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Biomedical subjects

H F Prechtl

Publications and source records attributed to H F Prechtl.

At least 55 records · Page 3Linked to original sources
PubMed1990

Qualitative changes of general movements in preterm infants with brain lesions.

The aims of the study were (1) to replicate previous quantitative studies of motor activity in low-risk and high-risk preterm infants and (2) to apply a new method of systematic analysis of the qualitative characteristics of general movements in these two groups of infants. Sequential one-hour videorecordings of the unstimulated infants in the incubator were made during the preterm period and then continued during the postterm period until about 20 weeks. The high-risk group consisted only of infants with signs of haemorrhage and/or leucomalacia in the repeated ultrasonograms of the brain. The neurological follow-up continued up to a minimum of one and a maximum of three years of corrected age. The quantification of the various motor patterns in 12 matched pairs of low-risk and high-risk preterm infants revealed a slight but significant (P = 0.05) excess of isolated arm movements in the low-risk cases during the activity phase. No other movement pattern differed significantly. The qualitative assessment of general movements during the preterm period resulted in all but one of the 14 low-risk cases having a normal quality of general movements. In the lesion-group (N = 29) all the infants had an abnormal quality during the preterm period. Eight cases later became neurologically normal although 1 of them had strabism. In addition, one infant was blind (ROP) and retarded and one other had mental retardation. Nineteen infants later developed cerebral palsy (two monoplegia of a leg, three hemiplegia, 5 diplegia and 9 quadriplegia). Strabism was present in 48.3% of the whole group of 29 cases. A semi-quantitative estimation of various aspects of the abnormal general movements made a typology of abnormal patterns possible. A graphic display of developmental trajectories of individual cases, depicting the course of abnormal aspects along the time axis, helps document the evolution of abnormal signs. Their course is a better predictor of the neurological outcome than the nature and localization of the lesion, detected by imaging techniques. The qualitative assessment of general movements from videorecordings is a reliable, quick, cheap and totally non-intrusive method in neonatology for the early detection of functional impairment of the nervous system.

Brain Diseases↗
PubMed1990

Does reduction of amniotic fluid affect fetal movements?

The effect of the amount of amniotic fluid on the form of fetal general movements was studied longitudinally in 19 pregnancies complicated by premature rupture of the amniotic membranes (PROM). Before birth, general movements were studied weekly by means of 1-h ultrasound observations, performed under standardized conditions. In the early postnatal period, 11 of these infants were followed with video recordings of their spontaneous movements. In the fetus, speed and amplitude of general movements were directly related to the reduction in amniotic fluid. A moderate reduction of amniotic fluid was associated with a decrease in amplitude, while a more severe reduction of amniotic fluid caused a decrease in speed as well. Postnatally, the small amplitude and low speed showed a marked tendency to normalize between 1 and 5 weeks. These results are important for the qualitative assessment of motor behaviour in pregnancies with obstetrical complications that are associated with oligohydramnios (such as PROM or intra-uterine growth retardation).

Amniotic Fluid↗
PubMed1990

Body and breathing movements in near-term fetuses and newborn infants of type-1 diabetic women.

The generation of body and breathing movements was studied in relation to behavioural states in near-term fetuses (n = 12) and newborn infants (n = 7) of women with well-controlled type-1 diabetes. Results obtained from low-risk fetuses (n = 12) and neonates (n = 14) were used for comparison. Before birth, 2-h recordings were made of fetal heart rate and of fetal body movements, breathing and eye movements; the neonates were studied polygraphically during 6 h for heart rate, body movements, respiration, eye movements and EEG-pattern. The generation of body movements was similar in the fetuses of the diabetic and control groups. After birth, the duration per burst was longer in the diabetic group, both in state 1 and state 2, resulting in increased incidences. The incidence of fetal breathing movements tended to be higher in the diabetic group, but differences with the control group did not reach statistical significance. Breathing rate was considerably slower in fetuses of diabetic women than in control fetuses, both in C1F (P less than 0.001) and C2F (P less than 0.002). This indicates altered regulation of breathing movements in diabetic pregnancy. In the neonates, breathing rate was identical in both groups. In either group breathing was slower in state 1 than in state 2; such a difference was not present before birth. Periodic breathing occurred more often in the infants of diabetic women, especially in state 2 (P less than 0.02). Behavioural state organization was poor in the diabetic group, both before and after birth and resembled that of more immature fetuses and infants. The continuity of the poor behavioural state regulation from prenatal into postnatal life indicates that this cannot be attributed to the instantaneous unfavourable condition before birth.

Female↗
PubMed1989

Fetal behaviour.

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Female↗
PubMed1989

Posture and spontaneous motility in fullterm infants.

Posture and spontaneous motor patterns during the first days of life were studied in ten healthy fullterm infants by direct observation and videorecording. The aim of the study was to provide a description of motor and postural characteristics of normal newborns. The infants were recorded for 1 h on their first and fourth day of life, when unstimulated in an incubator. Incidence and duration of the different body postures and motor patterns were scored during the replay of the videorecordings. The preference for the fully flexed posture of arms and legs described in the literature could not be confirmed. There was a large intra- and inter-individual variability in the postural repertoire. No particular posture, characteristic for each behavioural state, existed. Similar postures rarely occurred in the same infant on the first and fourth day. Extended postures more often occurred on the fourth day. Spontaneous motility consisted of several distinct movement patterns, the occurrence of which in states 1 and 2 was computed for day 1 and day 4. Motor patterns were differently related to the states. No differences were noted in the motor activity between the first and fourth days. Large inter-individual differences, but an intra-individual consistency, were found in the rates of specific motor patterns: infants who showed a low or high rate of particular movements on day 1 maintained the same characteristic on day 4. There was no overall low or high motor activity.

Female↗
PubMed1989

Vibro-acoustic stimulation of the human fetus: effect on behavioural state organization.

Vibro-acoustic stimulation of the human fetus in being increasingly performed both antenatally and during labour, to differentiate between poor and good fetal health in cases of flat or otherwise suspect fetal heart rate patterns. In a controlled study we investigated the effect of the electronic artificial larynx (EAL) on fetal behavioural state organization. In 10 healthy women with normal pregnancies of 38-40 weeks of gestation, recordings of fetal heart rate, body movements and eye movements, with a duration of 120-210 min, were carried out during two consecutive days. In each fetus, 3-4 episodes of state 1F and consecutive state 2F were studied, one of which served as a control observation. EAL stimulation during state 1F was associated with excessive fetal movements and with a state change in 7 out of 9 observations (four times into 2F; three times into 4F). Stimulation during state 2F was associated with a change into 4F in four of the nine observations. On days with EAL stimulation the fetuses spent more time in state 4F or in an episode not classifiable (because of an atypical FHR pattern with tachycardia and small accelerations) than control fetuses (21% vs. 3% of time). Disorganized states or periods of state 4F sometimes lasted for more than 1 h following the stimulation. It is concluded that stimulation with the EAL induces excessive fetal movements, a prolonged tachycardia, non-physiological state changes and a disorganisation and change in the distribution of fetal behavioural states. Until more is known regarding the safety and risks of vibro-acoustic stimulation, it should not be used in a routine clinical setting.

Acoustic Stimulation↗
PubMed1989

The effect of (induced) maternal emotions on fetal behaviour: a controlled study.

In ten healthy near-term pregnant women the effect of induced maternal emotions on fetal motor behaviour was studied. Emotions were induced by showing a film of a normal delivery. Fetal behaviour was recorded by means of real-time ultrasound observations of general movements and eye movements and by fetal heart rate monitoring. The observations had a duration of 2 h. The data were compared with those obtained during a 2-h control period, which took place the day before (n = 5) or after the study period (n = 5). Maternal emotions (induced) were measured by means of psychological tests. No effects on fetal motor activity or on behavioural state organization could be found as a result of this film. There was, however, a significant positive correlation (P less than 0.01) between the mean level of anxiety of the women and the motor activity of the fetuses.

Adult↗
PubMed1988

The emergence of fetal behaviour. III. Individual differences and consistencies.

Intra- and inter-fetal consistencies and differences in motor activity were studied in 12 healthy nulliparous women during the first half of gestation. Real-time ultrasound observations, lasting 60 min, were performed weekly from 7 to 15 weeks of gestation and at 17 and 19 weeks. The various types of movements were categorized according to a previously developed classification system. Data on general movements during the second half of gestation were carried out on the same group of women and these results are also included in this study. Intra-individually there appeared to be a relative week-to-week consistency in the amount of total motor activity, i.e. the sum of all the movement patterns. There was a slight tendency of intra-fetal consistency when the incidence of general movements during the first half of gestation was compared to that during the second half. The other movement patterns did not show these consistencies, namely, each fetus showed large fluctuations in the week-to-week incidences. Inter-individually there were large differences in the amount of the different types of movements at the various ages, which resulted in wide ranges. The sum of the rank orders which for total activity and general movements, were found weekly, were compared to those which could be expected to occur in a homogeneous population. Two fetuses appeared to be significantly different from the others on mathematical grounds. One consistently showed a high and one a low motor output. Week-to-week stability in the rank orders of the various movement patterns was studied by adding up a sum score of all the weekly changes in ranks. Three fetuses were found to be stable and three showed large fluctuations. The others were in between these extremes. The ranks of the movements from high to low frequency, appeared to be strictly age dependent, whereby all the fetuses followed the same developmental trend. There were no differences between female and male fetuses in any of the movement patterns.

Embryonic and Fetal Development↗
PubMed1988

Developmental neurology of the fetus.

The use of modern ultrasound equipment has opened the way to fetal neurology. The aim is to provide the obstetrician with standardized and comprehensive methods to evaluate the neurological condition in compromised fetuses. Such possibilities will greatly improve assessments which have so far been based only on fetal heart rate monitoring and quantitative counts of fetal motility. The most important candidates for neurological assessment are the quality of fetal movements, in particular of general movements, and in the near-term fetus the organization of behavioural states. Less suitable, because of limited sensitivity, is the quantitative assessment of fetal movements, even when carried out with ultrasound. The most problematic approach is testing the fetus with vibro-acoustic stimuli, which induce abnormal behavioural states of prolonged duration and are therefore potentially harmful.

Central Nervous System↗
PubMed1988

The blood flow velocity waveform in the fetal internal carotid and umbilical artery; its relation to fetal behavioural states in the growth retarded fetus at 37-38 weeks gestation.

In eight women whose fetuses showed evidence of intrauterine growth retardation (IUGR), the relation was examined between the blood flow velocity waveform in the fetal internal carotid and umbilical artery and fetal behavioural states at 37-38 weeks gestation. In both vessels there was a virtual overlap of pulsatility index values originating from state 1F and 2F, reflecting behavioural state independency. In the internal carotid artery this state independency is associated with moderately reduced pulsatility index values.

Blood Flow Velocity↗
PubMed1987

Transient flattenings in the EEG of newborns--a benign variation.

A report on 43 instances of transient flattening of the EEG in sleeping newborns occurring near the onset of state 1 is presented. The depression of EEG activity is variable and lasts about 1 min. It is followed usually by highly discontinuous activity (tracé discontinu) which fades after a variable time (less than 1.5 min in 75% of cases), into a normal state 1 pattern. The incidence was 24% in a mixed group of infants of 43 weeks CA and under. Bilateral events were twice as common as unilateral ones. Flattenings were only seen at or close to the onset of the first state 1 in a sleep episode. We suspect that the phenomenon reflects the unusual functioning of mechanisms underlying the normal process of change from the low voltage continuous EEG in behavioural state 2 (active or REM sleep) to the higher voltage so-called synchronized discontinuous pattern of state 1 (non-REM or quiet sleep). Flattenings have no clinical significance beyond their importance as a normal variation in the neonatal EEG, about whose existence electroencephalographers should be aware. Post-flattening bursting should not be misinterpreted as epileptic activity.

Child Behavior↗
PubMed1987

Diurnal and other variations in fetal movement and heart rate patterns at 20-22 weeks.

It was investigated when diurnal and other variations in fetal movements and in heart rate pattern emerge during the course of pregnancy. Real-time ultrasound observations were made at 13 weeks of gestation in 7 nulliparous women and at 20-22 weeks in 10 nulliparous women. The observations took place at 0800, 1300 and 2200 and lasted 60 min/session at 13 weeks and 120 min at 20-22 weeks. The fetal heart rate was recorded for 24 h at 20-22 weeks using electrocardiographic electrodes. No diurnal variations were found for any of the movement patterns at 13 weeks. At 20-22 weeks, however, significant diurnal changes were observed in the total activity, the incidence of general movements and the breathing movements, with the lowest values in the morning and the highest during the evening. Fetal breathing movements already appeared to be related to maternal meals at 20-22 weeks as their incidence was significantly lower during the third hour after meals compared to the second hour. The rank order of the incidence of movements (from high to low incidence) was fairly constant over the course of the day both at 13 and at 20-22 weeks. This confirms earlier findings that the rank order of movements is strictly age dependent. Diurnal rhythms were observed for both the fetal heart rate and its variation. The fetal heart rate was lowest between 2400 and 0600 and the heart rate variation was lowest between 0600 and 1100. The incidence of accelerations and decelerations showed no systematic fluctuations over the 24-h period. Decelerations occurred more frequently than accelerations. Episodes of high heart rate variation were associated with an increased incidence of general movements. The various diurnal variations over 24 h at 20-22 weeks generally followed the same temporal sequence as those found near term, although the changes were considerably smaller.

Circadian Rhythm↗
PubMed1987

Emergence of behavioural states in fetuses of type-1-diabetic women.

The aim of this study was to investigate the effects of tightly controlled maternal (type-1-)diabetes mellitus on the development of fetal behavioural states. Seventeen diabetic women, who required insulin (White's class C predominantly) and were treated with continuous subcutaneous insulin infusion (CSII) therapy, participated in the study. Adjustment to an insulin-pump occurred before conception or during early pregnancy. In all diabetic women (near-)normoglycemia was achieved during pregnancy, with glycosylated hemoglobin-values within the normal range (6-8.5%). Fifty-three 2-h recordings of fetal heart rate, uterine contractions and of real-time ultrasound scanning for fetal body movements, breathing and eye movements were obtained from the 17 fetuses. The fetuses were longitudinally studied between 32 and 40 weeks post menstrual age, at intervals of 2 weeks. The 3 state variables, fetal heart rate, body movements and eye movements, were analyzed for the presence of combinations meeting the definitions of the four fetal behavioural states. Findings in the fetuses of diabetic women were compared with those obtained from 28 low risk fetuses. The criteria of states were met in only 3 of 8 fetuses studied at 38 weeks and in one of two studied at 40 weeks. For comparison: in low risk fetuses studied at 38 and 40 weeks, states were present in 70% and 90% of the cases, respectively. This poorly developed state organization exhibited by the near term fetuses of the diabetic group, was related to maternal parity, but not to pre- or postconceptional onset of CSII-treatment. Fetuses of nulliparous diabetic women showed more often asynchrony of transitions (greater than 3 min) and interruption of periods of concordant association. This resulted in significantly higher percentages of 'no-coincidence' and in low incidence of behavioural states as compared with control fetuses of nulliparous women. In the few multiparous diabetic cases studied near term the development of fetal behavioural states was normal. We conclude therefore that, despite tight control of maternal diabetes, the development of behavioural states is disturbed in fetuses of nulliparous diabetic women.

Adult↗
PubMed1987

The blood flow velocity waveform in the fetal internal carotid and umbilical artery; its relation to fetal behavioural states in normal pregnancy at 37-38 weeks.

The relation between the blood flow velocity waveform in the fetal internal carotid artery (n = 12) and umbilical artery (n = 15) and fetal behavioural states at 37-38 weeks of gestation was studied. In the fetal internal carotid artery, under standardized fetal heart rate conditions, the pulsatility index (PI), as a measure of peripheral vascular resistance, was significantly lower during behavioural state 2F (active sleep) compared with state 1F (quiet sleep) according to the classification by Nijhuis et al. (1982), suggesting increased fetal cerebral blood flow during state 2F. In the umbilical artery, no significant difference in PI between the two behavioural states could be established. This suggests a fetal origin of the state dependency observed in fetal blood flow velocity waveforms.

Blood Flow Velocity↗
PubMed1986

Fetal behaviour in early pregnancy.

The emergence of embryonic and fetal movements in the first half of gestation is described. From their emergence onwards movements are specific and easily recognizable and during the course of gestation their appearance hardly changes; they closely resemble movement patterns observed in preterm and full-term newborn infants. Most of the movements described during the course of gestation have already emerged before 16 wk. The quantity of the distinct motor patterns undergoes several changes before 20 wk of gestation. This holds for their incidence and for their temporal sequence. The fact that fetal movements are specific and easily recognizable from their onset onwards makes them useful for assessing the development of the nervous system in normal and abnormal conditions.

Female↗
PubMed1986

Fetal behaviour in type-1 diabetic women.

Real-time ultrasound observation of fetal movement patterns can be used to assess the development of the motor component of the nervous system. Data are presented on the emergence of fetal movements in the first trimester of pregnancy, and on the development of fetal behavioural states in the third trimester, in women with type-1 (insulin dependent) diabetes. In the first trimester there is a delay in emergence of movement patterns. This delay is, however, not specific but parallels that of growth. In the third trimester there is a delay in emergence of fetal behavioural states. It is concluded that a tight metabolic control, achieved with continuous insulin infusion, does not prevent these disturbances in development.

Diabetes Mellitus, Type 1↗
PubMed1986

New perspectives in early human development.

A new hypothesis is presented concerning the maturation of the human nervous system and the duration of pregnancy. It has been found that many neural functions characteristic of the fetus continue after birth until a major transformation takes place at the end of the second postnatal month. From a comparative perspective the duration of pregnancy in man is relatively short among primates. An explanation may be found in metabolic constraint. The special energy demands of a large fetal nervous system and the build-up of a subcutaneous fat deposit may have prevented a proportional prolongation of pregnancy during evolution of hominids.

Animals↗