Backward walking highlights gait asymmetries in children with cerebral palsy.

To investigate how early injuries to developing motor regions of the brain affect different forms of gait, we compared the spatiotemporal locomotor patterns during forward (FW) and backward (BW) walking in children with cerebral palsy (CP). Bilateral gait kinematics and EMG activity of 11 pairs of leg muscles were recorded in 14 children with CP (9 diplegic, 5 hemiplegic; 3.0-11.1 yr) and 14 typically developing (TD) children (3.3-11.8 yr). During BW, children with CP showed a significant increase of gait asymmetry in foot trajectory characteristics and limb intersegmental coordination. Furthermore, gait asymmetries, which were not evident during FW in diplegic children, became evident during BW. Factorization of the EMG signals revealed a comparable structure of the motor output during FW and BW in all groups of children, but we found differences in the basic temporal activation patterns. Overall, the results are consistent with the idea that both forms of gait share pattern generation control circuits providing similar (though reversed) kinematic patterns. However, BW requires different muscle activation timings associated with muscle modules, highlighting subtle gait asymmetries in diplegic children, and thus provides a more comprehensive assessment of gait pathology in children with CP. The findings suggest that spatiotemporal asymmetry assessments during BW might reflect an impaired state and/or descending control of the spinal locomotor circuitry and can be used for diagnostic purposes and as complementary markers of gait recovery. NEW & NOTEWORTHY Early injuries to developing motor regions of the brain affect both forward progression and other forms of gait. In particular, backward walking highlights prominent gait asymmetries in children with hemiplegia and diplegia from cerebral palsy and can give a more comprehensive assessment of gait pathology. The observed spatiotemporal asymmetry assessments may reflect both impaired supraspinal control and impaired state of the spinal circuitry.

Immature Spinal Locomotor Output in Children with Cerebral Palsy.

Detailed descriptions of gait impairments have been reported in cerebral palsy (CP), but it is still unclear how maturation of the spinal motoneuron output is affected. Spatiotemporal alpha-motoneuron activation during walking can be assessed by mapping the electromyographic activity profiles from several, simultaneously recorded muscles onto the anatomical rostrocaudal location of the motoneuron pools in the spinal cord, and by means of factor analysis of the muscle activity profiles. Here, we analyzed gait kinematics and EMG activity of 11 pairs of bilateral muscles with lumbosacral innervation in 35 children with CP (19 diplegic, 16 hemiplegic, 2-12 years) and 33 typically developing (TD) children (1-12 years). TD children showed a progressive reduction of EMG burst durations and a gradual reorganization of the spatiotemporal motoneuron output with increasing age. By contrast, children with CP showed very limited age-related changes of EMG durations and motoneuron output, as well as of limb intersegmental coordination and foot trajectory control (on both sides for diplegic children and the affected side for hemiplegic children). Factorization of the EMG signals revealed a comparable structure of the motor output in children with CP and TD children, but significantly wider temporal activation patterns in children with CP, resembling the patterns of much younger TD infants. A similar picture emerged when considering the spatiotemporal maps of alpha-motoneuron activation. Overall, the results are consistent with the idea that early injuries to developing motor regions of the brain substantially affect the maturation of the spinal locomotor output and consequently the future locomotor behavior.

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

OBJECTIVES: We 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. METHODS: One hundred and sixty-five children with CP ages 6-16 years (mean age, 11years) 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. RESULTS: An 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. CONCLUSIONS: Our 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.

Perceptual-motor abilities in pre-school preterm children.

BACKGROUND: Several studies report a high percentage of premature infants presenting perceptual motor difficulties at school age. The new version of the Movement Assessment Battery for Children allows the assessment of perceptual-motor abilities in children from the age of 3years. AIMS: To evaluate early perceptual-motor abilities in prematurely born children below the age of 4years. STUDY DESIGN: The Movement Assessment Battery for Children 2nd edition was administered to 105 low-risk prematurely born children (<32weeks gestation) and in a control group of 105 term-born children matched for age and sex. All children were assessed between the age of 3years and 3years-11months. RESULTS: 63 children (60%) had total scores above the 15th percentile, 15 (14.3%) had scores between the 5th and the 15th percentile, and 13 (12.4%) below the 5th percentile. The remaining 14 children (13.3%) refused to perform or to complete the test. The difference between preterm and control group was significant for total scores, Manual Dexterity and Aiming and Catching scores. In the preterm group there was a correlation between age at testing, total scores and Aiming and Catching subscores. The Movement ABC-2 subscores were significantly lower in children born below 29weeks. CONCLUSION: Perceptual-motor difficulties can already be detected on the assessment performed before the age of 4years. Prematurely born children assessed between 3years and 3years-3months appeared to have more difficulties in performing the test than the older ones or their age matched term-born peers. These findings support the possibility of a delayed maturation in the younger age group.

Early visual assessment in preterm infants with and without brain lesions: correlation with visual and neurodevelopmental outcome at 12 months.

BACKGROUND: Several studies have reported the development of various aspects of visual function in infancy and early childhood in both preterm and term-born infants, but only a few studies have focused on the predictive power of neonatal visual findings in infants with brain lesions. AIMS: To explore visual findings at term age, and at 3 and 12 months corrected age in preterm infants (gestational age <33 weeks) with and without brain lesions; to compare the assessment at term age and at 12 months; and to assess the relationship between visual findings and neurodevelopmental outcome at 12 months. STUDY DESIGN: Cranial ultrasound scans (US) were classified in normal, mild or major abnormalities. One-hundred and forty-five infants were assessed with age specific tests for visual function at term age, and at 3 and 12 months. Neurodevelopmental assessment (Griffiths' Scales) was performed at 12 months. RESULTS: A good correlation was found between early and late visual assessment and neurodevelopment outcome. Of the 121 infants with normal neonatal visual assessment, 119 were also normal at 12 months and 116 had normal developmental quotient. Of the 24 infants with abnormal neonatal visual assessment, 12 were also abnormal at 12 months. All the false positives had normalised by 3 months. Of the 35 infants with major US abnormalities, 20 had normal and 15 abnormal scores on the neonatal assessment. At 1 year 17 had normal and 18 abnormal scores. CONCLUSION: A normal visual assessment at term age is a good predictor of normal visual and neurodevelopmental outcome at 12 months. An abnormal visual examination in the neonatal period was a less reliable prognostic indicator, infant should be reassessed at 3 months.

North Star Ambulatory Assessment, 6-minute walk test and timed items in ambulant boys with Duchenne muscular dystrophy.

The North Star Ambulatory Assessment is a functional scale specifically designed for ambulant boys affected by Duchenne muscular dystrophy (DMD). Recently the 6-minute walk test has also been used as an outcome measure in trials in DMD. The aim of our study was to assess a large cohort of ambulant boys affected by DMD using both North Star Assessment and 6-minute walk test. More specifically, we wished to establish the spectrum of findings for each measure and their correlation. This is a prospective multicentric study involving 10 centers. The cohort included 112 ambulant DMD boys of age ranging between 4.10 and 17 years (mean 8.18±2.3 DS). Ninety-one of the 112 were on steroids: 37/91 on intermittent and 54/91 on daily regimen. The scores on the North Star assessment ranged from 6/34 to 34/34. The distance on the 6-minute walk test ranged from 127 to 560.6 m. The time to walk 10 m was between 3 and 15 s. The time to rise from the floor ranged from 1 to 27.5 s. Some patients were unable to rise from the floor. As expected the results changed with age and were overall better in children treated with daily steroids. The North Star assessment had a moderate to good correlation with 6-minute walk test and with timed rising from floor but less with 10 m timed walk/run test. The 6-minute walk test in contrast had better correlation with 10 m timed walk/run test than with timed rising from floor. These findings suggest that a combination of these outcome measures can be effectively used in ambulant DMD boys and will provide information on different aspects of motor function, that may not be captured using a single measure.