Janice Townsend

RELATION BETWEEN ULTRASOUND APPEARANCE OF THE BRAIN OF VERY PRETERM INFANTS AND NEURODEVELOPMENTAL IMPARIMENT AT EIGHT YEARS

The relation between the ultrasound appearance of the brain and neurodc.velopmenial outcome aT eight years oi age was investigated in 206 infants born berwecn 1979 and 1992 at <3 3 wecks gestation (600 to ZSOOg birthweights). Only 4 prr cent of the 112 infants with normal scans at discharge from the neonatal unir developed major. disabling impairment. No signiiicant adverse effect of uncomplicated periventricular haemorrhage was detected. The probability of a major impairment in infants with ventricular dilatation or hydroccphalus was 27 per cent, and 69 per cent in those with cerebral atrophy. 4‐1 per cent of the children demonstrated significant differcnccs in their cognitive processing skills, which appeared capable of affecting learning and may possibly habc been caused by undetected hyposic‐ischaemic damage 10 callosal fibres.

Relation of deranged neonatal cerebral oxidative metabolism with neurodevelopmental outcome and head circumference at 4 years

Cerebral oxidative metabolism was studied using phosphorus magnetic resonance spectroscopy during the first week of life and neurodevelopmental outcome was assessed at 4 years in 62 infants who had clinical and/or biochemical evidence consistent with birth asphyxia (critically impaired intrapartum gas exchange). Twenty‐one died and the neurodevelopmental status of the 41 who survived was assessed by a range of tests at age 4 years. The minimum recorded values for the cerebral phosphocreatine:inorganic phosphate concentration ratio (an index of oxidative metabolism) were related to outcome. The results showed significant relations between the extent of derangement of neonatal oxidative metabolism and a range of adverse outcomes, including death, and at 4 years reduced head growth and the presence and severity of neuromotor impairments, overall neurodevelopmental impairments, and cognitive functioning. Strong correlations between the extent of derangement of neonatal oxidative metabolism and outcome at 1 and 4 years were also shown. We conclude that the severities of adverse outcomes at 1 and 4 years of age were closely related to the extent of cerebral energy derangement in the first week of life, and we also conclude that primary intrapartum hypoxic‐ischaemic cerebral injury was generally responsible for the events that led to death, microcephaly, and impaired

Relationship between neurodevelopmental status of very preterm infants at one and four years.

The neurodevelopmental status of 171 very preterm infants was assessed at one and four years of age. At one year 17 had major impairments and 14 had minor ones. At four years the numbers had increased to 25 with major and 25 with minor impairments. Infants with no impairments at one year had a 4 per cent probability of a major impairment at four years, whereas infants with a major impairment had a 94 per cent probability. Infants who later proved to have major neuromotor impairments had been accurately identified at one year, as had infants with sensorineural hearing‐loss. Infants with minor impairments of tone and reflexes at one year did not develop cerebral movement disorder, but as a group their scores on tests of cognitive functioning were low. An additional group of infants with cognitive impairments was identified who were unimpaired at one year. The emergence of cognitive deficits largely accounted for the increase in impairments between one and four years.

Abnormal cerebral haemodynamics in perinatally asphyxiated neonates related to outcome

AIM To measure changes in cerebral haemodynamics during the first 24 hours of life following perinatal asphyxia, and relate them to outcome. METHODS Cerebral blood volume (CBV), its response (CBVR) to changes in arterial carbon dioxide tension (PaCO2), and cerebral blood flow (CBF) were measured using near infrared spectroscopy (NIRS) in 27 term newborn infants with clinical and/or biochemical evidence consistent with perinatal asphyxia. RESULTS Both CBF and CBV were higher on the first day of life in the infants with adverse outcomes, and a CBV outside the normal range had a sensitivity of 86% for predicting death or disability. The mean (SD) CBVR on the first day of life was 0.13 (0.12) ml/100 g/1/kPa, which, in 71% of infants, was below the lower 95% confidence limit for normal subjects. CONCLUSION An increase in CBV on the first day of life is a sensitive predictor of adverse outcome. A reduction in CBVR is almost universally seen following asphyxia, but is not significantly correlated with severity of adverse outcome.

Early brain proton magnetic resonance spectroscopy and neonatal neurology related to neurodevelopmental outcome at 1 year in term infants after presumed hypoxic-ischaemic brain injury

This study investigated the accuracy of prediction of neurodevelopmental outcome at 1 year using cerebral proton magnetic resonance spectroscopy (MRS) and structured neonatal neurological assessment in term infants after presumed hypoxic–ischaemic brain injury. Eighteen control infants and 28 infants with presumed hypoxic–ischaemic brain injury underwent proton MRS investigation. Studies were carried out as soon as possible after the cerebral insult, most within 48 hours. Infants had an early structured neurological assessment at a median of 19 hours (range 0 hours to 9 days) from the presumed hypoxic–ischaemic insult and a late assessment at a median of 7 days (range 3 to 25 days) during recovery. The maximum cerebral peak–area ratio lactate:N‐acetylaspartate measured by proton MRS accurately predicted adverse outcome at 1 year with a specificity of 93% and positive predictive value of 92%. Neurological assessment had a tendency for false‐positive predictions. However, both early and late neurological examination can be used as a reliable indicator for a favourable outcome at 1 year having negative predictive values of 100% and 91% respectively.

PREDICTION OF NEURODEVELOPMENTAL IMPAIRMENT AT FOUR YEARS FROM BRAIN ULTRASOUND APPEARANCE OF VERY PRETERM INFANTS

The neurodevelopmental status of 171 very preterm infants whose brains had been scanned prospectively with ultrasound was assessed blind at four years using a wide range of tests, including tests of cognitive function. Highly significant correlations were found between the ultrasound appearance of the brain and outcome. The probability of a major neurodevelopmental impairment among the 137 children who had a normal ultrasound scan or uncomplicated periventricular haemorrhage at discharge from the unit was 7 per cent; and for any neurodevelopmental impairment (major plus minor) it was 22 per cent. The probabilities for major, or any, neurodevelopmental impairment among the 18 children who had ventricular dilatation were 33 and 50 per cent, respectively; and for the 16 with hydrocephalus and/or cerebral atrophy (loss of brain‐tissue from any cause) the probabilities were 56 and 69 per cent. Impairments predicted from lesions detected by ultrasound were largely neurological. There was no evidence that cognitive impairments could be predicted among infants free of neurological impairments.

Neurodevelopmental status at 1 year predicts neuropsychiatric outcome at 14–15 years of age in very preterm infants

BACKGROUND Neurodevelopmental and behavioural problems have been repeatedly reported in very preterm survivors, often showing themselves later in childhood as poor school performance. Early identification of problems would mean that appropriate remedial therapy can be implemented. We have previously shown that neurodevelopmental status at 1 year was predictive of outcome at 8 years in a cohort of preterm infants. The aim of this paper was to see if neurodevelopmental outcome in adolescence could be predicted by assessment by 1 year in the same cohort of preterm infants. STUDY DESIGN Prospective cohort study. SUBJECTS 150 adolescents, born before 33 weeks gestation. OUTCOME MEASURES Neurological examination, developmental quotient, vision and hearing by 1 year. At 14-15 years, neurological examination, school performance questionnaire, Schonnell test of reading age, a premorbid adjustment score, Rutter behavioural score and for those born from 1981, cognitive tests (WISC-R). RESULTS A highly significant relationship existed between neurological status by 1 year and the need for extra educational provision, overall neurodevelopmental status, cognitive function in those that had their IQs measured and premorbid adjustment score of prepsychotic symptoms in adolescence. However, status at 1 year was not predictive of adolescent reading age or behavioural score. CONCLUSIONS Neurodevelopmental assessment at 1 year is predictive of school performance and outcome in the adolescent period.

A comparision of linear-array and mechanical-sector cranial ultrasound scanning techniques to predict neurodevelopmental outcome at 8 years in preterm newborn infants

Two methods of neonatal cranial ultrasound (US) scanning, linear-array and mechanical-sector, were compared for their accuracy in predicting neurodevelopmental outcome in a cohort of 854, of whom 782 (92%) infants, all born less than 33 weeks of gestation and cared for on the Neonatal Intensive Care Unit at University College Hospital, London between 1979 and 1988, were included in the analysis. A total of 205 infants were studied by linear-array and 577 infants by mechanical-sector scan. Ultrasound findings were grouped into three risk categories on the basis of the US diagnosis. Outcome was assessed at 8 years of age. The probability estimates for neurologically disabling and nondisabling impairments, extra education and mean IQ were compared for the two US methods. There was no significant difference between the two methods in the accuracy of prediction of neurodevelopmental outcome.

Does Neonatal Ultrasound (US) Predict Mri Findings in Adolescence? 129

Hypothesis: in very preterm (VPT) subjects at 14 years a) serious neonatal US lesions persist b) MRI identifies more lesions than US.

Preterm Infants and Controls : Comparison of Brain MRI at 14 Years. 130

Hypothesis: at 14 years, subjects born before 33 weeks of gestation (VPT) have more brain lesions than their peers born at term.