Neonatal neurologic examinations of very preterm infants: comparison of results with ultrasound diagnosis of periventricular hemorrhage.

Seventy infants born before 33-weeks gestation were studied by serial ultrasound brain scans from the first days of life; twenty had periventricular hemorrhage (PVH). Weekly neurologic examinations were performed from age 5 to 10 days. Only measures of passive tone could be elicited before an age equivalent to 34-weeks gestation because the infants were very sick, and many were receiving treatment with mechanical ventilation. Gestation was the most important determinant of this aspect of neurologic functioning, and no effect of time from birth was noted. Before ages equivalent to 34-weeks gestation, no significant relationship was found between measures of passive tone, including the size of the popliteal angle, and PVH diagnosed by ultrasound. At ages equivalent to 34 weeks or more, measures of active as well as passive tone and reflexes were consistently elicited. No single measure discriminated between infants with or without PVH, but serial observations indicated that persisting imbalance of active tone and clonus were only noted in infants with PVH, including 7 of the 8 infants who had PVH complicated by ventricular enlargement. It was concluded that neurologic examination does not reliably diagnose PVH during the neonatal period in sick, very preterm infants. At an age equivalent to term, it may help to distinguish infants who sustained permanent brain damage in association with neonatal PVH which may lead to adverse sequelae at follow-up.

Ultrasound appearance of the brain in very preterm infants and neurodevelopmental outcome at 18 months of age.

The brains of 158 consecutively admitted very preterm infants were repeatedly examined with real time ultrasound. Abnormalities, most commonly periventricular haemorrhage, were detected in 79 (50%). The 109 infants who survived were followed up until they were 16-23 months old. Major or minor neurological or developmental sequelae were found in 5 of 62 infants (8%) with normal ultrasound scans and in an identical proportion, 2 of 25 infants (8%), with uncomplicated periventricular haemorrhage. By contrast, 15 of 21 infants (71%) whose ventricles became enlarged (with or without periventricular haemorrhage) had abnormalities at follow up. The proportion with sequelae depended on the cause and extent of the enlargement. Three of 8 infants (38%) with mild (usually transient) ventricular distension had sequelae, compared with 3 of 4 (75%) with hydrocephalus and 9 of 9 (100%) with cerebral atrophy (2 of whom also had hydrocephalus). Adverse neurodevelopmental sequelae at follow up appeared more often to be attributable to cerebral ischaemia and infarction than to periventricular haemorrhage.

Timing and antecedents of periventricular haemorrhage and of cerebral atrophy in very preterm infants.

The brains of 95 consecutively admitted infants born at less than 33 weeks gestation were scanned with ultrasound. Thirty-six (38%) had periventricular haemorrhage (PVH). Eight (8%) had cerebral atrophy (together with PVH in 5). Twelve (40%) of the 30 infants in whom satisfactory timing of PVH was possible bled on the first day of life, but the median age when PVH was first detected was during the second day. The median age when PVH reached its maximum extent was the fourth day. The most significant antecedents of PVH were very short gestation and the presence of severe respiratory illness, particularly hyaline membrane disease, necessitating mechanical ventilation. Analysis of variance showed that pneumothorax arising during ventilation was the single most significant antecedent of PVH. Other significant antecedents, notably prolonged coagulation times, were found almost exclusively in infants with severe respiratory illness. Cerebral atrophy appeared usually to be attributable either to severe asphyxia during delivery or later, or to the formation of cysts at the site of previous haemorrhage into brain tissue.

Accuracy of imaging of the brains of newborn infants by linear-array real-time ultrasound.

Comparisons were made in 69 newborn infants of the appearance of the brain as visualised by linear-array real-time ultrasound, computerised tomography and at autopsy, in order to evaluate the accuracy of ultrasound for the detection of lesions in the brain. Ultrasound was found to give a good estimate of the presence and extent of haemorrhage into the germinal layer and ventricles, and also to be very useful for assessing the appearance of the ventricular system. Ultrasound diagnosed extradural haemorrhages but was unhelpful for identifying subarachnoid haemorrhages or lesions in the posterior fossa.

Outcome for infants of very low birthweight: survey of world literature.

Reports from developed countries world wide describing the outcome for infants of very low birthweight (VLBW, less than or equal to 1500 g) born since 1946 show that, in general, mortality rates and the prevalence of major handicap in survivors were high until 1960. Since then the chances of healthy survival have trebled, whereas the handicap-rate has remained stable and relatively low at 6--8% of VLBW live births.

PIP: 22 reports on very low birthweight infants (VLBW; 1500 g) were reviewed to see if inferences can be drawn about trends in healthy survival, mortality rate, and handicap rate in VLBW infants born in countries with modern medical services. Data from the studies were pooled according to the quinquennium of birth and subjected to statistical tests and analysis. In the 1940's and 1950's, very few VLBW infants survived because of inadequate treatment and knowledge of neonatal diseases (phase 1 of perinatal care). In the late 50's and 60's, knowledge concerning the normal physiology of VLBW infants and derangement which cause death and damage in newborns increased. Treatments were developed and mortality rate started declining but sometimes at the expense of increased prevalaence of handicap among the survivors (phase 2). From the early 1960's onward, chances of healthy survival of VLBW infants increased, and prevalence of handicap remained stable and relatively low, 6 to 8% of total VLBW births (phase 3). Care of VLBW infants is probably entering phase 4 of perinatal care. Use of computerized tomography and real-time ultrasound enable diagnosis of derangements and lesions which contribute to neonatal deaths. It is hoped that social and obstetric measures will contribute to a decline in the number of VLBW requiring intensive care.

Prediction of death and major handicap in very preterm infants by brain ultrasound.

A linear-array real-time ultrasound scanner was used to examine the brains of all 95 infants born at less than 33 weeks of gestation who were admitted to the neonatal unit of University College Hospital in 1979. Abnormalities were detected in 41 (43%). 36 infants had haemorrhages into the germinal layer (GLH) and/or ventricles (IVH). 8 infants had cerebral atrophy (together with GLH/IVH in 5 infants). 8 (13%) of 63 infants with normal scans or small (grade-I) GLH/IVHs died, whereas 19 (59%) of 32 infants with larger haemorrhages or other intracranial lesions died (p less than 0.0005). At follow-up, at a median corrected age of 45 weeks, only 2 (4%) of 53 infants with normal scans or grade-I haemorrhages had evidence of major neurodevelopmental handicaps, but 5 (38%) of 13 infants with more extensive haemorrhages or cerebral atrophy had major handicaps (p less than 0.005). Brain scanning with ultrasound in the first days of life identified most infants in the population studied who subsequently died or survived with handicaps severe enough to be detected within the first year.

Pneumothorax and cerebral haemorrhage in preterm infants.

Real-time ultrasound was used to examine the brains of all 95 infants born at less than 33 weeks of gestation who were admitted to the neonatal unit of University College Hospital in 1979. Evidence was obtained which strongly suggested that pneumothorax causes and aggravates haemorrhage into the germinal layer and ventricles of preterm infants.