Search PubMed⌕ Search

Biomedical subjects

M S Scher

Publications and source records attributed to M S Scher.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cardiorespiratory behavior during sleep in full-term and preterm neonates at comparable postconceptional term ages.

Cardiorespiratory behavior during sleep has been investigated by comparing visually analyzed minutes of EEG sleep with the digitized values of these two physiologic variables for each corresponding minute. Continuous 3-h nighttime sleep studies on 37 full-term and preterm neonates at comparable postconceptional term ages were acquired under controlled conditions, using a 24-channel computerized monitoring system and an automated event-marker program. Five thousand, two hundred ninety-four minutes were assigned an EEG state by traditional criteria. Eighteen preterm infants were compared with 19 full-term infants with respect to six cardiac and six respiratory measures: two nonspectral calculations (i.e. average per minute and variance of the means) and four spectral calculations of the cardiorespiratory signal (i.e. bandwidth, spectral edge, mean frequency, and ratio of harmonics). The relative capabilities of these measures to predict a sleep state change were investigated using discriminant analysis. A stepwise selection algorithm in discriminant analysis was used to identify the order of significance for the remaining variables. Eight cardiorespiratory measures were then submitted to multivariate analysis of variance to assess sleep state or preterm-full-term differences: mean frequency, bandwidth, average per minute, and ratio of harmonics for cardiac signals; and spectral edge, mean frequency, logarithm of variance, and ratio of harmonics for respiratory signals. Differences among the sleep states and between neonatal groups were highly significant (p < 0.0001). Interaction between sleep state and neonatal group was also significant (p < 0.034). Two variables differentiated preterm from full-term respiratory behavior: ratio (p < or = 0.001) and mean frequency (p < or = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Physiological Phenomena↗
PubMed1993

EEG and the neuropathology in premature neonates with intraventricular hemorrhage.

Eighty-eight EEGs from 32 premature neonates with autopsy-verified periventricular-intraventricular hemorrhage (PVH-IVH) were compared with associated neuropathological findings. PVH-IVH was rarely an isolated lesion at autopsy. Twenty-seven infants (84%) had additional parenchymal brain lesions, such as periventricular leukomalacia (47%), ischemic neuronal necrosis (22%), pontosubicular necrosis (22%), cerebral infarction (13%), and/or cerebellar hemorrhage (13%). A significant correlation was found between the patient's most abnormal EEG and the severity of morphological changes. Infants with more abnormal EEGs had more extensive brain lesions. On the other hand, IVH grade did not correlate with the degree of parenchymal brain lesions, with the exception of IVH with intraparenchymal involvement. Positive rolandic sharp wave transients (PRS) were observed in eight patients (25%). All infants with PRS had white matter lesions. The sensitivity of PRS for white matter lesions, however, was only 38%. EEG has limited value in the diagnosis of PVH-IVH or specific anatomical changes but provides useful electrographic information that correlates with the severity of brain damage in infants with PVH-IVH.

Asphyxia Neonatorum↗
PubMed1993

Electrographic seizures in preterm and full-term neonates: clinical correlates, associated brain lesions, and risk for neurologic sequelae.

Electrographically confirmed seizures in preterm and term neonates were compared with respect to clinical correlates, incidence, associated brain lesions, and risk for neurologic sequelae. Over a 4-year period, 92 neonates from a neonatal intensive care unit population of 4020 admissions at a large obstetric hospital with 40,845 livebirths had electrographically confirmed seizures. Sixty-two neonates were preterm and 30 were full-term for gestational age. Chi-square calculations were used to compare the two groups. While the incidence of seizures for all neonates admitted to a neonatal intensive care unit was 2.3%, outborn neonates were more likely to have seizures than inborn neonates. Preterm neonates of < or = 30 weeks gestational age had a seizure frequency of 3.9%, which was significantly higher than that of older preterm neonates and full-term neonates. Clinical criteria contemporaneous with electrographic seizures were noted in only 28 (45%) of 62 preterm, and 16 (53%) of 30 full-term neonates. Subtle seizures coincident with electrographically confirmed seizures were the most predominant clinical type for both term and preterm neonates (71% and 68%, respectively). The distribution of clonic, myoclonic, and tonic seizures was also similar for both groups. Autonomic signs coincident with electrographically confirmed seizures (ie, blood pressure, heart rate, oxygenation, respiration changes) were more frequently observed in preterm than full-term neonates with subtle seizures; 7 (37%) of 19 compared with 1 (6%) of 16. Electrical seizures without clinical correlates were noted more frequently than electroclinical seizures for both populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsants↗
PubMed1992

Sleep architecture and continuity measures of neonates with chronic lung disease.

Electroencephalographic (EEG) sleep studies of 25 preterm neonates with chronic lung disease (CLD) corrected to a fullterm postconceptional age were compared with recordings from two groups of neonates without CLD: a fullterm appropriate for gestational age group (9 patients) and a preterm group studied at a corrected term postconceptional age (15 patients). Electrographic/polygraphic studies were obtained using 21-channel EEG recordings. Scores were tabulated based on minute-by-minute visual analyses of sleep state, number and duration of arousals, body movements and rapid eye movements (REM). A significant reduction in the percentage of active sleep was noted in the CLD group compared to both control groups (31.15% vs. 47.01% and 52.9%, respectively). The mean percentage of indeterminate sleep was significantly increased in the study group as compared to both control groups (31.23% vs. 15.18% and 11.5%). In addition, significant differences were noted between the CLD group and the healthy preterm control group with respect to the number (0.29/minute vs. 0.13/minute) and duration (4.8 seconds vs. 2.94 seconds) of arousals as well as the total number of body movements (1.57/minute vs. 0.74/minute). These data suggest that neurophysiological organization of the immature brain, as reflected in neonatal sleep architecture and continuity measures, is adversely affected in neonates with CLD. EEG sleep architecture and continuity measures may be helpful in predicting the longitudinal outcome of infants with CLD as this group is at risk for adverse neurodevelopmental outcome.

Cerebral Cortex↗
PubMed1992

Comparison of EEG sleep measures in healthy full-term and preterm infants at matched conceptional ages.

Continuous electroencephalogram (EEG) sleep studies were obtained on healthy full-term and preterm infants at matched conceptional ages. Studies were recorded under environmentally controlled conditions. Eighteen healthy preterm infants were matched to 18 full-term infants based on conceptional age, sex, race and socioeconomic class. The initial 3 hours of a 12-hour recording were simultaneously recorded on paper and computer. The visually scored data based on the paper recordings for sleep architecture and continuity measures were studied. Differences in each sleep organization for the preterm infants included the following: a longer ultradian sleep cycle (70 minutes vs. 53 minutes, p = 0.02) was noted. More abundant tracé alternant (34% vs. 28%, p = 0.02) and less abundant low-voltage irregular active sleep (13% vs. 17%, p = 0.05) were noted. Although no differences were observed for sleep latency and efficiency, the preterm infants had fewer numbers and shorter durations of arousals, fewer body movements and rapid eye movement (REM) (p < 0.01), particularly during quiet sleep. The extrauterine experience or the earlier birth of the preterm infant may influence specific sleep architecture and continuity measures when compared with the sleep of full-term infants who experienced a complete intrauterine gestation.

Arousal↗
PubMed1991

Destructive brain lesions of presumed fetal onset: antepartum causes of cerebral palsy.

Antepartum events have been associated with fetal brain injury and may contribute to later neurological sequelae. However, children with these injuries may be asymptomatic or exhibit few clinical signs during the neonatal period. Six neonates are presented with destructive brain lesions of fetal onset based on radiological and neurophysiological studies at birth. No intrapartum difficulties were noted in any of the cases. Two maternal histories were significant for either placental bleeding or toxemia during the second or third trimesters of pregnancy. Fetal porencephaly from presumed intraventricular hemorrhage was documented by serial abdominal sonography for these two children. No causes could be assigned for the remaining four patients with destructive brain lesions. All six children had normal results on neurological examinations at birth, although four neonates later presented with isolated seizures at 8 to 30 hours of life which resolved after administration of anti-epileptic medication. In all cases initial neonatal electroencephalographic records showed abnormalities consisting of major background asymmetries or seizures. Initial documentation of cerebral lesions was made by fetal sonography (two patients) and computed tomography scan (four patients) during the initial 30 hours of life, timing the lesions to the antepartum period. Cerebral palsy has been documented in all children; one child had resolution of her deficits by 6 months of age. Better surveillance of events during the antepartum period may help identify specific pathophysiological conditions that contribute to cerebral palsy. Neurophysiological and imaging studies should be used during the immediate new-born period for neonates believed to have cerebral lesions based on maternal sonography or isolated seizures.

Brain Diseases↗
PubMed1990

Computer analyses of EEG-sleep in the neonate: methodological considerations.

Neonatal EEG interpretation can aid in the estimation of central nervous system maturation, as well as provide diagnostic and prognostic information of the high-risk infant. However, one cannot easily visualize the complex interrelationships coupling EEG and polysomnographic components of the EEG-sleep rhythm. This is particularly relevant for the preterm neonate, in whom a rudimentary sleep cycle has not yet been clearly delineated. Computer analysis can augment the information derived from the visual interpretation of scalp-generated EEG activity. Automated techniques for EEG-sleep analysis have only recently been applied to a neonatal population. Such studies have been limited to full-term rather than preterm infants and rely on conventional methods that assume stationarity of neurophysiologic signals. We describe a computer system that simultaneously compares behavioral and electrographic components of EEG-sleep in a manner that preserves the integrity of the signals over time, while investigating the time- and frequency-dependent relationships among signals. Strategies for on-line and off-line editing, data storage, and off-line signal processing are described. Computational algorithms regarding analyses of EEG power, motility, and cardiorespiratory data are being used to study the ontogeny of EEG-sleep in asymptomatic preterm and full-term neonates. Computer strategies are based on both principles of stationarity and nonstationarity of physiologic signals and are applied depending on the temporal resolution required for specific signal processing needs.

Computer Systems↗
PubMed1990

Cerebral infarcts and seizures in the neonate.

A retrospective analysis was performed on 54 infants who suffered perinatal hypoxic-ischemic insults and came to autopsy, in an attempt to assess the association of cerebral infarcts with seizures. Fifty infants had several types of cerebrovascular lesions, including intraventricular hemorrhage (32 cases), periventricular leukomalacia (24), ischemic neuronal necrosis (18), pontosubicular necrosis (12), cerebral infarct (9), and cerebellar hemorrhage (7). Of these infants, nine had electroencephalographic seizures. Among a variety of cerebrovascular lesions, cerebral infarcts represented the single lesion most highly correlated with seizures. The incidence of seizures in infants with cerebral infarcts (44%) was significantly higher than with other types of vascular lesions.

Asphyxia Neonatorum↗
PubMed1989

Controversies concerning neonatal seizures.

Five issues are discussed with respect to the diagnosis, etiology, treatment, prognosis, and pathogenesis of neonatal seizures. The presentation of a newborn with seizures represents a true emergency and frequently indicates significant neurologic dysfunction or damage to the immature nervous system. Despite the urgency to establish a diagnosis, several unique aspects of neonatal seizures impede prompt recognition. In addition, several etiologic possibilities may be associated with seizures. The efficacy of antiepileptic drugs and the prediction of outcome of patients with neonatal seizures are controversial. Experimental research in developing animals suggests both a selective vulnerability and resistance of the brains of immature animals subjected to neonatal seizures.

Asphyxia Neonatorum↗
PubMed1989

Serial EEGs in normal and abnormal infants with birth weights less than 1200 grams--a prospective study with long term follow-up.

Serial EEGs were recorded during the postnatal period from 62 infants with birth weights less than or equal to 1200 gms. Neurological examinations were performed in proximity to the EEG and each infant had at least one imaging study of the brain in the immediate postnatal period. All infants were examined at 2-3 years age. Neurological sequelae were seen in all infants with markedly abnormal neonatal EEGs and in the majority of those with persistently moderately abnormal tracings. A particularly unique EEG abnormality consisting of an arrest of maturation of cerebral electrical activity was seen in infants with bronchopulmonary dysplasia who suffered neurological sequelae. A persistently asymmetric EEG background was recorded in infants with hemispheric pathology who were found to have hemisyndromes at long term follow-up. Serial EEGs were better predictors of long term outcome than imaging studies and the neurological examination.

Brain↗
PubMed1989

Neonatal electroencephalography and neuropathology.

One-hundred-eight EEGs from 47 newborn infants were compared with the postmortem neuropathological findings. The degree of EEG background abnormality had good correlation with the severity of the brain lesion; the more severe the EEG background abnormality, the more extensive and intensive the morphological change. Widespread encephalomalacia was demonstrated in six infants who manifested isoelectric tracings. In particular, cerebral cortex, corpus striatum, thalamus, midbrain, and pons were affected in all patients with this abnormal EEG pattern. Burst-suppression patterns, which were seen in seven infants, also correlated with multifocal severe brain damage, but there was no common structure that was consistently affected for all patients with this pattern. Positive rolandic sharp-wave transients (PRS) appeared highly specific for white matter lesions. All eight infants with PRS had white matter lesions. However, the sensitivity of PRS for white matter lesions was not high (32%), and the white matter lesions of PRS-positive patients were not necessarily composed of periventricular leukomalacia. The sensitivity of EEG asymmetry was also low (40%) for the focality of morphological change, although the specificity was relatively high (85%). The origin of seizure discharges, on the other hand, had poor correlation with the site of the brain lesion.

Brain↗
PubMed1989

Visual and neurological outcome of infants with periventricular leukomalacia.

Visual acuity, visual fields and neurological status were assessed in 10 infants with periventricular leukomalacia (PVL), tested at 16, 36, 48 and 72 weeks from the expected date of confinement. Monocular acuity development was normal in eight of the 10 infants, but was below normal in one infant at eight months and in another at 18 months. Over half the infants tested at 16, 36 and 48 weeks had smaller visual fields than those of 95 per cent of healthy preterm infants tested at the same ages, but by 72 weeks only two of six infants tested had restricted visual fields. Nine of the 10 infants were neurologically abnormal at ages under one year, but only four remained so beyond one year. These results indicate more favourable outcomes for visual acuity and neurological status in infants with non-cavitary PVL than have been reported in infants with cavitary PVL. The most compromised infants were one with cavitary PVL and another with extensive non-cavitary PVL who had the longest-lasting EEG abnormalities of all 10 infants.

Aging↗
PubMed1989

Clinical significance of focal periodic discharges in neonates.

Of 1,114 EEG recordings obtained for 592 neonates, focal periodic discharges were noted on 57 (5%) of recordings for 34 neonates (26 preterm and eight term). Periodic lateralized epileptiform discharges (PLEDs) were noted on four of these recordings. Sixteen patients (47%) with focal periodic discharges also had electrographic seizures on the same or a subsequent record. Stroke was the most common brain lesion (53%) in this neonatal population. Preterm neonates had discharges that were less than 60 seconds in duration and located in the parasagittal regions, while discharges in term neonates were longer in duration and were located in the temporal regions. Of the 34 neonates, 15 (44%) died, and 58% (11/19) of the survivors were abnormal with respect to neurological development. Focal periodic discharges in neonates, including PLEDs, have the same clinical significance as PLEDs recorded on EEGs in older children and adults.

Electroencephalography↗
PubMed1988

Midline electrographic abnormalities and cerebral lesions in the newborn brain.

Electroencephalographic (EEG) abnormalities arising from the midline region were identified in 154 of 1008 (15.2%) consecutive neonatal EEGs during a 24-month period. These records were obtained on 97 neonates with a variety of clinical diagnoses. Premature infants made up 79% (77/97) of this group. All patients received at least one cranial ultrasound at 7 to 10 days of life. Sixty-two percent (60/97) of the patients had radiographic and/or neuropathological documentation of cerebral lesions: intraventricular hemorrhage (25), periventricular leukomalacia (18), cerebral infarction (10), cerebral malformation (4), and miscellaneous lesions (3). Six types of midline EEG abnormalities are described: negative sharp waves, positive sharp waves, electrographic discharges associated with myoclonus, electrographic seizures, attenuation of background, and rhythmic monofrequencies. Approximately 90% of the patients with background attenuation, discharges with myoclonus, and positive sharp waves and 72% of patients with EEG seizures had cerebral lesions. Midline positive sharp waves were associated with periventricular leukomalacia as well as intraventricular hemorrhage. No midline positive sharp waves, attenuation, EEG seizures or discharges with myoclonus were found in 25 healthy, asymptomatic neonates. Besides positive sharp waves, other specific midline EEG abnormalities can be associated with cerebral lesions in the neonate. The rapid identification of midline EEG abnormalities in neonatal recordings can enhance the accuracy of both electrographic diagnosis and anatomic localization of associated cerebral lesions.

Brain Diseases↗
PubMed1988

The effects of prenatal alcohol and marijuana exposure: disturbances in neonatal sleep cycling and arousal.

Neonatal EEG and sleep findings are presented from a longitudinal study of the effects of maternal alcohol and marijuana use during pregnancy. Infant outcome has been examined relative to the trimester(s) of pregnancy during which use occurred. Disturbances in sleep cycling, motility, and arousals were noted that were both substance and trimester specific. Alcohol consumed during the first trimester of pregnancy was associated with disruptions in sleep and arousal, whereas marijuana use affected sleep and motility regardless of the trimester in which it was used. Although these findings are preliminary and based on a small sample of women exhibiting only moderate substance use during pregnancy, they do suggest that specific neurophysiological systems may be differentially affected by prenatal alcohol or marijuana exposure even in the absence of morphological abnormalities.

Arousal↗
PubMed1988

Right-sided brain lesions in infants following extracorporeal membrane oxygenation.

In retrospective review of survivors of neonatal extracorporeal membrane oxygenation, eight patients with varying degrees of right hemispheric brain injury were identified. The extent of preextracorporeal membrane oxygenation hypoxia and ischemia was documented: five of eight patients had arterial PO2 values of less than 40 mm Hg, seven of eight required dopamine for blood pressure support, and five of eight required cardiopulmonary resuscitation. Two patients had proven neurologic abnormalities before extracorporeal membrane oxygenation. Postextracorporeal membrane oxygenation CT brain scans showed right hemispheric focal abnormalities in three patients. Seven infants had neuromotor abnormalities which were lateralizing in nature; all were left sided, suggesting right-sided brain injury. EEGs showed an increased incidence of slowing and attenuation over the right hemisphere. These findings indicate that right-sided brain abnormalities exist after extracorporeal membrane oxygenation and that carotid artery ligation for extracorporeal membrane oxygenation is not without risk.

Brain↗
PubMed1987

Cerebral infarction in persistent pulmonary hypertension of the newborn.

Persistent pulmonary hypertension of the newborn and its attendant hypoxemia may place the infant at high risk for hypoxic-ischemic injury. In 19 infants with persistent pulmonary hypertension of the newborn, 16 of whom suffered intrapartum asphyxia, we evaluated a series of electroencephalograms (EEGs) for evidence of major focal cerebral injury, ie, persistent voltage attenuation and/or focal electrical-seizure activity. Of the 15 infants (78.9%) with such EEG findings, nine infants (47% of the total population) had cerebral infarction documented by cranial sonograms, computed tomographic scans, or autopsy findings. In eight (89%) of the nine infants with infarction, electrical seizures were noted during periods of muscle paralysis. We recommend (1) the use of electroencephalography in this population, particularly during periods of muscle paralysis, to detect underlying cerebrovascular lesions and (2) the use of cranial computed tomography if persistent, focal EEG abnormalities are noted.

Cerebral Infarction↗