Parenchymal brain injury in the preterm infant: comparison of cranial ultrasound, MRI and neurodevelopmental outcome.

AIM: Magnetic resonance imaging (MRI) is increasingly being used in high-risk preterm neonates. Cranial ultrasound (US) was compared with MRI in preterm patients with parenchymal injury and related to neurodevelopmental outcome. PATIENTS AND METHODS: Studies were performed in 61 patients. Twelve infants with normal US (Group 1) had an MRI within the first 4 weeks of life (early MRI), and 10 also at term age (late MRI). Eight out of 20 infants with intraventricular haemorrhage with parenchymal involvement (IVH + PI) (Group 2) had an early as well as a late MRI and 12 a late MRI. Of the 20 patients with cystic-periventricular leukomalacia (c-PVL) (Group 3), 7 had an early MRI, 1 had an MRI on both occasions and 12 had a late MRI. All 9 children with focal infarction (FI) (Group 4) had a late MRI. RESULTS: MRI was conform with cranial US in Group 1. Early MRI in Group 2 showed contralateral c-PVL in one infant and an additional contralateral occipital parenchymal haemorrhage and blood in the posterior fossa in another infant. Late MRI showed an asymmetrical posterior limb of the internal capsule (PLIC) (n=6), which predicted later hemiplegia. Early MRI in Group 3 showed more cysts (n = 5), punctate white matter lesions (n = 6), lesions in the basal ganglia (n = 1) and once involvement of the cerebellum. Late MRI showed involvement of the centrum semiovale (n = 2) lesions in the basal ganglia (n = 2) and bilateral abnormal signal intensity of the PLIC in 7 infants who all went on to develop cerebral palsy. In Group 4 MRI showed signal intensity changes suggestive of cystic lesions compared to persisting echogenicity on US (n = 3) and an asymmetrical PLIC (n = 5), which predicted hemiplegia in 4. CONCLUSION: Early MRI especially provided additional information in those with c-PVL. MRI at term age could assess the PLIC, which was useful in children with unilateral parenchymal involvement, for prediction of subsequent hemiplegia and, to a lesser degree, in bilateral c-PVL for prediction of diplegia or quadriplegia.

Relation between visual perceptual impairment and neonatal ultrasound diagnosis of haemorrhagic-ischaemic brain lesions in 5-year-old children.

Visual-perceptual abilities were assessed in 5-year-old children with the following neonatal neurological conditions: born preterm with normal ultrasound scan (NL, n=17); born preterm with ultrasound diagnosis of intraventricular haemorrhage (IVH, n=17); born preterm with ultrasound diagnosis of periventricular leukomalacia (PVL, n=12); born term with hypoxic-ischaemic encephalopathy (HIE, n=11). Visual-perceptual ability was evaluated with the L94: eight visual-perceptual tasks designed to evaluate different aspects of visual perception at the preschool level in children with multiple disabilities. Impairment was established in comparison to the performance age obtained on non-verbal intelligence subtests, instead of chronological age. Frequency of L94 impairment was highest in children with PVL, while children with IVH did not differ from the NL control group. Impairment rates were increased also in children with transient periventricular echodensities, and in children with HIE. Impairments were only moderately related to the delay of visual acuity maturation in infancy.

Amplitude integrated EEG 3 and 6 hours after birth in full term neonates with hypoxic-ischaemic encephalopathy.

AIM: To assess the prognostic value of amplitude integrated EEG (aEEG) 3 and 6 hours after birth. METHODS: Seventy three term, asphyxiated infants were studied (from two different centres), using the Cerebral Function Monitor (CFM Lectromed). The different aEEG tracings were compared using pattern recognition (flat tracing mainly isoelectric (FT); continuous extremely low voltage (CLV); burst-suppression (BS); discontinuous normal voltage (DNV); continuous normal voltage (CNV)) with subsequent outcome. RESULTS: Sixty eight infants were followed up for more than 12 months (range 12 months to 6 years). Twenty one out of 68 infants (31%) showed a change in pattern from 3 to 6 hours, but this was only significant in five cases (24%). In three this changed from BS to CNV with a normal outcome. One infant showed a change in pattern from CNV to FT and had a major handicap at follow up. Another infant showed a change in pattern from DNV to BS, and developed a major handicap at follow up. The other 16 infants did not have any significant changes in pattern: 11 infants had CLV, BS, or FT at 3 and 6 hours and died (n = 9) in the neonatal period or developed a major handicap (n = 2). Five infants had a CNV or DNV pattern at 3 and 6 hours, with a normal outcome. The sensitivity and specificity of BS, together with FT and CLV, for poor outcome at 3 hours was 0.85 and 0.77, respectively; at 6 hours 0.91 and 0.86, respectively. The positive predictive value (PPV) was 78% and the negative predictive value (NPV) 84% 3 hours after birth. At 6 hours the PPV was 86% and the NPV was 91%. CONCLUSION: aEEG could be very useful for selecting those infants who might benefit from intervention after birth asphyxia.

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.

UNLABELLED: 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.

Visual, cognitive, and neurodevelopmental outcome at 51/2 years in children with perinatal haemorrhagic-ischaemic brain lesions.

To determine predictive values of early visual and neurocognitive assessment in children with perinatally acquired haemorrhagic or ischaemic brain lesions selected on the basis of ultrasound, 63 children (37 boys, 26 girls), who had been followed and examined until the age of 18 months, were reexamined at 5 1/2 years. Good correlations between visual and neurodevelopmental assessments at 18 months and at 5 1/2 years were found. When ultrasound abnormalities were combined with early visual and neurocognitive assessment data, good predictive values, especially for the group of children who had grade 2 to 4 leukomalacia, were found for visual acuity and neurodevelopment.

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.

The predictive value of cranial ultrasound and of somatosensory evoked potentials after nerve stimulation for adverse neurological outcome in preterm infants.

Thirty-nine preterm infants were studied to compare the predictive value of somatosensory evoked responses (SEPs) following median-nerve and posterior tibial-nerve stimulation with the predictive value of cranial ultrasound. With regard to the SEP, a normal median-nerve response was by no means a guarantee of a normal outcome. A normal posterior tibial-nerve response, however, almost guaranteed a normal outcome, but the test was very time consuming and the number of false positive responses was high (sensitivity 95.6%, specificity 50%). The presence of parenchymal involvement, either due to a haemorrhage or cystic leukomalacia predicted cerebral palsy with a sensitivity of 95.6% and specificity of 68.5%. The combination of an abnormal posterior tibial response and the presence of parenchymal brain lesions had the best predictive value with a sensitivity of 91.3% and a specificity of 81.2%. These results show that, although posterior tibial-nerve responses have a better predictive value than median-nerve responses, these values were lower than that of cranial ultrasound. The best prediction was obtained when a combination of posterior-tibial responses and cranial ultrasound was used.

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.

The posterior fontanelle: a neglected acoustic window.

The additional information, obtained when using the posterior fontanelle routinely as the second acoustic window, is illustrated in four infants. Three of them are full-term infants with hypoxic ischaemic encephalopathy. In newborn infants, who are still too unstable to be transported to the magnetic resonance unit, extensive damage in the occipital subcortical white matter and/or cortex can be visualised by performing cranial ultrasound through the posterior fontanelle.

Early predictors of cerebral visual impairment in infants with cystic leukomalacia.

A longitudinal prospective follow-up study looking at the correlation between haemorrhagic-ischaemic lesions on neonatal cranial ultrasound (US) and the development of cerebral visual impairment (CVI) in infancy resulted in the detection of nine infants with severe visual impairment, which was not due to opthalmological abnormalities. Extensive cystic leukomalacia proved to be highly predictive of CVI, as well as of severe mental and motor deficit in these nine infants. The present report outlines the results of different examinations (acuity card procedure [ACP], visual evoked potential [VEPs], magnetic resonance imaging [MRI]) performed during the first 18 months, to find out which combination of examinations would be the most predictive of CVI at an early stage. The results indicated that infants with a gestational age of 35 weeks or more, who sustained extensive cystic leukomalacia during the neonatal period, and were subsequently not fixating at the acuity cards at term and at three months of age, invariably developed CVI. VEPs were also severely abnormal in the infants with the worst visual outcome, but were not providing a more reliable prognosis. Also, a good correlation between MRI-abnormalities of the optic radiations and/or the visual cortex and CVI was found, but MRI was usually performed beyond the age of 12 months.

[Findings in cerebral proton spin resonance spectroscopy in newborn infants with asphyxia, and psychomotor development]. / Bevindingen bij cerebrale protonkernspinresonantie-spectroscopie bij pasgeborenen met asfyxie, en psychomotore ontwikkeling.

OBJECTIVE: To determine the relationship between the results of cerebral proton magnetic resonance spectroscopy (1H-MRS) and neuromotor development in neonates with hypoxia. DESIGN: Descriptive. SETTING: Wilhelmina Childrens' Hospital and University Hospital, Utrecht, The Netherlands. METHODS: 32 infants with hypoxic-ischaemic encephalopathy (Sarnat grade I (mild; n = 5), grade II (moderate; 20), grade III (severe; 7)) were examined at a mean of 8 days following the hypoxic event (range 2-22). 1H-MRS of the periventricular white matter and part of the basal ganglia was performed in a 1.5 T field: TR/TE: 2000/272 ms. Peak-to-peak NAA/Cho ratios were calculated. The presence of a lactate resonance was considered abnormal. Assessment of neuromotor development of the survivors was performed at 6, 9 and 18 months of age. RESULTS: 6 patients died (all grade III), 10 survived with handicaps (I grade III, 9 grade II). Handicaps consisted of spastic quadriplegia (n = 7), hemiplegia and mental retardation (n = 1), and global developmental delay (n = 2). The other 16 survivors were normal at 18 months. 1H-MRS showed NAA/Cho ratios of 0.97 (SD:0.13) in the patients with a normal outcome and 0.74 (0.17) in the patients with an adverse outcome (handicaps or death); p < 0.0001 (t-test). Lactate was demonstrated in all 7 grade III neonates, but not in any of the other infants. CONCLUSION: Cerebral 1H-MRS was related to neurodevelopmental outcome of neonates with HIE. A low NAA/Cho ratio and presence of a lactate resonance predicted an adverse outcome.

Somatosensory evoked potentials in preterm infants with intrauterine growth retardation.

In order to further evaluate both the maturation as well as the prognostic value of the somatosensory evoked potentials (SEPs) with regard to neurodevelopmental outcome, SEPs were performed after the first week of life in 56 small-for-gestational age (SGA) preterm neonates. Twenty-five had a prolonged N1 latency while 30 had a normal N1 latency around discharge. One child had an accelerated N1 latency. No correlation was found between the severity of intrauterine growth retardation in relation to birthweight, head circumference or birthweight ratio. None of the children developed cerebral palsy (CP) at follow-up. Developmental quotient (DQ) was calculated in 42 children. The mean DQ of the 21 neonates with an abnormal SEP at discharge was 79.24 +/- 18.56 while the mean DQ of the 21 children with a normal SEP at discharge was 92.52 +/- 11.31. Among the children with a normal N1 latency at discharge the number of breast-fed children was significantly higher than the number of formula-fed neonates (P < 0.05). We conclude that an abnormal SEP around term age in SGA preterm neonates does not imply an increased risk of developing CP. Breast-milk appears to have a beneficial effect on the development of the SEPs in children with intrauterine growth retardation.

Predictive value of early neuroimaging, pulsed Doppler and neurophysiology in full term infants with hypoxic-ischaemic encephalopathy.

To evaluate their prognostic value, five different non-invasive techniques were used on 34 full term infants with hypoxic-ischaemic encephalopathy (HIE) within six hours of delivery. Cranial ultrasonography, the resistance index (RI) of the middle cerebral artery obtained with Doppler ultrasonography, somatosensory evoked potentials (SEPs), visual evoked potentials (VEPs) and the cerebral function monitor (CFM) were used. According to the criteria of Sarnat, 11 infants developed mild, seven moderate, and 16 severe encephalopathy. The CFM had the highest positive (PPV 84.2%) and negative predictive value (NPV 91.7%). All but one of the infants with a continuous pattern had a good outcome. The CFM of 11 cases with a suppression-burst pattern changed to a continuous pattern over 24 to 48 hours in four infants, and was associated with a normal outcome in three. All five cases with an isoelectric CFM died. The SEPs also provided useful information (PPV 81.8%; NPV 91.7%). VEPs were often delayed during the first hours or life and did not carry a poor prognosis in five of 14 cases (PPV 77.3%). Both ultrasonography and Doppler RI were of little value, as they were almost always normal at this early stage. In 34 full term infants with HIE, studied within 6 hours of life, the CFM and SEPs provided the most useful information about the expected course of encephalopathy and subsequent neurodevelopmental outcome.

Haemorrhagic-ischaemic lesions of the neonatal brain: correlation between cerebral visual impairment, neurodevelopmental outcome and MRI in infancy.

The relationship between the degree of cerebral visual impairment, established using the acuity card procedure, and the extent of neurological sequelae was assessed in 65 at-risk neonates in a prospective follow-up study. MRI and CT scans were performed in all infants with severe neurological sequelae. 11 of 12 children with an acuity at or below the 10th centile at 18 months developed cerebral palsy: the underlying condition was extensive cystic leukomalacia in all. An acuity above the 10th centile was no guarantee of normal development, as 10 out of 52 such infants developed cerebral palsy. MRI and CT scans showed that periventricular high signal intensity in the occipital area was a non-specific finding with regard to visual function. Extensive periventricular white matter loss and involvement of the striate/parastriate cortex was found in the most severely visually impaired infants.

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)

The use of evoked potentials in the neonatal intensive care unit.

The data reported in the literature and our own findings have shown, that evoked potentials (EPs) can be performed at the bedside and provide additional information about the integrity of the central nervous system. Auditory brainstem responses (ABRs) are especially useful for early identification of audiological problems and whenever possible, at risk newborn infants (table II) should be screened using either ABRs or other methods like the otoacoustic emission before discharge. ABRs appear to be less useful in predicting neurological impairment, especially in the preterm infant. Visual evoked potentials (VEPs) can easily be performed at the bedside and are of predictive value for both neurological and visual outcome in the fullterm infant with hypoxic ischaemic encephalopathy (HIE) and the preterm infant in whom the cysts extend into the deep white matter. VEPs will help to identify at an early stage those infants who will suffer severe visual impairment being cortically mediated. Somatosensory evoked potentials (SEPs) are the most difficult to perform of the EPs, but adapting filter settings and stimulation rate it is also possible to obtain responses following stimulation of both the median and posterior tibial nerve. Median nerve SEPs are of predictive value in the fullterm infant with HIE with regard to neurodevelopmental outcome. In the preterm infant however, the predictive value is not so good for the median nerve and more data are needed to assess the predictive value of the posterior tibial nerve SEP.