Neuroimaging and neurodevelopmental outcome of preterm infants with a periventricular haemorrhagic infarction located in the temporal or frontal lobe

AIM

The aim of the study was to compare clinical and neuroimaging characteristics and neurodevelopmental outcome in preterm infants with a periventricular haemorrhagic infarction (PVHI) located in the temporal or frontal periventricular white matter.

METHOD

The study was a retrospective hospital-based study of preterm infants with a frontal PVHI (n=21; 11 males, 10 females; mean birthweight 1527g; mean gestational age 30.3wks) or temporal PVHI (n=13; five males, eight females; mean birthweight 1205g; mean gestational age 30.2wks) admitted to the neonatal intensive care unit between 1990 and 2012. The clinical course, results of neuroimaging studies, and neurodevelopmental outcomes of preterm infants with a gestational age less than 34 weeks with a confirmed PVHI on early cranial ultrasonography and/or magnetic resonance imaging were reviewed. For assessment of neurodevelopmental outcome we used the Griffiths Mental Development Scales, the Movement Assessment Battery for Children, the Gross Motor Function Classification System, the Wechsler Preschool and Primary Scale of Intelligence, the Child Behavior Checklist, and ophthalmological assessment. An unfavourable neurodevelopmental outcome was defined as moderately or severely atypical neurological examination during the last visit: presence of cerebral palsy, epilepsy, a hearing or visual impairment, and/or atypical cognitive development (Griffiths Mental Development Scales developmental quotient or Wechsler Preschool and Primary Scale of Intelligence <85).

RESULTS

Unfavourable outcome was observed in 12 out of 13 children with a temporal PVHI compared with six out of 21 children with a frontal PVHI (p=0.002). Only one of the included infants with a PVHI in the temporal white matter developed cerebral palsy, which was due to a parietal PVHI in the contralateral hemisphere. Cognitive impairment was noted in seven infants with a frontal PVHI and five with a temporal PVHI. There were more infants with a temporal PVHI who developed visual impairment (n=5) or behavioural problems (n=7) compared with those with a frontal PVHI (visual impairment (n=2), behavioural problems (n=3).

INTERPRETATION

PVHI located in the temporal or frontal lobe is almost invariably related to a typical motor outcome, but carries a risk of cognitive, behavioural, and visual problems, especially in infants with a PVHI located in the temporal lobe.

Hydrocortisone treatment for bronchopulmonary dysplasia and brain volumes in preterm infants

OBJECTIVE

To assess whether there was an adverse effect on brain growth after hydrocortisone (HC) treatment for bronchopulmonary dysplasia (BPD) in a large cohort of infants without dexamethasone exposure.

STUDY DESIGN

Infants who received HC for BPD between 2005 and 2011 and underwent magnetic resonance imaging at term-equivalent age were included. Control infants born in Geneva (2005-2006) and Utrecht (2007-2011) were matched to the infants treated with HC according to segmentation method, sex, and gestational age. Infants with overt parenchymal pathology were excluded. Multivariable analysis was used to determine if there was a difference in brain volumes between the 2 groups.

RESULTS

Seventy-three infants treated with HC and 73 matched controls were included. Mean gestational age was 26.7 weeks, and mean birth weight was 906 g. After correction for gestational age, postmenstrual age at time of scanning, the presence of intraventricular hemorrhage, and birth weight z-score, no differences were found between infants treated with HC and controls in total brain tissue or cerebellar volumes.

CONCLUSIONS

In the absence of associated parenchymal brain injury, no reduction in brain tissue or cerebellar volumes could be found at term-equivalent age between infants with or without treatment with HC for BPD.

Ultrasound measurements of the lateral ventricles in neonates: why, how and when? A systematic review

Germinal matrix-intraventricular haemorrhage and subsequent post-haemorrhagic ventricular dilatation (PHVD) are frequently encountered complications in preterm neonates. As progressive dilatation of the lateral ventricles may be associated with elevated intracranial pressure, ultrasound measurements of ventricular size play a major role in the evaluation of neonates at risk of ventricular dilatation as well as in assessing the effect of intervention for PHVD. A systematic search was carried out in Medline and Embase to identify neonatal and foetal ultrasound studies on lateral ventricular size. This review presents an overview of the available data concerning neonatal reference values for lateral ventricular size, the influence of gender, ventricular asymmetry and the effect of the mode of delivery on the phenomenon of ventricular reopening following birth.

CONCLUSION

Serial cranial ultrasound measurements of the lateral ventricles play a key role in the early recognition and therapeutic evaluation of post-haemorrhagic ventricular dilation and can be of prognostic value in neonates with ventricular dilatation.

Long-term effects of neonatal hydrocortisone treatment for chronic lung disease on the developing brain and heart

Despite modern perinatal intensive care techniques, chronic lung disease remains a problem in preterm-born infants. The most commonly and almost exclusively prescribed drug to treat this disorder is dexamethasone. Corticosteroids improve short-term respiratory function; however, many side-effects have been reported and the adverse long-term effects of dexamethasone on neurodevelopment are particularly alarming. Hydrocortisone could be a suitable alternative for dexamethasone, if equally effective with fewer side-effects. This review evaluates the current literature on neonatal hydrocortisone treatment for chronic lung disease with regards to long-term neurodevelopmental outcome and cardiovascular effects. The neurodevelopmental studies do not show any adverse effects of hydrocortisone on neurocognitive and motor outcome, nor on incidence of brain abnormalities on magnetic resonance imaging or on long-lasting programming effects on the hypothalamus-pituitary-adrenal axis. At school age, cardiovascular stress response was the same in hydrocortisone-treated children compared with a reference group. Hydrocortisone seems a safe alternative to dexamethasone, but more double-blind randomised studies are needed.

Corpus callosum size in relation to motor performance in 9- to 10-year-old children with neonatal encephalopathy

Magnetic resonance imaging studies have contributed to recognize the patterns of cerebral injury related to neonatal encephalopathy (NE). We assessed whether a smaller corpus callosum (CC) explained the difference in motor performance between school-age children with NE and controls. Frontal, middle, and posterior areas of the CC were measured in 61 9-10-y-old children with NE and in 47 controls. Motor performance was determined using the Movement Assessment Battery for Children (M-ABC). Linear regression was used to assess whether differences in M-ABC between NE children and controls could be explained by CC size. The CC of 11/30 children with NE type I according to Sarnat (NE I) and 19/36 children with NE type II according to Sarnat (NE II) showed generalized or focal thinning, compared with 8/49 controls. Children with NE II had significantly smaller middle and posterior parts and total areas of the CC. Children with NE scored significantly worse on the M-ABC than controls. The reduction in size of the posterior part of the CC partly explained the mean differences on the M-ABC. Children with NE have poorer motor skills than controls, which is partly explained by a smaller size of the CC.

Postnatal hydrocortisone treatment for chronic lung disease in the preterm newborn and long-term neurodevelopmental follow-up

The benefits versus the risks of postnatal administration of steroids in preterm-born infants are still debatable. This review examines the literature on postnatal hydrocortisone treatment for chronic lung disease (CLD) in preterm-born infants with a particular focus on the effects of such treatment on long-term neurodevelopmental outcomes. Quantitative published evidence does not point to a clear advantage of treatment with hydrocortisone over dexamethasone with regard to the impact on long-term neurological outcomes. However, in the absence of a randomised comparison, a consensus may soon have to be reached on the basis of the best available evidence whether hydrocortisone should replace dexamethasone in the treatment of CLD.

Neonatal hydrocortisone treatment: neurodevelopmental outcome and MRI at school age in preterm-born children

OBJECTIVE

To investigate neurodevelopment at school age in preterm infants treated with hydrocortisone for bronchopulmonary dysplasia (BPD) in the neonatal period.

STUDY DESIGN

Preterm infants (n = 226; gestational age < or = 32 weeks and/or body weight < or = 1500 grams) performed subtests of the Wechsler Intelligence Scale for Children-Revised, the Visual Motor Integration test, a 15-Word Memory Test and the Movement Assessment Battery for Children at school age. Conventional MRI of the brain was obtained. Sixty-two children who received hydrocortisone for BPD (starting dose, 5 mg/kg/day; median duration, 27.5 days) were compared with 164 nontreated neonates.

RESULTS

Hydrocortisone-treated infants were younger, lighter, and sicker than their non-steroid-treated counterparts. Adjustments for gestational age, body weight, sex, mechanical ventilation, and small for gestational age were made. Adjusted mean Intelligence Quotient, Visual Motor Integration test, and memory test results were the same in the hydrocortisone-treated group and the non-steroid-treated group (99 versus 101, P = .62; 97 versus 99, P = .49, 7.9 versus 7.5, P = .42, respectively). Motor function and incidence of cerebral palsy in both groups was not different (11% versus 7%, P = .97). Occurrence of brain lesions on MRI was similar for the two groups.

CONCLUSIONS

Neonatal hydrocortisone treatment for BPD had no long-term effects on neurodevelopment.

Incidence of infections of ventricular reservoirs in the treatment of post-haemorrhagic ventricular dilatation: a retrospective study (1992-2003)

BACKGROUND

Since 1992, infants with progressive posthaemorrhagic ventricular dilatation (PHVD) have been treated in the Neonatal Intensive Care Unit, Wilhelmina Children's Hospital, Utrecht, The Netherlands, with a ventricular reservoir.

OBJECTIVE

To retrospectively study the incidence of infection using this invasive procedure.

METHODS

Between January 1992 and December 2003, 76 preterm infants were treated with a ventricular reservoir. Infants admitted during two subsequent periods were analysed: group 1 included infants admitted during 1992-7 (n = 26) and group 2 those admitted during 1998-2003 (n = 50). Clinical characteristics and number of reservoir punctures were evaluated. The incidence of complications over time was assessed, with a focus on the occurrence of infection of the reservoir.

RESULTS

The number of punctures did not change during both periods. Infection was significantly less common during the second period (4% (2/50) v 19.2% (5/26), p = 0.029).

CONCLUSION

The use of a ventricular reservoir is a safe treatment to ensure adequate removal of cerebrospinal fluid in preterm infants with PHVD. In experienced hands, the incidence of infection of the ventricular reservoir or major complications remains within acceptable limits.

Neonatal hydrocortisone treatment related to 1H-MRS of the hippocampus and short-term memory at school age in preterm born children

Animal studies have shown that corticosteroids (dexamethasone) cause neuronal loss in the hippocampus and deficits in short term memory. Proton magnetic resonance spectroscopy can measure brain metabolites in vivo and give an indication of neuronal integrity. We investigated whether prolonged administration of hydrocortisone during the neonatal period for bronchopulmonary dysplasia (BPD) in preterm born children changes the metabolism in the hippocampus, measured at school age. Secondly, we investigated whether hippocampal metabolism and short-term memory and neurodevelopmental outcome are related. In this observational study 37 preterm born children (< or = 32 wk (range 25.0-33.0) and/or a birth weight < or = 1500 g) underwent proton spectroscopy of the hippocampus at school age. Eighteen children were treated with hydrocortisone for BPD (starting dose 5 mg/kg/d tapered over a minimum period of 22 d, median duration 28 d) and 19 never received corticosteroids during the perinatal period. N-acetyl aspartate/ Choline + Creatine/phosphocreatine (NAA/(Cho + Cr)) ratios were determined. A 15-word recall memory test and an IQ measurement were obtained on the same day. Hydrocortisone treated children were younger, lighter and sicker than their nonsteroid treated counterparts. Mean NAA/(Cho + Cr) ratios in the hippocampus were not significantly different in the hydrocortisone group compared with the non-steroid group. Performance on the 15-word memory test and IQ were similar in the two groups. There was no relation between NAA/(Cho + Cr) ratios and memory nor between NAA/(Cho + Cr) ratios and IQ. We conclude that hydrocortisone in the mentioned dose, administered in the neonatal period for BPD, does not appear to have any long-term effects on memory and/or hippocampal metabolism.

Neonatal cranial ultrasound versus MRI and neurodevelopmental outcome at school age in children born preterm

AIM

To examine the correlation between neonatal cranial ultrasound and school age magnetic resonance imaging (MRI) and neurodevelopmental outcome.

METHODS

In a prospective 2 year cohort study, 221 children (gestational age < or =32 weeks and/or birth weight < or =1500 g) participated at a median age of 8.1 years (inclusion percentage 78%). Conventional MRI, IQ (subtests of the WISC), and motor performance (Movement Assessment Battery for Children) at school age were primary outcome measurements.

RESULTS

Overall, there was poor correspondence between ultrasound group classifications and MRI group classifications, except for the severe group (over 70% agreement). There was only a 1% chance of the children with a normal cranial ultrasound having a major lesion on MRI. Mean IQ (standard deviation) was significantly lower in children with major ultrasound or MRI lesions, but was also lower in children with minor lesions on MRI compared to children with a normal MRI (91+/-16, 100+/-13, 104+/-13 for major lesions, minor lesions, and normal MRI, respectively). Median total impairment score (TIS) was significantly higher in children with major lesions on ultrasound or MRI as well as in children with minor lesions on MRI (TIS 4.0 and 6.25 for normal and minor lesions on MRI, respectively; p<0.0001).

CONCLUSIONS

A normal neonatal cranial ultrasound excluded a severe lesion on MRI in 99% of cases. MRI correlated more strongly with mean IQ and median TIS than ultrasound. Subtle white matter lesions are better detected with MRI which could explain the stronger correlation of MRI with IQ and motor performance.

Larger corpus callosum size with better motor performance in prematurely born children

The objective of this study is to determine the relation between the size of the corpus callosum (CC) and motor performance in a population-based cohort of preterm children. Preterm born children (n = 221) with a gestational age less than or equal to 32 weeks and/or a birth weight below 1500 g were eligible for this study. At the age of 7 or 8 years, frontal, middle, posterior, and total areas (mm2) of the corpus callosum were measured on true midsagittal MRI. Due to anxiety of 10 children and motion artifacts in 7 other children, 204 MRIs could be assessed in the preterm group (mean GA 29.4 weeks, sd 2.0,mean BW 1200 g, sd 323). The preterm group consisted of 15 children with cerebral palsy (CP) and 189 children without CP. Motor function was established by using the Movement Assessment Battery for Children, and the Developmental Test of Visual Motor Integration was obtained. The same examinations were performed in 21 term born children. The mean total cross-sectional CC area was significantly smaller in preterm born infants compared with their term born controls (338 mm2 versus 422 mm2, P < 0.0001). The preterm children with CP had significantly smaller mean CC areas compared with the preterms who did not develop CP (P < 0.0001-P < 0.002). However, the preterms born without CP also had significantly smaller body, posterior, and total CC areas compared with term born controls (P < 0.0001-P < 0.002). Only the difference in frontal area measurements dilrc) -3.3 mm2/score point (95% CI -4.5, -2.1). The association existed in all parts of the CC but increased in the direction of the posterior part: frontal: lrc -0.8 mm2/score point (-1.2, -0.4), middle: lrc -1.1 mm2/score point (-1.7, -0.5) and posterior: lrc -1.4 mm2/score point (-1.8, -0.9). An association between CC area and its subareas and the standard scores of the VMI was also found. A larger CC was strongly related t o better scores onthe VMI test total area CC: lrc 0.05 score/mm2 (95% CI 0.03, 0.07), frontal: lrc 0.12 score/mm2 (0.05,0.19), middle: lrc 0.10 score/mm2 (0.05, 0.15) and posterior: lrc 0.12 score/mm2 (0.06, 0.18). After adjustment for gestational age, birth weight, and total cerebral area, these associations were still significant. There is a strong association between the size of the corpus callosum (total midsagittal cross area as well as frontal, middle, and posterior area) and motor function in preterm children, investigated at school age. A poorer score on the Movement ABC was related to a smaller CC. A larger CC was strongly associated with better VMI standard scores.

Ultrasound abnormalities preceding cerebral palsy in high-risk preterm infants

OBJECTIVE

To assess sequential high-resolution cranial ultrasound (US) in high-risk preterm infants to predict cerebral palsy (CP).

STUDY DESIGN

Preterm infants were prospectively studied (n=2139), 1636 <or=32 weeks gestational age (GA) (group A) and 503 with a GA of 33 to 36 weeks (group B). US was performed once a week until discharge and at 40 weeks postmenstrual age (PMA), using a 7.5-MHz transducer. Grade III and IV hemorrhage, cystic periventricular leukomalacia (c-PVL), and focal infarction were considered major US abnormalities. A diagnosis of CP was made at a minimum age of 24 months.

RESULTS

Seventy-six (5%) of the 1460 survivors in group A developed CP. US abnormalities were present in 70 of 76 (92%) infants, being major in 58 (83%) and minor in 12 (17%). In 29% of the CP cases with major US abnormalities, cysts were first detected beyond day 28. A further 6 infants without US abnormalities developed CP, and 3 of these infants developed ataxic CP. Twenty-nine (6%) of the 469 survivors in group B developed CP. US abnormalities were present in 28 of 29 (96%) infants, being major in 25 (89%) and minor in 3 (11%). One infant without US abnormalities developed CP. Considering the major US abnormalities, a specificity of 95% and 99% and a sensitivity of 76% and 86% were found for group A and B, respectively. The positive predictive value was 48% in group A and 83% in group B.

CONCLUSION

Seventy-nine percent of our CP cases had major US abnormalities. To detect c-PVL, the most predictive US marker for CP, sequential scans with a 7.5-MHz transducer are required.

Early versus late treatment of posthaemorrhagic ventricular dilatation: results of a retrospective study from five neonatal intensive care units in The Netherlands

Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. As earlier studies have failed to show a benefit of early intervention, it is recommended that PHVD be first treated when head circumference is rapidly increasing and/or when symptoms of raised intracranial pressure develop. Infants with PHVD, admitted to 5 of the 10 Dutch neonatal intensive care units were studied retrospectively, to investigate whether there was a difference in the time of onset of treatment of PHVD and, if so, whether this was associated with a difference in the requirement of a ventriculo-peritoneal (VP) shunt and/or neurodevelopmental outcome. The surviving infants with a gestational age <34 wk, born between 1992 and 1996, diagnosed as having a grade III haemorrhage according to Papile on cranial ultrasound and who developed PHVD were included in the study. PHVD was defined as a ventricular index (VI) exceeding the 97th percentile according to Levene (1981), and severe PHVD as a VI crossing the p 97 + 4 mm line. Ninety-five infants met the entry criteria. Intervention was not deemed necessary in 22 infants, because of lack of progression. In 31 infants lumbar punctures (LP) were done before the p 97 + 4 mm line was crossed (early intervention). In 20/31 infants, stabilization occurred. In 9 a subcutaneous reservoir was placed, with subsequent stabilization in 6. In 5/31 infants a VP shunt was eventually inserted. In 42 infants treatment was started once the p 97 + 4 mm line was crossed (late intervention). In 30 infants LPs were performed and in 17 of these a VP shunt was eventually inserted. In 11 infants a subcutaneous reservoir was immediately inserted and in 8 of these infants a VP shunt was needed. In one infant a VP shunt was immediately inserted, without any other form of treatment. Infants with late intervention crossed the p 97 + 4 mm earlier (p 0.03) and needed a shunt (26/42; 62%) more often than those with early intervention (5/31; 16%). Early LP was associated with a strongly reduced risk of VP-shunting (odds ratio = 0.22, 95% confidence interval: 0.08-0.62). The number of infants who developed a moderate or severe handicap was also higher (11/42; 26%) in the late intervention group, compared with those not requiring any intervention (3/22; 14%) or treated early (5/31; 16%).

CONCLUSION

In this retrospective study, infants receiving late intervention required shunt insertion significantly more often than those treated early. A randomized prospective intervention study, comparing early and late drainage, is required to further assess the role of earlier intervention.

Unilateral parenchymal haemorrhagic infarction in the preterm infant

A unilateral parenchymal haemorrhage associated with a germinal matrix-intraventricular haemorrhage (GMH-IVH) is still an important problem in the preterm infant and especially in those who are very immature. This type of lesion is now considered mainly to be caused by impaired drainage of the veins in the periventricular white matter and is often referred to as a venous infarction. The risk factors and neonatal imaging findings, as well as neurodevelopmental outcome and imaging data in infancy, of this type of lesion differ from those found in children with bilateral periventricular leukomalacia. An effort should, therefore, always be made to make a distinction between these two types of lesions. In our experience it is possible to make this distinction in most cases, when performing both sequential ultrasonography as well as selective magnetic resonance imaging during the neonatal period.

Asymmetrical myelination of the posterior limb of the internal capsule in infants with periventricular haemorrhagic infarction: an early predictor of hemiplegia

AIM

To prospectively assess the predictive value of asymmetrical myelination on MRI of the posterior limb of the internal capsule (PLIC) in newborn infants with an intraventricular haemorrhage (IVH) associated with unilateral haemorrhagic parenchymal involvement (PI), for subsequent development of a hemiplegia.

METHODS

12 preterm infants (GA 25-36 wks) and 4 full-term infants were studied. Using cranial ultrasound (US), the pre-term infants were diagnosed to have an IVH with unilateral PI. The term infants presented with a porencephalic cyst (PC) on the first postnatal US, following an antenatal IVH with PI. MRI was performed at 40 wks postmenstrual age in the pre-term infants and during the first 2 weeks of life in the full-term infants, using a 1.5T magnet. Using an inversion recovery sequence, the myelination of the internal capsule was recorded as normal, abnormal or equivocal. Neurological assessment > or = 12 months disclosed the presence of a hemiplegia or asymmetry in tone pattern.

RESULTS

All 4 cases with a normal internal capsule had a normal outcome in spite of the development of a PC. All 9 cases with an abnormal PLIC developed a hemiplegia, while 1 of the 3 cases with an equivocal PLIC is normal on neurological assessment, one developed a mild asymmetry in tone and 1 a mild hemiplegia.

CONCLUSION

While a symmetrical signal intensity within the internal capsule on MRI, performed at 40 weeks PMA, in infants with an IVH and unilateral PI appears to be strongly related to a normal outcome, an asymmetrical PLIC is an early predictor of future hemiplegia.

Correlation between neonatal cranial ultrasound, MRI in infancy and neurodevelopmental outcome in infants with a large intraventricular haemorrhage with or without unilateral parenchymal involvement

During a 7-year-period, 1625 infants of 34 weeks gestation or less were enrolled in a prospective ultrasound (US) study. One hundred and eleven (6.8%) infants developed a large intraventricular haemorrhage (IVH) with or without unilateral parenchymal involvement (PI). Fifty-six of these 111 infants survived (50.4%) and in 23 (41%) of them a magnetic resonance imaging (MRI) study was performed beyond 12 months corrected age. There appeared to be a good agreement between neonatal ultrasound findings and MRI changes noted in infancy. Of the 10 cases with a large IVH without PI (group A), seven had a VP shunt with complete decompression of previously enlarged ventricles. Six of these seven infants had periventricular hyperintensity (PVHI) but none developed cerebral palsy (CP). Two of the ten cases without a VP shunt had irregular ventricular enlargement (VE) with PVHI in one. Both developed CP. Seven cases showed thinning of the corpus callosum. Of the 13 cases with a large IVH associated with PI (group B), the site of the PI could still be recognised on MRI and the degree of communication of the porencephalic cyst (PC) with the lateral ventricles correlated well with neonatal US findings. On MRI, VE was present in only 6 cases. Wallerian degeneration was present in 9/13 infants and all but one developed a hemiplegia. In 12/13 cases there was thinning of the corpus callosum, either focal or diffuse. PVHI was present in all infants. In 6/13 PVHI was only present around the PC. Neurodevelopmental outcome differed for both groups. CP was only present in 2/10 infants in group A, compared to 11/ 13 in group B. Global delay, in the absence of CP, was more common in infants with a large IVH than in those with associated PI.

CONCLUSION

Combining neonatal US with MRI in infancy enhances our understanding of the long-term effects of severe haemorrhagic brain lesions, occurring in preterm infants.

Antenatal onset of haemorrhagic and/or ischaemic lesions in preterm infants: prevalence and associated obstetric variables

AIM

To assess the prevalence of an antenatal onset of haemorrhagic and/or ischaemic lesions in preterm infants; to identify possibly related obstetric risk factors.

METHODS

A prospective cohort study was made of 1332 infants born at less than 34 completed weeks, using cranial ultrasound, for the presence of antenatal brain lesions (group A) involving the periventricular white matter (PVWM) or central grey matter. Entry criteria were presence of (i) cysts in the PVWM < 7 days; (ii) increased PVWM echogenicity < 6 hours, confirmed to be white matter necrosis at post mortem examination; (iii) a unilateral porencephalic cyst < 3 days; (iv) an intraventricular haemorrhage with unilateral parenchymal involvement < 6 hours; and (v) symmetrical areas of increased echogenicity in the thalami, confirmed to be areas of calcification on post mortem examination. Group B consisted of infants with a normal early neonatal ultrasound scan with subsequent development of the lesions mentioned above.

RESULTS

Twenty four cases met the entry criteria for group A: 17 died and five of the seven survivors developed cerebral palsy at follow up. Of the whole cohort, 156 (11.7%) infants died and in 63 (40.3%) of these a large ultrasound lesion was present. In 17 (26.9%) cases this lesion was considered to be of antenatal onset. Sixty eight of the 1176 (5.8%) survivors developed cerebral palsy and this was attributed to antenatal onset in five (7.3%). A comparison of the obstetric risk factors between the infants in group A and B, who either died or developed cerebral palsy, showed a significant difference in gestational age between the two groups (30.9 vs 28.9 weeks; p < 0.001). Prolonged rupture of membranes was significantly more common in group B (p = 0.03), while an ominous cardiotachogram was significantly more common in group A (p = 0.01), and this remained significant following logistic regression analysis.

CONCLUSIONS

Although these data suggest that most preterm infants did not develop their brain lesions in utero, an antenatal onset was not uncommon, especially in those with PVWM lesions, who did not survive the neonatal period.

Early cerebral proton MRS and neurodevelopmental outcome in infants with cystic leukomalacia

The present study tested the hypothesis that proton magnetic resonance spectroscopy (1H-MRS) predicted neurodevelopmental outcome in infants with cystic leukomalacia (CL). Nineteen infants with CL (grade 2, N = 7; grade 3, N = 7; grade 4, N = 5), graded according to the authors' classification, were examined at corrected ages of mean 1.5 +/- 2.1 SD weeks. 1H-MRS of the basal ganglia and the periventricular white matter was performed. Two infants died, 16 had an adverse neurodevelopmental outcome and one was normal at follow-up. N-acetylaspartate (NAA):choline (Cho) ratios were mean 1.12 +/- 0.19 (SD) (grade 2), mean 0.95 +/- 0.11 (SD) (grade 3), and mean 0.71 +/- 0.13 (SD) (grade 4). These differences are significant (P < 0.01, ANOVA). NAA:Cho ratios showed a positive correlation with developmental quotient (DQ) at the age of > or = 1 year (P < 0.05). In 13 infants lactate (Lac) was found. Lac:NAA ratios showed a negative correlation with NAA:Cho ratios, but not with DQ. We conclude that a low NAA:Cho ratio predicted a poor outcome, whereas some infants developed unfavourably despite a normal NAA:Cho ratio. We speculate that partial volume effects might explain this observation.

Infarcts in the vascular distribution of the middle cerebral artery in preterm and fullterm infants

Twenty-three infants with an infarct in the territory of the middle cerebral artery are reported. The diagnosis was made using cranial ultrasound in all, confirmed on postmortem in two cases and on MRI, performed during the neonatal period or in infancy, in 18 of the 20 survivors. Involvement of the main branch was present in 7 cases and three of these had a gestational age of less than 35 weeks. In the other 16 infants, involvement of a cortical branch or one or more of the lenticulostriate branches was present and all but three of these had a gestational age of 34 weeks or less. While involvement of the main branch was usually diagnosed on postnatal day 1 or 2 using ultrasound, involvement of the lenticulostriate branches was noted as a wedgeshaped echogenic lesion in the caudate nucleus, thalamus or putamen, between day 4 up till day 24, and at term age in one of the cases. Neurodevelopmental outcome of those with involvement of the main branch was disappointing as all survivors developed a hemiplegia, associated with epilepsy in two; while so far only three of the other 16 infants developed cerebral palsy, one a hemiplegia and one athetoid cerebral palsy. Global delay was present in a further three cases. Infarcts in the region of the middle cerebral artery can occur in both preterm as well as fullterm infants. Involvement of the main branch also occurred in infants with a gestational age below 35 weeks and resulted in the development of a hemiplegia in all survivors. Involvement of one of the other branches was especially common in preterm infants, who had a more favourable outcome. As the lesion in the latter group was usually not present before the end of the first week, serial ultrasound up till term age is needed in order to identify these lesions.

Rapidly progressive enlargement of the fourth ventricle in the preterm infant with post-haemorrhagic ventricular dilatation

Six preterm infants who developed disproportionate enlargement of the 4th ventricle during the neonatal period, associated with post-haemorrhagic ventricular dilatation (PHVD), before shunt placement are reported. Five of the six preterm infants developed cyanotic spells and/or bradycardias at the time of rapid enlargement of the 4th ventricle, suggestive of raised posterior fossa pressure, which resolved following insertion of and drainage from a subcutaneous reservoir. In one of the three survivors an isolated 4th ventricle was subsequently diagnosed later in infancy, requiring drainage. These data suggest that a combination of an enlarged 4th ventricle on ultrasound and cyanotic spells and/or bradycardias should lead to rapid release of raised pressure in the posterior fossa. Long-term follow-up of these children is necessary, as isolation of the 4th ventricle can subsequently develop.

Intracranial lesions in the fullterm infant with hypoxic ischaemic encephalopathy: ultrasound and autopsy correlation

To test the hypothesis that cranial ultrasound correlated with post-mortem findings in neonates with hypoxic ischaemic encephalopathy (HIE), the brains of 20 infants who died after at least two real time ultrasound scans were examined. The ultrasound abnormalities detected in the periventricular/subcortical white matter, cortex or thalami were compared with the macroscopic and histological appearances. Comparing the last ultrasound scan which was performed no longer than 12 hours before the infant died, with histological data, the sensitivity and specificity for lesions in the thalamus was 100% and 83.3% respectively; for cortical lesions 76.9 and 100% respectively and for lesions in the periventricular white matter 80% and 75% respectively. The value of cranial ultrasound for detecting intracranial abnormalities in infants with HIE was considerably better than reported previously. This could mainly be attributed to the use of a 10 MHz transducer which was of critical importance to identify lesions in the superficial cortical layer.

Unilateral haemorrhagic parenchymal lesions in the preterm infant: shape, site and prognosis

In a prospective cranial ultrasound study of 544 infants with a gestational age of 32 weeks or less, 20 (3.6%) infants were diagnosed as having a unilateral parenchymal lesion (PL). Based on the shape of the PL and the evolution on ultrasound, the infants were divided into three groups: group I consisted of 11 infants, in whom the PL was triangular/fan-shaped and separate from the ventricle. The PL evolved into small cystic lesions; group II comprised 3 infants who had a PL with a similar shape, but partially communicating with the ventricle; group III consisted of 6 infants who had a globular-shaped lesion in communication with the ventricle. In groups II and III, the PL evolved into one porencephalic cyst. The PL was considered to be due to venous infarction in all cases with intraventricular haemorrhage preceding the PL in 7 cases. Sixteen infants survived. A postmortem was performed in 2 of the 4 infants who died, confirming the diagnosis of venous infarction. Neurological sequelae were present in only 2 cases in the first group, while all 6 survivors of the other two groups developed mild to severe hemiplegia. Long-term follow-up was not always available and 4 of the 18 survivors were still less than 18 months when last seen. In 9 of the 11 infants in group I, the PL was localized in the frontoparietal region, while in 8 of the 9 infants in group II or III, the PL was beyond the trigone in the occipital region. The outcome of the unilateral PL is not always unfavourable.(ABSTRACT TRUNCATED AT 250 WORDS)

Subependymal pseudocysts: ultrasound diagnosis and findings at follow-up

During a two-year period, subependymal pseudocysts were diagnosed in 24 infants using cranial ultrasound: 8 were located at the external angle of the lateral ventricle and 16 at the caudothalamic notch. Associated congenital anomalies were present in six infants and CMV was isolated in one case. Four of the eight infants with pseudocysts at the external angle were one half of twins. As all but one of the surviving infants with pseudocysts were normal at follow-up (at 3-24 months of age), it is important to make a distinction between pseudocysts and extensive cystic periventricular leukomalacia, as the latter condition invariably leads to cerebral palsy and/or visual impairment.