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Biomedical subjects

L R Ment

Publications and source records attributed to L R Ment.

At least 91 records · Page 5Linked to original sources

Postpartum perfusion of the preterm brain: relationship to neurodevelopmental outcome.

Bayley developmental assessments were performed at 12 months corrected age on 11 preterm infants, all of whom had undergone 133-Xenon cerebral blood flow measurements (CBF) on the 1st day of life and neonatal computerized tomography scans for the detection of intraventricular hemorrhage. The Bayley mental index was found to vary as a quadratic function of CBF to the left hemisphere, with moderate CBF values associated with more favorable outcomes than either low or high CBF values.

Cerebral Hemorrhage↗

Beagle puppy model of intraventricular hemorrhage: randomized indomethacin prevention trial.

The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). By randomized computerized design, indomethacin, a known inhibitor of prostaglandin synthetase, was administered to newborn beagle puppies, all of which underwent the experimental model of hemorrhagic hypotension followed by volume reexpansion for the production of IVH, to determine whether indomethacin can prevent intraventricular hemorrhage in this model. Nine percent of all pups receiving indomethacin experienced intraventricular hemorrhage, compared with 80% of animals who received the saline vehicle. In addition, significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult were noted in this group when compared with control animals.

Animals↗

Evaluation of level of consciousness by the Glasgow coma scale in children with Reye's syndrome.

The Glasgow Coma Scale, which was designed to evaluate level of consciousness after head trauma, has been compared to the Lovejoy scale in 21 patients with Reye's syndrome. Like other investigators, we have noted a poorer prognosis in those patients with higher peak NH3 levels and rapid progression of disease. However, we have also noted that the Glasgow coma scale provides a better, earlier indicator of progressive central nervous system disease than the Lovejoy scale and, therefore, helps physicians caring for such patients to institute intracranial pressure (ICP) monitoring and vigorous measures for the control of elevated ICP earlier than they might otherwise.

Child↗

Beagle puppy model of intraventricular hemorrhage. Effect of indomethacin on cerebral blood flow.

The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). A study was designed to determine if indomethacin can prevent IVH and if indomethacin would produce changes in cerebral blood flow (CBF). Newborn beagle puppies were randomized by computer into two groups: one was pretreated with indomethacin, a known inhibitor of prostaglandin synthetase, and the other was saline. The dogs in both groups were then assigned either to undergo hemorrhagic hypotension/volume reexpansion insult or to receive no insult. Twenty percent of all pups receiving indomethacin and undergoing the insult experienced IVH, compared to 71% of the pups undergoing insult that had been pretreated with saline. Significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult were noted in the former group compared to the saline-pretreated pups subjected to insult. Finally, employing carbon-14 autoradiography for the determination of CBF, it was demonstrated that indomethacin decreases resting CBF of the newborn beagle pups and, in indomethacin-pretreated animals subjected to insult, prevents the increases in CBF seen in the saline-pretreated traumatized pups.

Animals↗

Beagle puppy model of intraventricular hemorrhage.

Intraventricular hemorrhage (IVH) is a major neurological problem of the preterm infant and originates in the germinal matrix tissues of the developing brain. The newborn beagle pup has been demonstrated to provide an excellent model for this neonatal neuropathological condition. By the production of hemorrhagic hypotension followed by relative volume reexpansion, such hemorrhages can be produced in this animal. Carbon-14 (14C)-iodoantipyrine was used for measuring the cerebral blood flow in this experimental model and demonstrated that, although the germinal matrix is a relatively low-flow area in the newborn beagle pup, the selective flow to this region increases significantly in animals with IVH.

Animals↗

Local cerebral glucose utilization in the beagle puppy model of intraventricular hemorrhage.

Local cerebral glucose utilization has been measured by means of carbon-14(14C)-autoradiography with 2-deoxyglucose in the newborn beagle puppy model of intraventricular hemorrhage. Our studies demonstrate gray matter/white matter differentiation of uptake of 14C-2-deoxyglucose in the control pups, as would be expected from adult animal studies. However, there is a marked homogeneity of 14C-2-deoxyglucose uptake in all brain regions in the puppies with intraventricular hemorrhage, possibly indicating a loss of the known coupling between cerebral blood flow and metabolism in this neuropathological condition.

Animals↗

A scale for the assessment of neonatal neurologic status.

We have described early experience with the neonatal arousal scale. The infant's best response to bell and light are assessed and scored in addition to the observation of his spontaneous motor activity or response to tactile stimulation. This approach offers the prospect that rapid, reliable, and repetitive neurologic assessment may be carried out by all levels of personnel caring for small and critically ill neonates. The results of our experience in 100 consecutive patients who survived longer than 24 have been reported.

Arousal↗

Absence of hydrocephalus despite disproportionately increasing head size after the neonatal period in preterm infants with known intraventricular hemorrhage.

Of a group of 20 infants weighing less than 1,250 g at birth and surviving with intraventricular hemorrhage (IVH) documented by computed tomography, 6 exhibited excessive head growth between 6 and 14 weeks after birth with no evidence of neurologic deterioration. Repeat computed tomography was normal in all 6 infants. Rapid head growth after the immediate neonatal period can be expected in some infants with a history of lesser degrees of IVH and is not in itself indicative of posthemorrhagic hydrocephalus.

Cephalometry↗

Benign enlargement of the subarachnoid spaces in the infant.

The authors report 18 infants with benign enlargement of the subarachnoid spaces seen at their institution during a 1-year time interval. This condition is characterized by the computerized tomography findings of dilatation of the subarachnoid spaces, normal or slightly enlarged ventricular size, and prominence of the basilar cisterns. Most cases were found in children referred for the evaluation of abnormally increasing head circumference measurements. Although it was not possible to document the development, and, in several cases, improvement of this process, in these patients enlargement of the subarachnoid spaces was a benign diagnosis, not associated with serious neurological dysfunction.

Head↗

Alterations in cerebral blood flow in preterm infants with intraventricular hemorrhage.

Xenon-133 inhalation hemispheric cerebral blood flow (HCBF) determinations at one to two days and four to six days postnatally and at 37 weeks postconceptual age have been correlated with computed tomography (CT) scan and autopsy findings in 15 preterm infants weighing less than 1,250 gm at birth. Ten of these infants had germinal matrix hemorrhages (GMH) or intraventricular hemorrhages (IVH). Although HCBF obtained at one to two days showed no mean difference between the GMH/IVH group and the nonhemorrhage infants, hemispheric flow ratios showed significant discrepancies in the GMH/IVH group. In addition, in four of five patients in whom the hemorrhage appeared asymmetric on CT scan, the side of higher flow correlated with the hemorrhage. At four to six days HCBF showed a lower mean value in the GMH/IVH patients than in the nonhemorrhage patients and differences in the interhemispheric ratios in the GMH/IVH group persisted. There were no differences in the mean HCBF values or hemispheric ratios between the two groups of infants at 37 weeks postconceptual age.

Cerebral Hemorrhage↗

A follow-up study of very low-birthweight infants receiving ventilatory support by face mask.

Recent evidence has suggested that face-mask ventilation of very low birthweight (VLBW) infants may have serious neurological consequences. The 30 surviving VLBW infants from the neonatal intensive care unit at Hammersmith Hospital who had received ventilatory support via face masks over a 25-month period have been reviewed and compared with a control group. Neuropathological findings in the VLBW infants who died during this time have also been reviewed in relation to their ventilatory management. The findings suggest that face-mask treament did not have a major deleterious effect on the surviving infants. The factors which may determine the neurological sequelae of this form of ventilatory support are discussed.

Brain Diseases↗

Evaluation of complicated migraine in childhood.

We report on 3 patients with complicated migraine of childhood. Family history was positive for migraine in each case, and all experienced the acute onset pf neurologic deficits in associated with throbbing hemicranium. Abnormalities of cerebral blood flow determinations, electroencephalograms and cerebral arteriograms in addition to persistent neurologic sequelae were demonstrated. We propose that complicated migraine of childhood is not an entirely benign symptom complex.

Adolescent↗

The treatment of pneumopericardium in the newborn infant.

Pneumopericardium with cardiac tamponade is a life-threatening emergency in the newborn infant. The case fatality rate is high (75% in 41 documented cases in the English literature), and diagnosis often delayed (in 13 of 29 deaths the pneumopericardium was diagnosed postmortem). Treatment is frequently unsatisfactory, and recurrence of the pneumopericardium with tamponade is likely after initial pericardial needle aspiration--an incidence of 53%. A case of pneumopericardium in a critically ill newborn is reported; the details of successful management, using a large bore intrapericardial catheter with continuous drainage, are discussed.

Cardiac Catheterization↗

Neurodevelopmental assessment of very low birth weight neonates: effect of germinal matrix and intraventricular hemorrhage.

During a recent 36-month interval, all neonates of less than or equal to 1250 gram birth weight who were admitted to our Newborn Special Care Unit and survived the first 36 postnatal hours underwent either computed tomography or echoencephalography or both for the assessment of neonatal germinal matrix hemorrhage and intraventricular hemorrhage. Seventy of the 164 long-term surviving infants experienced neonatal germinal matrix and/or intraventricular hemorrhage (GMH/IVH Group), whereas 94 infants had studies that were negative (Non-hemorrhage Group). Serial neurodevelopmental assessments were performed on 142 (87%) of the 164 long-term surviving infants; these assessments included the Bayley Scales of Infant Development at 3, 6, 12, and 18 months (corrected age) and the Stanford-Binet and Peabody Picture Vocabulary examinations at 30 months (corrected age). At 30 months (corrected age), the incidence of major neurologic abnormalities was extremely low in both the GMH/IVH and the Non-hemorrhage groups. In addition, although there were few survivors of the more severe grades of intraventricular hemorrhage, we could detect no difference between the developmental scores of the GMH/IVH and the Non-hemorrhage Group infants.

Brain Damage, Chronic↗

Bacterial meningitis as an etiology of perinatal cerebral infarction.

Despite significant improvement in mortality rate, survivors of neonatal bacterial meningitis experience a significant incidence of neurodevelopmental sequelae. Neuropathologic studies have demonstrated vasculitis, arachnoiditis, and ventriculitis with secondary edema and encephalomalacia. Areas of cerebral infarction, most commonly thought to be venous in origin, have been reported as well. We performed cranial computed tomographic scans on all eight neonates with bacterial meningitis admitted to our Newborn Special Care Unit within the past 36 months and demonstrated abnormalities in seven. Six of these infants were found to have large areas of infarction related primarily to major arterial vascular distributions. We suggest computed tomographic studies for all neonates with bacterial meningitis and subsequent scans at 4-6 months of age in those with abnormal neonatal scans in order to plan better for early intervention services.

Bacterial Infections↗