Sick call in pediatric residency programs: the chief resident perspective.
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Biomedical subjects
Publications and source records attributed to E L Zalneraitis.
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It is unknown whether the decreased cerebral blood flow seen in infants with a large patent ductus arteriosus is associated with cerebral dysfunction. Decreased cerebral blood flow in adult human and animal models has been associated with altered electroencephalography (EEG), spectral-analyzed EEG, and EEG response to photic stimulation. Cerebral blood flow velocity, EEG, spectral analysis of EEG, and photic alteration of EEG spectra were evaluated in 8 infants before and after closure of a significant patent ductus arteriosus and in 10 control infants without a patent ductus arteriosus. All infants with patent ductus arteriosus had moderate or large shunts associated with a 25% mean reduction in cerebral blood flow velocity. There were no differences, however, in EEG, spectral analysis of EEG, or photic alteration of the spectral analysis for these infants before and after patent ductus arteriosus closure as compared to controls. It is concluded that the degree of decreased cerebral blood flow in infants with a significant patent ductus arteriosus is not sufficient to cause measurable alteration in electrocortical activity.
To determine the prevalence of clinically significant nervous system disease attributable to transplacental transmission of Borrelia burgdorferi, we surveyed neurologists in areas of the United States in which Lyme disease is endemic (i.e., Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Wisconsin, and Minnesota). Overall, 162 of the 176 (92%) pediatric neurologists contacted responded to the survey with a range of 90-100% in the different geographic areas. One pediatric neurologist was following 3 children who were labeled as having "congenital Lyme disease," but none of the 3 met our case definition. None of the other pediatric neurologists surveyed had ever seen a child whose mother had been diagnosed as having Lyme disease during pregnancy. Similarly, none of the 37 adult neurologists in Connecticut surveyed had ever seen a child whose mother had been diagnosed as having had Lyme disease during pregnancy. We conclude that congenital neuroborreliosis is either not occurring or is occurring at an extremely low rate in areas endemic for Lyme disease.
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Five preterm infants who had episodes of conjugate downward gaze 2-3 months after birth were evaluated. Three were extremely preterm, born at 22-25 weeks gestation, and 2 were twins, born at 28 weeks gestation. In all patients, multiple, brief episodes of downward gaze occurred daily, with each lasting for several seconds. In 3 infants, downward gaze occurred more often with stimulation, while in another it occurred more frequently prior to feeding. There was never an associated change in vital signs, level of consciousness, muscle tone, or focal neurologic deficit. All infants had bronchopulmonary dysplasia. Neuroimaging studies were normal in 3 patients and demonstrated nonspecific abnormalities in 2. At follow-up (6 1/2-34 months corrected age), intermittent downward gaze had completely resolved in 3 infants and was decreased in frequency and severity in the youngest 2. Four infants had normal development and neurologic examinations, while 1 child demonstrated mildly increased asymmetric muscle tone with normal development. Intermittent tonic downward gaze can be seen in extremely preterm infants who subsequently have normal development, and may represent a maturational delay in upward gaze reflex systems.
Previous studies in the fetal lamb have demonstrated that hyperglycemia stimulates the fetal metabolic rate. The present study examined the effects of chronic fetal hyperglycemia on fetal cerebral metabolic rate and electrocortical activity. Nine chronically instrumented fetal lambs had measurements of cerebral blood flow and cerebral uptake/excretion of oxygen, glucose, lactate, and beta-hydroxybutyrate taken before and during a 48-h fetal glucose infusion. Electrocortical activity was also recorded. The fetal arterial glucose concentration was 19.8 +/- 2.0 mg/dl before glucose infusion and 48 +/- 4.5 to 54.6 +/- 6.6 mg/dl during the infusion period. Cerebral blood flow and cerebral glucose and oxygen uptake increased by 219, 209, and 171%, respectively, by the end of the infusion period. There was a linear relationship between the fetal arterial glucose concentration and cerebral blood flow and cerebral glucose and oxygen uptakes. The electroencephalogram showed significant slowing with increases in the cerebral metabolic rate. These findings suggest that fetal hyperglycemia is associated with significant metabolic stimulation of the brain.
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In contrast to previous investigations, a recent study of polycythemic lambs suggested that cerebral glucose delivery (concentration x blood flow), not arterial glucose concentration, determined cerebral glucose uptake. In the present study, the independent effects of arterial glucose concentration and delivery on cerebral glucose uptake were examined in two groups of chronically catheterized newborn lambs (control and polycythemic). Arterial glucose concentration was varied by an infusion of insulin. CBF was reduced in one group of lambs (polycythemic) by increasing the hematocrit. At all arterial glucose concentrations, the cerebral glucose delivery of the polycythemic group was 59.6% of the control group. At arterial glucose concentrations of greater than 1.6 mmol/L, cerebral glucose uptake was constant and similar in both groups. At arterial glucose concentrations of less than or equal to 1.6 mmol/L, cerebral glucose uptake was unchanged in the control group, but was significantly decreased in the polycythemic group. In contrast, the cerebral glucose uptake was similar in both groups over a broad range of cerebral glucose delivery values. At cerebral glucose delivery values less than or equal to 83 mumols/min/100 g, there was a significant decrease in cerebral glucose uptake in both groups. During periods of low cerebral glucose delivery and uptake, cerebral oxygen uptake fell in the control group but remained unchanged in the polycythemic group. Maintenance of cerebral oxygen uptake in the polycythemic group was associated with an increased extraction and uptake of lactate and beta-hydroxybutyrate. We conclude that cerebral glucose delivery, not arterial glucose concentration alone, determines cerebral glucose uptake.
A child with typical histopathologic changes of Leigh's subacute necrotizing encephalomyelopathy presented with a chronic demyelinating neuropathy. During her 11-year course, she developed an unusual myopathy and cardiomyopathy in addition to many of the previously described manifestations of Leigh's disease. Despite an extensive evaluation, the biochemical basis of her condition was never identified. This case demonstrates another unique constellation of clinical alterations associated with subacute necrotizing encephalomyelopathy, and that chronic demyelinating neuropathy can be an important initial presentation of the disease.
Eight infants with severe early infantile spinal muscular atrophy diagnosed by clinical presentation and muscle biopsy were studied. The extent of alterations in muscle histology, histochemistry, and ultrastructure did not reflect the relative severity of the clinical presentation or the course of the illness. In seven biopsies, ultrastructural studies demonstrated empty sleeves of basal lamina projecting from the surface of small myofibers. We conclude that severe infantile spinal muscular atrophy often results in myofiber atrophy similar to that found in other motor neuron diseases, and it is not solely a hypotrophic process. Muscle biopsy findings are important because they help to establish the diagnosis, but they do not help predict the severity of disease among infants with this condition.
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Serial neurosonography was performed in 210 high-risk, preterm neonates. Eleven (5.8%) demonstrated small cystic formations in the subependymal lining of the lateral ventricles. These subependymal cysts were unilateral and were detected at the exact site of a previous subependymal hemorrhage in two cases. These 11 infants were not significantly different in maturity, size, or clinical parameters from our main high-risk newborn population. Ten survivors had marked motor retardation at follow-up ages of 9-13 months, and one died from neonatal sepsis.
The distribution of substance P and leucine-enkephalin in selected regions of brain obtained postmortem from patients with Huntington's disease and from neurologically normal persons has been studied with immunocytochemical techniques. In the normal brain, substance P immunoreactivity was identified in medium-sized neurons in the neostriatum, in neurons of the external segment of the globus pallidus, and in fine fibers in teh neostriatum, inner segment of the globus pallidus, and in the pars reticulata of the substantia nigra. Huntington's disease brains all exhibited a marked decrease in substance P fiber density in the substantia nigra and globus pallidus. A few medium-sized neurons with substance P immunoreactivity remained in the neostriatal remnant. Leucine-enkephalin immunoreactive processes were present throughout the neostriatum of normal brain, and were densely packed in the external segment of the globus pallidus and in the substantia nigra. A uniform population of medium-sized neurons containing immunoreactive leucine-enkephalin was present in the caudate and putamen. By contrast, in the Huntington's disease brains there was a marked diminution of fiber staining in the globus pallidus and substantia nigra. A few medium-size neurons and sparse fibers with leucine-enkephalin immunoreactivity persisted in the atrophic neostriatum. These observations are consistent with previous reports of regional peptide concentrations in both normal and Huntington's disease brain. Cells containing substance P and leucine-enkephalin immunoreactivity persist in the basal ganglia in brains from patients with Huntington's disease, and we have no evidence that cellular content of one or the other peptide is associated with disproportionate cell death or survival.
Three cases of choreoathetosis which developed during phenytoin therapy in children less than 2 years of age are described. The most striking clinical manifestations included the sudden onset of restlessness and agitation with superimposed choreoathetosis. None of these children had toxic levels of phenytoin in the blood. Discontinuation of phenytoin resulted in prompt cessation of the symptoms. Phenytoin-induced choreoathetosis should be a diagnostic consideration in children with a preexisting CNS insult who manifest violent choreoathetosis during therapy for seizure control. This consideration is especially pertinent in the pediatric intensive care unit, where other more common causes of agitation could be misdiagnosed.
We examined the pathologic findings in four infants of mothers with myotonic dystrophy. Four of the anomalies present in these infants (nesidioblastosis, renal blastema, cryptorchidism, and patent ductus arteriosus) represent persistence of fetal organ structures or configurations. We suggest that a maturational defect may be present not only in muscle, but also in other tissues.
This is a report of an infant with cutaneous hemangiomas who underwent successful resection of an extensive hemangioma of the liver as well as multiple intestinal hemangiomas. Later, he developed hydrocephalus due to a cerebellar cystic hemangioblastoma. This case documents the usefulness of cranial computed tomography (CCT) in determining the extent of involvement in disseminated neonatal hemangiomatosis.