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Biomedical subjects

M Hadders-Algra

Publications and source records attributed to M Hadders-Algra.

At least 55 records · Page 3Linked to original sources
PubMed1997

Spontaneous motility in preterm, small-for-gestational age infants. II. Qualitative 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 Prechtl's 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.

Child Development↗
PubMed1997

Regression of polyneural innervation in the human psoas muscle.

During the early stages of mammalian ontogeny muscle fibres are innervated by more than one axon. This polyneural innervation is replaced by mononeural innervation in the course of development. The regression of polyneural innervation in the psoas muscle in the human is the topic of the present study. Innervation patterns were studied in fetuses from 15 1/2 weeks of post menstrual age (PMA) and in babies until 80 weeks PMA (40 weeks after term age) and compared to data from two adults. Motor endplates were stained by a combined acetylcholinesterase stain. Innervation patterns and motor endplate morphology were studied and the sizes of endplates were measured. As a main result of our study polyneural innervation of the psoas muscle remains at a level of about 2 endings per endplate (range 1-5 terminals) until 18-25 weeks PMA and decreases thereafter. From 52 weeks PMA (12 weeks post term) onwards, muscle fibres are predominantly mononeurally innervated. During development the morphology of the terminal patterns of the nerve endings becomes more complex and the size of endplates increases, implying that the adult pattern of muscle innervation is reached at the age at which a major functional transformation in the neurobehavioural repertoire occurs (i.e. the end of the second and the beginning of the third month.

Acetylcholinesterase↗
PubMed1997

[Assessment of spontaneous motor activity in young infants: an effective method for the detection of brain function disorders].

A method for the assessment of the brain function of young infants was recently introduced. It consists of evaluation of the quality of spontaneously generated generalized movements (general movements, GMs). GMs appear at an early stage of pregnancy and persist until approximately the 4th month after term. Normal GMs are characterized by the triad of complexity, variation and fluency. Mildly abnormal GMs. indicating mild dysfunction of the nervous system, are not fluent but jerky or stiff. Markedly abnormal GMs, indicating major nervous system dysfunction, are characterized mostly by absence of complexity and variation of the movements: the movements are monotonous and stereotyped. The quality of the GMs can be evaluated by means of so-called global Gestalt perception. The technique can be learned in a few days. The quality of the GMs has a clear predictive significance for the child's development. Children with normal GMs will be free of handicaps in later life, whereas three-quarters of the children showing clearly abnormal GMs throughout the postnatal GM period do develop handicaps. Assessment of the quality of the GMs is a relatively cheap, non-invasive method of evaluating the current and future brain function of young infants.

Brain Damage, Chronic↗
PubMed1997

Assessment of general movements: towards a better understanding of a sensitive method to evaluate brain function in young infants.

The consistent presence of an abnormal quality of general movements (GMs) during the first postnatal months points to a high risk for the development of a neurological disability. To elucidate the significance of abnormal GMs during a single assessment, a classification system for abnormal GMs was developed. To this end six term and ten preterm infants with abnormal GMs were studied longitudinally with video and electromyographic (EMG) recordings till 59 weeks postmenstrual age (PMA). Two basic categories of abnormal GMs were distinguished: (1) mildly abnormal GMs (two types), which lacked fluency while conserving pattern complexity, and (2) definitely abnormal GMs (four types), which lacked fluency and complexity altogether. GM type before 39 weeks PMA correlated with findings on neonatal ultrasound brain scans. GM quality after 47 weeks PMA was strongly related to neurodevelopmental outcome at 1 1/2 years of age, suggesting that the absence of the age-specific 'fidgety' character of GMs could be a herald of disability.

Brain↗
PubMed1997

Nature and nurture in the development of postural control in human infants.

Nowadays, the controversy on "nature" and "nurture" in motor development focuses on the development of automatic motor patterns. The present paper discusses this issue within the framework of a recent study on the effect of maturation and training on the development of postural adjustments in sitting infants. This study revealed that already before the age of sitting without help, highly variable but direction-specific muscle activation patterns are present. This suggests that postural adjustments develop via an innate repertoire of primary direction-specific response patterns. The following developmental step consists of a decrease in muscle activation patterns, which results in selection of the most complete patterns of synergist activation. In accordance with Edelman's neuronal group selection theory, pattern selection turned out to be experience dependent, as it appeared to be guided by cues on head stabilization and enhanced by daily balance training.

Child Development↗
PubMed1996

Ontogeny of postural adjustments during sitting in infancy: variation, selection and modulation.

1. The aim of the study was to find out whether the development of postural adjustments occurs via a coupling of simple muscle responses, such as stretch reflexes, or via selection from an innate repertoire of centrally generated response patterns. 2. Postural responses during sitting on a moveable platform were assessed in eleven healthy infants at 5-6, 7-8 and 9-10 months of age. Multiple surface EMGs and kinematics were recorded while the infants were exposed to slow and fast horizontal forward (Fw) and backward (Bw) displacements of the platform. 3. From the youngest testing age onwards, largely variable but direction-specific muscle activation patterns were present. Fw translations resulted predominantly in an activation of the neck flexor, the rectus abdominis and rectus femoris muscle, while the neck-, thoracal- and lumbar extensor muscles (NE, TE, LE) and the hamstrings (Ham) showed varying amounts of inhibition. During Bw translations NE, TE, LE and Ham were preferably activated. The muscle activity could not be explained by simple stretch reflex mechanisms, but is likely to reflect centrally generated motor activity maturing in a predetermined way. However, indications for a contribution of stretch reflex mechanisms were also present. 4. With increasing age the variation in muscle activation patterns decreased, resulting in a selection of the most complete patterns. The ability to modulate the amplitude of the selected, most complete patterns during Fw translations, with respect to platform velocity and initial pelvis position, emerged at 9-10 months.

Afferent Pathways↗
PubMed1996

Training affects the development of postural adjustments in sitting infants.

1. The present study addressed the question of whether daily balance training can affect the development of postural adjustments in sitting infants. 2. Postural responses during sitting on a moveable platform were assessed in twenty healthy infants at 5-6, 7-8 and 9-10 months of age. Multiple surface EMGs and kinematics were recorded while the infants were exposed to slow and fast horizontal forward (Fw) and backward (Bw) displacements of the platform. After the first session the parents of nine infants trained their child's sitting balance daily. 3. At the youngest age, when none of the infants could sit independently, the muscle activation patterns were direction specific and showed a large variation. This variation decreased with increasing age, resulting in selection of the most complete responses. Training facilitated response selection both during Fw and Bw translations. This suggests a training effect on the first level of the central pattern generator (CPG) model of postural control. 4. Training also affected the development of response modulation during Fw translations. It accelerated the development of: (1) the ability to modulate EMG amplitude with respect to platform velocity and initial sitting position, (2) antagonist activity and (3) a distal onset of the response. These findings point to a training effect on the second level of the CPG model of postural adjustments.

Age Factors↗
PubMed1996

Postural control in children with spastic diplegia: muscle activity during perturbations in sitting.

To clarify the neural mechanisms controlling equilibrium during sitting, and the implications for the optimal sitting position for children with CP, automatic postural adjustments after perturbations of the support surface during sitting were investigated in seven children with spastic diplegia and in seven age-matched controls. A sudden backward sway of the body evoked brisk responses in ¿ventral' muscles in both groups. However, the order of muscle recruitment, which in most non-disabled children was caudal, was reversed in the children with diplegia, whose first response was in the neck flexors. The children with diplegia also co-activated antagonistic neck and hip muscles. The authors concluded that although children with spastic diplegia may produce a basic muscle activation pattern (first level of the central pattern generator, CPG), they cannot adjust the pattern in response to external changes (second level of the CPG).

Cerebral Palsy↗
PubMed1996

The assessment of general movements is a valuable technique for the detection of brain dysfunction in young infants. A review.

Recently, a new assessment technique by which to evaluate brain function in the fetus and newborn infant has been developed. The method is based on the assessment of the quality of General Movements (GMs). GMs are complex movements involving all parts of the body. They are present throughout fetal life and postnatally until about 3-4 months post-term. The persistent presence of abnormal GMs during the neonatal period and the absence of age-specific characteristics ("fidgety" movements) around 3 months-post term are both powerful predictors of the development of handicap.

Brain Diseases↗
PubMed1995

Perinatal exposure to polychlorinated biphenyls and dioxins and its effect on neonatal neurological development.

Polychlorinated biphenyls (PCBs) and dioxins (polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs)) are widespread environmental contaminants which are neurotoxic in animals. Perinatal exposure to PCBs, PCDDs, and PCDFs occurs prenatally via the placenta and postnatally via breast milk. To investigate whether such an exposure affects the neonatal neurological condition, the neurological optimality of 418 Dutch newborns was evaluated with the Prechtl neurological examination. Half of the infants were breast-fed, the other half were formula-fed, representing a relatively high against a relatively low postnatally exposed group, respectively. As an index of prenatal exposure, four non-planar PCBs in cord and maternal plasma were used. These PCB levels were not related to neurological function. As measures of combined pre- and early neonatal exposure, 17 dioxin congeners, three planar, and 23 non-planar PCB congeners were determined in human milk in the second week after delivery. Higher levels of PCBs, PCDDs, and PCDFs in breast milk were related to reduced neonatal neurological optimality. Higher levels of planar PCBs in breast milk were associated with a higher incidence of hypotonia. This study confirms previous reports about the neurotoxic effects of these compounds on the developing brain of newborn infants.

Benzofurans↗
PubMed1994

Infantile chorea in an infant with severe bronchopulmonary dysplasia: an EMG study.

Recently a new movement disorder has been described which develops in some preterm infants with bronchopulmonary dysplasia. The present report provides a detailed description (including polyelectromyographical and serial cranial ultrasound findings) of this syndrome in a single infant. The authors suggest that the movement disorder be called infantile chorea, because the movement characteristics and EMG bursting pattern resemble those of adult chorea. It is hypothesized that 'infantile chorea', which is assumed to be caused by dysfunction of the striato-thalamic circuitry, emerges at the age of two to three months post-erm as thalamo-cortical connections are supposed to become functionally active.

Bronchopulmonary Dysplasia↗
PubMed1994

Neurobehavioural relationships after the onset of puberty.

The behavioural and cognitive development were studied of 68 children with and 259 without minor neurological function (MND) at 14 years, when the majority of children showed three or more physical signs of puberty. MND was differentiated into fine manipulative disability, co-ordination problems, choreiform dyskinesia and hypotonia. The normal group was subdivided into those who had been normal at 12 years and those who had had MND. All types of MND were related to cognitive and behavioural problems. Fine manipulative disability was related to behavioural and cognitive difficulties; co-ordination problems to learning difficulties; and choreiform dyskinesia and hypotonia were related to attention difficulties and school failure, notwithstanding normal IQ. Besides MND, socio-economic class, family adversities and female gender contributed to the development of behavioural and cognitive problems. The behaviour of children with MND at 12 years who were normal at 14 years did not differ from that of normal children.

Adolescent↗
PubMed1993

The effect of behavioural state on general movements in healthy full-term newborns. A polymyographic study.

In a group a eight healthy full-term newborns 6-h polygraphic recordings, which included EMG recording of eight arm muscles, were made to investigate the effect of behavioural state on general movement (GM) organization. Simultaneous video recordings supplied information about the form of the GMs. Additionally the effect of non-nutritive sucking during State 4 was evaluated. Behavioural state had a distinct effect on the makeup of GMs. GMs during State 4 displayed best the fluency and elegance which are characteristic of normal GMs. State-1-GMs were rare, had a short duration and sometimes had an abrupt onset. During State 2 GMs had a fragmented appearance. EMG differences between GMs in State 2 and State 4 were demonstrated in burst duration (longer during State 2) and tonic background activity in the upper arm muscles (lower during State 2). Occasionally State-2-GMs had an abrupt onset. These abrupt GMs were less often preceded by rapid eye movements and heart rate changes than State-2-GMs with a gradual onset. GMs during State 5 were abrupt and vigorous and often had a high frequency tremor superimposed. The EMGs of State-5-GMs revealed a shorter interval between the EMG bursts and a higher EMG burst amplitude in the upper arm muscles than present during State-4-GMs. Non-nutritive sucking during State 4 induced a reduction of movement amplitude, a increase of EMG burst duration and an increase of tonic background activity in the biceps brachii and the extensor carpi muscles.

Behavior↗
PubMed1993

General movements in early infancy: what do they tell us about the nervous system?

Developmental changes in muscle coordination patterns of normal and abnormal general movements (GMs) are described. GMs were studied simultaneously with video-recording and polymyography (polyEMG). GMs of normal full-term infants gradually lose their neonatally slow and 'writhing' character, to be turned into the elegant flow of small movements of 'fidgety' GMs at the age of 2-3 months. This transformation coincides with changes in the polyEMG. Tonic background activity decreases concurrent with a reduction in amplitude and duration of phasic bursts. The coordination between antagonistic muscles does not change, co-activation remains the prevailing pattern. Secondly, preliminary results on healthy preterms (n = 6) are presented. At the examination age of 33-34 weeks postmenstrual age the preterms showed so-called 'preterm' GMs, which are characterized by variation and graceful complexity. EMG burst duration was significantly longer during 'preterm' GMs than during 'writhing' GMs of full-term newborns. The percentage of co-activation during 'preterm' GMs varied considerably. The polyEMG of 'writhing' GMs of two preterms, who were followed longitudinally, differed from that of 'writhing' GMs of full-terms. At 'fidgety' age the EMG differences between preterms and full-terms had disappeared. Finally the first results on abnormal GMs are reported. A synchronized onset of muscle activity in all extremity muscles and 'packaging' of EMG-bursts into subunits of 5-8 Hz. seemed to be specific properties of these abnormal GMs. This could indicate a loss of supraspinal control.

Electromyography↗
PubMed1993

Minor neurological dysfunction after the onset of puberty: association with perinatal events.

In order to study the hypotheses that puberty is related to a decrease of minor neurological dysfunction (MND) and that persisting MND is associated with perinatal factors, two groups (174 normal, 172 MND) of the Groningen Perinatal Project were followed from 12 to 14 years. At 14 years almost all the children had entered puberty (n = 329) defined as the presence of three or more puberty signs. In the MND group 55% of the children were normal at 14 years and in 45% MND signs were still present, though in a less extensive form. The latter phenomenon was most clear in children who had just begun puberty. The effect of puberty was similar in both sexes. MND which persisted into puberty was related to neonatal neurological deviancy, lower social class, lower obstetrical optimality score and male sex. After differentiation with specific MND clusters, it appeared that fine manipulative disability was associated with neonatal neurological deviancy, with minor physical anomalies and with lower social class; choreiform dyskinesia with asphyxia; hypotonia with constitutionally related factors; and coordination problems with pre-maturity (< 32 weeks).

Adolescent↗
PubMed1993

Is minor neurological dysfunction at 12 years related to behaviour and cognition?

Behavioural and cognitive development at 12 years were studied in 172 children with and 174 children without minor neurological dysfunction (MND). MND could be differentiated into fine manipulative disability, co-ordination problems, hypotonia and choreiform dyskinesia. Fine manipulative disability related significantly to problems of cognition and behaviour; co-ordination problems to cognitive problems; and hypotonia and choreiform dyskinesia to behavioural problems, the former more than the latter. Socio-economic status and family adversity contributed to the risk for development of both cognitive and behavioural problems; gender did not. The onset of puberty seemed to change these relationships: follow-up is needed for definite conclusions.

Achievement↗