Maturation of cerebral electrical activity and development of cortical folding in young very preterm infants.

OBJECTIVE: The aim of this study was to examine the relationship between cortical development and cerebral electrical activity at early gestational ages. METHODS: We obtained EEGs (7.2+/-3.8 days) and MR brain images (3.2+/-2.9 days) after birth in 17<30 week gestation infants without evidence of focal brain injury The EEGs were assessed for discontinuity and characteristic maturational features (delta brush, occipital and temporal sawtooth); cortical development was quantified from MR scans using a specially designed computer programme to measure cortical folding. RESULTS: The inter-burst interval shortened and cortical folding increased with increasing post-menstrual age (PMA). In contrast, the minimum duration of bursts was independent of PMA and cortical folding. Delta brush (8-20 Hz activities) was seen at all PMAs; temporal and occipital sawtooth activities were always more prominent than delta brush but were seen less frequently with increasing PMA and complexity of cortical folding. CONCLUSION: There was a positive correlation between some but not all maturational features of the preterm neonatal EEG and the complexity of whole brain cortical folding and PMA. These relationships were strong for the inter-burst interval, a global measure of maturation, but not strongly seen for regional features such as occipital and temporal sawtooth within this gestational age range. SIGNIFICANCE: Combining neurophysiological examination with detailed neuroimaging gives insights into developmental changes occurring in the very preterm brains and suggests further comparative studies focusing on measures of focal brain development at different gestational ages.

Auditory attention at the onset of West syndrome: correlation with EEG patterns and visual function.

At the onset of West syndrome a specific impairment of visual function has been clearly demonstrated, while other aspects of sensorial development, and in particular of the auditory function, have been less studied. The aim of this study was to evaluate auditory function and orienting responses at the onset of West syndrome, and to relate the results with EEG patterns, visual function and neurodevelopmental competence. A prospective multicentric study was performed on 25 successively enrolled infants with West syndrome; all the patients underwent a full clinical assessment, including MRI and video-EEG, visual function and auditory orienting responses (AORs) as well as Griffiths' developmental scales. The whole assessment performed at the onset of spasms (T0) was repeated after two months (T1). AORs resulted significantly impaired both at T0 and T1. At the onset of spasms a highly significant relationship of auditory attention with visual function and neurodevelopmental competence was shown in both cryptogenic and symptomatic forms, but it was no longer present after two months. Our results may suggest a possible pervasive effect of the epileptic disorder on sensory processing, associated to a deficit of neurodevelopment. Although we failed to show a significant correlation between auditory orienting responses and EEG patterns, some evidence seems to support at least partially an influence of the epileptic disorder per se on the genesis of the sensorial impairment. A longer follow up and a larger cohort will be useful for a better clarification of these findings.

Neurological and perceptual-motor outcome at 5 - 6 years of age in children with neonatal encephalopathy: relationship with neonatal brain MRI.

OBJECTIVE: The aims of this study were 1) to determine the incidence of minor neurological dysfunction and perceptual-motor difficulties in children aged 5-1/2 -- 6-1/2, who had been born full-term but presented with neonatal encephalopathy (NE) and low Apgar scores and 2) to examine the relationships between the presence/absence of these difficulties with neonatal brain MRI. PARTICIPANTS AND METHODS: Sixty-eight full-term infants with one minute Apgar scores less than or equal to 5 and neurological abnormalities during the first 48 hours after birth were included in the study. All children had a neonatal MRI brain scan. Surviving infants were assessed between the age of 5 and 6 years using the Touwen Examination, the Movement ABC and the WPPSI-R. RESULTS: Fifteen of the 68 infants (22 %) died in the neonatal period. Of the 53 surviving infants, 19 (36 %) had cerebral palsy. The remaining 34 were considered normal at 2 years of age but, when assessed at school age, 8 (15 %) had minor neurological dysfunction and/or perceptual-motor difficulties, 1 (2 %) had only cognitive impairment and 25 (47 %) were normal. The outcome largely reflected the pattern of lesions on brain imaging. While 83 % of those with a normal outcome had normal scans or minimal white matter lesions, 80 % of those with minor neurological dysfunction and/or perceptual-motor difficulties had mild or moderate basal ganglia or more marked white matter lesions. CONCLUSION: Continued surveillance is recommended for children with apparently normal outcome at two years of age after NE, particularly when abnormalities are detected on brain MRI.

Combined use of electroencephalogram and magnetic resonance imaging in full-term neonates with acute encephalopathy.

OBJECTIVE: The electroencephalogram (EEG) is widely used in full-term infants with acute neonatal encephalopathy, and its prognostic value has been confirmed by several studies. Magnetic resonance imaging (MRI) of the brain has also been applied in these patients, and increasing numbers of reports affirm its prognostic reliability. The aim of this study has been to investigate the correlation between an early EEG and MRI findings in infants with acute neonatal encephalopathy and to assess the prognostic value of a combination of EEG and MRI findings. PARTICIPANTS AND METHODS: Twenty-five full-term infants had an EEG recorded within the first 72 hours after birth and a neonatal brain MRI scan after the end of the first week. RESULTS: Both EEG and MRI were predictive of outcome. A normal MRI was always associated with normal EEG background activity and normal outcome and severe abnormalities on MRI with marked EEG abnormalities and an abnormal outcome. When the MRI showed moderate abnormalities, the EEG in all cases but one identified patients with normal and abnormal outcome.EEG, MRI, HIE, neurodevelopment.

Periodic lateralized epileptiform discharges (PLEDs) as early indicator of stroke in full-term newborns.

We report on periodic lateralized epileptiform discharges (PLEDs) on EEG in two infants with neonatal convulsions. In both neonates, the EEG abnormalities were seen soon after the onset of seizures, at a time when cranial ultrasound scans were thought to be normal. Subsequent Magnetic Resonance Imaging scans demonstrated cerebral infarction in both patients. In one case, the localisation of the lesion on MRI was concordant with that of the EEG abnormalities, as usually observed in adults with focal lesions. The other infant showed similar EEG abnormalities, but her MRI showed a localised lesion in the basal ganglia, which has also been reported to be involved in the genesis of these abnormalities.

Occipital sawtooth: a physiological EEG pattern in very premature infants.

OBJECTIVE: To evaluate EEG maturational features in preterm infants below 27 weeks postmenstrual age. METHODS: EEGs recorded from 5 preterm infants (postmenstrual age 24-26 weeks) were examined and selected maturational features were scored and quantified. The five infants also had serial cranial ultrasound scans (US) and magnetic resonance images of the brain within the first weeks after birth. RESULTS: Background activity was markedly discontinuous in all patients and very variable. Temporal sawtooths occurred but less frequently than in older preterm infants. All 5 infants also showed a particular novel feature, characterized by rhythmic, regularly shaped, medium-high amplitude 4-7 Hz activities, lasting 0.5-3 s and located in the occipital regions. This pattern was symmetrical but sometimes asynchronous. CONCLUSIONS: Occipital sawtooth, so called because it shares shape and frequency with temporal sawtooth but has an occipital localisation, constitutes a physiological EEG pattern characteristic of premature infants between 24 and 26 weeks of postmenstrual age.

Head growth in infants with hypoxic-ischemic encephalopathy: correlation with neonatal magnetic resonance imaging.

OBJECTIVES: The aims of the study were to establish the relationship between head growth in the first year of life with the pattern on injury on neonatal magnetic resonance imaging (MRI) in infants with hypoxic-ischemic encephalopathy (HIE) and to relate these to the neurodevelopmental outcome. METHODS: Fifty-two term infants who presented at birth with a neonatal encephalopathy consistent with HIE and who had neonatal brain MRI were entered into the study. Head circumference charts were evaluated retrospectively and the head growth over the first year of life compared with the pattern of brain lesions on MRI and with the neurodevelopmental outcome at 1 year of age. Suboptimal head growth was classified as a drop of >2 standard deviations across the percentiles with or without the development of microcephaly, which was classified as a head circumference below the third percentile. RESULTS: There was no statistical difference between the neonatal head circumferences of the infants presenting with HIE and control infants. At 12 months, microcephaly was present in 48% of the infants with HIE, compared with 3% of the controls. Suboptimal head growth was documented in 53% of the infants with HIE, compared with 3% of the controls. Suboptimal head growth was significantly associated with the pattern of brain lesions, in particular to involvement of severe white matter and to severe basal ganglia and thalamic lesions. Suboptimal head growth predicted abnormal neurodevelopmental outcome with a sensitivity of 79% and a specificity of 78%, compared with the presence of microcephaly at 1 year of age, which had a sensitivity of only 65% and a specificity of 73%. The exceptions were explained by infants with only moderate white matter abnormalities who had suboptimal head growth but normal outcome at 1 year of age and by infants with moderate basal ganglia and thalamic lesions only who had normal head growth but significant motor abnormality.

Perceptual-motor, visual and cognitive ability in very low birthweight preschool children without neonatal ultrasound abnormalities.

Thirty-six children born preterm with very low birth weight without neonatal brain disorders and normal cerebral ultrasound findings were examined at pre-school age: visual, perceptual motor, attention, behaviour and cognitive assessments were performed in the study group as well as in a control group of term children matched for age, sex and parental educational and occupational status. The results showed a significant lower scoring in perceptual motor skills in the study group, associated with a defect of accuracy in spatial attention and a higher incidence of stereopsis impairment related with perceptual motor disabilities. Behavioural disorders, in terms of emotional maturation and hyperactivity, were significantly more frequent in the study group. To prevent behavioural and learning problems at school, a complete longitudinal assessment including visual functions and perceptual motor abilities seems mandatory in preterm born children, even in the absence of neonatal brain disorders including abnormal cerebral ultrasound findings.

Epileptic disorders with onset in the first year of life: neurological and cognitive outcome.

We examined prospectively a series of 150 children with epilepsy beginning in the first year of life. We classified the types of epilepsy into five categories: West syndrome, other epileptic encephalopathies, generalized, partial and undetermined epilepsies. Of 150 patients, 15 died; 135 were followed for at least 4 years. In order to define possible factors influencing prognosis we evaluated neurological and cognitive outcome and made percentage comparisons between groups, for aetiology, age of onset, family history of epilepsy, and psychomotor development before onset. Epileptic encephalopathies as well as the symptomatic forms of West syndrome showed a very poor neurological and cognitive outcome. As previously recognized, only cryptogenic forms of West syndrome had a benign prognosis. For the generalized epilepsies, analysis of different factors, namely late age at onset, cryptogenicity and absence of primary cognitive impairment, indicated a good prognosis. In contrast, partial epilepsies usually had a poor outcome, irrespective of the aetiology, whether cryptogenic or symptomatic.

Visual outcome in children with congenital hemiplegia: correlation with MRI findings.

Fourteen children with congenital hemiplegia were studied with a detailed assessment of various aspects of vision (linear acuity, stereopsis, visual fields) and MRI. The aim of this study was to evaluate the effect of a congenital lesion on visual function. The results showed a very high incidence (78%) of children who had abnormal results on at least one of the visual tests. Visual abnormalities were not correlated with the clinical severity of hemiplegia or with a specific pattern of lesion on MRI. Similarly no constant association could be found between visual structures (optic radiations and primary visual cortex) and visual function. Finally, our results would suggest that all the children with congenital hemiplegia need to be investigated irrespective of the clinical severity or of the type or the extent of the lesion. This would help to identify children with minor visual abnormalities which can affect everyday life performance.