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

Serial measurements of cerebral blood flow velocity in preterm infants during the first 72 hours of life

Serial measurements of cerebral blood flow velocity (CBFV) were made in 29 preterm infants, using continuous wave Doppler ultrasound. CBFV was measured in both anterior cerebral arteries and quantitative measurements of CBFV were determined using the area under the velocity curve. In all ventilated infants, CBFV increased significantly during the first 6 hours of life and continued to increase until 16 hours of age. Thereafter, CBFV remained relatively constant. This increase in CBFV was primarily the result of increased diastolic flow. Three infants who had evidence of intraventricular haemorrhage on cranial ultrasound, had similar CBFV compared with the infants with no evidence of haemorrhage. Two infants died and both demonstrated areas of periventricular leukomalacia at autopsy. These infants had a prolonged period of low CBFV. These measurements provide normal data for ventilated, preterm infants. As previously suggested in term infants, the initial rise in CBFV may be secondary to closure of the ductus although a generalized decrease in peripheral vascular resistance could also be a contributing factor. Fluctuations in CBFV rather than individual readings are probably more important in the genesis of IVH. An episode of significantly reduced CBFV is a poor prognostic sign.

Precision of ultrasound diagnosis of pathologically verified lesions in the brains of very preterm infants

Abnormalities detected by a mechanical sector scanner were compared 'blind' with autopsy findings in the brains of 56 infants born at less than 33 weeks gestation. Intraventricular haemorrhage was found in 53 of 112 hemispheres and had been accurately diagnosed by ultrasound (sensitivity 91 per cent; specificity 81 per cent). Isolated germinal layer haemorrhage was less successfully identified (sensitivity 61 per cent; specificity 78 per cent); false-positive diagnoses were partly due to difficulty in distinguishing haemorrhage from the normal choroid plexus in extremely preterm infants. Haemorrhagic parenchymal lesions were correctly identified in nine infants (sensitivity 82 per cent; specificity 97 per cent). Only 11 of 39 hemispheres with histological evidence of hypoxic-ischaemic injury, without marked bleeding, were correctly identified by ultrasound (sensitivity 28 per cent), mainly because of failure to detect small areas of periventricular leucomalacia and diffuse gliosis. 10 hemispheres with periventricular echodensities thought to represent leucomalacia showed no histological evidence of hypoxic-ischaemic injury (specificity 86 per cent). Ventricular dilatation in seven infants was always associated with evidence of hypoxic-ischaemic injury at autopsy.

Effect of timing of cerebral ultrasonography on the prediction of later neurodevelopmental outcome in high-risk preterm infants

To determine the predictive value of cranial ultrasonographic examination in high-risk preterm infants at different postnatal ages, we scanned 110 infants less than or equal to 32 weeks gestational age at 1, 2, 3, and 6 weeks postnatal ages and at 40 weeks postconceptional age (PCA). Cranial abnormalities detected by ultrasonography at each postnatal age of examination were classified as minor (periventricular superolateral echogenicity with or without intraventricular hemorrhage, grades 1 to 3) or major (cystic periventricular leukomalacia with or without intraventricular hemorrhage, grade 4) and correlated with neurodevelopmental outcome determined by 1 year of age. Major abnormalities detected by ultrasonography were present in four infants at 1 week, four at 2 weeks, eight at 3 weeks, and 11 infants at 6 weeks and 40 weeks PCA, respectively. Nineteen infants (17%) had moderate to severe functional handicaps defined as cerebral palsy, cognitive or visual deficit, or deafness. The positive and negative predictive values of ultrasound examinations, with regard to later neurodevelopmental outcome, improved with increasing postnatal age at examination and was best at 40 weeks PCA. Negative results of ultrasound study at 40 weeks PCA most correctly predicted satisfactory outcome. Although only 58% of moderately to severely handicapped infants were correctly identified by ultrasound examination at 40 weeks PCA, all infants with major ultrasonographic abnormalities at 40 weeks PCA had moderate or severe handicap. Our data demonstrate that the timing of cerebral ultrasonography is important in the prediction of later neurodevelopmental outcome in high-risk preterm infants.

Prediction of long-term outcome in high-risk infants: the use of objective measures of brain structure and function in the neonatal intensive care unit

The ability to predict long-term outcome on the basis of objective measures made shortly after the birth of an infant has introduced a completely new approach to the investigation of the aetiology of childhood impairments and disabilities, and the evaluation of the effects of perinatal management regimes designed to avoid or ameliorate them. This approach also has important implications for the management of sick and vulnerable infants, both in the perinatal period and later. From the use of ultrasound brain scanning, a great deal has been learnt about all aspects of the aetiology, evolution and prognosis of GLH, IVH and IPH in very preterm infants; and from autopsy correlation studies, about the underlying pathological processes causing the lesions. There are, however, three observations which have particular implications for the choice of neonatal measure to be used for predictive purposes and for the interpretation of results. First, the long-term prognosis for infants with uncomplicated GLH and IVH who never develop ventricular dilatation, hydrocephalus or evidence of loss of brain tissue is indistinguishable from that of very preterm infants of similar gestational age with no detectable lesions on the ultrasound scan. Second, hypoxic-ischaemic injury is a much more common cause of the neurodevelopmental impairments seen at follow-up in sick or preterm infants than haemorrhage. Third, ultrasound is very poor at detecting hypoxic-ischaemic lesions in the absence of bleeding. These lesions are only reliably recognized with ultrasound when the necrotic process is sufficiently advanced for loss of brain tissue or cerebral atrophy to occur. As a consequence, hypoxic-ischaemic injury is only likely to be identified in the early stages of its evolution following the causal insult by demonstrating deranged cerebral intracellular energy metabolism or cerebral haemodynamics. From these observations it may be deduced that ultrasound brain scanning in the first week of life is a poor predictor of adverse neurodevelopmental outcome at follow-up, depending largely on the diagnosis of haemorrhagic lesions for its 'power'. According to the size of haemorrhage and the outcome considered, the sensitivity may be calculated at 61-73.5% and the positive predictive value at only 32-50% (Stewart ef al, 1987; Cooke, 1987). Nevertheless, the marked echodensities which indicate intraparenchymal haemorrhage (IPH or haemorrhagic PVL) carry a very bad prognosis and thus detect a small group of infants with a probability estimate of serious neurodevelopmental impairment of about 90% (Table 1).(ABSTRACT TRUNCATED AT 400 WORDS)

Ventricular haemorrhages and hypoxic-ischaemic lesions in preterm infants: neurodevelopmental outcome at 3 1/2 years

The association of cerebral ultrasound images and developmental outcome at age 3 1/2 years was studied in 50 preterm infants (mean gestational age 31 weeks, mean birthweight 1450 g). 25 children had normal neonatal scans and 25 had abnormal neonatal scans; 11 without and 14 with ventricular dilatation. At one year a repeat scan was done and neurodevelopmental outcome was assessed. Follow-up results at 3 1/2 years stress the importance of long-term follow-up: at one year four of the 50 children had developmental deficits, at 3 1/2 years 13 had such deficits. At 3 1/2 years the risk of neurodevelopmental deficits was extremely high for children with persistent haemorrhagic and/or atrophic ventricular dilatation. There was significant over-representation of children with developmental deficits in the group with abnormal scans, both neonatally and at one year. The incidence of cerebral palsy was high in the group with large haemorrhages extending into the parenchyma and/or periventricular leucomalacia. In the group with periventricular leucomalacia there was also a greater risk of mental retardation with severe behavioural problems. Follow-up at a later age than 3 1/2 years will be necessary to determine the effects on the motor, intellectual and emotional development of these children.

Prediction of cerebral palsy in very low birthweight infants: prospective ultrasound study

The value of regular cerebral ultrasound scanning in predicting cerebral palsy (CP) was assessed in very low birthweight infants. The infants were scanned before discharge, and their vision and hearing were assessed at age 9 months and neurodevelopment was assessed at 18 months. Ultrasound abnormalities, defined before the study, were periventricular haemorrhage (PVH), "prolonged flare" (echodensity persisting in the periventricular white-matter for more than 2 weeks without cavitating), and cystic periventricular leukomalacia (PVL). The incidence of these three conditions in surviving infants was 49%, 15%, and 8%, respectively. 158 infants survived to be discharged from hospital and 156 had neurodevelopmental assessment at 18 months of corrected age. All infants with PVH alone and confined to the lateral ventricles were normal at follow-up. The presence of cysts accurately predicted abnormal outcome (94%) and was highly specific (96%). Prolonged flare predicted adverse outcome but the accuracy (79%) was less good than for cystic PVL. 12 infants had CP, and 10 of these had ultrasound evidence of PVL. 8 of the 13 infants with cysts had spastic CP. 4 of these were walking independently and had mild CP. No infant with ultrasound evidence of a single cyst or with cysts confined to the frontal region or centrum semiovale had severe CP. Cysts involving the periventricular white-matter in the occipital region were associated with a poor prognosis. Echolucent cystic lesions detected by ultrasound in the neonatal period accurately predict adverse outcome, and if multiple and present in the occipital region, confer a very high risk of severe CP.

Early and late cranial ultrasonographic appearances and outcome in very low birthweight infants

Of 798 very low birthweight infants admitted to a regional neonatal intensive care unit over a five year period, 547 were discharged home and 524 available for follow up at two to five years later. Eighty-seven infants had a major impairment. Both early and late cerebral ultrasonographic appearances gave useful prognostic information, but the presence of cystic lesions, particularly if bilateral, was highly significant. There was a close correlation between late parenchymal lesions and previous ipsilateral intraventricular haemorrhage, suggesting a causal relation.

Outcome of shunted posthemorrhagic hydrocephalus in premature infants

Patient histories of 29 infants were reviewed whose birth weights were less than 2,000 gm and who had received ventricular shunts in the neonatal period for posthemorrhagic hydrocephalus. This procedure was performed at a time when routine screening of low birth weight infants for intracranial hemorrhage was not undertaken and serial lumbar puncture usually was not employed. The overall outcome was poor, with 62% of shunted infants either dying or surviving with moderate or severe handicap. Neurodevelopmental outcome was associated with the interval between the diagnosis of hydrocephalus and shunting; an adverse outcome was associated with an increased interval. Current practices for treating posthemorrhagic hydrocephalus are discussed.

Epidemiology of infantile hydrocephalus in Sweden. III. Origin in preterm infants

The aetiology of infantile hydrocephalus (IH) was studied in a population-based series of 61 children with IH born 1967-82 at less than 37 weeks of gestation. A prenatal origin was present in 17 children (28%), a pre- and perinatal in 17 (28%), a perinatal in 26 (43%) and a postnatal in one (1%). The predominant single cause was postaemorrhagic IH, which was diagnosed in 19 (31%). In addition, an undiagnosed cerebral haemorrhage was considered to be the cause in another 25%. The outcome differed between pathogenetic groups. Children with a clear onset of IH (pre-, peri- or postnatal) were found to be at high risk for early death or multiple impairments. Sixteen of 39 (41%) within these groups had died before 2 years of age and 18 of the 23 (78%) survivors showed major neurological dysfunction. This contrasted to no mortality and 41% major dysfunction in children with a less clear onset of IH. A new subgroup consisting of infants born before 28 weeks of gestation emerged in the early 1980s. All infants with IH in this group developed a severe multihandicap condition.

EEG depression and germinal layer haemorrhage in the newborn

Amplitude integrated EEG (aEEG) recordings from 32 mechanically ventilated infants, gestational age 32 weeks or less, were analysed. All recordings were started within 24 h of birth and continued for at least 50 h. Germinal layer haemorrhage (GLH) was diagnosed by repeated ultrasonography. In six infants neither GLH nor hypocalcaemia were diagnosed; aEEG in these infants rapidly became more active after birth: at 30 h of age continuous background activity was present for more than 20% of the time, and a seizure-like pattern was exceptional. In seven infants without GLH but with hypocalcaemia and other signs of metabolic derangement, continuous background activity appeared later and seizure-like activity was frequent. In the infants with GLH, depression of the background activity was apparent. This finding was particularly distinct in the presence of severe haemorrhages. Four infants developed GLH after 30 h of age. All these infants had depressed aEEG before the development of GLH, with less than 20% continuous activity at 30 h of age. In ten infants an analysis of the aEEG during the occurrence of GLH was possible. In six of these, cortical electrical activity decreased. Due to the limitation of GLH timing, it was not possible to decide whether this decrease closely preceded or followed GLH. We suggest that GLH primarily occurs in brains with a preceding metabolic and neurophysiologic abnormality, and that further functional deterioration is caused by the most severe haemorrhages.

Real time ultrasound, arterial pulsation and neonatal cerebral infarction

This paper describes an infant whose cranial ultrasound scan showed marked unilateral cerebral arterial pulsation and enlargement without other abnormality. Subsequent computerized tomogram showed extensive cortical infarction in an area not readily accessed by ultrasound. It is concluded that the real time dimension of cranial ultrasound is of diagnostic value in the absence of demonstrable parenchymal or intraventricular abnormality.

Periventricular intraparenchymal cerebral haemorrhage in preterm infants: the role of venous infarction

Haemorrhage into cerebral parenchymal tissue supero-lateral to the angles of the lateral ventricles is a major cause of death and disability in preterm infants. It is frequently associated with germinal layer and intraventricular haemorrhage but the mechanism by which parenchymal haemorrhage occurs is uncertain. Recent studies have suggested that it is due to bleeding into tissue previously damaged by ischaemia following cerebral hypoperfusion. We have studied 68 preterm infant brains, of which four contained early intraparenchymal haemorrhage supero-lateral to the angles of the lateral ventricles which were associated with large germinal layer and intraventricular haemorrhages. The anatomical distribution and histological features of these haemorrhages suggested that they resulted from venous infarction and that the venous drainage of the periventricular tissues had been obstructed by the germinal layer haemorrhages. In these four infants, bleeding into parenchymal tissues could be regarded as a complication of germinal layer and intraventricular haemorrhage rather than of cerebral hypoperfusion.

Probability of neurodevelopmental disorders estimated from ultrasound appearance of brains of very preterm infants

The neurodevelopmental status of 342 very preterm infants who had undergone prospective ultrasound brainscans was assessed at a median corrected age of 52 weeks. The probabilities for neurodevelopmental disorders were calculated according to the ultrasound findings. The results showed that the probability of a major or minor disorder was low for infants whose scans did not show periventricular haemorrhage or markedly increased parenchymal echodensities in the first week of life, and for those whose scans at discharge gave no evidence of ventricular dilatation, hydrocephalus or cerebral atrophy. By contrast, the probability of a disorder was very high for infants with markedly increased parenchymal echodensities in the first week, and for infants with evidence of cerebral atrophy at discharge. The majority of the infants could be assigned, on the basis of the ultrasound scan at discharge, either to a large group who were at low risk of neurodevelopmental disorders or to a small group who were at high risk; the remainder were at intermediate risk. These findings may be used as a guide to the prognosis for other infants whose ultrasound scans show similar appearances.

Periventricular leucomalacia and neurodevelopmental outcome in preterm infants

During an 18 month period, 120 preterm infants of 34 weeks' gestation or less were prospectively examined for periventricular leucomalacia (PVL) by cerebral ultrasound. Neurological and developmental assessment was carried out at 18 months of age corrected for prematurity in 82 surviving neonates. The developmental outcome (Griffiths development quotient) was above 80 and similar in infants with normal scans (n = 41), isolated periventricular-intraventricular haemorrhage (n = 13), and post-haemorrhagic hydrocephalus (n = 4), and no major handicap was diagnosed in these groups. By contrast, the prognosis was variable and poorer in infants with PVL (n = 24) and depended on the extent and site of the lesion. Infants with frontal PVL (n = 13) developed normally. Major sequelae (n = 8) were closely related to frontal-parietal PVL and frontal-parietal-occipital PVL and could be ascribed to the presence of cysts as well as to a persistent hyperechogenic ultrasonographic PVL appearance. A relation between size and site of the lesion and type and severity of the handicap was established.

Cerebral lesions in early prematurity: EEG prognostic value in the neonatal period

The new radiological technics show the incidence of intraventricular hemorrhage (IVH), intraparenchymal hemorrhage (IPH), or of porencephaly (PL), in the neonatal period. Discrepancies between the initial extent of lesions and the outcome have been observed. We tried to appreciate the EEG value in infants having had such lesions during the first month of life. We studied serial EEGs and neuroradiological exams in 34 babies: with IVH (group I, 17 cases), with IPH and/or PL (group II, 17 cases). Their gestational age (GA) was between 27 and 34 weeks; they all had a neurological follow-up between one and five years. Infants with favourable outcome (76% in gr. I, 47% in gr. II) had normal or slightly abnormal EEGs, whatever the extent of lesions. Nine babies had very abnormal EEGs (numerous positive rolandic spikes (PRSs) and/or EEG background without physiological rhythms); one developed moderate sequelae, the other 8 major sequelae (2 with infantile spasms). In gr. II, babies with major sequelae had a higher GA than babies with good outcome. The PRSs were more often observed with periventricular lesions than with IVH only and in babies with higher GA; they lasted up to 12 weeks on serial EEGs in one case with porencephaly (major sequelae with infantile spasms); they appeared before scan abnormality in another case which developed later porencephaly (major sequelae). Thus, EEGs give valuable information on brain function and help to forecast outcome in premature babies.

Head size, brain growth, and lateral ventricles in very low birthweight infants

Ninety eight newborn infants weighing less than 1500 g at birth and with gestational ages from 26 to 32 weeks were followed prospectively. They were grouped according to real time ultrasound scans in the neonatal period: infants in group A (n = 20) had periventricular haemorrhage (PVH) and normal ventricles; infants in group B (n = 26) had PVH and dilated ventricles (none with clinical hydrocephalus); and infants in group C, who formed the control group (n = 52), had no PVH and normal ventricles. At outpatient follow up a static image ultrasound scanner was used to measure the width of the lateral ventricles and brain hemispheres. The three groups of infants showed similar growth in occipitofrontal circumference, biparietal diameter, and brain hemispheres irrespective of a history of PVH or ventricular dilatation. The relation of ventricle size to biparietal diameter was similar in those infants in groups A (PVH alone) and C (controls) who had a good outcome. About a third (n = 8) of the infants in group B had persistent ventricular dilatation in relation to biparietal diameter and a poor outcome associated with developmental delay and cerebral palsy. By contrast, the remaining two thirds (n = 18) of the infants in group B who later had smaller ventricles in relation to biparietal diameter showed fewer neurodevelopmental sequelae. It is suggested that persistent ventricular dilatation in relation to biparietal diameter at follow up carries a bad prognosis, which might be due to brain atrophy.

Obstetrical and neonatal risk factors in very low birth weight infants related to their neurological development

An analysis of pre- and perinatal risks in very low birth weight (VLBW) infants showed that children later suffering from severe neurodevelopmental sequelae were exposed to a significantly higher number of risk factors compared to normally developed VLBW controls. This was not only due to a higher incidence of specific risks, but to the accumulation of risk factors, which consequently made an ischaemic or haemorrhagic brain lesion more likely to occur. This result suggests that brain lesions in VLBW infants are essentially multifactorial. The improved outcome of VLBW infants cared for in the NICU of the Children's Hospital of Tübingen during 1977-1983 was accompanied by a decreasing incidence of obstetrical and neonatal risks. This was mainly due to more frequent transport in utero, earlier obstetrical intervention, and immediate postnatal stabilization of the infant's condition. These changes in perinatal care strategy evidently favoured the postnatal course and thus also improved the neurodevelopmental outcome.

Motor and cognitive development of infants with intraventricular hemorrhage, ventriculomegaly, or periventricular parenchymal lesions

Two hundred twenty-six moderate- or high-risk newborn infants were studied to examine the relationship between ultrasound findings in the newborn period and at 6 months and motor and cognitive deficits at 1 year. A three-part classification of abnormal ultrasound findings was used to grade intraventricular hemorrhage, ventriculomegaly, and parenchymal lesions. Abnormal ultrasound findings were observed in 48 infants, of whom 21 had intraventricular hemorrhage, 18 persistent ventriculomegaly, and nine parenchymal lesions. The incidence of deficits was as follows: normal ultrasound examination, 20%; intraventricular hemorrhage, 33%; persistent ventriculomegaly, 67%; and parenchymal lesions, 89%. The present study indicates that serial ultrasound examinations are indicated in preterm newborn infants less than 1500 gm and in selected newborn infants at risk and greater than 1500 gm at birth. The three-part classification of abnormal ultrasound findings should be used because of the predictive significance of persistent ventriculomegaly and parenchymal lesions for motor and cognitive deficits at 1 year of age.

Neurodevelopmental outcome of periventricular haemorrhage and leukomalacia in infants 1250 g or less at birth

The brains of 50 consecutively admitted infants weighing 1250 g or less at birth were serially examined beyond the neonatal period for periventricular haemorrhage and for periventricular leukomalacia with real-time ultrasound. There was significant correlation between the presence or absence and the severity of haemorrhage with survival. A prospective neurodevelopmental assessment was completed at 2 years of age, corrected for prematurity, on all survivors. None of the 20 survivors with normal scans or germinal layer haemorrhages had evidence of major disability and all four survivors with intracerebral haemorrhage or periventricular leukomalacia had major disability. The mental performance on the Bayley scales of infant development was also significantly worse in the latter group. Six of the eight survivors with intraventricular haemorrhage had no major disability, including three who had post-haemorrhagic hydrocephalus. Our results showed that cerebral ultrasound detection of brain pathology is a good predictor of neurodevelopmental outcome in such extremely low birthweight infants. However, as the maximum extent of periventricular haemorrhage may develop beyond one week of age and cystic periventricular leukomalacia commonly develops after the neonatal period, serial scanning is mandatory to ensure diagnostic accuracy for both periventricular haemorrhage and leukomalacia.

Ocular sequelae of preterm birth and their relation to ultrasound evidence of cerebral damage

The eyes of 177 very preterm (less than 33 weeks' gestation) infants, born between 1979 and 1982 and admitted to a neonatal intensive care unit, were examined as part of an ongoing follow-up study of neurodevelopmental outcome. Ocular pathology was diagnosed in 37 (21%) of the 177 infants: 14 (8%) had retinopathy of prematurity (ROP)--progressive in three--and nine (5%) infants had delayed visual maturation (DVM). The ocular pathology was permanent in 26 (15%) of the 177 infants. Refractive errors were the commonest problem and accounted for permanent sequelae in eight of the 14 infants with ROP and two of the nine with DVM. The presence or absence of ROP was related to a wide range of prospectively coded perinatal variables and to the results of routine neonatal ultrasound brain scans and neurodevelopmental follow-up assessments made in the first 18 months of life. As in previous studies, infants with ROP were of shorter gestation, lower birth weight, and required oxygen therapy for longer than unaffected infants, but the condition was only weakly associated with other indices of respiratory illness. In contrast, ROP was strongly associated with evidence of brain damage, often consistent with hypoxic ischaemic injury. We conclude that an underlying lesion in ROP may be hypoxic ischaemic damage to the retinal circulation.

Impaired energy metabolism in brains of newborn infants with increased cerebral echodensities

Intracellular energy metabolism was studied by phosphorus magnetic resonance spectroscopy in the brains of 27 preterm and term infants with increased echodensities consistent with hypoxic-ischaemic injury and 18 comparable normal infants. In the normal infants the phosphocreatine (PCr)/inorganic orthophosphate (Pi) ratio increased significantly from 0.77 +/- 0.24 (95% confidence limits) at a gestational plus postnatal age of 28 weeks to 1.09 +/- 0.24 at 42 weeks. 9 of the 15 infants with increased echodensities whose PCr/Pi ratios fell below the normal range died; in all 6 survivors cerebral atrophy developed (cysts in brain tissue or microcephaly). In contrast, all 12 infants with increased echodensities whose PCr/Pi ratios remained within the normal range survived, although cerebral atrophy developed in 3 with ratios towards the lower limit of normal.

Periventricular leukomalacia: ultrasonic diagnosis and neurological outcome

The ultrasonographic findings and neurological development of 15 preterm infants, born between August 1981 and July 1984, who developed periventricular leukomalacia (P.V.L.) are described. The incidence of P.V.L. in infants with a birth weight less than 1 500 g was 2.3%. Nine of the 15 infants demonstrated areas of increased echogenicity in the periventricular regions prior to the development of cystic changes. The mean age for the appearance of cysts was 26 days. At follow-up 14 infants showed evidence of abnormal motor development and 8 infants had visual defects. All infants appear to have normal hearing, but 3 infants show signs of delayed speech. To date, only 2 infants demonstrate signs of mental retardation, but many of the infants are too young to assess intelligence accurately.

Developmental outcome of infants with severe intracranial-intraventricular hemorrhage and hydrocephalus with and without ventriculoperitoneal shunt

Thirty-six infants who developed grade III and IV intraventricular hemorrhages during the neonatal period were followed up to determine their developmental quotient. All of these infants had ventriculomegaly and 15 of them required a ventriculoperitoneal (VP) shunt during the neonatal period prior to discharge from Intensive Care Nursery. The mean developmental quotient for the infants with the VP shunt was 67.93. The mean developmental quotient for the infants with ventriculomegaly but no VP shunt was 88.71 (P less than 0.02). Among the nonshunted group of infants, 13 (61.9%) had developmental quotients greater than 85, and among the shunted group 5 infants (33.3%) had developmental quotients greater than 85. Fifty percent of the total group of infants had normal developmental quotients at a mean chronological age of 16.25 +/- 7.5 months (and corrected age 14 months). Infants developing posthemorrhagic hydrocephalus and requiring VP shunts had a poorer developmental outcome compared to those who did not require shunts.

Cerebral blood flow in preterm infants during the first week of life

Forty-two preterm infants of 28-33 weeks of gestation were studied once during the first week of life by 133-Xenon clearance after intravenous injection to estimate global cerebral blood flow. Count rates detected over the chest were corrected for chest wall contribution and used as arterial input function. A neonatal blood-brain partition coefficient of Xenon was used for the calculation of a mean flow estimator (CBF-infinity). The technique was internally validated by use of differently obtained arterial input functions. In 11 infants without respiratory distress, CBF-infinity was 19.8 ml/100 g/min +/- 5.3 SD. In 24 infants treated with mechanical ventilation CBF-infinity was 11.8 ml/100 g/min +/- 3.2 SD. In 7 infants treated with continuous positive airway pressure CBF-infinity was 21.3 ml/100 g/min +/- 12.0 SD. When the reduction of CBF-infinity associated with mechanical ventilation was taken into account, the 9 infants with subependymal/intraventricular haemorrhage had increased CBF-infinity. The effects of gestational age, birthweight, mode of delivery, postnatal age, mean arterial blood pressure, PaCO2, blood haemoglobin and phenobarbitone medication were also analysed and found inconsistent. In conclusion, CBF was lower than expected and in infants requiring mechanical ventilation the values were lower still.

Status at two years in 121 very low birth weight survivors related to neonatal intraventricular haemorrhage and mode of delivery

All 121 infants with birthweight less than or equal to 1500 g (VLBW) discharged from our department through an 18-month period were followed up at two years of age. All but 10 infants were examined by cranial ultrasound scanning in the neonatal period. Six had died after discharge; and of these two had severe brain damage following neonatal intraventricular haemorrhage. Twelve children had definite neuromotor abnormality; of these, the nine children with spastic types of cerebral palsy had all been delivered vaginally. Of the remaining children, one half had at least one neurodevelopmental symptom suggesting perinatal brain damage. Outcome was associated to neonatal intraventricular/subependymal haemorrhage when complicated by ventricular dilatation. Outcome in children with simple haemorrhage was similar to that in children without haemorrhage. The association between outcome and haemorrhage was considerably reduced by simultaneously considering the associations of gestational age at birth and the use of mechanical ventilation in the neonatal period. Head circumference at follow-up was greatest in those children with haemorrhage complicated by ventricular dilatation, when adjusted for actual body weight, birth weight, and gestational age at birth.

Development of cerebral palsy after ultrasonographic detection of periventricular cysts in the newborn

Cysts in the periventricular region of the brain were demonstrated by ultrasound in eight of 102 preterm infants (birthweight less than 1501g or less than 34 weeks gestation) during a 14-month period. All eight babies survived, but developed serious neurological problems: five had spastic quadriplegia and three had spastic diplegia. Six had impaired vision and six had delayed speech development, but there was no evidence of impaired hearing. The cysts probably represent the infarcted lesions of periventricular leukomalacia.

Perinatal events which precede periventricular haemorrhage and leukomalacia in the newborn

Ultrasound brain scans were obtained daily for the first 5 days after birth, on day 7 and then weekly until discharge from hospital in 86 babies during a 12-month period. The babies weighed less than 1501 g or were less than 34 weeks gestational age. Fifty-one (59%) had normal scans, 34 (40%) developed periventricular haemorrhage, and seven (8%) developed periventricular cysts (associated with periventricular haemorrhage in six). Factors associated with periventricular haemorrhage were perinatal hypoxia, acidosis, hypercapnia and hypoxia after birth. Babies who developed periventricular cysts (periventricular leukomalacia) were more likely to have been hypoxic at birth and in four of the seven there had been a maternal antepartum haemorrhage. The association of perinatal hypoxia with periventricular haemorrhage and leukomalacia suggests that intrapartum events may predispose to the onset of these lesions which then develop postnatally. Prevention of perinatal hypoxia may play an important role in diminishing the disability caused by these conditions.

Mortality and two year outcome of infants of birthweight 500-1500 g: relationship with neonatal cerebral ultrasound data

Cranial ultrasounds were performed on 218 (96%) of 227 liveborn infants of birthweight 500-1500 g delivered in the Royal Women's Hospital, Melbourne, Australia, in an 18-month period concluding in March 1982. Seventy-two (31.7%) of the children died; 28 children (38.9%) had cerebroventricular haemorrhage, 35 (48.6%) showed no bleeding and there were nine (12.5%) with no data. Paired necropsy and ultrasound data were congruent in 22 (88%) of 25 children. One hundred and forty-eight (95.5%) of 155 survivors were seen at 2 years of age. Forty-one (28%) had cerebroventricular haemorrhage; nine children (6%) had both ventricular dilatation and haemorrhage and two had ventricular dilatation alone. Apart from a marginal advance in gestation and higher number of immigrant and less educated mothers in children without cerebroventricular haemorrhage, all other perinatal, biographical and social variables between those with haemorrhage and those without were similar. The major handicap rate overall was 14.2% (21 patients). The children with cerebroventricular haemorrhage had a trend for greater prevalence of handicap and lower mean Bayley psychological scores. This was even more evident with ventricular dilatation being present. Of children with major handicap 57.1% (12/21) had normal serial ultrasound findings during their primary hospitalization. Major handicap occurred in 15% (3/20) of children with grade 1 haemorrhage, 23.5% (4/17) with grade 2 or 3 bleeds and 25% (1/4) of those with grade 4 haemorrhage. Laterality of cerebral palsy did not correlate with ultrasound findings. Ultrasound findings did not improve statistical prediction of deaths or major handicap.

Cerebrospinal fluid pressure during post haemorrhagic ventricular dilatation in newborn infants

Post haemorrhagic ventricular dilatation occurs in a minority of newborn infants, but is associated with a high risk of cerebral palsy and developmental delay. Neither the relation of ventricular size to cerebrospinal fluid (CSF) pressure, nor the effect of CSF removal on prognosis, have been established. Normal CSF pressure measured at subarachnoid cannulation was mean (SD) 2.8 (1.4) mm Hg. Values were significantly higher in post haemorrhagic ventricular dilatation--9.1 (3.7) mm Hg when the ventricles were expanding, and 4.5 (2.4) mm Hg when they were static or contracting. No significant relation between head circumference and CSF pressure was found in this series. Raised CSF pressure is associated with progressive ventricular dilatation, and may contribute to the increased risk of neurological abnormality.

Neurodevelopmental outcome at 12 months of age related to cerebral ultrasound appearances of high risk preterm infants

A prospective neurological and developmental assessment at 12 months of age corrected for prematurity was performed on 54 surviving preterm infants of 34 weeks' gestation or less. The babies were allocated into three groups according to their ultrasound (US) appearances: Group I (n = 29), normal scan; Group II (n = 10), isolated periventricular-intraventricular haemorrhage (PVH); Group III (n = 15), association of PVH, periventricular leukomalacia (PVL) and ventricular dilatation. The developmental outcome evaluated with the Griffiths' development quotient (DQ) was good and similar in Groups I and II, while it was worse and variable in Group III. There was also a higher incidence of neurological abnormalities in Group III, as 47% of children only were found to be normal compared to 86% and 80% in Groups I and II, respectively. A major handicap was diagnosed in 5 children of Group III. Infants with small lesions of PVH or PVL or with ventricular dilatation developed as well as children with normal US scan, whereas more diffuse or extensive US changes of PVL had a poorer prognosis. The outcome of a cerebral injury seems to depend on the type, the size and localisation of the lesion, and to some extent, on the neuroplasticity of the developing brain.

Cranial ultrasound and clinical studies in preterm infants

Serial ultrasound imaging of the brain was used to determine the ventricular index (VI), and the ratio (VR) of the VI to the cranial hemidiameter during the nursery course and first year post-term in preterm infants of less than 33 weeks gestation. Twenty-nine of the infant survivors with no intracranial hemorrhage or major medical complication during their nursery course composed group 1. Twenty-two survivors with intracranial hemorrhage unassociated with early ventricular dilation composed group 2. Group 3 was comprised of 10 other survivors who had neonatal intraventricular hemorrhage with early ventriculomegaly; all 10 infants had at least one major medical complication during their neonatal course. In groups 1 and 2 the VR decreased and the VI increased significantly with age post-conception. Infants in group 3, compared with those in groups 1 or 2, had decreased occipitofrontal growth during the early postnatal period and increased VR and VI during the neonatal period and first year post-term. These results suggest that the ventriculomegaly associated with neonatal intracranial hemorrhage cannot be explained by posthemorrhagic hydrocephalus alone and may also be related to cerebral atrophy or decreased brain growth or both. Neurodevelopmental assessments at 20 to 30 months of age disclosed significantly lower Bayley Motor Development scores in group 3 compared with groups 1 or 2. Four infants in group 3, but none in groups 1 or 2, had cerebral palsy. The neurodevelopmental deficits in group 3 infants may reflect the complex pathogenesis of the ventriculomegaly as well as the effects of the intraventricular hemorrhage and posthemorrhagic hydrocephalus.

Identification of sensory neural hearing loss in very preterm infants by brainstem auditory evoked potentials

Brainstem auditory evoked potentials were recorded in 117 newborn infants of less than 33 weeks of gestation. The potentials were absent in 10 infants (bilaterally in eight and unilaterally in two) and present in 107. By 1 year of age nine of the 10 infants with absent brainstem auditory evoked potentials were shown to have sensory neural hearing loss and required hearing aids: the remaining infant had secretory otitis media. None of the 107 infants whose auditory evoked potentials were present were found to have sensory neural hearing loss but 13 had secretory otitis media. Measurement of brainstem auditory evoked potentials is an accurate method of identifying sensory neural hearing loss in very preterm infants.

Progressive ventriculomegaly following minor intracranial hemorrhage in premature infants

Progressive hydrocephalus following subependymal-intraventricular hemorrhages (SEH-IVH) in premature infants has been noted after moderate to severe degrees of hemorrhage. The ventricular dilatation often has been noted to resolve spontaneously, or not continue to progress after four weeks of age. 11 premature infants with moderate to marked degrees of ventricular enlargement following minor degrees of SEH-IVH have been identified over an 18-month period, and in six of these infants the dilatation continued to progress after one month of age. This sequence of events has not been well documented, and it emphasizes the need to closely follow all infants who have sustained any degree of intracranial hemorrhage. The authors recommend routine real-time ultrasound brain-scans at one month of age for all infants with SEH-IVH, and continued close observation with serial head-measurements of those with enlarged ventricular systems at that time.

Factor V deficiency and antenatal intraventricular haemorrhage

Serial obstetric ultrasound showed the development of asymmetrical ventricular dilatation between 28 and 32 weeks' gestation. After delivery at 38 weeks, progressive ventricular dilatation required a ventriculo-atrial shunt. Investigation of postoperative bleeding into the cerebral ventricles consistently showed factor V values of only two per cent.

Acquired perinatal leukoencephalopathy

Between 36 and 44 weeks after conception, telencephalic white matter in the newborn appears to be particularly vulnerable to insults that result in morphological disturbances. Available evidence indicates that this disorder (or group of disorders), named acquired perinatal leukoencephalopathy, reflects a decrease in blood flow through the distal vessels supplying paraventricular white matter and/or a metabolic disturbance produced by, or in response to, an infectious agent. Major advances in our understanding of the causes, mechanisms, and sequelae of acquired perinatal leukoencephalopathy may be made in the next decade because of improvement in brain imaging techniques, improved survival of high-risk babies, and relatively routine follow-up of these high-risk babies.