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Biomedical subjects

N Paneth

Publications and source records attributed to N Paneth.

At least 73 records · Page 4Linked to original sources
PubMed1994

Sonographic diagnosis of cisternal subarachnoid hemorrhage in the premature infant.

PURPOSE: To evaluate sonographic criteria for the diagnosis of subarachnoid, and particularly cisternal, hemorrhage in the preterm infant. METHODS: The subarachnoid cisterns were studied on cadaveric anatomic sections and on postmortem ultrasonograms, as well as on in vivo ultrasonograms of healthy neonates. Based on the normal ultrasound appearances of these cisterns, criteria were developed for the recognition of abnormal cisternal fluid collections, which strongly suggest the presence of subarachnoid hemorrhage in the premature infant. These criteria were evaluated prospectively in a group of 63 preterm infants who underwent subsequent autopsy. RESULTS: In the 63 infants with neuropathologic verification, increased echogenicity and/or increased echo-free content of the subarachnoid cisterns correctly predicted subarachnoid hemorrhage with an accuracy of 75%, sensitivity of 69%, and specificity of 93%. The positive and negative predictive values were 97% and 46%, respectively. In 47% of the cases, ultrasound correctly detected cisternal subarachnoid hemorrhage before intraventricular hemorrhage could be diagnosed. CONCLUSION: A highly specific, although somewhat insensitive, sonographic diagnosis of subarachnoid hemorrhage can be made from the appearance of the subarachnoid cisterns. The diagnosis of subarachnoid hemorrhage may predate the ultrasound diagnosis of intraventricular hemorrhage and may alert the neonatologist to the need for follow-up sonograms in the absence of ultrasound evidence of intraventricular hemorrhage.

Cisterna Magna↗
PubMed1993

Incidence and timing of germinal matrix/intraventricular hemorrhage in low birth weight infants.

Incidence and time of onset of germinal matrix/intraventricular hemorrhage (GM/IVH) were prospectively ascertained in 1,105 infants weighing < or = 2,000 g at birth, a cohort comprising about 85% of all births of that weight born from September 1984 to June 1987 in the central New Jersey counties of Ocean, Monmouth, and Middlesex. Cranial ultrasonography was performed as nearly as possible to age 4 hours, 24 hours, and 7 days. Each scan was reviewed by two independent readers and, if necessary, a third; consensus was achieved on scan of first diagnosis of GM/IVH in 965 of the 1,079 infants with assessable scans. The cumulative incidence of GM/IVH in the first week of life was 24.6% (265/1,079). In the 965 infants with consensus diagnoses, the first scan, at 4.9 +/- 2.2 hours, yielded the highest incidence--10.6% (95/899). Incidence by the second scan (25.1 +/- 4.9 hours) was 6.0% (49/813), and by the third scan (7.2 +/- 0.8 days), 9.0% (64/715). The iterative algorithm for interval-censored data developed by Turnbull (J R Stat Soc [B] 1976;8:290-5) was used to estimate the most likely time of onset based on time of first diagnosis. From 34% to 44% of hemorrhages were present at the first opportunity to scan, which in these data was at age 1 hour. At least a third of GM/IVH in infants < or = 2,000 g appears to be of congenital or immediate postnatal onset.

Age Factors↗
PubMed1993

Neurobehavioral effects of power-frequency electromagnetic fields.

Some laboratory experiments have suggested that power-frequency electric and magnetic fields (EMF) may be capable of influencing calcium efflux from cell membranes, pineal function, and circadian rhythms. As yet, however, no consistent, replicable laboratory model has been developed for any of these effects. Most assessments of human volunteers exposed to EMF have been negative, but occasional effects on vigilance or alertness and some modest effects on circadian rhythmicity have been reported. Several carefully performed studies of workers occupationally exposed to high electric-field strengths have failed to find effects on behavior or cognitive functioning. Although the bulk of human research on the effects of EMF on cognitive performance is negative, there has been less assessment of behavior and psychiatric symptomatology. Because some studies, in both humans and animals, have described effects of EMF on circadian rhythms, future research might concentrate profitably on the assessment of EMF in relation to depression and other cyclically mediated psychiatric disorders.

Animals↗
PubMed1993

Impact of improved survival of very low birth weight infants on recent secular trends in the prevalence of cerebral palsy.

OBJECTIVE: To review recent secular trends in the prevalence of cerebral palsy in industrialized countries that have population-based cerebral palsy registries and to estimate such time-trends for the United States, where until recently such registries were absent. DATA SOURCES: Recent epidemiologic studies of cerebral palsy published in peer-reviewed journals in English, and US vital data bearing on the principal demographic determinants of cerebral palsy--birth rates, the birth weight distributions, birth weight-specific mortality risk, and cerebral palsy risk among survivors. RESULTS: Most epidemiologic studies from industrialized countries show a rise in the childhood prevalence of cerebral palsy in recent decades, largely because of the increasing contribution of children of low and very low birth weight to its prevalence. The only demographic determinant of cerebral palsy prevalence that is changing rapidly in the United States is survival of low birth weight and very low birth weight infants. Based on the magnitude of change in the survival of low and very low birth weight infants, it is estimated that childhood prevalence of cerebral palsy rose about 20% between 1960 and 1986 in the United States. CONCLUSION: An apparently unavoidable side effect of the increasing success of newborn intensive care is a moderate rise in the childhood prevalence of cerebral palsy.

Australia↗
PubMed1993

Electronic fetal monitoring and later outcome.

The principal rationale for the almost universal use of electronic fetal monitoring (EFM) in labor is that its use can effectively prevent the full expression of brain-damaging birth asphyxia by timely intervention in labor. This central hypothesis of EFM has never been adequately tested, in part because of the difficulty of obtaining a large enough sample. However, for this hypothesis to be true, 3 simpler conditions must be met. The first is that EFM be reliable, i.e., that substantial inter-observer agreement exist as to the identity and meaning of EFM patterns. The second is that EFM be valid, i.e., that one or more EFM patterns be statistically associated with the adverse neurological outcome to be prevented. The third condition is that if EFM and adverse outcome are related, the association is causal. A review of the literature indicates that none of these 3 conditions has been met thus far. Future research should concentrate on establishing the reliability and validity of specific EFM patterns; only those patterns truly predictive of adverse outcome and detectable by most practitioners are worth considering as indicators for intervention in labor.

Asphyxia Neonatorum↗
PubMed1993

The causes of cerebral palsy. Recent evidence.

Cerebral palsy (CP), unlike many other neurodevelopmental disorders, is associated with abnormalities of pregnancy and birth, particularly 'birth asphyxia' and low birthweight. Associations, however, need not be causal, and some prenatally damaged infants manifest clinical signs suggestive of birth asphyxia in the perinatal period. The lack of a clinically reliable indicator of impaired fetal-placental gas exchange limits our confidence that birth asphyxia plays a true causal role in cerebral palsy. Premature delivery is the single most important antecedent of cerebral palsy, and the increase in survival of very small infants resulting from newborn intensive care may augment this contribution in the future. Cranial ultrasound imaging can describe patterns of neonatal brain damage in the low birthweight infant that are highly predictive of later cerebral palsy. Future research on the causes of cerebral palsy may benefit from improvements in the neurological assessment of the fetus prior to labor and from a clearer understanding of the role of endocrine factors, particularly thyroid disorders, in neurologic development.

Asphyxia Neonatorum↗
PubMed1992

The central New Jersey neonatal brain haemorrhage study: design of the study and reliability of ultrasound diagnosis.

Over a 34-month period, 1105 newborns weighing between 501 and 2000 g at birth were enrolled in a prospective study of the aetiology and consequences of neonatal brain haemorrhage. The three participating hospitals care for approximately 85% of births in the study weight range in Middlesex, Monmouth and Ocean counties, New Jersey. Cranial ultrasonographic imaging through the anterior fontanelle was carried out a mean age of 4.9 +/- 2.2 hours, 25.5 +/- 4.8 hours and 7.2 +/- 0.8 days to detect haemorrhage and other brain lesions. In 93.2% of study infants, scans were read by two independent expert readers (blind to the clinical status of the child) with submission of the scan to a third reader in cases of disagreement. Confirmation of both presence or absence and, when present, scan of first diagnosis of germinal matrix and/or intraventricular haemorrhage (GM/IVH) by two independent readers was achieved in 76.3% of study infants. The first two readers agreed as to presence or absence of GM/IVH in 82.4% of infants (Kappa = 0.56). Interobserver agreement was affected by the reported scan quality and by the number of scans available, but not by the hospital of origin, race or birthweight of the infant.

Birth Weight↗
PubMed1991

The reliability of neonatal head circumference measurement.

Interobserver reliability in head circumference measurement was assessed in a cohort of 1105 low birthweight (less than or equal to 2000 g) infants enrolled in a study of brain hemorrhage. In 927 (83.9%) subjects, head circumference was measured both by a pediatric resident or admitting pediatrician, and by a trained ultrasound technologist. The Pearson correlation coefficient for these two sets of measurements was 0.934 (p less than 0.01), and the intraclass correlation coefficient was 0.933. By contrast, analysis of differences revealed that the limits of agreement were from -1.99 to 2.03 cm, indicating that 5% of measurements differed by 2 cm or more. Using clinicians' measurements as the gold standard, ultrasound technologists detected abnormal head circumferences with a sensitivity of 91.2%, a specificity of 97.2%, and a positive predictive value of 88.0%. For clinical purposes this level of reliability may be acceptable, but in research studies this degree of misclassification would lead to attenuation of the odds ratio.

Anthropometry↗
PubMed1990

Racial differences in pregnancy duration and its implications for perinatal care.

The average length of gestation is about 5 days shorter in black populations than in white populations. Although some of this difference is accounted for by higher preterm delivery rates in blacks, the most common gestational week of delivery at term is the 39th in black populations, the 40th in white. Black gestational age specific neonatal mortality is lower than that of whites until the 37th week of gestation, but higher thereafter. These observations suggest the hypothesis that complications of postmaturity occur sooner in black fetuses. If this hypothesis is confirmed, antepartum surveillance for signs of fetal compromise should be initiated earlier in gestation in black parturients, perhaps by setting the estimated date of confinement at 275 days after the LMP, rather than the conventional 280 days.

Black People↗
PubMed1990

White matter damage in preterm newborns--an epidemiologic perspective.

Prior to 1980, white matter abnormalities of the preterm newborn were known exclusively as pathological entities, but now cranial ultrasonography can image white matter abnormalities in life. Ultrasonographic white matter echodensities and echolucencies in low birthweight babies predict later handicap (especially cerebral palsy) more accurately than any other antecedent. With the increased availability of high resolution cranial ultrasonography and the improved skill in obtaining and reading cranial ultrasonograms, rapid gains can be expected in our understanding of white matter disorders. These advances are likely to be made in the diagnosis and classification of white matter disorders and in their epidemiologic and prognostic features, topics explored in this review.

Brain↗
PubMed1990

White matter necrosis in very low birth weight infants: neuropathologic and ultrasonographic findings in infants surviving six days or longer.

We describe the neuropathologic and ultrasonographic findings in 22 very low birth weight infants (mean weight 948 gm) who survived at least 6 days and for whom cranial ultrasonography had been performed three or more times in life. White matter necrosis was found in 15 of the 22 subjects and was judged chronic (5 days' duration or longer) in seven subjects. The most common pattern was diffuse necrosis of hemispheric white matter, found in 10 of 15 infants; restriction of necrosis to the periventricular region was found in only three infants. The classic histologic features of periventricular leukomalacia were absent from 7 of the 15 infants with necrosis. Seventeen infants had intraventricular hemorrhage, but extension of ventricular blood into white matter unaffected by infarction was not found. Two ultrasonographic features were associated with white matter necrosis: increased parenchymal echogenicity and ventricular enlargement. One or both of these findings were present in 67% of infants with white matter necrosis, in 90% of infants with diffuse necrosis, but in no infant without necrosis. Increased parenchymal echogenicity was seen in all four infants with hemorrhagic necrosis, in 60% of infants with diffuse necrosis, but in none of the five infants with localized necrosis. We conclude that the very small infants now dying in nurseries have a form of white matter damage that is more extensive than, and in some cases histologically different from, periventricular leukomalacia as originally described. Ultrasonography as used in this study identified most but not all infants with pathologically verified white matter necrosis.

Brain↗
PubMed1990

Neonatal cranial ultrasound abnormalities: association with developmental delay at age one in low birth weight infants.

Relationships between abnormalities on neonatal serial cranial ultrasound and cognitive development at age one year were examined in 153 low birth weight (LBW) infants. Infants with complex injury (persistent parenchymal echogenicity, lucency, or persistent ventricular enlargement) scored significantly lower on the Bayley Mental Development Index than noninjured infants. Nine of 11 infants with complex injury had severe developmental delay in contrast to 3/110 of the noninjured. Adjusting for birth weight, gestational age, head circumference and social class, infants with complex injury were 33 times more likely to be severely delayed than noninjured infants. Risk for severe delay associated with LBW appeared to be indirect, through increased probability of ultrasonographic abnormality. The poorest developmental outcome was seen in infants with both complex perinatal brain injury and either very LBW or very young gestational age. However, very LBW infants with normal neonatal ultrasounds were at negligible risk for severe delay at age one.

Birth Injuries↗