The purpose of this study was to investigate the use of the heart-rate (HR) version of the energy expenditure index (EEIHR) as a proxy for measurement of walking oxygen consumption (VO2) in children with cerebral palsy (CP). Thirteen children (eight males, five females; mean age 11 years 2 months [SD 3 years], age range 6 to 15 years) with hemiplegic CP, participated in this study. The study was conducted over three sessions. During session 1, participants were familiarized with testing procedures and given 5 minutes of treadmill walking practice. In session 2, participants completed three 5-minute walking bouts on the treadmill at 0.67m·s-1 to familiarize themselves with treadmill locomotion. During the final session participants walked at 0.67, 0.89, and 1.12m·s-1 for 5 minutes while gross oxygen consumption (gross VO2; walking VO2/speed), net VO2 ([walking VO2–resting VO2]/speed), and EEIHR ([walking HR–resting HR]/speed) were measured during the last 2 minutes of each bout. Correlational analyses indicated no relationship (p>0.05) between measures of gross VO2 and EEIHR at each speed. Although no association was evident between net VO2 and EEIHR at 0.67 and 0.89m·s-1, a moderate relationship (r=0.64; p<0.05) was present between these variables at 1.12m·s-1. Examination of individual data revealed that most participants displayed an unmatched pattern of response between net VO2 and EEIHR. Our results suggest that caution should be applied when using EEIHR to estimate walking energy expenditure in children with CP.

Postural control during reaching with the dominant arm was assessed in 58 preterm children with cerebral palsy (CP) aged 2 to 11 years, comprising 34 with spastic hemiplegia (17 males, 17 females) and 24 with bilateral spastic CP (bilateral CP; 15 male, 9 females). Assessments were made by multiple surface electromyogram (EMG) and kinematic recording. Mean gestational age at birth for the children with spastic hemiplegia and those with bilateral CP was 28.6 weeks (SEM 0.33) and 28.2 weeks (SEM 0.34) respectively; their mean birthweights were 1158g (SEM 58) and 1190g (SEM 59) respectively. All but one of the children with spastic hemiplegia could walk without restriction, the exception being a child who had self-mobility with limitations. In the group of children with bilateral CP, nine walked without assistive devices, 10 could walk with assistive devices, and five children needed a wheelchair for self-mobility. Comparison data of 29 typically developing children (10 males, 19 females) born at term with appropriate birthweight were available. Results indicated that in most children with CP the basic level of postural control (‘direction-specificity’, ie. muscle activation on the side opposite to direction of body sway) was intact. However, the children with CP showed dysfunctions in: (1) recruitment order of the postural muscles, i.e. they exhibited a stereotyped top-down recruitment; and (2) the ability to modulate muscle contraction (that registers on EMG) to task-specific conditions. The latter dysfunction was more pronounced in children with bilateral CP than in those with spastic hemiplegia. Postural dysfunctions were correlated to some extent with the degree of disability in everyday activities as assessed by the Pediatric Evaluation of Disability Inventory.

Effects of perinatal exposure to polychlorinated biphenyls (PCBs) on auditory P300 latencies and amplitudes were evaluated in children from a Rotterdam cohort. From this cohort of healthy, term babies, the 26 lowest and 26 highest prenatally PCB-exposed children from the breastfed and the formula-fed groups (n=104) were invited for P300 assessment when they were 9 years of age. For P300 assessment an auditory simple odd-ball paradigm was used. In the 83 participating children, 60 assessments (32 males, 28 females) satisfied the measurement criteria and were included in the data analyses. After adjusting for confounding variables, children with high prenatal exposure were found to have longer P300 latencies than children with low prenatal exposure. Lactational exposure to PCBs through breastfeeding milk was not related to P300 latencies. P300 latencies were shorter in children breast-fed for at least 16 weeks than in children breastfed for 6 to 16 weeks and formula-fed children. P300 amplitudes were not related to perinatal PCB exposure nor breastfeeding. Results of this exploratory study suggest that prenatal exposure to environmental levels of PCBs and related compounds delays mechanisms in the central nervous system that evaluate and process relevant stimuli, whereas breastfeeding accelerates these mechanisms.

The aims of this study were to assess the characteristics of three-dimensional displacement of the centre of mass of the body (CMb) during walking in healthy children and to compare it with those of young adults. Twenty-one children (11 males, 10 females; age range 1 to 9 years) were recruited from the nursery and school attached to the Université catholique de Louvain, Brussels, Belgium; and three young adults (one male, two females; mean age 26 years 4 months) were recruited from the Rehabilitation and Physical Medicine Unit of the same university. Displacement of CMb was assessed at different walking velocities in the children and adults by two successive mathematical integrations of ground reaction forces, measured by a large strain-gauge force platform. Displacement of CMb was controlled for leg length of the participant to eliminate the scaling effect that is dependent on growth. Results showed that vertical and lateral amplitudes of the CMb when controlled for leg length were greater for children before 4 years of age and that the forward amplitude when controlled for leg length was greater for children before 7 years of age. We conclude that the development of mature human CMb displacement during independent walking is a gradual neural process, evolving until the age of 7 years.

Preterm infants are at increased risk for cognitive disorders, including impairments in recognition memory. This study evaluated the effects of extreme prematurity on the neural pathway for auditory recognition memory using event-related potentials (ERPs), a neurophysiological technique widely used in cognitive neuroscience. ERPs were recorded at term postmenstrual age in 35 preterm infants born at less than 32 weeks' gestation (22 males, 13 females; mean birthweight ([BW] 1154g, SD 374g) with normal brain ultrasounds, compared with 40 healthy, term newborns (1 to 3 days of age; 20 males, 20 females; BW 3672g, SD 420g). Because infants must be able to detect and discriminate sounds before recognizing them, two paradigms were used to assess these functions. The first evaluated the detection and discrimination of speech sounds. The second tested recognition of the mother's voice compared with a stranger's. Results showed significantly different patterns of speech sound discrimination in preterm infants compared with term infants. No evidence of maternal voice recognition was elicited from the preterm infants. No specific patterns of auditory detection or discrimination were associated with patterns of recognition memory, suggesting that the function of multiple neural pathways may have been altered in this group of preterm infants. These results provide a functional corroboration of magnetic resonance imaging studies showing effects of prematurity on early brain development, even among preterm infants with normal cranial ultrasonography.

Neonatal screening programmes allow early treatment to limit the consequences of congenital hypothyroidism on maturation of the central nervous system, and on psychomotor and educational outcome. Consequences of age at thyroid stimulating hormone (TSH) normalization on postural control were evaluated in 17 children with congenital hypothyroidism (14 females, three males; median age 12 years 1 month, range 7 to 14 years) and in 11 control individuals (eight females, three males: median age 10 years 6 months, range 8 to 14 years). Children with congenital hypothyroidism were split into two groups according to time of TSH normalization: before (group 1) or after (group 2) 3 months of age. Posturography (static and dynamic tests), educational (school performance), and psychomotor (WISC and revised Bruininks Oseretsky tests) evaluations were carried out. Group 2 results showed significant abnormalities in postural, educational, and psychomotor aptitudes in comparison with group 1 and control children (stability, Bruininks-Oseretsky, school performance: p[les ]0.05 or p[les ]0.01). Early TSH normalization is necessary to allow for normal development of the neurosensorial afferent pathways (vestibular, proprioceptive) and of central integration (cerebellum, vestibular nuclei).

Attention-deficit–hyperactivity disorder (ADHD), while largely thought to be a genetic disorder, has environmental factors that appear to contribute significantly to the aetiopathogenesis of the disorder. One such factor is pretern birth with vulnerable cerebrovascular homeostasis. We hypothesised that cerebral ischaemia at birth could contribute to persistent deficient dopaminergic neurotransmission, which is thought to be the pathophysiological basis of the disorder. We examined dopamine D2/3 receptor binding with positron emission tomography (PET) using [11C] raclopride as a tracer, and continuous reaction times (RT) with a computerized test of variables (TOVA) in six adolescents (12–14 years of age, one female) who had been examined with cerebral blood flow (CBF) measurements at preterm birth and had a subsequent history of attention deficit. We found that high dopamine receptor availability (‘empty receptors’) was linked with increased RT and RT variability, supporting the concept of a dopaminergic role in symptomatology. High dopamine receptor availability was predicted by low neonatal CBF, supporting the hypothesis of cerebral ischaemia as a contributing factor in infants susceptible to ADHD.

Turner syndrome, a genetic disorder that results from the complete or partial absence of an X chromosome in females, has been associated with specific impairment in visuospatial cognition. Previous studies have demonstrated a relationship between parietal lobe abnormalities and visuospatial deficits in Turner syndrome. We used high-resolution magnetic resonance imaging to measure parietal lobe subdivisions in 14 participants with Turner syndrome (mean age 13 years 5 months, SD 5 years) and 14 age-matched controls (mean age 13 years 5 months, SD 4 years 7 months) to localize neuroanatomical variations more closely. Scans were acquired and analyzed for 14 females with Turner syndrome. Analyses of variance were used to investigate differences in regional parietal lobes. Females with Turner syndrome showed a bilateral parietal lobe reduction, specifically in the superior parietal and postcentral gyri. Full-scale IQ scores were significantly positively correlated with postcentral tissue volume in the Turner syndrome group. Structural differences in the parietal lobe are localized specifically to the anterior and superior parietal lobe and might be related to the visuospatial and visuomotor deficits associated with Turner syndrome.

This study explored the relationships between the Gross Motor Function Classification System (GMFCS), limb distribution, and type of motor impairment. Data used were collected in the Ontario Motor Growth study, a longitudinal cohort study with a population-based sample of children with cerebral palsy (CP) in Canada (n=657; age 1 to 13 years at study onset). The majority (87.8%) of children with hemiplegia were classified as level I. Children with a bilateral syndrome were represented in all GMFCS levels, with most in levels III, IV, and V. Classifications by GMFCS and ‘limb distribution’ or by GMFCS and ‘type of motor impairment’ were statistically significantly associated (Pearson's χ2p<0.001), though the correlation for limb distribution (two categories) by GMFCS was low (tau-b=0.43). An analysis of function (GMFCS) by impairment (limb distribution) indicates that the latter clinical characteristic does not add prognostic value over GMFCS. Although classification of CP by impairment level is useful for clinical and epidemiological purposes, the value of these subgroups as an indicator of mobility is limited in comparison with the classification of severity with the GMFCS.

The aim of the present study was to analyze the ability to programme and execute reaching movements in individuals with myelomeningocele (MMC) and in a control group. Thirty-one participants (18 males, 13 females; mean age 12 years 11 months, SD 2 years 7 months, range 9 to 19 years) with MMC and 31 participants (matched for age and sex) without disabilities were investigated. Reaching was performed with and without visual feedback toward three targets displayed on a computer screen and data were collected using a digitizing tablet linked to a computer. The kinematics of reaching were analyzed and analysis of variance was used for statistical analysis. Results showed that both groups were able to programme reaching movements under both visual conditions. Although the execution of reaching was poor in the MMC group compared with the control individuals, as indicated by larger end-point errors (p=0.002), less straight movements (p=0.018), and shorter deceleration phases (p=0.004), movement time was not prolonged in the MMC group. Those with shunt treatment (n=21) had more difficulties when visual feedback was provided. Those with symptoms of early brainstem dysfunction (n=5) had shorter deceleration phases under both visual conditions.

We assessed the influence of digitigrade gait pattern, topographical types, severity of motor involvement, and locomotor experience on the body's centre of mass (COM) displacement during gait in children with spastic cerebral palsy (CP). Three-dimensional COM displacements were computed from ground reaction forces in 51 independent digitigrade walkers (29 males, 22 females; mean age 10 years 6 months, SD 2 years 7 months, range 7 to 15 years). Results obtained from 10 participants without disabilities (five males, five females), in the same age range as the patients with CP, were used as a reference plantigrade group. Vertical and forward COM displacements were significantly different between the digitigrade and the plantigrade walkers. Neither the topographical type (quadriplegia, n=5; diplegia, n=20; right hemiplegia, n=13; left hemiplegia, n=13), nor the severity of motor involvement, nor the locomotor experience influenced COM displacements. We conclude that the COM displacement during gait in patients with CP was mainly influenced by the digitigrade gait pattern encountered in this neurological disorder rather than the different topographical types and motor involvements.

Recent studies show that children with developmental coordination disorder (DCD) have difficulties in generating an accurate visuospatial representation of an intended action, which are shown by deficits in motor imagery. This study sought to test this hypothesis further using a mental rotation paradigm. It was predicted that children with DCD would not conform to the typical pattern of responding when required to imagine movement of their limbs. Participants included 16 children with DCD and 18 control children; mean age for the DCD group was 10 years 4 months, and for controls 10 years. The task required children to judge the handedness of single-hand images that were presented at angles between 0° and 180° at 45° intervals in either direction. Results were broadly consistent with the hypothesis above. Responses of the control children conformed to the typical pattern of mental rotation: a moderate trade-off between response time and angle of rotation. The response pattern for the DCD group was less typical, with a small trade-off function. Response accuracy did not differ between groups. It was suggested that children with DCD, unlike controls, do not automatically enlist motor imagery when performing mental rotation, but rely on an alternative object-based strategy that preserves speed and accuracy. This occurs because these children manifest a reduced ability to make imagined transformations from an egocentric or first-person perspective.

The purpose of this study was to determine the effectiveness of muscle-release surgery for children with cerebral palsy (CP) using longitudinal and stratified analysis. Twenty-five children with CP (15 females, 10 males; age range 4 to 16 years; mean age 8 years 2 months, SD 3 years 2 months) were selected from five treatment centres in Japan. Twenty-two children had spastic diplegia, two had spastic quadriplegia, and one had athetospastic quadriplegia. Motor function for each child was assessed using the Gross Motor Function Measure (GMFM). Assessment was conducted on eight separate occasions: 1 month and 1 week before surgery, and 1, 2, 4, 6, 9, and 12 months after surgery. Participants' motor function before surgery was classified using the Gross Motor Function Classification System (GMFCS). Six children were classified at level I, three at level II, six at level III, and 10 at level IV. A significant difference was found after surgery in the GMFCS levels III and IV groups (p<0.05). Improvement in GMFM scores between 1 week before surgery and 12 months after surgery were 1, 5, 8.5, and 8.5 for GMFCS levels I to IV respectively. Results indicate that this treatment is advantageous for improving motor function in children within GMFCS levels III and IV.

This study investigated the reliability of the modified Tardieu scale in the assessment of biceps spasticity in the upper limbs of children with hemiplegic cerebral palsy (CP). Ten children, with hemiplegic CP participated in the study: six males (mean age 9 years, SD 4 years) and four females (mean age 12 years, SD 3 years). Blinded, duplicate measures of dynamic elbow extension were performed on the hemiplegic arm at time 0 and 7 days later, using the three angular velocities described in the Tardieu scale (V1, slow; V2, speed of gravity; V3, as fast as possible). The resulting elbow joint angles were defined as R1, the angle of catch following a fast velocity stretch at either V2 or V3; and R2, the passive range of movement achieved following a slow velocity stretch at V1. Both elbow joint angle and movement angular velocity were measured by three-dimensional kinematics. Median error in measured elbow joint angle within one session ranged from 3 to 5°. Between sessions median absolute differences in measured elbow joint angle ranged from 4 to 13°, with measurement errors of up to 25 to 30° in some participants at the fastest velocity (V3). The therapist was able to apply three significantly different angular velocities as required for the Tardieu scale (p<0.001). However, the ranges of the three angular velocities overlapped, with fast velocities for some participants being equivalent to slow velocities for other participants. Three out of 10 participants had an intersessional difference in their R2–R1 score of more than 20°. From this study, we concluded that the R2–R1 value determined from the modified Tardieu scale may be of limited value in assessing biceps spasticity the upper limbs in children with hemiplegic CP.

We hypothesized that conventional phototherapy (CPT) and fibre-optic phototherapy (FPT) could exert different effects on cerebral blood perfusion. Our aim was to assess this hypothesis in a prospective study of the cerebral haemodynamics in preterm infants. Twenty-three infants (gestational age <34 weeks) were randomized for CPT (n=12) and for FPT (n=11). Cerebral Doppler ultrasounds were performed on all infants immediately before phototherapy (time 0), 6–12 hours (time 1) and 24–36 hours (time 2) after the start of phototherapy, and 6–12 hours after discontinuing phototherapy (time 3). CPT and FPT were associated with a significant increase of peak-systolic blood flow velocity and mean blood flow velocity at time 1 and 2, which disappeared at time 3, whereas end-diastolic blood flow velocity and resistance index were unchanged. No difference was shown between the groups. CPT and FPT were found to exert similar effects on cerebral haemodynamics. Both were associated with an increase of cerebral blood flow velocity which ended when phototherapy was stopped.

This study compared the energy cost of walking in children with cerebral palsy (CP) classified at different levels of the Gross Motor Function Classification System (GMFCS) with that in children with typical development. Sixteen female and 14 male children with CP (mean age 9 years 6 months, SD 2 years 4 months, range 6 years 4 months to 13 years 4 months) and 14 male and 13 female typically developing children (mean age 10 years, SD 1 year 6 months, range 7 years 1 month to 12 years 11 months) participated. Children with CP were classified at GMFCS level I, n=5; level II, n=10; level III, n=9; and level IV, n=6. Energy cost was assessed by the gas dilution method as each child walked around an oval track wearing a dilution mask. Significant differences were found across GMFCS levels (p<0.0001) and between adjacent levels (p[les ]0.013). Children with CP displayed a higher energy cost of walking than the typically developing children (p<0.0001). A strong correlation (0.87) was found between the energy cost of walking and GMFCS level (p<0.01) when children with typical development were assigned a GMFCS level of zero to allow statistical analysis. This indicates increasing energy cost of walking with increasing severity of functional involvement. These differences in energy cost across GMFCS levels provide another distinguishing factor between GMFCS levels and further emphasize the importance of considering metabolic demand in determining treatment options.

Maple syrup urine disease (MSUD) is a rare metabolic disease due to deficiency in the enzyme that breaks down branched chain amino acids. Lack of the enzyme causes accumulation of these amino acids and, if untreated, causes severe neurological damage. A case study of a 10-day old female infant, born after 40 weeks' gestation with a birthweight of 2740g with MSUD hospitalized in the acute stage with respiratory failure and severe brain oedema is described. As part of the neurological evaluation, auditory nerve brainstem evoked response testing was conducted and revealed bilateral presence of the first wave from the auditory nerve, with no later brainstem waves. Over the course of days when her condition improved following dialysis treatment and a diet to reach balanced levels of branched chain amino acids, the later brainstem waves appeared on one side, and several weeks later they were also observed on the other side. The possible mechanisms of the reversibility of the appearance of brainstem waves in this case are discussed.

This study examined spatial and temporal organization of muscle activity in response to seated forward platform perturbations in typically developing (TD) infants and in infants at risk for ongoing neuromotor delays. Twelve high-risk (HR) infants (six males, six females) and 12 TD infants (nine males, three females) aged 8 to 10 months (corrected for prematurity), who were all independent sitters, participated in this study. Surface electromyograms recorded muscle responses to forward perturbation in the neck, trunk, and leg (6cm amplitude, 12cm/s). Center of pressure measures were also recorded. The TD infants demonstrated significantly more phasic responses than the HR infants, who had more trials with tonic activity and more trials with no burst of muscle activity (Mann–Whitney U test, two-tailed, p=0.006). The TD infants demonstrated caudalcephalo, directionally appropriate recruitment patterns more often than the HR infants. There were some similarities between the two groups, with no significant difference between any of the center of pressure measures or onset latencies. Results suggest that postural development in HR infants with motor delays is complex. Some elements of seated postural control appear to be developmentally appropriate, e.g. presence of phasic activity in directionally appropriate muscles sequenced in a caudalcephalo pattern. However, frequency of these age appropriate responses was significantly lower in HR infants, who demonstrated many normal, albeit immature, responses, such as cephalocaudally sequenced muscle activity.

This study examined the relationship between lead exposure and attention regulation in children from low-income families. Children with lead exposure were expected to have lower attention regulation abilities than children who were not exposed. The 57 participants (39% male, 61% female) were children aged 4 and 5 years (mean age 4y 7mo [SD5mo]); 24 children were lead-exposed (10–29µg/dl) and 33 were non-exposed comparisons (1–6µg/dl). Both groups qualified to be enrolled in programs for low-income families. A puzzle-matching task was completed in parent–child and child-alone conditions. Attention allocation and puzzle-matching performance were assessed in the two conditions. Children who were lead-exposed demonstrated less self-regulated attention than comparisons and had poorer puzzle performance in the child-alone condition. Attention patterns did not differ in the parent–child condition. This study extends previous knowledge concerning effects of lead exposure on preschool children from disadvantaged environments and suggests that lead exposure affects specific attention regulation abilities.

This study aimed at broadening our insight into ipsi- and contra-lesional control of prehension after unilateral brain damage. Six male adults with hemiparetic cerebral palsy (mean age 17 years 3 months, SD 15 months) performed unrestricted grasping of discs that differed in size (40, 60, and 80mm in diameter) and which were placed at different distances from the participants (150mm and 30mm). A precalibrated Optotrak 3020 system was used for recording motion. Kinematics of the transport and grasp component, and hand orientation at the moment of grasping, were determined. A marker on the wrist was used to calculate the kinematics of the transport component. The distance between the markers on the index finger and thumb was used for the calculation of the grasp component. Kinematic variables of the transport and grasp component were remarkably similar between both sides of the body. However, with the contra-lesional side, more time was spent in contact with the object before it was lifted, and movements were performed less fluently compared with the ipsi-lesional side. Maximum grasp aperture was attained very late during reaching. For final hand orientation, results showed a large standard deviation both within and between participants. These findings show that, despite the ostensible awkward prehension movements of the contra-lesional side (slowness and decreased fluency), similarities in the kinematics between both sides of the body are present, which may be indicative of intact central control of the movement. The results of variant final hand orientation, combined with the relative late occurrence of peak aperture, suggest that these participants encounter difficulties with forward planning and may use a step-by-step control strategy.