Arend F. Bos

An early marker for neurological deficits after perinatal brain lesions

BACKGROUNDnIn normal awake infants, fidgety movements are seen from the age of 6 weeks to 20 weeks. The aim of the study was to test the predictive value of absent or abnormal spontaneous movements in young infants for the later development of neurological deficits.nnnMETHODSnIn a collaborative study involving five hospitals we collected data on the normal and abnormal quality of fidgety movements of 130 infants and compared it with assessments of neurological development done longitudinally until the age of 2 years. On the basis of ultrasound scans infants were classified as at low-risk or at high-risk of neurological deficits. Infants were videoed for 1 h every week from birth to discharge and then for 15 min every 3 to 4 weeks; quality of general movements was assessed. Repeated neurological assessments were also done until 24 months of corrected age.nnnFINDINGSn67 (96%) of 70 infants with normal fidgety movements had a normal neurological outcome. Abnormal quality or total absence of fidgety movements was followed by neurological abnormalities in 57 (95%) of the 60 infants (49 had cerebral palsy and eight had developmental retardation or minor neurological signs). Specificity and sensitivity of fidgety movement assessment were higher (96% and 95%, respectively) than of ultrasound imaging of the infants brain (83% and 80%, respectively).nnnINTERPRETATIONnOur technique of assessing spontaneous motor activity can identify and distinguish between those infants who require early intervention for neurological abnormalities and those who do not. Our technique is simple, non-intrusive, reliable, quick, and can be done on very young infants.

The qualitative assessment of general movements in preterm, term and young infants — review of the methodology

We describe the state of the art of Prechtls method for the qualitative assessment of general movements as a diagnostic tool for early detection of brain dysfunction. After discussing the optimal technique for video recording general movements in preterm, term and young infants, attention is focused on the proper analysis of this spontaneous motor pattern. Recently, a group of active researchers in the field reached consensus on the various qualities of normal and abnormal general movements. These definitions are reported here in full. Since it is a newly introduced method careful investigation into its reliability is required. Various groups of investigators have obtained data which demonstrate the robust character of the method (interscorer agreement: 78-98%). Finally, we discuss the validity of this early assessment method on the basis of the reports published so far. While the methods sensitivity is similar in all age groups studied (preterm, term, first month, second month, and third month age epochs), and averages 94.5%, the specificity of the method is age-dependent. It is low during the early ages, increases gradually and reaches 82 to 100% at 3 months post-term. This phenomenon is explained by spontaneous recovery of early dysfunction. In contrast, consistent abnormalities of general movements are linked to neurological deficits found at the 2 year follow-up.

Spontaneous motility in preterm, small-for-gestational age infants - I. Quantitative aspects

In order to document in detail the developmental course of qualitative aspects of early spontaneous motility in intrauterine growth-retarded infants, sequential videotape recordings were made in 19 preterm infants with a birth weight below the 5th percentile. The quality of general movements (GMs) was studied longitudinally during the preterm and postterm period until approximately 20 weeks corrected age, using Prechtls method of quality assessment. An abnormal quality of GMs was present in 15 out of 19 infants. Compared to a low-risk group, consisting of appropriate-for-gestational age preterm infants, the proportion of infants with normal findings on brain scans who had an abnormal quality of GMs was high. The presence of abrupt chaotic GMs was related to late fetal heart-rate decelerations and ischaemic alterations of the placenta. The quality of GMs normalized before or during the third month postterm in most infants with abnormal GMs. In four infants, the GMs did not normalize during the study period. The quality of fidgety movements was, in particular, a marker for neurological outcome at 24 months. This study demonstrates that intrauterine growth retardation may cause prolonged, but in most cases transient brain dysfunction; the qualitative assessment of GMs may help to identify infants at increased risk for neurodevelopmental abnormalities.

Role of vision on early motor development: lessons from the blind

For a better understanding of the contribution vision makes to the development of other sensory systems and to movement and posture, we studied effects of early blindness by examining video recordings of 14 totally blind infants. Infants were born at term or preterm and showed no evidence of brain damage. During preterm and term periods no noticeable changes in motor activity were observed. Around 2 months postterm all infants showed clear delay in head control and abnormal, exaggerated type of ‘fidgety movements’. Later, postural control was characterized by a prolonged period of ataxic features. Results indicate a lack of normal calibration exerted by vision on proprioceptive and vestibular systems. Early visuomotor coordination such as coordinated eye‐head scanning and head orientating were present but disappeared after several weeks.

Intrauterine growth retardation, general movements, and neurodevelopmental outcome: a review

Intrauterine growth retardation (IUGR) due to placental dysfunction is a risk factor for an impaired neurodevelopmental outcome. This is the case particularly in growth-retarded foetuses whose conditions in utero are so compromised that they have to be delivered before term. In recent years, neonatal treatment and care have improved markedly, and this has led to increased chances of survival of very immature and extremely low-birthweight infants. The optimal time to deliver IUGR infants remains difficult to assess. There is an obvious need for methods that accurately monitor foetal and neonatal condition, and it is important that the implications of these methods are evaluated for the neurodevelopmental outcomes of these infants. It is vitally important to be able to predict the outcome, whether it is normal or abnormal. A method that covers both aspects is the qualitative assessment of spontaneous motility of foetuses and newborn infants.

Functioning of 7-Year-Old Children Born at 32 to 35 Weeks’ Gestational Age

OBJECTIVE: To compare neuropsychological functions in moderately preterm (32–35 weeks’ gestation) and full-term children at the age of 7 years and identify gender differences. METHODS: Community-based prospective cohort study of 248 moderately preterm children (138 boys) and 130 full-term children (58 boys). Neuropsychological tests included IQ, memory, attention, visual perception, motor skills, visuomotor skills, and parental report of executive functioning. RESULTS: The moderately preterm group performed significantly worse on total and performance IQ, visuospatial reasoning, attention control, inhibition, and executive functioning. No differences were found in verbal IQ, verbal memory, and visuomotor and motor skills. Preterm children were at higher risk for scores <10th percentile on intelligence, visuospatial reasoning (relative risk ratio both: 1.69 [95% confidence interval: 1.29–2.28]), and executive functioning problems (relative risk: 1.94 [95% confidence interval: 1.51–2.57]). Using gender-specific norms, preterm boys performed significantly worse than full-term boys on visuospatial reasoning (P < .01); preterm girls performed significantly worse than full-term girls on visuospatial reasoning, intelligence, attention, and executive functioning (P < .05). CONCLUSIONS: Moderately preterm birth is associated with lower intelligence and poorer neuropsychological functioning at early school age. No differences in motor skills and verbal memory were found. Using gender-specific norms, our data suggest that moderately preterm boys catch up, whereas moderately preterm girls lag behind their peers on various neuropsychological functions by the age of 7 years.

The influence of septicaemia on spontaneous motility in preterm infants

The qualitative assessment of general movements (GMs) in preterm infants is a sensitive method to investigate the integrity of the central nervous system. The question arises whether systemic infections affect the quality of GMs in a similar fashion to brain lesions. We were able to provide an answer to this problem in six infants (gestational age 24.4-32.4 weeks, birth weight 600-1660 grams), who had initially normal GMs as analyzed from sequential video-recordings. All infants sustained a proven septicaemia (Candida albicans in two, Staphylococcus aureus in three, a coagulase-negative staphylococcus in one infant). Unintentionally, recordings were also made during the acute phase. The complexity and variability of the GMs remained largely intact in five of the six infants; only one infant had transiently abnormal GMs. Compared with 1 week before the acute phase, the speed and amplitude of the GMs were diminished, giving the GMs a sluggish appearance. One to two weeks after the acute phase of septicaemia, the quality of GMs, i.e. speed and amplitude, had normalized in all infants. This study demonstrates that it is possible to discriminate between abnormal GMs due to cerebral lesions and sluggish GMs due to severe systemic infections, when the complexity of the GMs is considered as the main characteristic for judgement of normality of GM-quality.

Less efficient elementary visuomotor processes in 7- to 10-year-old preterm-born children without cerebral palsy: An indication of impaired dorsal stream processes

Follow-up studies of preterm children without serious neurological complications have consistently found deficits in visuomotor skills. To determine whether these deficits may be related to impaired elementary visuomotor processes, we investigated movement programming and execution of simple pointing movements in 7- to 10-year-old preterm (<34 weeks g.a. and/or b.w. <1800 g) and full-term children. Such detailed analysis of simple pointing movements provides information on the extent to which processes associated with dorsal and/or cerebellar functions are impaired. Multi-level analysis showed that movement programming and execution were slowed in the 7-, 9-, and 10-year-old preterm groups. This indicates impaired dorsal visual stream functioning in preterm children, but do not rule out impaired cerebellar functioning. At 8 years of age, there were no differences between the two groups in movement execution time. This could have reflected a transition in the development of movement control in the control group, which has been associated in typically developing children with a decrease in motor speed. Interestingly, a similar decrease was not found in the preterm group at 8 years of age.

Difference rather than delay in development of elementary visuomotor processes in children born preterm without cerebral palsy: a quasi-longitudinal study.

Follow-up studies of preterm children without serious neonatal medical complications have consistently found poor visuomotor and visuospatial skills. In the first round of current follow-up study, we found a deficit in elementary visuomotor processes in preterm children without Cerebral Palsy (CP). To determine whether the development of these processes was delayed or different, we carried out a quasi-longitudinal study in which kinematic characteristics of pointing movements in 7- to 11-year-old preterm born children without CP and in an age-matched full-term group were analyzed. Multi-level analysis suggested a difference rather than a delay in the preterm born group: we found a regression around 8 years of age in the control but not in the preterm group. To our knowledge, this study is the first to provide longitudinal data confirming this regression in the development of movement control in typically developing children. Our results are also consistent in suggesting that elementary visuomotor processes are less efficient in preterm born children without CP: their movements were either slower or less accurate. While these differences were subtle, they persisted until 11 years of age.

Treating Preterm Infants at Risk for Chronic Lung Disease with Dexamethasone Leads to an Impaired Quality of General Movements

Mortality rates do not decline markedly after postnatal corticosteroid therapy and concern has been raised about its neurological sequelae. We studied 37 preterm infants with Prechtl’s method for the qualitative assessment of general movements before, during and after dexamethasone therapy and found that the quality of general movements was impaired in 9 of 13 initially normal infants (p = 0.004, McNemar test). The quality of fidgety movements at 3 months was abnormal in the majority of the infants and correlated strongly with neurological abnormalities at 2 years (Spearman r = 0.785, p < 0.001). Prechtl’s method may prove useful for the early neurological evaluation of alternative corticosteroid treatment strategies for the treatment of chronic lung disease.