Patricia H. Ellison

Cerebral blood flow in the newborn infant: Comparison of Doppler ultrasound and 133xenon clearance

Two techniques of Doppler ultrasound examination, continuous-wave and range-gated, applied to the anterior cerebral artery and to the internal carotid artery, were compared with 133xenon clearance after intravenous injection. Thirty-two sets of measurements were obtained in 16 newborn infants. The pulsatility index, the mean flow velocity, and the end-diastolic flow velocity were read from the Doppler recordings. Mean cerebral blood flow was estimated from the 133Xe clearance curves. The correlation coefficients between the Doppler and the 133Xe measurements ranged from 0.41 to 0.82. In the subset of 16 first measurements in each infant, there were no statistically significant differences between the correlation coefficients of the various Doppler ultrasound variables, but the correlation coefficients were consistently lower for the pulsatility index than for mean flow velocity or end-diastolic flow velocity, and they were consistently higher for the range-gated than for the continuous-wave Doppler technique.

A scoring system to predict outcome following neonatal seizures

Ninety-six newborn infants with seizures were scored during the initial hospitalization on abnormality of EEG, neurologic examination, etiology of seizures, length of seizure, type of seizure, and birth weight under or over 1,500 gm. At 3 months, corrected for gestational age, the 80 surviving infants were scored on abnormality of current EEG, neurologic examination, etiology of seizure, presence or absence of seizure since hospital discharge, and birth weight under or over 1,500 gm. At age 10 months, 76 of 77 surviving infants were evaluated with the Gesell Developmental Inventory, physical examination, and neurologic examination. Chi square analysis documented that the scoring system was an accurate predictor of those infants with seizure disorders, mental retardation, and motor dysfunction. The score may assist the clinician in making decisions in regard to anticonvulsant therapy during initial hospitalization or at age 3 months.

CHANGES IN CEREBRAL HEMODYNAMICS IN PRETERM INFANTS WITH AND WITHOUT PATENT DUCTUS ARTERIOSUS

ABSTRACT. We compared anterior cerebral pulsatility index (ACPI), anterior cerebral mean flow velocity (ACMFV), common carotid pulsatility index (CPI) and common carotid mean flow velocity (CMFV) in three groups of preterm infants with birth‐weights less than 1500 grams: 6 without evidence of PDA (group A), 6 with PDA treated with fluid restriction, diuretics or digoxin (group B) and 6 with surgical ligation of PDA (group C). Infants were assessed in three time periods: the first four days of life, five days before surgical ligation and five days post‐ligation. Analyses of variance showed no significant differences in the three groups for the four measures in time 1. In time 2, ACPI was 0.61 for group A, 0.58 for group B, 0.78 for group C (p<0.01). ACMFV was 9.22 for group A, 7.71 for group B, 6.37 for group C (p<0.05). CPI was 0.84 for group A, 0.83 for group B, 0.90 for group C (NS); CMFV was 7.80 for group A, 5.63 for group B, 4.28 for group C (p<0.01). In time 3, significant differences (p<0.01) were found only for CMFV.

Transcephalic impedance in the neonate: an indicator of intracranial hemorrhage, asphyxia, and delayed maturation.

Increased transcephalic impedance readings (greater than 3 SD) were recorded in 13 asphyxiated infants 35 weeks or more in gestation, and in 13 preterm infants 34 weeks or less in gestation and with intracranial hemorrhage (greater than 2 SD). Six infants had decreased TCZ recordings in the weeks following intracranial hemorrhage, without ultrasound evidence of ventricular enlargement. TCZ provides quick, inexpensive, noninvasive indication of tissue necrosis, moderate-to-severe intracranial hemorrhage, and delayed brain maturation.

The Evolution of a Simplified Method for Interpretation of EEG in the Preterm Neonate

ABSTRACT. We describe the evolution of a simplified method for the interpretation of serial EEG in preterm enonates which was tested in a first sample and revised and unproved in a second sample of preterm neonates. There were 185 EEGs in the first sample and 206 EEGs in the second sample. The interpretation of the EEGs was related to mental, motor and neurological outcome in late infancy. Serial EEG is an excellent indicator of brain function in the preterm neonate.

The relationship of motor and cognitive function in infancy, pre‐school and early school years

The progression of motor abnormalities from infancy through early school years are described, citing studies from infants initially treated in the neonatal intensive care unit and the large sample of children in the National Collaborative Perinatal Project. In children who have incurred some insult to the brain in the prenatal, delivery or postnatal period, motor abnormality is most prevalent during infancy. Many children “outgrow”; these motor abnormalities during late infancy and pre‐school years but retain residual fine motor, memory, general cognitive or behavioral deficits. The role and limitations of the pediatric neurologist as a part of assessment and planning for the educational program is discussed.

The Relationships of Transcephalic Impedance, Head Growth and Caloric Intake to Outcome in Preterm Infants

ABSTRACT. Twenty‐two preterm infants with birth weights less than 1400 g were measured weekly with transcephalic impedance and occipital‐frontal head circumference. Mean caloric intake/kg/ day was calculated weekly. All infants were assessed at one year of age with Bayley Mental and Motor Scales and neurological assessment. Univariate and multivariate analyses were performed indicating that transcephalic impedance was the most powerful of the three measures as a predictor of sequelae.

Considerations in evaluating changes in outcome for infants weighing less than 1,501 grams

Neonatal mortality for 285 infants and developmental outcome for 158 infants with birth weights of 751 to 1,500 gm, born in the Capital Regional Perinatal Center between July 1975 and December 1979, were compared with the findings in 1952, in 1965 to 1967, and in 1968 to 1970. In the 1,001- to 1,500-gm group, mortality decreased and there was an 18% incidence of major neuropsychiatric disability compared to the 48% found in 1952 when the same examination techniques and diagnostic criteria were used. More 751- to 1,000-gm infants survive now also, but 40% have a major handicap. There is a high incidence of preconceptional, prenatal, perinatal, and postnatal abnormalities in this group of very low-birth-weight infants, but the incidence is significantly higher in those with major disabilities. The infants who die and those who have subsequent major neuropsychiatric abnormalities require the sophisticated techniques of neonatal intensive care, whereas these procedures are not needed or are used only briefly for the infants who are normal. In upper New York State, the demographic shifts in race, age, parity, education, and induced abortions account for 13% of the drop in neonatal mortality in the 1,001- to 1,500-gm group. These demographic as well as social and medical care changes must be taken into account in any evaluation of the decreasing mortality and morbidity that has occurred. Improvements in prenatal, obstetric, and neonatal care appear to be doing for the 751- to 1,000-gm group now what the then high-level care in 1952 did for the 1,001- to 1,500-gm group, when mortality decreased but only half of those who survived were normal.

1573 TRANSCEPHALIC IMPEDANCE AND SERUM CREATINE KINASE BB IN PRETERM INFANTS AS PREDICTORS OF BRAIN DAMAGE

As an indicator of brain damage in premature infants, we measured transcephalic impedance (TCZ) and serum creatine kinase BB (brain fraction-CK-BB) in 16 premature infants with gestational ages 24 to 32 weeks, all with birth weights less than 1500 grams. Both TCZ and CK-BB were measured within 24 hours and at weekly intervals. CK-BB values above 15 were considered abnormal (Becker and Menzel, 1978; Shields, 1979; Cuestas, 1980). TCZ values 2 standard deviations above normal were indicative of tissue damage from asphyxia (Ranck, 1964; Ellison, 1979), or IVH (Siddiqui, 1980). Persistently low TCZ, i.e. those under 30 ohms were considered to reflect delayed brain maturation (Ellison & Evers, 1980.)13 infants had an elevated CK-BB during hospitalization. 10 infants had an elevated TCZ during the first postnatal week. 8 infants had both TCZ and CK-BB elevated. 4 infants had persistently low TCZ values associated with delayed maturation.Of the 8 infants with elevation of both TCZ and CK-BB, 5 (63%) have moderate to severe neurological sequelae. 3 (37%) have mild neurological sequelae. 3 of the 4 infants with persistently low TCZ have developmental delay.TCZ and CK-BB are accurate predictors of neurologic compromise in the preterm infant.

CEREBRAL BLOOD FLEW IN THE NEWBORN VARIABLES WHICH EXPLAIN THE RELATIONSHIP BETWEEN DOPPLER ULTRASOUND AND 133-XENON CLEARANCE

We have previously reported correlations between 133-Xenon cerebral blood flow measures and two forms of Doppler ultrasound measure — continuous wave and range-gated — in studies of neonatal cerebral blood flow (Greisen, Johansen, Ellison et al). In the present study, the contributions of pCO2, heart rate (HR), gestational age (GA) and blood pressure (BP) to these correlations were analyzed. Using jackknife techniques (Mosteller and Tukey), we also examined the stability of prediction of 133-Xenon flow from the ultrasound measures.GA was a major contributor to the covariance between 133-Xenon and the 12 ultrasound measures (two methods, three measures — pulsatility index (PI), mean flow velocity (MFV) and end diastolic flow velocity (EDFV), at two sites - anterior cerebral artery (ACA) and internal carotid artery (ICA)). The contributions of pCO2, HR and BP were small, both singly and in combination, after the removal of that portion of the covariance accounted for by GA. We suggest that investigators should control for GA in studies of neonatal CBF.Four ultrasound measures accounted for a notable portion of the 133-Xenon CBFT variance and were significantly stable predictors according to the jackknife analysis: EDFV of the ICA by continuous wave Doppler, and three measures by range-gated Doppler -- MFV of the ACA, MFV of the ICA and EDEV of the ICA. None of the PI measures at either site by either Doppler technique had stable and noteworthy relations to 133-Xenon CBF measures.The results, the methods of data analyses and their implications will be discussed.