Methodological concerns are a major reason behind having to turn down papers offered to Developmental Medicine and Child Neurology. One important cause is inadequate validation of measures used in the work. The validity of a test is one of its most important attributes, whether it is a clinical assessment, laboratory assay, electrophysiological or neuroimaging investigation, or a measurement of function, such as motor or IQ scales. With such a plethora of tests used in both everyday clinical work and research, and with the difficulties involved, it is not surprising that some are incompletely validated.

The original study by Badawi et al. investigated risk factors for neonatal encephalopathy (NE) and/or neonatal seizures in term infants. They used a broad definition appropriate for examining etiology and capable of asking such questions as: what proportion of NE arises after birth asphyxia? The answer was: some, but not much. That study was, and still is, the only large population-based investigation of multiple potential risk factors for NE, and it identified novel risk factors such as maternal thyroid disease, family history of seizures, and placental abnormalities. Several of these factors have been found to be risk factors for NE, neonatal seizures, or cerebral palsy (CP) in other studies.

Cerebral palsy (CP) can occur in term infants with or without preceding newborn encephalopathy. We compared the type and severity of CP and associated disability in these two groups. Participants from a population-based case-control study of term newborn encephalopathy were followed up for 6 years and linked to the Western Australian Cerebral Palsy Register. The remaining term infants with CP for the same period were also identified from the Cerebral Palsy Register. 13% of neonatal survivors of term newborn encephalopathy had CP, a rate of 116 per 1000 term live births. Overall, 24% of term infants with CP followed newborn encephalopathy. CP following newborn encephalopathy was more likely to: affect males (72% vs 56%); be severe (47% vs 25%); and be of spastic quadriplegia or dyskinetic types. Cognitive impairment was more common (75% vs 43%) and severe (41% vs 16%), as was epilepsy (53% vs 29%) in survivors of encephalopathy. These children were also more likely to: be non-verbal (47% vs 22%); have a severe composite disability score (47% vs 26%); and die between time of diagnosis of CP and age 6 years (5-year cumulative mortality 19% vs 5%). Children born at term who develop CP following newborn encephalopathy have a poorer prognosis than those with CP who were not encephalopathic in the first week of life.

This study aimed to determine whether neonatal feeding performance can predict the neurodevelopmental outcome of infants at 18 months of age. We measured the expression and sucking pressures of 65 infants (32 males and 33 females, mean gestational age 37.8 weeks [SD 0.5]; range 35.1 to 42.7 weeks and mean birthweight 2722g [SD 92]) with feeding problems and assessed their neurodevelopmental outcome at 18 months of age. Their diagnoses varied from mild asphyxia and transient tachypnea to Chiari malformation. A neurological examination was performed at 40 to 42 weeks postmenstrual age by means of an Amiel-Tison examination. Feeding performance at 1 and 2 weeks after initiation of oral feeding was divided into four classes: class 1, no suction and weak expression; class 2, arrhythmic alternation of expression/suction and weak pressures; class 3, rhythmic alternation, but weak pressures; and class 4, rhythmic alternation with normal pressures. Neurodevelopmental outcome was evaluated with the Bayley Scales of Infant Development–II and was divided into four categories: severe disability, moderate delay, minor delay, and normal. We examined the brain ultrasound on the day of feeding assessment, and compared the prognostic value of ultrasound and feeding performance. There was a significant correlation between feeding assessment and neurodevelopmental outcome at 18 months (p<0.001). Improvements of feeding pattern at the second evaluation resulted in better neurodevelopmental outcome. The sensitivity and specificity of feeding assessment were higher than those of ultrasound assessment. Neonatal feeding performance is, therefore, of prognostic value in detecting future developmental problems.

This purpose of this study was to investigate visual-object and visual-spatial long-term memory (LTM) abilities in individuals with Williams syndrome (WS) and Down syndrome (DS). Four groups comprised of 15 participants were included: WS group (10 males) with a mean chronological age (CA) of 18 years 5 months, SD 6 years 4 months, and mean mental age (MA) of 6 years 8 months, SD 1 year 5 months; WS control group (eight males) comprised of typically developing children (CA mean 6y 7mo, SD 8mo); DS group, (10 males, CA mean 16y 5mo, SD 5y 10mo; MA mean 5y 4mo, SD 8mo); and DS control group (seven males) formed by typically developing children (CA mean 5y 6mo, SD 7mo). In the WS and DS groups mental age and IQ were evaluated with the Form L-M of the Stanford-Binet Intelligence Scale. Results showed that individuals with WS showed decreased learning of visual-spatial material but substantially typical learning of visual-object patterns as compared to a group of mental-age-matched typically developing children. Individuals with DS showed the opposite profile, i.e. typical learning of visual-spatial sequences but impaired learning of visual-object patterns. These results, showing an interesting double dissociation between these two genetic syndromes in the learning of visual-object patterns as opposed to visual-spatial data, support the interpretation of learning disability as a heterogeneous condition, characterized by potentially very different qualitative profiles of cognitive impairment.

Little is known about the development of postural adjustments during early ontogeny. We examined postural adjustments due to sudden perturbations during sitting in 40 healthy term infants (28 males, 12 females) assessed in groups of eight at 1, 2, 3, 4, and 5 months of age. Surface electromyograms of neck, trunk, and leg muscles were recorded while the infants were exposed to a random series of horizontal forward and backward displacements of the surface of support. Video recordings of spontaneous motor behaviour were analyzed. For part of the analyses, previously collected data on 26 infants aged 6 to 10 months were included. In general, postural adjustments at all ages were direction specific and showed large variation. Within the variation developmental changes could be observed, revealing a transient decrease in postural activity at 3 months of age. After this transition, direction-specific postural activity was correlated with spontaneous motor behaviour. This was true, in particular, for dorsal postural activity. The clinical relevance of these findings is discussed.

This study investigated the adaptive gait pattern in obstacle clearance in 12 normally developing (ND) children (six males, six females; mean age 10y 2mo, SD 10mo) and 12 children who had spastic diplegic cerebral palsy (CP) and who were independent ambulators (10 males, two females; mean age 13y 5mo, SD 2y 7mo). Children in both groups had 8 to 12 years of walking experience. They walked up to and crossed over obstacles of a height of 0%, 10%, and 20% of their leg length. Kinematic aspects of the three-dimensional leg movements were captured with the Vicon system and analyzed with one-way analysis of variance with repeated measure. Both groups increased foot clearance for higher obstacles. Children with CP were slower in approach and crossing speed, and used a wider base of support than the ND children when the obstacle height was increased. Results suggest that motor problems in obstacle clearance in children with CP lie in the implicit process of motor control, i.e. torque dynamics, not the explicit process, i.e. movement-match with the environmental constraints.

Muscle strength, neuromuscular activation, and motor-unit firing characteristics (firing rate, recruitment, and short-term synchronization) were assessed during voluntary contractions of the medial gastrocnemius (GAS) and tibialis anterior (TA) muscles of 10 participants with spastic diplegic or hemiplegic cerebral palsy (CP). The participants (six females, four males; age range 6 to 37y) walked with equinus gait at Gross Motor Function Classification System levels II to III. These were compared with 10 age-matched controls (five females; age range 7 to 35y). Neuromuscular activation was estimated by the ratio of surface electromyogram amplitude to M-wave amplitude elicited by supramaximal electrical nerve stimulation. Participants with CP produced significantly less torque (normalized by leg length) compared with controls (TA: mean 2.3, SD 1.6 vs mean 8.9, SD 3.4N m/m; GAS mean 13.7, SD 7.1 vs mean 28.6, SD 5.1Nm/m, p<0.001). Neuromuscular activation during maximum voluntary contraction was significantly reduced in the participants with CP compared with controls (mean 2.4, SD 1.5 vs mean 9.7, SD 2.7Nm/m for TA; mean 1.04, SD 0.41 vs mean 3.1, SD 1.2Nm/m for GAS, p<0.001). When compared at the same submaximal level of neuromuscular activation, motor-unit recruitment and firing rates were not different between the groups, although short-term synchronization in TA was reduced in the participants with CP. These data indicate that weakness, known to be an important component of the motor deficit in CP, has a strong central component. Although the relation between recruitment and firing rate remained substantially intact at the low and moderate force contractions tested, results suggest that the participants with CP were unable to recruit higher threshold motor units or to drive lower threshold motor units to higher firing rates.

Force control ability was investigated in 10 males and 10 females, between 5 and 15 years old with spastic hemiplegia (mild and moderate hand dysfunction), and an aged-matched control group (eight males, 12 females). An isometric force production task at five different levels of maximum voluntary contraction (MVC) was performed. Results showed that MVC generated with the affected hand (AH) was only one-third of that generated by the non-affected hand (NAH; p<0.001), time to peak was almost twofold at the highest force level (p<0.001), and the coefficient of variation was twice as high (p<0.001). Results for the NAH did not differ from those of the control children. Correlations between clinical and experimental variables were significant for the relation between Ashworth score for elbow flexors, MVC and variability at the highest force level. In conclusion, the findings for the AH suggests that strength training should be considered for agonist spastic muscles.

Ring chromosome 20 (r[20]) syndrome is characterized by mild to moderate learning disability, behavioural disorders, epilepsy, and various dysmorphic features. Although still considered rare, r(20) syndrome is being increasingly diagnosed. More than 30 cases have been described in the literature since 1976. Here we report an additional case of a 14-year-old male with r(20). He had moderate to severe learning disability and epileptic seizures manifesting at about 18 months of age. During the 13 years' follow-up period he showed intractable epileptic seizures, behavioural disorders, and mild dysmorphological features including microcephaly, strabismus, micrognathia, down-slanting eyelids, and ear abnormalities. Frequent episodes of atypical absence or non-convulsive status associated with electroencephalogram changes were seen in follow-up. He was treated with several classical and new antiepileptic drugs, including intravenous immunoglobulin, corticotropin, and vagal nerve stimulation, with unsuccessful control of seizures. Finally, surgical treatment (corpus callosotomy) was performed at the age of 13 years; severity of tonic seizures was diminished, but frequency was unchanged. Although his behavioural problems, e.g. hyperactivity, were mild in early childhood they became more severe when he was 11 years old. Aggressiveness, compulsiveness with self-injury, and panic attacks developed at the age of 13 years, and were more pronounced after callosotomy. This case report provides the first description of deterioration in psychological situation in patients with r(20) intractable epilepsy. The patient was diagnosed with r(20) syndrome after 13 years of clinical follow-up. Karyotype analysis should, therefore, be performed in every patient with intractable epilepsy of unknown aetiology.

Feeding problems are common in children with neuromotor impairments. For example, a community-based survey by Reilly et al. demonstrated oral motor dysfunction in more than 90% of a sample of 49 children with cerebral palsy (CP). The sample contained 21 children with diplegia, 20 with quadriplegia, and six with hemiplegia. Most had either predominantly spastic (n=20) or mixed (n=22) signs. Thirty-three children were classified as having severe to profound functional impairment according to the Standard Recording of Central Motor Deficit. Over one-third of the sample had severe oromotor impairment and was at risk of chronic undernourishment. Although oral motor impairment was observed in all types of CP, moderate to severe oromotor dysfunction was more common in children with four limbs involved. In clinical populations, 60% of children with CP were found to have swallowing problems, with evidence of chronic aspiration in 41%. In assessing children with dysphagia, two issues are, therefore, paramount: is feeding safe, and is it adequate?

Studying the increase in the rate of oxygen uptake (V[dot above]O2) during the transition from rest to exercise (V[dot above]O2 kinetics) provides important information about aerobic function during a metabolic state that mimics habitual activity far more closely than traditional steady-state exercise. The time constant of V[dot above]O2 (τ V[dot above]O2) provides a method of quantifying the V[dot above]O2 kinetic response in the non-steady state. It can also be used to quantify the O2 deficit, which provides a means of assessing the ‘strain’ on non-aerobic energy sources at exercise onset. Children with spastic cerebral palsy (CP) do not tolerate exercise well, and report early fatigue. Precise causalities are not known, although investigating V[dot above]O2 kinetics in this population has the potential to enhance our understanding of the underlying mechanisms. In addition, there are an increasing number of practitioners in the field of paediatric CP who use V[dot above]O2 measurements to evaluate the efficacy of interventions and rehabilitation regimens. Measuring V[dot above]O2 kinetics can complement the traditional cardiorespiratory outcome measures, providing much useful information about the combined function of the respiratory, circulatory, and metabolic systems. Importantly, this can be achieved by using submaximal exercise intensities, reducing the stress placed on participants. To our knowledge there are no published data describing the V[dot above]O2 kinetic responses of children with CP. This review seeks (1) to summarize the main findings from V[dot above]O2 kinetics research involving non-impaired adults and children so that measuring V[dot above]O2 kinetics in children with CP can be considered within an appropriate framework, and (2) to address methodological issues directly related to measuring kinetics in children with CP.