Heinz F.R. Prechtl

The behavioural states of the newborn infant (a review)

Summary The concept of behavioural states in the young infant has been used in two connotations: (1) as a descriptive categorisation of behaviour; and (2) as an explanation of brain mechanismswhich modify the responsiveness of the infant. States have been either directly observed or assessed from polygraphic recordings. The criteria and definitions of states vary widely between investigators. States can be defined as finite and discrete vectors representing distinct and qualitatively different conditions, each of them considered as particular modes of nervous activity. The hypothesis of a continuum of arousal is rejected.

Are there behavioural states in the human fetus

The aim of this study was to search for the existence of behavioural states in the human fetus and to describe their developmental course. In a longitudinal study, 14 low-risk fetuses were studied at 2-week intervals from 32 weeks of gestation onward. Fetal body movements as well as fetal eye movements, visualized by means of real-time ultrasonic imaging, and fetal heart rate patterns, recorded by means of a cardiotocograph, were used as state variables. At 38 and 40 weeks, four distinct behavioural states, named states 1F through 4F and corresponding respectively to states 1 through 4 of the neonate, could be identified. That these constellations of parameters represented true behavioural states was demonstrated by the stability of association of parameters for prolonged periods and by the simultaneity of change of parameters at state transitions. There is evidence for episodes of wakefulness in the fetus. Before 36 weeks, cycles were present in each of the state variables and combinations of parameters typical of particular states were observed. However, the relatively short durations of these combinations and the lack of simultaneity of change in the three state variables support the conclusion that these periods of coincidence occurred by chance and did not represent organized behavioural states.

The emergence of fetal behaviour. I. Qualitative aspects

Abstract The emergence of spontaneous fetal motility during the first 20 weeks of gestation was studied longitudinally in 11 healthy nulliparae, using real-time ultrasound. The aim of this investigation was to study the onset and developmental course of spontaneously generated specific fetal movement patterns. 60-min observations were repeated weekly from 7 to 15 weeks and at 16/17 and 18/19 weeks. The qualitative aspects of fetal motility and posture were analyzed during video recording. Sixteen distinct movement patterns (just discernible movements; startle; general movements; hiccup; breathing; isolated arm or leg movements; isolated retroflexion/rotation and anteflexion of the head; jaw movements; sucking and swallowing; hand-facecontact; stretch; yawn; rotation), closely resembling those observed in preterm and fullterm newborn infants, could be distinguished and a detailed description is presented. The first movements were observed at 7.5 weeks postmenstrual age. A scatter of two weeks was found for the ages at which frequently occurring movement patterns could be observed for the first time. By the age of 15 weeks all 16 movement patterns could be observed. There were no major changes between 8 and 20 weeks in the appearance of the different movements, which meant that they were easy to recognize at all ages studied. A systematic assessment of position and posture showed a preference for the supine position before 16 weeks, and for the lateral position after 16 weeks. There was no consistent intra-individual preference for position or posture. Two specific motor patterns could be identified as causing either somersault or rotation around the longitudinal axis. The number of changes in fetal position increases from 10 weeks onwards, reaches a peak at 13–15 weeks and decreases after 17 weeks.

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.

State of the art of a new functional assessment of the young nervous system. An early predictor of cerebral palsy

The paper provides a survey of the state of the art of a new neurological diagnostic procedure in fetuses, preterm and term infant as well as in young infants. This method consists of a judgement of the movement quality of a particular type of spontaneous movements, the so-called general movements. At a very early age normal and abnormal general movement quality predicts the neurological outcome over 2 years, in particular cerebral palsy. The reliability of this method turned out to be very robust. Recent animal experiments on isolated parts of the central nervous system provide convincing evidence of endogenously generated neural activity. Similar neural mechanisms must provide the basis for spontaneous movements seen in the human at early ages. Those neural defects leading to qualitative changes of general movements are described in detail.

Abnormal motor behaviour in anencephalic fetuses

In eight anencephalic fetuses ultrasound observations of movement patterns were made and correlated with the morphological findings at postmortem. In all fetuses the movements were qualitatively abnormal: they were forceful, jerky in character and of large amplitude. In some of the most defective cases classification of the movements was hardly possible as they showed little similarity to those observed in normal fetuses. In these cases movements tended to occur in burst-pause patterns in contrast to being scattered over the record. Excessive activity occurred also only in the more defective cases. In fetuses with no evident cervical cord present isolated arm movements were observed. Fetal lung hypoplasia occurred as early as 16 weeks and in a fetus which showed both hiccups and breathing movements. It is concluded that with a severely defective fetal central nervous system, already in the first half of pregnancy movement patterns are abnormal. This abnormality mainly concerns the quality of the different movements. Secondly, movements can occur despite severe reduction in the amount and alteration in the organisation of the fetal central nervous system.

Preterm and early postterm motor behaviour in low-risk premature infants

The development of spontaneous motility and posture was studied longitudinally in 14 carefully selected low-risk preterm infants. The aim of this investigation was to provide a set of data suitable for comparison with fetuses and with neurologically abnormal preterm infants. The infants were videorecorded weekly, for one hour in a supine position, from birth until their discharge from the hospital. Ten of them were thereafter also observed at home at 3-week intervals from 3 to 18 weeks of corrected age, together with 10 healthy fullterm infants. Occurrence and duration of motor patterns and postures in periods of rest and activity were obtained by off-line analysis of the videotapes. Few significant changes were found from birth until term age in the composition and quantity of the spontaneous movement patterns. Only twitches and stretches during activity periods showed a small decline approaching term age. However, notable inter-individual differences and intra-individual fluctuations from week to week were observed. Postterm development of preterm infants was similar to that of the fullterms. Both showed considerable changes in the qualities of general movements after the first postterm weeks. Only fidgety character movements occur earlier in preterm infants. No age-specific preference postures of the limbs were found in the preterm period. Midline position of the head in supine was observed at about the same postterm age in preterm and fullterm groups. Asymmetrical tonic neck postures were very inconsistently present before term age and rapidly disappeared after term, earlier so in preterm infants.

Comparison between observation of spontaneous movements and neurologic examination in preterm infants

OBJECTIVE The Prechtl method of qualitative assessment of general movements (GMs) has been shown to be a good predictor of neurologic outcome in fetuses, preterm infants, and term infants. The aim of this study was to compare the results of this new technique with those of traditional neurologic examination and of cranial ultrasonography in preterm infants. METHODS Serial videotape recordings (with off-line assessment of GMs), ultrasound examination of the brain, and neurologic examinations were performed from birth until about 6 months of corrected age, on a group of 66 preterm infants whose gestational age ranged from 26 to 36 weeks (mean 30.7 weeks). The agreement between the two techniques and their predictive power, with respect to the neurologic outcome at 2 years of corrected age, were evaluated for five different age groups from preterm age to 65 weeks of postmenstrual age. RESULTS Overall agreement of the neurologic and GM findings was 80.3% and strongly age related (lower during the preterm and term periods and higher thereafter). At all ages the results of GM observation correlated highly with neurologic outcome; they showed higher sensitivity and specificity than the neurologic examination. This held true in particular before term age, when poor neurologic responses might be related to transient complications, and at term age, mainly because of infants with normal neurologic examination results but unfavorable outcome. During the preterm period the ultrasound results showed a better specificity and a lower sensitivity to outcome than GM findings. CONCLUSIONS The results of this study indicate that quality assessment of GMs should be added to traditional neurologic assessment, neuroimaging, and other tests of preterm infants for diagnostic and prognostic purposes.

Is the Early Development of Girls with Rett Disorder Really Normal

An apparently normal early development was one of the initial criteria for classical Rett syndrome. However, several investigators considered Rett syndrome to be a developmental disorder manifesting very soon after birth. Videos of 22 Rett cases were assessed carefully for movements, posture, and behavior during the first 6 mo of life. All signs that deviated from the normal standard were recorded meticulously. Special attention was paid to the face, the hands, and body movements. A detailed analysis clearly demonstrated an abnormal quality of general movements (100%), tongue protrusion (62%), postural stiffness (58%), asymmetric eye opening and closing (56%), abnormal finger movements (52%), hand stereotypies (42%), bursts of abnormal facial expressions (42%), bizarre smile (32%), tremor (28%), and stereotyped body movements (15%). Our study is the first to apply specific standardized measures of early spontaneous movements to Rett infants, proving conclusively that the disorder is manifested within the first months of life. Although not necessarily specific, the signs that we have observed will be of value in alerting clinicians to the possibility of the diagnosis at an early stage, when intervention is likely to be most effective.

General movement assessment as a method of developmental neurology: new paradigms and their consequences The 1999 Ronnie MacKeith Lecture

During the past 40 years, research in developmental neurology has provided a number of significant new paradigms on the functional development of the human nervous system. It is important to understand the historical background to the previous paradigms and the reasons why they became outdated and how they have been replaced on empirical grounds.