children with DD (12.3), and highest in children with ASD (18.2; between-group p < 0.001). Among children with ASD, significant associations were observed with higher ADHD symptoms and poorer adaptive and cognitive functioning (adjusted beta for hyperactivity score in association with: Vineland composite = −5.63, p = 0.0005; Mullen visual reception scale = −2.94, p = 0.02; for the highest vs. lowest quartile of hyperactivity score, odds of lowest quintile of these scores was approximately doubled). Exploratory analyses highlighted associations with inattention-related items specifically.ConclusionThese results suggest ADHD symptoms may play a key role in the functioning of young children with ASD.     

A telehealth approach to conducting clinical swallowing evaluations in children with cerebral palsy

BackgroundAccurate and timely evaluation of dysphagia in children with cerebral palsy (CP) is critical. For children with limited access to quality healthcare, telehealth is an option; however, its reliability needs to be investigated.AimTo test the reliability of an asynchronous telehealth model for evaluating dysphagia in children with CP using a standardized clinical assessment.Methods and proceduresNineteen children (age range 6.9–17.5) were assessed at three mealtimes via the Dysphagia Disorder Survey (DDS) by three clinicians (face-to-face evaluations). Mealtimes were video-recorded to allow asynchronous evaluations by a remote clinician who also completed approximately 1/3 of face-to-face evaluations. Agreement was tested on DDS variables and dysphagia severity.Outcomes and resultsResults revealed substantial to excellent agreement between face-to-face and remote assessments by the same rater (78–100%, K_W = 0.64–1) on all, but two variables (oral transport and oral pharyngeal swallow) and by different raters (69–89%, K_W = 0.6–0.86) on all but one variable (orienting). For dysphagia severity, intrarater agreement was excellent (100%, K_W = 1); interrater agreement was substantial (85%; K_W = 0.76).Conclusions and implicationsAsynchronous clinical swallowing evaluations using standardized tools have acceptable levels of agreement with face-to-face evaluations, and can be an alternative for children with limited access to expert swallowing care.     

Gait characteristics in children and adolescents with cerebral palsy assessed with a trunk-worn accelerometer

This study aimed to investigate gait characteristics reflecting balance and progression in children and adolescents with cerebral palsy (CP) compared with typically developing (TD) children. Gait characteristics variables representing aspects of balance were trunk acceleration, interstride regularity and asymmetry of accelerations while gait characteristics representing progression were gait speed, cadence, step time and step length. Children in the age range 5–18 years (mean age 11.1 years) with spastic CP (n = 41) and a gross motor function corresponding to GMFCS I–III and children with TD (n = 29) were included. The children walked back and forth along a 5 m pathway with a tri-axial accelerometer worn on the lower back to allow assessment of their gait characteristics. Data were recorded along the anterioposterior (AP), mediolateral (ML), and vertical (V) axes. To assess the magnitude of potential differences in gait characteristics, standard deviation scores were calculated, using TD children as reference. Gait parameters related to balance, such as AP, ML, and V accelerations, were higher in the children with CP (z-scores between 0.4 and 0.7) and increased with increasing GMFCS levels. The differences in accelerations in the AP and V directions increased between children with CP and TD children with increasing speed. Also asymmetry in trunk accelerations differed significantly between the two groups in all three directions (z-scores between 0.8 and 1.8 higher in the CP group), while interstride regularity differed only slightly between children with CP and TD children, and only in the AP direction. Gait characteristics also differed between children with the spastic subtypes unilateral and bilateral CP, for accelerations and asymmetry in the AP and ML directions. Our results showed significant differences in gait characteristics between children with CP and TD children. The differences may be more related to balance than progression, and these problems seem to rise with increasing gross motor impairment and speed.     

Epilepsy,school readiness in Canadian children: Data from the National Longitudinal Study of Children and Youth (NLSCY)

PurposeUtilizing data from the National Longitudinal Survey of Children and Youth (NLSCY) we evaluated the association between childhood epilepsy and health impairments on measures of school readiness employed in the survey.MethodsStandard scores on the Peabody Picture Vocabulary Test-Revised (PPVT-R) were employed in a regression analysis to compare scores in children with and without epilepsy. We also examined the effect of impairments in any of the 8 domains of the Health Utilities index (HUI) on test scores.ResultsA total sample size of 39,130 children (20,044 males, and 19,086 female were included in the analysis, 33,560 children were administered the PPVT-R at a mean age of 4.5 years. There were 70 children with epilepsy, 21 had a score of 1 on the HUI, 21 were assessed to have a HUI < 1 (signifying health impairments in one or more of the 8 domains). In the remainder, the PPVT scores were missing. Using the Ordinary Least Squares (OLS) regression for continuous outcomes model for PPVT-R scores as the outcome variable, females scored 1.1 points higher (β = 1.1, 95%CI 0.755, 1.444, p = 0.000), children without epilepsy and HUI score of <1 scored 3.84 points lower (β = −3.843 95%CI −4.232, −3.452, p = 0.000). Children with epilepsy and a HUI score of 1 scored 9.90 points lower (β = −9.902, 95%CI −16.343, −3.461, p = 0.003) while those with epilepsy and HUI < 1 scored 17.30 lower (β = −17.308, 95%CI −23.776, −10.839, p = 0.000).ConclusionThe data provide objective evidence that children with epilepsy are at risk of scholastic underachievement at school entry, while those with additional health impairments as measured by the HUI are at greater risk of underachievement.     

Evaluation of group versus individual physiotherapy following lower limb intra-muscular Botulinum Toxin-Type A injections for ambulant children with cerebral palsy: A single-blind randomized comparison trial

This study aimed to evaluate efficacy of group (GRP) versus individual (IND) physiotherapy rehabilitation following lower limb intramuscular injections of Botulinum Toxin-Type A (BoNT-A) for ambulant children with cerebral palsy (CP). Following lower limb BoNT-A injections, 34 children were randomly allocated to GRP (n = 17; mean age 7y8m SD 2.0; 13 males; Gross Motor Function Classification System (GMFCS) I = 5, II = 8, III = 4) or IND physiotherapy (n = 17; mean age 8y7m SD 2.0; 11 males; GMFCS I = 9, II = 5, III = 3). Primary outcomes were the Canadian Occupational Performance Measure (COPM) and Edinburgh Visual Gait Score (EVGS) assessed at baseline, 10 and 26 weeks post intervention. There were no baseline differences between groups. GRP intervention had greater, but not clinically meaningful, improvement in COPM satisfaction (estimated mean difference EMD 1.7, 95% CI 0.4–3.1; p < 0.01) at 26 weeks. Both groups demonstrated clinically significant improvements in COPM performance and satisfaction, but minimal change in quality of gait (EVGS). Six hours of direct physiotherapy (either GRP or IND) with an additional indirect dose (median 16 episodes) of individualized home programme activities following lower limb BoNT-A injections, however, was inadequate to drive clinically meaningful changes in lower limb motor outcomes.     

Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy

This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P = 0.007) and T10 (P < 0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P = 0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P = 0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner.     

The development of pragmatic skills in children after hemispherotomy: Contribution from left and right hemispheres

PurposeHemispherotomy (H) is the standard treatment used to cure hemispheric epileptic syndromes in childhood. The postoperative linguistic profile involves hemispheric specialization processes and developmental cognitive plasticity. This research concerns pragmatic aspects of language as a tool for communication which involves both linguistic and extralinguistic communication in context. Our aim was to analyze whether any correlation exists with age at surgery and side of surgery on pragmatic skills following H.MethodForty children who underwent H (23 females, 16 right H) were evaluated at a mean age of 12.8 years (± 2.6) with two receptive tasks (oral comprehension and syntactic judgment), the Children's Communication Checklist (CCC) rating scale, and the Behavioral Rating Inventory of Executive Function (BRIEF) questionnaire in order to evaluate the role of executive functions on pragmatic skills. Children operated on before the age of 18 months were considered the “early” group (5 right H and 9 left H), while those operated on later were called the “late” group (11 right H and 15 left H).Key findingsThe whole group had significant deficits in all three measures. We demonstrated a statistically significant crossed interaction between the side of H and the age at H with pragmatic language impairments (F(1,36) = 17.48; p = .0002) and disorders in executive function (F(1,36) = 5.80; p = .021) in left early H and in right late H patients. These findings are consistent with the previous studies of pragmatic language impairments concerning adolescents and adults with right hemisphere damage and emphasize the contribution of structural language in the early stage of verbal communication.SignificanceThese results emphasize for the first time that hemispherotomized children have pragmatic language impairments that are independent of receptive language. Our findings are congruent with the recent theory on pragmatic language development in childhood with evidence of a participation of the left hemisphere at the early age followed by right hemispheric specialization and involvement of executive functions, independently of receptive language.     

Calcified parenchymal central nervous system cysticercosis and clinical outcomes in epilepsy

ObjectiveThis study aimed to compare clinical outcomes including seizure frequency and psychiatric symptoms between patients with epilepsy with neuroimaging evidence of past brain parenchymal neurocysticercosis infection, patients with other structural brain lesions, and patients without structural neuroimaging abnormalities.Material and methodsThe study included retrospective cross-sectional analysis of all patients treated for epilepsy in a community-based adult neurology clinic during a three-month period.ResultsA total of 160 patients were included in the analysis, including 63 with neuroimaging findings consistent with past parenchymal neurocysticercosis infection, 55 with structurally normal brain neuroimaging studies, and 42 with other structural brain lesions. No significant differences were detected between groups for either seizure freedom (46.03%, 50.91%, and 47.62%, respectively; p = 0.944) or mean seizure frequency per month (mean = 2.50, S.D. = 8.1; mean = 4.83, S.D. = 17.64; mean = 8.55, S.D. = 27.31, respectively; p = 0.267). Self-reported depressive symptoms were more prevalent in those with parenchymal neurocysticercosis than in the other groups (p = 0.003). No significant differences were detected for prevalence of self-reported anxiety or psychotic symptoms.ConclusionsCalcified parenchymal neurocysticercosis results in refractory epilepsy about as often as other structural brain lesions. Depressive symptoms may be more common among those with epilepsy and calcified parenchymal neurocysticercosis; consequently, screening for depression may be indicated in this population.     

Role of serum levels of neurotensin in children with autism spectrum disorder

AimNeuroinflammation may play a role in the pathogenesis of autism in some patients. The aim of this study was to measure serum levels of neurotensin (NTS) in relation to the degree of the severity of autism.MethodsSerum NTS was measured in autistic children (n = 38; mean age 7.02 ± 2.03 years) and healthy, unrelated sex matched controls (n = 39); mean age 7.25 ± 1.64 years). The severity of autism symptoms was assessed using Childhood Autism Rating Scale (CARS) scores.ResultsThe serum level of NTS was significantly (P < 0.001) lower in autistic children (mean ± S.D. = 54.71 ± 12.4 pg/ml) than control group (mean ± S.D. = 77.58 ± 10.29 pg/ml). Children with severe autism had significantly lower serum NTS levels than patients with mild to moderate autism (P < 0.002). There was significant negative correlation between serum levels of NTS and CARS SCORES (r² = 0.79, P = 0.001).ConclusionsSerum NTS levels were elevated in some autistic children and they were significantly correlated with the severity of autism. However, this is an initial report that warrants further research to determine the pathogenic role of NTS and its possible link to neuroinflammation in autism.     

Differences in autonomic functions as related to induced stress between children with and without cerebral palsy while performing a virtual meal-making task

BackgroundEfforts to improve the participation and performance of children with cerebral palsy (CP) are often related to the adaptation of environmental conditions to meet their cognitive and motor abilities. However, the influence of affective stimuli within the environment on emotion and performance, and their ability to improve or impede the children's participation has not been investigated in any systematic way although the emerging evidence suggests that it affects the individuals in many levels.Objectives(1) To measure autonomic responses to affective stimuli during a simulated Meal-Maker task in children with CP in comparison to children who are typically developing, and (2) to examine the interactions between autonomic functions, subjective reports of stress, and task performance among children with and without CP.MethodsFifteen children with CP and 19 typically developing peers (6 to 12 years) participated. After completing behavioral questionnaires (e.g., State and Trait Anxiety Inventories), children prepared meals within a camera tracking virtual Meal-Maker environment. Either a negative, positive, or neutral visual stimulus was displayed, selected from the International Affective Picture System. Children also passively viewed the same pictures while rating their valence and arousal levels. Heart rate (HR) and skin conductance were recorded synchronously with stimulus onset.ResultsSignificant differences in autonomic functions were found between groups, i.e., a higher “low frequency” to “high frequency” (LF:HF) ratio in the children with CP during the meals associated with a negative stimulus (p = 0.011). Only children with CP had significant positive correlations between trait anxiety and LF:HF ratio during virtual meal-making associated with positive (p = 0.049) and negative stimuli (p = 0.003) but not during neutral stimuli. For children with CP the amplitude of skin conductance response during passive picture viewing was significantly higher for negative than for positive stimuli (p = 0.017) but there were no significant changes in autonomic responses during virtual Meal-Maker task.Significant correlations between trait anxiety, autonomic activity during the calm state and Meal-Maker performance outcomes were found only for children with CP.ConclusionsIn general, the Meal-Maker virtual environment was shown to be a feasible platform for the investigation of the effect of emotionally loaded stimuli on the balance of autonomic functions in children with and without CP. Anxiety level appears to play a significant role in children with CP and should be considered as a potentially important factor during clinical evaluation and intervention. Further studies are needed to develop additional measurements of emotional responses and to refine the types of affective interference.     

The relation between spasticity and muscle behavior during the swing phase of gait in children with cerebral palsy

There is much debate about how spasticity contributes to the movement abnormalities seen in children with spastic cerebral palsy (CP). This study explored the relation between stretch reflex characteristics in passive muscles and markers of spasticity during gait. Twenty-four children with CP underwent 3D gait analysis at three walking velocity conditions (self-selected, faster and fastest). The gastrocnemius (GAS) and medial hamstrings (MEHs) were assessed at rest using an instrumented spasticity assessment that determined the stretch-reflex threshold, expressed in terms of muscle lengthening velocity. Muscle activation was quantified with root mean square electromyography (RMS-EMG) during passive muscle stretch and during the muscle lengthening periods in the swing phase of gait. Parameters from passive stretch were compared to those from gait analysis.In about half the children, GAS peak muscle lengthening velocity during the swing phase of gait did not exceed its stretch reflex threshold. In contrast, in the MEHs the threshold was always exceeded. In the GAS, stretch reflex thresholds were positively correlated to peak muscle lengthening velocity during the swing phase of gait at the faster (r = 0.46) and fastest (r = 0.54) walking conditions. In the MEHs, a similar relation was found, but only at the faster walking condition (r = 0.43). RMS-EMG during passive stretch showed moderate correlations to RMS-EMG during the swing phase of gait in the GAS (r = 0.46–0.56) and good correlations in the MEHs (r = 0.69–0.77) at all walking conditions. RMS-EMG during passive stretch showed no correlations to peak muscle lengthening velocity during gait.We conclude that a reduced stretch reflex threshold in the GAS and MEHs constrains peak muscle lengthening velocity during gait in children with CP. With increasing walking velocity, this constraint is more marked in the GAS, but not in the MEHs. Hyper-activation of stretch reflexes during passive stretch is related to muscle activation during the swing phase of gait, but has a limited contribution to reduced muscle lengthening velocity during swing. Larger studies are required to confirm these results, and to investigate the contribution of other impairments such as passive stiffness and weakness to reduced muscle lengthening velocity during the swing phase of gait.