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Biomedical subjects

R W Coen

Publications and source records attributed to R W Coen.

At least 19 recordsLinked to original sources
PubMed1993

Electroencephalographic and neuroimaging findings in neonates undergoing extracorporeal membrane oxygenation.

Electroencephalograms (EEGs) were recorded on 36 infants who were treated with arteriovenous extracorporeal membrane oxygenation (ECMO) between 1986 and 1989. Twelve of 36 infants had EEGs prior to and during ECMO. Twenty-one infants who met ECMO criteria but were treated with mechanical ventilation only served as a comparison (COMP) group. Electrographic seizures occurred in 7 of the 36 (19%) ECMO patients and in 3 of the 21 (14%) COMP patients. Five of 7 ECMO infants had electrographic status epilepticus. Three infants developed electrographic seizures during ECMO in association with an acute cerebral injury. These patients did not have significant hemispheric predominance in the origin of electrographic seizures (2 right, 3 left and 2 bilateral). Repetitive or periodic discharges (RPD) with frequencies between 0.5 and 5 Hz were seen after starting therapy in 23 of the 36 (64%) ECMO patients and 15 of the 21 (71%) of the COMP group. Only in the ECMO patients did RPD arise significantly more frequently from the right hemisphere (13 right, 4 left and 6 bilateral; p = 0.015). Neuroimaging studies showed evidence of ischemic lesion in 8 of the 36 (22%) ECMO patients with significantly right-sided predominance (5 right, 1 left and 2 bilateral; p = .05). Cerebellar hemorrhages occurred in 3 ECMO patients. Ischemic lesions occurred in 3 of the 21 (14%) COMP patients, all occurring on the left side. In the ECMO group, severe outcome or death was significantly associated with the presence of electrographic seizures, status epilepticus, and suppression-burst pattern (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Injuries↗
PubMed1992

Detection of neonatal seizures through computerized EEG analysis.

Neonatal seizures are a symptom of central nervous system disturbances. Neonatal seizures may be identified by direct clinical observation by the majority of electrographic seizures are clinically silent or subtle. Electrographic seizures in the newborn consist of periodic or rhythmic discharges that are distinctively different from normal background cerebral activity. Utilizing these differences, we have developed a technique to identify electrographic seizure activity. In this study, autocorrelation analysis was used to distinguish seizures from background electrocerebral activity. Autocorrelation data were scored to quantify the periodicity using a newly developed scoring system. This method, Scored Autocorrelation Moment (SAM) analysis, successfully distinguished epochs of EEGs with seizures from those without (N = 117 epochs, 58 with seizure and 59 without). SAM analysis showed a sensitivity of 84% and a specificity of 98%. SAM analysis of EEG may provide a method for monitoring electrographic seizures in high-risk newborns.

Action Potentials↗
PubMed1987

Positive rolandic sharp waves in the EEG of the premature infant.

Ninety-seven EEGs from 30 premature infants found to have multifocal white matter necrosis on ultrasound (US) or autopsy were reviewed retrospectively. Twenty infants had intraparenchymal echodensities on US that developed into cystic lesions, a finding consistent with periventricular leukomalacia; 8 had intraparenchymal hemorrhages; and 2 had white matter necrosis at autopsy. Four of these infants had no intraventricular hemorrhage. Positive sharp waves in the central (rolandic) regions (PRS) were identified in 22 of these 30 infants (73%) and in 0 of 30 age-matched controls (p less than 0.001). The presence of PRS on the EEG of the premature infant has a high correlation with white matter necrosis rather than with intraventricular hemorrhage. In all cases, this EEG pattern was present prior to the development of cavitations when echodensities were present on US.

Brain↗
PubMed1985

Real time ultrasound diagnosis of hemorrhagic pathological conditions in the posterior fossa of preterm infants.

Real time echoencephalography (RTE) was used to diagnose and serially follow intracranial pathological conditions in the posterior fossa of infants with a gestational age of less than 34 weeks. The posterior fossa was studied in four planes (coronal, modified coronal, sagittal, and parasagittal) with a sector scanner equipped with a high frequency transducer that was placed on the fontanelles and the sutures. Hemorrhagic complications were easily differentiated from normal anatomy. RTE diagnosis was confirmed with computed tomographic scans (5 patients) and postmortem examination of the brain (18 infants). RTE is a precise and noninvasive technique to visualize hemorrhagic and other forms of abnormalities in the infratentorial compartment.

Cerebral Hemorrhage↗
PubMed1985

Dating the time interval from meconium passage to birth.

The gross and microscopic effects of exposing placenta and umbilical cord to meconium were studied in vitro. Gross staining begins with one hour and is a surface phenomenon proportional to length of exposure and meconium concentration. Pigment penetration into the membranes with subsequent uptake by macrophages is dependent primarily on exposure length. Eight of 11 placentas exposed to various meconium solutions were found to have meconium pigment-laden macrophages in the amnion after one hour. These were seen in the chorion somewhat later. Although only three of 11 placentas showed chorionic pigmented macrophages at one hour, 12 of 12 exhibited this finding after three hours. Amniotic epithelial degeneration also showed a time correlation. These findings, especially the microscopic changes described, permit more accurate determination of the defecation-to-birth interval.

Defecation↗
PubMed1983

[Rhythmic alpha activity in the EEG of premature and newborn infants].

The EEG of the newborn consists of a mixed activity which varies from 1 to 22/s. Waves in the alpha band may occur, but they indicate cerebral dysfunction if they are seen in a rhythmic uninterrupted sequence. Eight newborns who showed rhythmic alpha activity in their EEG are included in our study. This activity occurred together with rhythmic theta waves or was followed by them as part of ongoing electrographic seizure activity. All newborns studied were very sick. Three suffered from severe perinatal asphyxia with persistent fetal circulation; in addition one of them had bacterial meningitis. Two infants suffered from herpes encephalitis. In those cases the rhythmic alpha activity temporarily showed a certain periodicity. This EEG pattern was also seen in a small for gestational age premature infant who had septicemia and subarachnoid hemorrhage and in two extremely premature babies with intraventricular hemorrhage. Four infants were curarized. All of the others also had clinically observed seizures. Rhythmic alpha-activity in the neonatal EEG represents an electrical seizure discharge. It may also occur in premature infants who suffer from intraventricular hemorrhage. Obviously it does not have a diagnostic value. The prognostic value depends upon the underlying disease and the grade of background suppression in the EEG. Anticonvulsant therapy should be administered early using a sufficient dosage.

Alpha Rhythm↗
PubMed1982

Preschool assessment of infants with a patent ductus arteriosus: comparison of ligation and indomethacin therapy.

We report the preschool growth and development of preterm infants with problematic patent ductus artferiosus requiring either surgical ligation or indomethacinn treatment in the neonatal period. Of 60 who completed longitudinal growth assessments, no differences in growth to 3 years could be demonstrated except for four cases of regressed retinopathy of prematurity among the ligated infants. Developmental tests (Bayley Scales of Infant Development and the Peabody Picture Vocabulary Test) showed no group differences at preschool ages. Although psychomotor performance on the Bayley Scales in the first 1 1/2 years was significantly lower among the surgically treated infants, later analysis showed that a similar number in both treatment groups scored within the normal range. No selective short- or long-term adverse effects of indomethacin treatment could be demonstrated.

Body Height↗
PubMed1982

Phenobarbital therapy in neonatal seizures and the prognostic value of the EEG.

High plasma levels of phenobarbital are known to produce profound effects on the EEG background activity. Phenobarbital therapy frequently is administered to the neonate with seizures prior to the first EEG recording. Therefore, it is questionable whether in these neonates alterations of the EEG background activity are related to anticonvulsive therapy. A total of 26 neonates with seizures had an EEG while on phenobarbital therapy. In five cases an EEG was available prior to this treatment. Suppression of the background activity in the EEG was seen in 17 neonates of whom two had an inactive tracing and three a burst-suppression pattern. Moderate suppression occurred in five infants, mild suppression is seven infants. The suppression of the background activity correlated with the clinical outcome. The phenobarbital plasma levels in the group with severe or moderate suppression, mild suppression and normal background activity did not show statistically significant differences. Thus, the suppression of the EEG background activity in neonates with phenobarbital plasma levels of 1.3 to 5.9 mg/dl are secondary to brain pathology rather than medication.

Electroencephalography↗
PubMed1980

Postpartum glycosylated hemoglobin levels in mothers of large--for--gestational age infants.

Glycosylated hemoglobin levels were determined in 19 women who were delivered of large--for--gestational age (greater than 4,082 grams) infants and compared to control values. Although the mean level for each group did not differ significantly (6.7% +/- 1.5% versus 6.5% +/- 0.2%) three women had increased hemoglobin glycosylation. In this series the birth of a large infant correlated with prepregnancy obesity and greater weight gain during pregnancy.

Birth Weight↗
PubMed1980

Esophageal perforations in premature infants and comments on the diagnosis.

Traumatic perforation of the esophagus follows oropharyngeal suctioning or endotracheal intubation. The diagnosis frequently is made from a routine chest roentgenogram that shows a nasogastric tube in the right pleural space with or without a pneumothorax. The lesion is seen most often in infants of low birth weight.

Esophageal Perforation↗
PubMed1980

Diagnosis and follow-up of intraventricular and intracerebral hemorrhages by ultrasound studies of infant's brain through the fontanelles and sutures.

A technique to diagnose subependymal hemorrhage (SEH), intraventricular hemorrhage (IVH), intracerebral hemorrhage, and posthemorrhage hydrocephalus in tiny infants, using real time ultrasound studies of the brain ventricular system, is described. This is a bedside technique that visualizes the brain through the fontanelles and the sutures, in three planes: coronal, sagittal, and horizontal. Excellent visualization of the ventricular system, caudate nuclei, the thalamus, the choroid plexus, the corpus callosum, and the foramen of Monro is obtained. This method has good definition using high frequency transducers since there is no bone interference. The ultrasound diagnosis correlated well with computed tomography (CT) and with direct pathologic studies. This technique was more sensitive in diagnosing small IVH/SEH and organized clots than were CT studies. IVH/SEH were found in 90% of 113 infants less than or equal to 34 weeks of gestation; 49% of the hemorrhages were large and 41% were small. Most hemorrhages were found in the first scan, usually shortly after birth. Twenty-one premature infants who never had perinatal asphyxia or respiratory distress syndrome had IVH/SEH. The hemorrhages were followed until disappearance, usually in one to three months in cases of large hemorrhages.

Cerebral Hemorrhage↗
PubMed1979

Coagulation studies in infants of diabetic mothers.

Coagulation studies on 17 infants of diabetic mothers were compared with 11 control infants. Only minor differences were noted, including lower platelet counts in the former group. On the basis of these findings, the increased thrombotic tendency in diabetic progeny cannot be attributed to altered hemostasis.

Blood Cell Count↗