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Power spectral density measured from central cortical EEG recordings during sleep was compared in two groups of 20 infants each at intervals between 1 week and 6 months of age. One group consisted of siblings of infants who had previously... more
Power spectral density measured from central cortical EEG recordings during sleep was compared in two groups of 20 infants each at intervals between 1 week and 6 months of age. One group consisted of siblings of infants who had previously died of the sudden infant death syndrome, as determined by history and autopsy report (sibling group). The second group was made up of age, sex, and socioeconomically matched infants with no familial history of sudden infant death (control group).
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A device for recording eye movements from infants over long time periods is described. The device consists of an infrared light-emitting diode and a phototransistor mounted in a small package which covers one eye. The eyepiece is... more
A device for recording eye movements from infants over long time periods is described. The device consists of an infrared light-emitting diode and a phototransistor mounted in a small package which covers one eye. The eyepiece is insensitive to EEG, EKG, or EMG potentials, and avoids irritation of the infant's skin from application of electrode paste. Detection of eye movements compares favorably to conventional eye movement electrodes.
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This study examined fetal heart rate (FHR) variables during maternal sleep in subsequent siblings of infants who died of sudden infant death syndrome (SIDS) and who are thus at increased statistical risk for SIDS, and controls. Four... more
This study examined fetal heart rate (FHR) variables during maternal sleep in subsequent siblings of infants who died of sudden infant death syndrome (SIDS) and who are thus at increased statistical risk for SIDS, and controls. Four findings differentiated the tracings of subsequent siblings of SIDS infants and controls: 1) FHR variability in subsequent siblings of SIDS infants ranged between 11 and 25 beats/min, compared with 6 to 10 beats/min in controls (P less than .001). 2) Bradycardia was more frequent in subsequent siblings of SIDS infants. 3) FHR accelerations (more than 150 beats/min) followed by heart rates below 120 beats/min were elevated in subsequent siblings of SIDS infants (P less than .01). 4) Strong respiratory arrhythmia was more frequent in subsequent siblings of SIDS infants. These siblings exhibited more reactive FHR patterns. Although these data cannot be interpreted as clinical markers to identify the infant who will die of SIDS, they are compatible with the ...
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Infants at low and increased risk for sudden infant death syndrome (SIDS) from five clinical centers in the United States are being studied at home using a cardiorespiratory monitor that stores physiologic data surrounding detected events... more
Infants at low and increased risk for sudden infant death syndrome (SIDS) from five clinical centers in the United States are being studied at home using a cardiorespiratory monitor that stores physiologic data surrounding detected events and normative data unrelated to events. The monitor records breathing waveforms by inductance plethysmography (IP), and transthoracic impedance (TTT), ECG, beat-beat heart rate, hemoglobin
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Page 1. Sleep and Respiratory Control Dynamics 32.1-4 ONTOGENESIS OF ULTRADIAN BIOLOGICAL RHYTHMS Toke Hoppenbrouwers ... Dev Psychobiol 20A25-442, 1987 3. Hon EF, Lee ST: Electronic evaluation of the fetal heart rate. WI. ...
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Ultradian cycles constitute a broad spectrum in the hour, minute, second and millisecond domain (Hildebrandt 1986). This chapter is restricted to those in the hour and minute domain and, with few exceptions, the data reviewed and... more
Ultradian cycles constitute a broad spectrum in the hour, minute, second and millisecond domain (Hildebrandt 1986). This chapter is restricted to those in the hour and minute domain and, with few exceptions, the data reviewed and presented were derived from human infants. There are a number of issues which have been a part of the debate about rhythms in ontogeny. The first issue is unique to the immature organism and deals with functional equivalence. Quite simply, at what point when observing cyclic behaviours in utero reminiscent of behaviours in the newborn is one justified in asserting that these behaviours are functionally equivalent? It leads to such questions as: “is the foetus awake?” “when can the basic rest-activity cycle (BRAC) be first identified?” and “what is the true birthday of the circadian rhythm?” These questions currently have no definitive answers, although attempts have been made to specify the criteria by which preliminary conclusions are reached (Nijhuis et al. 1982).
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The normal succession of sleep and waking states through a night is disturbed in infants at risk for the sudden infant death syndrome. Compared with normal infants, siblings of the sudden infant death syndrome victims have longer... more
The normal succession of sleep and waking states through a night is disturbed in infants at risk for the sudden infant death syndrome. Compared with normal infants, siblings of the sudden infant death syndrome victims have longer intervals between active sleep epochs at particular times during the night in the newborn period and a decreased tendency to enter short waking periods at 2 and 3 months of age. The latter finding is interpreted as an increased tendency to remain asleep, or a relative failure to arouse from sleep in infants at risk.
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... Toke Hoppenbrouwers, JE Hodgman, K. Arakawa, DJ McGinty, J. Mason, RM Harper, MB Sterman. ... En conclusion, los patrones fisiológicos y de comportamiento fueron muy similares en los grupos estudiados pero las diferencias encontradas... more
... Toke Hoppenbrouwers, JE Hodgman, K. Arakawa, DJ McGinty, J. Mason, RM Harper, MB Sterman. ... En conclusion, los patrones fisiológicos y de comportamiento fueron muy similares en los grupos estudiados pero las diferencias encontradas merecen mayor investigación. ...
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The periodic organization of waking, quiet sleep, and active sleep was studied in control infants and siblings of victims of the Sudden Infant Death Syndrome. Spectral estimates of all-night binary state time series recorded at 1 week and... more
The periodic organization of waking, quiet sleep, and active sleep was studied in control infants and siblings of victims of the Sudden Infant Death Syndrome. Spectral estimates of all-night binary state time series recorded at 1 week and 1, 2, 3, 4, and 6 months of age revealed disturbed patterns of sleep states, especially in active sleep, from as early as the first week of life. These disruptions continued until at least 6 months of age. These data support the contention that the temporal patterning of sleep state can be used as an important neurologic marker for development.
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To document the incidence of transient episodes of bradycardia in a group of healthy term and preterm infants during the first 1 to 6 months of life. Longitudinal polysomnographic study. Sleep laboratory in a university-affiliated urban... more
To document the incidence of transient episodes of bradycardia in a group of healthy term and preterm infants during the first 1 to 6 months of life. Longitudinal polysomnographic study. Sleep laboratory in a university-affiliated urban medical center. Fourteen healthy term-born infants, nine preterm infants with apnea in the nursery, and 10 preterm infants without apnea. Infants with neonatal morbidity except apnea were excluded. Transient episodes of bradycardia (< or = 100 beats per minute) were identified in 2- to 4-hour early evening polysomnographic tracings. The relationship with apnea, transcutaneous oxygen levels, and sleep state was determined. Transient episodes of bradycardia to 60 to 70 beats per minute were common, but there were no drops below 50 beats per minute. The incidence of transient episodes of bradycardia was inversely related to heart rate. Results for apneic and nonapneic premature infants were similar. Transient episodes of bradycardia are considered normal reflex responses and are not related to risk for sudden infant death syndrome. These results have implications for the setting of monitor alarms.
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A new physiologic monitor for use in the home has been developed and used for the Collaborative Home Infant Monitor Evaluation (CHIME). This monitor measures infant breathing by respiratory inductance plethysmography and transthoracic... more
A new physiologic monitor for use in the home has been developed and used for the Collaborative Home Infant Monitor Evaluation (CHIME). This monitor measures infant breathing by respiratory inductance plethysmography and transthoracic impedance; infant electrocardiogram, heart rate and R-R interval; haemoglobin O2 saturation of arterial blood at the periphery and sleep position. Monitor signals from a representative sample of 24 subjects from the CHIME database were of sufficient quality to be clinically interpreted 91.7% of the time for the respiratory inductance plethysmograph, 100% for the ECG, 99.7% for the heart rate and 87% for the 16 subjects of the 24 who used the pulse oximeter. The monitor detected breaths with a sensitivity of 96% and a specificity of 65% compared to human scorers. It detected all clinically significant bradycardias but identified an additional 737 events where a human scorer did not detect bradycardia. The monitor was considered to be superior to conventional monitors and, therefore, suitable for the successful conduct of the CHIME study.
Research Interests: Biomedical Engineering, Medicine, Electrocardiography, Computers, Humans, and 13 morePhysiological, Heart rate, Infant, Medical Physiology, Impedance cardiography, Newborn Infant, Electrocardiogram, Oximetry, Ambulatory BP monitoring, Plethysmography, Electrical And Electronic Engineering, Respiratory Mechanics, and Respiratory function tests
To compare the risk factors of 153 cases of apparent life-threatening event (ALTE) enrolled in the multicenter Collaborative Home Infant Monitoring Evaluation (CHIME) from 1994 to 1998 with the published risk factors for sudden infant... more
To compare the risk factors of 153 cases of apparent life-threatening event (ALTE) enrolled in the multicenter Collaborative Home Infant Monitoring Evaluation (CHIME) from 1994 to 1998 with the published risk factors for sudden infant death syndrome (SIDS). Trained CHIME interviewers gathered histories of infants with ALTE who met the criteria. The following risk factors were analyzed: male predominance, gestational age, low birth weight, very low birth weight, incidence of small for gestational age (SGA), age at the event, multiparity, maternal age, and smoking. Population-based SIDS studies with >100 deaths, focusing on 1 or more pertinent risk factors and carried out during the decade in which CHIME data were collected, were chosen for comparison. One of the 153 infants with ALTE in this study died during follow-up (0.6%). CHIME ALTE differed significantly from SIDS in 4 respects: fewer infants with low birth weight and SGA at birth, fewer teenage pregnancies, and a younger infant age at ALTE. Although a number of risk factors for ALTE are similar to those for SIDS, the differences warrant a separate focus on ALTE beyond that on SIDS.
Research Interests: Pediatrics, Epidemiology, Comparative Study, Pregnancy, Humans, and 16 moreFemale, Male, Infant, Risk factors, Sudden Infant Death Syndrome, Newborn Infant, Risk Factor, Maternal Age, Infant Mortality, Sex Factors, Retrospective Studies, Risk Factors, Parity, Apnea, Sensitivity and Specificity, and Cohort Studies
Apneic episodes in normal 10-, 20-, and 40-day-old kittens were assessed with polygraphic recordings. End expiratory apneas, usually preceded by somatic activity and/or augmented breaths, with durations less than 10 sec were observed in... more
Apneic episodes in normal 10-, 20-, and 40-day-old kittens were assessed with polygraphic recordings. End expiratory apneas, usually preceded by somatic activity and/or augmented breaths, with durations less than 10 sec were observed in quiet sleep, active sleep, and transitions between states in all age groups. The highest apnea density was found at state transitions. Heart rate decelerations occurred before, during, and following apneas, but decelerations were not related to apnea duration. Combined central and obstructive components were associated with 9% of apneas in normal kittens.
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To examine (1) sleep architecture of infants at varied risk for sudden infant death syndrome, (2) delays or advances in preterm infants at term postmenstrual age, (3) whether ventilatory support and gestational age alter sleep, (4)... more
To examine (1) sleep architecture of infants at varied risk for sudden infant death syndrome, (2) delays or advances in preterm infants at term postmenstrual age, (3) whether ventilatory support and gestational age alter sleep, (4) whether steroids alter sleep, (5) confounding influences of sex, small for gestational age, and maternal smoking. Overnight polysomnography. Percentage of active sleep, quiet sleep, indeterminate, and awake time per total recording time; mean and longest duration of state epochs; number of episodes > or = 10 minutes; and sleep efficiency. Collaborative Home Infant Monitoring Evaluation (CHIME). Two hundred one preterm and 198 term infants between 33 and 58 weeks postmenstrual age during polysomnography. Fifty-one term infants with an apparent life-threatening event without known etiology (apnea of infancy), 59 subsequent siblings of babies who died of sudden infant death syndrome, and 88 healthy term infants. Tracings of infants with apnea of infancy a...
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Research Interests: Pediatrics, Humans, Female, Male, Infant, and 6 morePediatric, Periodicity, Newborn Infant, Time Factors, Apnea, and Sleep Stages
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To test the hypotheses that there is a lack of correlation between extreme events and epidemiologic risk factors for sudden infant death syndrome (SIDS), and if conventional events are normal, their numbers should increase once a... more
To test the hypotheses that there is a lack of correlation between extreme events and epidemiologic risk factors for sudden infant death syndrome (SIDS), and if conventional events are normal, their numbers should increase once a circadian decrease in breathing rate is established. In addition, the number of events should decrease with maternal smoking. Three outcome variables were derived from the Collaborative Home Infant Monitoring Evaluation (CHIME) of 1082 infants: (1) at least 1 extreme event lasting > or = 30 seconds, (2) at least 1 conventional event lasting > or = 20 seconds, and (3) being part of the 50% of infants with the most events. Multivariate logistic regression analyses found that extreme events were not statistically associated with any known SIDS risk factors and occurred less often during the early morning. Healthy term infants had significantly fewer of these events compared with preterm infants, subsequent siblings of infants with SIDS, and infants with an apparent life-threatening event, a finding that was not evident after 43 weeks (3 weeks postterm). Conventional events increased during the night, whereas maternal smoking was associated with a decrease in conventional events. Apneic episodes persisting for > or = 40 seconds occurred in 1.8% of the infants. Extreme events are associated with immaturity and do not seem to be immediate precursors of or causally related to SIDS.
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Abstract The objective of this study was to identify and quantify fetal and maternal heart rate (FHR, MHR) periodicities and to examine their interrelation as well as the relation of fetal cycles with the maternal REM-NREM sleep cycle.... more
Abstract The objective of this study was to identify and quantify fetal and maternal heart rate (FHR, MHR) periodicities and to examine their interrelation as well as the relation of fetal cycles with the maternal REM-NREM sleep cycle. Heart rate periodicities of the same ...