Impaired language abilities and white matter abnormalities in children born very preterm and/or very low birth weight

Effects of prematurity on language acquisition and auditory maturation: a systematic review

Purpose

To verify which damages prematurity causes to hearing and language.

Research strategies

We used the decriptors language/linguagem, hearing/audição, prematurity/prematuridade in databases LILACS, MEDLINE, Cochrane Library and Scielo.

Selection criteria

randomized controlled trials, non-randomized intervention studies and descriptive studies (cross-sectional, cohort, case-control projects).

Data analysis

The articles were assessed independently by two authors according to the selection criteria. Twenty-six studies were selected, of which seven were published in Brazil and 19 in international literature.

Results

Nineteen studies comparing full-term and preterm infants. Two of the studies made comparisons between premature infants small for gestational age and appropriate for gestational age. In four studies, the sample consisted of children with extreme prematurity, while other studies have been conducted in children with severe and moderate prematurity. To assess hearing, these studies used otoacoustic emissions, brainstem evoked potentials, tympanometry, auditory steady-state response and visual reinforcement audiometry. For language assessment, most of the articles used the Bayley Scale of Infant and Toddler Development. Most studies reviewed observed that prematurity is directly or indirectly related to the acquisition of auditory and language abilities early in life.

Conclusion

Thus, it could be seen that prematurity, as well as aspects related to it (gestational age, low weight at birth and complications at birth), affect maturation of the central auditory pathway and may cause negative effects on language acquisition.

Early changes in brain structure correlate with language outcomes in children with neonatal encephalopathy

Global patterns of brain injury correlate with motor, cognitive, and language outcomes in survivors of neonatal encephalopathy (NE). However, it is still unclear whether local changes in brain structure predict specific deficits. We therefore examined whether differences in brain structure at 6 months of age are associated with neurodevelopmental outcomes in this population. We enrolled 32 children with NE, performed structural brain MR imaging at 6 months, and assessed neurodevelopmental outcomes at 30 months. All subjects underwent T1-weighted imaging at 3 T using a 3D IR-SPGR sequence. Images were normalized in intensity and nonlinearly registered to a template constructed specifically for this population, creating a deformation field map. We then used deformation based morphometry (DBM) to correlate variation in the local volume of gray and white matter with composite scores on the Bayley Scales of Infant and Toddler Development (Bayley-III) at 30 months. Our general linear model included gestational age, sex, birth weight, and treatment with hypothermia as covariates. Regional brain volume was significantly associated with language scores, particularly in perisylvian cortical regions including the left supramarginal gyrus, posterior superior and middle temporal gyri, and right insula, as well as inferior frontoparietal subcortical white matter. We did not find significant correlations between regional brain volume and motor or cognitive scale scores. We conclude that, in children with a history of NE, local changes in the volume of perisylvian gray and white matter at 6 months are correlated with language outcome at 30 months. Quantitative measures of brain volume on early MRI may help identify infants at risk for poor language outcomes.

•

Global volume loss after neonatal brain injury results in poorer language outcome.

•

Variability in language correlates specifically with left perisylvian brain volume.

•

Changes in regional brain volume are not correlated with motor or cognitive outcome.

Language and cognitive outcome for high-risk neonates at the age of 2-3 years - experience from an Arab Country

AIM

To investigate the effect of different neonatal risk factors on different language parameters as well as cognitive abilities among Arabic speaking Egyptian children at the age of two to three years of life and to find out which risk factor(s) had the greatest impact on language and cognitive abilities.

METHODS

This retrospective cohort study was conducted on 103 children with age range of 2-3 years (median age 31 mo). They were 62 males and 41 females who were exposed to different high-risk factors in the perinatal period, with exclusion of metabolic disorders, sepsis/meningitis, congenital anomalies and chromosomal aberrations. The studied children were subjected to a protocol of language assessment that included history taking, clinical and neurological examination, audiological evaluation, assessment of language using modified preschool language scale-4, IQ and mental age assessment and assessment of social age.

RESULTS

The studied children had a median gestational age of 37 wk, median birth weight of 2.5 kg. The distribution of the high-risk factors in the affected children were prematurity in 25 children, respiratory distress syndrome in 25 children, hypoxic-ischemic encephalopathy in 15 children, hyperbilirubinemia in 10 children, hypoglycemia in 13 children, mixed risk factors in 15 children. The results revealed that high-risk neonatal complications were associated with impairment of different language parameters and cognitive abilities (P < 0.05). The presence of prematurity, in relation to other risk factors, increases the risk of language and cognitive delay significantly by 3.9 fold.

CONCLUSION

Arabic-speaking children aged 2-3 years who were exposed to high-risk conditions in the perinatal period are likely to exhibit delays in the development of language and impairments in cognitive abilities. The most significant risk factor associated with language and cognitive impairments was prematurity.

Interpretation of ambiguities by schoolchildren with low birth weight from Embu das Artes, São Paulo state, Brazil

PURPOSE

To assess the development of language regarding the ability to recognize and interpret lexical ambiguity in low-birth-weight schoolchildren enrolled at the school system in the municipality of Embu das Artes, Sao Paulo state, compared with that of schoolchildren with normal birth weight.

METHODS

A case-control, retrospective, cross-sectional study conducted with 378 schoolchildren, both genders, aged 5 to 9.9 years, from the municipal schools of Embu das Artes. Study Group (SG) comprising 210 schoolchildren with birth weight < 2500 g. Control Group (CG) composed of 168 school children with birth weight ≥ 2500 g. Participants of both groups were compared with respect to the skills of recognition and verbal interpretation of sentences containing lexical ambiguity using the Test of Language Competence. Variables of interest: Age and gender of children; age and schooling of mothers. Statistical analysis: Descriptive analysis to characterize the sample and score per group; Student's t test for comparison between the total scores of each skill/subtest; Chi-square test to compare items within each subtest; multiple regression analysis for the intervening variables.

RESULTS

Participants of the SG presented lower scores for ambiguous sentences compared with those of participants of the CG. Multiple regression analysis showed that child's current age was a predictor for all metalinguistic skills regarding interpretation of ambiguities in both groups.

CONCLUSION

Participants of the SG presented lower specific and total scores than those of participants of the CG for ambiguity skills. The child's current age factor positively influenced the ambiguity skills in both groups.

Linguistic features in children born very preterm at preschool age

AIM

This cross-sectional study focused on the effect of very preterm (VPT) birth on language development by analysing phonological, lexical, grammatical, and pragmatic skills and assessing the role of cognitive and memory skills.

METHOD

Sixty children (29 males, 31 females) born VPT (<32wks) aged 5 years were compared with 60 children with typical development. The linguistic assessment was performed by administering a battery of Italian tests for the evaluation of language; cognitive and memory skills were assessed by Raven's coloured progressive matrices and digit span subtest (Wechsler Intelligence Scale for Children [WISC-III]).

RESULTS

Children born VPT showed delays in lexical (comprehension: z-score difference -1.18; 95% confidence interval [CI] -1.60 to -0.77; naming: -0.88; 95% CI -1.19 to -0.58) and pragmatic skills (comprehension: -0.76; 95% CI -1.02 to -0.49; narrative production: -0.47; 95% CI -0.72 to -0.23). Delays in phonology and grammar were less diffuse, involving productive skills (-1.09; 95% CI -1.64 to -0.54; -0.48; 95% CI -0.85 to -0.12, respectively), and were dependent by cognitive and memory skills. Lexical delays were more specific.

INTERPRETATION

The linguistic profile of children born preterm is characterized by some abilities more impaired than others. This highlights the need of a linguistic assessment at the end of preschool age in order to plan a focused intervention aimed at improving lexical and pragmatic skills.

Metaanálisis: efecto de las intervenciones para disminuir el nivel de estrés en padres de prematuros

Introducción: El nacimiento prematuro de un bebé genera estrés en los padres, por el riesgo de aumento en la morbimortalidadque esto conlleva. Existen intervenciones que disminuyen el nivel de estrés en los padres beneficiando a su vez el neurodesarrollo delrecién nacido. Objetivo: Categorizar los principales componentes de los programas de intervención temprana y determinar el efecto deestas intervenciones en la disminución del nivel de estrés en padres de prematuros hospitalizados. Método: Meta-análisis con 9 ensayosclínicos controlados, que cumplieron los criterios de rigurosidad metodológica. Resultados: las intervenciones aplicadas a los padresde prematuros hospitalizados, mostraron efecto de intensidad media-baja sobre el nivel de estrés percibido (d=0,36 IC [-0.68, -0,05]).Sin embargo, las pruebas de heterogeneidad indican alta variabilidad inter-estudio (Q(df=8) = p-val: <0,00001), I2=85% ), explicadaparcialmente por las características moderadoras codificadas para los estudios. Conclusiones: aunque las intervenciones mostraronefectos positivos en la disminución del nivel de estrés en los padres, se evidencia que la educación y el apoyo emocional en conjunto logranun mejor efecto. Las futuras investigaciones deben analizar aspectos como calidad de los estudios, intervenciones con apoyo emocional,edad de los padres y diversidad en los contextos de aplicación.

Receptive language and intellectual abilities in preterm children

OBJECTIVE

The aim of this study was to examine the association between receptive vocabulary performance and intellectual quotient (IQ) in preterm born children compared to children born at term.

METHOD

A total of 72 preschool-age children participated in the study. Participants were divided in four groups: EG-I, including 20 moderate to late preterm born children; EG-II, comprehending 16 extremely preterm born children; CG-I and CG-II with correspondingly 20 and 16 children born at term. EG-I and CG-I as well as EG-II and CG-II groups were matched according to gender, chronological age, and family SES. The mean age of children in each group was: EG-I and CG-I: 30.3months; EG-II and CG-II: 29.1months. The assessment information was collected using an anamnesis protocol, the Brazilian criterion of economic classification, the Peabody Picture Vocabulary Test, and the Stanford-Binet Intelligence Scale.

RESULTS

Mean scores for receptive vocabulary were significantly lower in both preterm groups (EG-I and EG-II) than in the corresponding matched groups (CG-I and CG-II). However, no significant differences were found among the preterm groups. Moreover, high correlations between vocabulary and IQ scores were found in both preterm groups (EG-I and EG-II). In contrast, no significant correlations were found when analyses considered each group of full-term born children (CG-I and CG-II).

CONCLUSION

Our findings indicate that prematurity status has an impact on receptive language performance and on the pattern of relationships between receptive vocabulary and general intellectual functioning.

Structural connectivity relates to perinatal factors and functional impairment at 7years in children born very preterm

OBJECTIVE

To use structural connectivity to (1) compare brain networks between typically and atypically developing (very preterm) children, (2) explore associations between potential perinatal developmental disturbances and brain networks, and (3) describe associations between brain networks and functional impairments in very preterm children.

METHODS

26 full-term and 107 very preterm 7-year-old children (born <30weeks' gestational age and/or <1250g) underwent T1- and diffusion-weighted imaging. Global white matter fibre networks were produced using 80 cortical and subcortical nodes, and edges were created using constrained spherical deconvolution-based tractography. Global graph theory metrics were analysed, and regional networks were identified using network-based statistics. Cognitive and motor function were assessed at 7years of age.

RESULTS

Compared with full-term children, very preterm children had reduced density, lower global efficiency and higher local efficiency. Those with lower gestational age at birth, infection or higher neonatal brain abnormality score had reduced connectivity. Reduced connectivity within a widespread network was predictive of impaired IQ, while reduced connectivity within the right parietal and temporal lobes was associated with motor impairment in very preterm children.

CONCLUSIONS

This study utilised an innovative structural connectivity pipeline to reveal that children born very preterm have less connected and less complex brain networks compared with typically developing term-born children. Adverse perinatal factors led to disturbances in white matter connectivity, which in turn are associated with impaired functional outcomes, highlighting novel structure-function relationships.

Validity of the language development survey in infants born preterm

BACKGROUND

Preterm infants are at greater risk of language delay. Early identification of language delay is essential to improve functional outcome in these children.

AIM

To examine the concurrent validity of Rescorla's Language Development Survey and the Bayley Scales of Infant and Toddler Development (Bayley-III) at 18months corrected age in preterm infants.

STUDY DESIGN

Test accuracy study.

PARTICIPANTS

189 preterm infants born <29weeks were assessed at 18months.

OUTCOME MEASURES

The Language Development Survey, a parent-reported screening instrument, was administered in French concurrently with the Language Scales of the Bayley-III. Receiver-Operating-Characteristics curves were used to determine optimal cut-off score on the Language Development Survey to identify Bayley-III score <85. Sensitivity, specificity, positive and negative predictive values, and κ coefficient were calculated.

RESULTS

Using Rescorla's original cut-off scores of ≤10 words for boys and ≤24 for girls, sensitivity was 76% and 88% for boys and girls, respectively, and specificity was 73% and 52% for boys and girls, respectively, in identifying language delay as per the Bayley-III. The optimal threshold was ≤10 words for both boys and girls. In girls, lowering the cut-off score decreased sensitivity (79%), but improved specificity (82%), thus lowering the number of false-positives.

CONCLUSION

Our findings support using the Language Development Survey as an expressive language screener in preterm infants.

Reading deficits in very low birthweight children are associated with vocabulary and attention issues at the age of seven

Aim

This Swedish study compared reading skills between seven‐year‐old children with a very low birthweight (VLBW) and controls with a normal birthweight, exploring associations between reading variables and cognition, parent‐rated behaviour, perinatal factors and family factors.

Methods

We studied 51 VLBW children, with no major neurodevelopmental impairments and attending their first year at a regular school, and compared them with the 51 sex‐ and age‐matched controls. The test battery, carried out at 7.8 ± 0.4 years of age, included reading skills, the Wechsler Intelligence Scale for Children – III and the Child Behaviour Checklist.

Results

Very low birthweight children with a mean birthweight of 1105 g (±291 g) and a gestational age of 28.8 (±2.2) weeks scored significantly lower in all reading subtests and cognition and demonstrated more behavioural problems than normal birthweight controls. We also found significant associations between poor vocabulary, combined with attention problems, and phonological awareness, rapid naming and spelling control. Perinatal factors had no association with reading function, and socio‐economic factors had very few.

Conclusion

Very low birthweight children demonstrated deficits in all reading domains and had poorer cognition and more behavioural problems at the age of seven, with reading ability related to vocabulary and attention.

Controversies in preterm brain injury

In this review, we highlight critical unresolved questions in the etiology and mechanisms causing preterm brain injury. Involvement of neurons, glia, endogenous factors and exogenous exposures is considered. The structural and functional correlates of interrupted development and injury in the premature brain are under active investigation, with the hope that the cellular and molecular mechanisms underlying developmental abnormalities in the human preterm brain can be understood, prevented or repaired.

Neurodevelopmental Outcomes and Neural Mechanisms Associated with Non-right Handedness in Children Born Very Preterm

Non-right handedness (NRH) is reportedly more common in very preterm (VPT; <32 weeks' gestation) children compared with term-born peers, but it is unclear whether neonatal brain injury or altered brain morphology and microstructure underpins NRH in this population. Given that NRH has been inconsistently reported to be associated with cognitive and motor difficulties, this study aimed to examine associations between handedness and neurodevelopmental outcomes in VPT 7-year-olds. Furthermore, the relationship between neonatal brain injury and integrity of motor tracts (corpus callosum and corticospinal tract) with handedness at age 7 years in VPT children was explored. One hundred seventy-five VPT and 69 term-born children completed neuropsychological and motor assessments and a measure of handedness at 7 years' corrected age. At term-equivalent age, brain injury on MRI was assessed and diffusion tensor measures were obtained for the corpus callosum and posterior limb of the internal capsule. There was little evidence of stronger NRH in the VPT group compared with term controls (regression coefficient [b] -1.95, 95% confidence interval [-5.67, 1.77]). Poorer academic and working memory outcomes were associated with stronger NRH in the VPT group. While there was little evidence that neonatal unilateral brain injury was associated with stronger NRH, increased area and fractional anisotropy of the corpus callosum splenium were predictive of stronger NRH in the VPT group. VPT birth may alter the relationship between handedness and academic outcomes, and neonatal corpus callosum integrity predicts hand preference in VPT children at school age. (JINS, 2015, 21, 610-621).

Neonatal MRI is associated with future cognition and academic achievement in preterm children

School-age children born preterm are particularly at risk for low mathematical achievement, associated with reduced working memory and number skills. Early identification of preterm children at risk for future impairments using brain markers might assist in referral for early intervention. This study aimed to examine the use of neonatal magnetic resonance imaging measures derived from automated methods (Jacobian maps from deformation-based morphometry; fractional anisotropy maps from diffusion tensor images) to predict skills important for mathematical achievement (working memory, early mathematical skills) at 5 and 7 years in a cohort of preterm children using both univariable (general linear model) and multivariable models (support vector regression). Participants were preterm children born <30 weeks' gestational age and healthy control children born ≥37 weeks' gestational age at the Royal Women's Hospital in Melbourne, Australia between July 2001 and December 2003 and recruited into a prospective longitudinal cohort study. At term-equivalent age ( ±2 weeks) 224 preterm and 46 control infants were recruited for magnetic resonance imaging. Working memory and early mathematics skills were assessed at 5 years (n = 195 preterm; n = 40 controls) and 7 years (n = 197 preterm; n = 43 controls). In the preterm group, results identified localized regions around the insula and putamen in the neonatal Jacobian map that were positively associated with early mathematics at 5 and 7 years (both P < 0.05), even after covarying for important perinatal clinical factors using general linear model but not support vector regression. The neonatal Jacobian map showed the same trend for association with working memory at 7 years (models ranging from P = 0.07 to P = 0.05). Neonatal fractional anisotropy was positively associated with working memory and early mathematics at 5 years (both P < 0.001) even after covarying for clinical factors using support vector regression but not general linear model. These significant relationships were not observed in the control group. In summary, we identified, in the preterm brain, regions around the insula and putamen using neonatal deformation-based morphometry, and brain microstructural organization using neonatal diffusion tensor imaging, associated with skills important for childhood mathematical achievement. Results contribute to the growing evidence for the clinical utility of neonatal magnetic resonance imaging for early identification of preterm infants at risk for childhood cognitive and academic impairment.

Accelerated corpus callosum development in prematurity predicts improved outcome

OBJECTIVES

To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their change from infancy to 7 years differed between very preterm (VP) and full-term (FT) children; (2) perinatal predictors of CC size and microstructure at 7 years; and (3) associations between CC measures at 7 years or trajectories from infancy to 7 years and neurodevelopmental outcomes.

EXPERIMENTAL DESIGN

One hundred and thirty-six VP (gestational age [GA] <30 weeks and/or birth weight <1,250 g) and 33 FT children had usable magnetic resonance images at 7 years of age, and of these, 76 VP and 16 FT infants had usable data at term equivalent age. The CC was traced and divided into six sub-regions. Fractional anisotropy, mean, axial, radial diffusivity and volume were measured from tractography. Perinatal data were collected, and neurodevelopmental tests administered at 7 years' corrected age.

PRINCIPAL OBSERVATIONS

VP children had smaller posterior CC regions, higher diffusivity and lower fractional anisotropy compared with FT 7-year-olds. Reduction in diffusivity over time occurred faster in VP than FT children (P ≤ 0.002). Perinatal brain abnormality and earlier GA were associated with CC abnormalities. Microstructural abnormalities at 7 years or slower development of the CC were associated with motor dysfunction, poorer mathematics and visual perception.

CONCLUSIONS

This study is the first to demonstrate an accelerated trajectory of CC white matter diffusion following VP birth, associated with improved neurodevelopmental functioning. Findings suggest there is a window of opportunity for neurorestorative intervention to improve outcomes. Hum Brain Mapp 36:3733-3748, 2015. © 2015 Wiley Periodicals, Inc.

The predictive validity of neonatal MRI for neurodevelopmental outcome in very preterm children

Very preterm children are at a high risk for neurodevelopmental impairments, but there is variability in the pattern and severity of outcome. Neonatal magnetic resonance imaging (MRI) enhances the capacity to detect brain injury and altered brain development and assists in the prediction of high-risk children who warrant surveillance and early intervention. This review describes the application of conventional and advanced MRI with very preterm neonates, specifically focusing on the relationship between neonatal MRI findings and later neurodevelopmental outcome. Research demonstrates that conventional MRI is strongly associated with neurodevelopmental outcome in childhood. Further studies are needed to examine the role of advanced MRI techniques in predicting outcome in very preterm children, but early research findings are promising. In conclusion, neonatal MRI is predictive of later neurodevelopment but is dependent on appropriately trained specialists and should be interpreted in conjunction with other clinical and social information.

Mother's voice and heartbeat sounds elicit auditory plasticity in the human brain before full gestation

Brain development is largely shaped by early sensory experience. However, it is currently unknown whether, how early, and to what extent the newborn's brain is shaped by exposure to maternal sounds when the brain is most sensitive to early life programming. The present study examined this question in 40 infants born extremely prematurely (between 25- and 32-wk gestation) in the first month of life. Newborns were randomized to receive auditory enrichment in the form of audio recordings of maternal sounds (including their mother's voice and heartbeat) or routine exposure to hospital environmental noise. The groups were otherwise medically and demographically comparable. Cranial ultrasonography measurements were obtained at 30 ± 3 d of life. Results show that newborns exposed to maternal sounds had a significantly larger auditory cortex (AC) bilaterally compared with control newborns receiving standard care. The magnitude of the right and left AC thickness was significantly correlated with gestational age but not with the duration of sound exposure. Measurements of head circumference and the widths of the frontal horn (FH) and the corpus callosum (CC) were not significantly different between the two groups. This study provides evidence for experience-dependent plasticity in the primary AC before the brain has reached full-term maturation. Our results demonstrate that despite the immaturity of the auditory pathways, the AC is more adaptive to maternal sounds than environmental noise. Further studies are needed to better understand the neural processes underlying this early brain plasticity and its functional implications for future hearing and language development.

Visual-motor deficits relate to altered gray and white matter in young adults born preterm with very low birth weight

Individuals born preterm and at very low birth weight (birth weight ≤ 1500 g) are at an increased risk of perinatal brain injury and neurodevelopmental deficits over the long term. This study examined whether this clinical group has more problems with visual-motor integration, motor coordination, and visual perception compared to term-born controls, and related these findings to cortical surface area and thickness and white matter fractional anisotropy. Forty-seven preterm-born very low birth weight individuals and 56 term-born controls were examined at 18-22 years of age with a combined cognitive, morphometric MRI, and diffusion tensor imaging evaluation in Trondheim, Norway. Visual-motor skills were evaluated with the Beery-Buktenica Developmental Test of Visual-Motor Integration-V (VMI) copying test and its supplemental tests of motor coordination and visual perception. 3D T1-weighted MPRAGE images and diffusion tensor imaging were done at 1.5 T. Cortical reconstruction generated in FreeSurfer and voxelwise maps of fractional anisotropy calculated with Tract-Based Spatial Statistics were used to explore the relationship between MRI findings and cognitive results. Very low birth weight individuals had significantly lower scores on the copying and motor coordination tests compared with controls. In the very low birth weight group, VMI scores showed significant positive relationships with cortical surface area in widespread regions, with reductions of the superior temporal gyrus, insula, and medial occipital lobe in conjunction with the posterior ventral temporal lobe. Visual perception scores also showed positive relationships with cortical thickness in the very low birth weight group, primarily in the lateral occipito-temporo-parietal junction, the superior temporal gyrus, insula, and superior parietal regions. In the very low birth weight group, visual-motor performance correlated positively with fractional anisotropy especially in the corpus callosum, inferior fronto-occipital fasciculus bilaterally, and anterior thalamic radiation bilaterally, driven primarily by an increase in radial diffusivity. VMI scores did not demonstrate a significant relationship to cortical surface area, cortical thickness, or diffusion measures in the control group. Our results indicate that visual-motor integration problems persist into adulthood for very low birth weight individuals, which may be due to structural alterations in several specific gray-white matter networks. Visual-motor deficits appear related to reduced surface area of motor and visual cortices and disturbed connectivity in long association tracts containing visual and motor information. We conjecture that these outcomes may be due to perinatal brain injury or aberrant cortical development secondary to injury or due to very preterm birth.

Very preterm birth and foetal growth restriction are associated with specific cognitive deficits in children attending mainstream school

AIM

This study investigated the association of prenatal and neonatal factors with cognitive outcomes in schoolchildren born very preterm without impairments at the age of nine.

METHODS

We recruited a prospective regional cohort of 154 very low gestational age (VLGA) children of <32 weeks and 90 term-born comparison children born between November 1998 and November 2002 at Oulu University Hospital, Finland. Cognitive outcome was assessed using an inclusive neuropsychological test repertoire at the age of nine.

RESULTS

The final study group comprised 77 VLGA children without cerebral palsy or any cognitive impairment and 27 term-born children. VLGA was associated with a 1.5-point [95% confidence interval (CI) 0.6-2.3] reduction in visuospatial-sensorimotor processing and a 1.2-point (95% CI 0.5-1.9) reduction in attention-executive functions scores. Foetal growth restriction (FGR) was the only clinical risk factor that was associated with cognitive outcome. Children with FGR had a significant decrease in language (1.7 points, 95% CI 0.50-3.0) and memory-learning (1.6 points, 95% CI 0.4-2.8) scores.

CONCLUSION

Children born very preterm without impairments had poorer performance in specific neurocognitive skills than term-born children. FGR was an independent risk factor for compromised neurocognitive outcome in VLGA children and predicted difficulties in language, memory and learning.

School children with low birth weight inserted in system of Embu's education: construction of sentences

PURPOSE

To characterize the construction of sentences in schoolchildren born with low weight.

METHODS

We selected 413 students from Embu das Artes (SP), Brazil. Application of Recreating Speech Acts of Test of Language Competence sub-test. We analyzed the number of words and the holistic score. Age group of 6-10 years old, female/male, with low birth weight (<2,500 g) in Study Group (SG; n=238), and birth weight above or equal to 2,500 g composing the Control Group (CG; n=175). Children with anomalies were excluded. The both groups' responses were considered as well as the association of the responses with variables birth weight, gender, age of child and maternal age and education, through Student's t-test, χ2test and linear regression.

RESULTS

The SG scored less on the total number of words and had worst performance in items that involved prepositions with a sense of temporality and place, with adverb functions. There was no difference between groups regarding the holistic score. It was found positive impact of the variables birth weight (p=0.002), age of child, age of mother and maternal education on standard test scores in both groups.

CONCLUSION

The SG had fewer words compared to CG. The higher the birth weight, the higher the score test pattern. It was evident the age-related changes in morpho-syntactic skills addressed in the study, and protection factors mother's schooling and age had a positive impact on language performance.

Long-term neurodevelopmental outcomes after preterm birth

CONTEXT

All over the the world, preterm birth is a major cause of death and important neurodevelopmental disorders. Approximately 9.6% (12.9 million) births worldwide are preterm.

EVIDENCE ACQUISITION

In this review, databases such as PubMed, EMBASE, ISI, Scopus, Google Scholar and Iranian databases including Iranmedex, and SID were researched to review relevant literature. A comprehensive search was performed using combinations of various keywords.

RESULTS

Cerebral palsy especially spastic diplegia, intellectual disability, visual (retinopathy of prematurity) and hearing impairments are the main neurodevelopmental disorders associated with prematurity.

CONCLUSIONS

The increased survival of preterm infants was not associated with lower complications. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, for preterm infants.

Neuropsychological outcomes of children born very preterm

Considerable research has investigated the consequences of being born very preterm (VP; <32 weeks of gestation), especially in relation to cognitive functioning. While numerous cognitive and neuropsychological outcome studies have been published, it is important to consider methodological issues when reviewing this research, as the generalizability of the studies varies greatly. This article describes the nature of cognitive difficulties confronting VP children, both in terms of the frequency and severity of deficits. The breadth of cognitive difficulties reported in this population implies a generalized cognitive impairment; however, the presence of selective or primary cognitive deficits is discussed. It is concluded that whereas mortality and neonatal morbidity rates have decreased significantly in VP infants in recent decades, these children continue to be at significant risk for cognitive impairments and need to be closely monitored throughout childhood.

Speech and language outcomes of very preterm infants

Speech and language impairments of both simple and complex language functions are common among former preterm infants. Risk factors include lower gestational age and increasing illness severity including severe brain injury. Even in the absence of brain injury, however, altered brain maturation and vulnerability imposed by premature entrance to the extrauterine environment is associated with brain structural and microstructural changes. These alterations are associated with language impairments with lasting effects in childhood and adolescence and increased needs for speech therapy and education supports. Studies are needed to investigate language interventions which begin in the neonatal intensive care unit.

Impact of the NICU environment on language deprivation in preterm infants

It is unclear whether the atypical language development commonly seen in preterm infants is a consequence of language deficiency experienced during their prolonged NICU stay. This review provides a novel viewpoint, which highlights the potential impact of the NICU design on the developmental origin of language disabilities in preterm infants.

CONCLUSION

Further research is needed to identify evidence-based design solutions for providing preterm infants with a healthier linguistic hospital environment that aids growth and development.

The role of neuroimaging in predicting neurodevelopmental outcomes of preterm neonates

Magnetic resonance imaging (MRI) is a safe and high-resolution neuroimaging modality that is increasingly used in the neonatal population to assess brain injury and its consequences on brain development. It is superior to cranial ultrasound for the definition of patterns of both white and gray matter maturation and injury and therefore has the potential to provide prognostic information on the neurodevelopmental outcomes of the preterm population. Furthermore, the development of sophisticated MRI strategies, including diffusion tensor imaging, resting state functional connectivity, and magnetic resonance spectroscopy, may increase the prognostic value, helping to guide parental counseling and allocate early intervention services.

Focal necrosis and disturbed myelination in the white matter of newborn infants: a tale of too much or too little oxygen

White matter disease in preterm infants comes along with focal destructions or with diffuse myelination disturbance. Recent experimental work with transgenic mice paves the way for a unifying molecular model for both types of brain injury, placing oxygen sensing by oligodendrocyte precursor cells (OPCs) at the center stage. Mice genetically altered to mimic high local oxygen tension in oligodendroglia lineage cells (via deletion of hypoxia-inducible factor, HIF) develop white matter disease resembling cystic periventricular leukomalacia within the first 7 days of life. Mice in which local hypoxia is mimicked in oligodendroglial cells (via genetic inhibition of HIF decay) display arrested OPC maturation and subsequent hypomyelination, reminiscent of the diffuse white matter disease observed in preterm infants and infants with congenital heart disease. These recent experimental findings on oxygen sensing and myelination are awaiting integration into a clinical framework. Gene regulation in response to hyperoxia or hypoxia, rather than oxidative stress, may be an important mechanism underlying neonatal white matter disease.

Specific impairment of functional connectivity between language regions in former early preterms

Very preterm (PT) birth (≤32 weeks of gestation) carries a high risk for an adverse neurodevelopmental outcome. In recent years, the importance of neurocognitive deficits in the language domain has been increasingly recognized, which can be well-characterized using neuropsychological testing and noninvasive imaging approaches. We compared former early PT born children and adolescents (PT, n = 29, 20M) and typically developing children (TD, n = 19, 7M), using conventional fMRI group analyses as well as functional connectivity analyses. We found only small regions with significantly different group activation (PT > TD) but significantly stronger connectivity between superior temporal lobe (STL) language regions in TD participants. There were also significant differences in local and global network efficiency (TD > PT). Surprisingly, there was a stronger connectivity of STL regions with non-STL regions both intrahemispherically and interhemispherically in PT participants, suggesting the coexistence of reduced and increased connectivity in the language network of former PTs. Very similar results were obtained when using task-based versus resting state functional connectivity approaches. Finally, lateralization of functional connectivity correlated with verbal comprehension abilities, suggesting that a more bilateral language comprehension representation is associated with better performance. Our results underline the importance of interhemispheric crosstalk for language comprehension.

Neonatal brain abnormalities and memory and learning outcomes at 7 years in children born very preterm

Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term-born controls. Neonatal brain abnormalities, and in particular deep grey-matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function.

Optimal timing of cerebral MRI in preterm infants to predict long-term neurodevelopmental outcome: a systematic review

SUMMARY

Advances in neonatal neuroimaging have improved detection of preterm brain injury responsible for abnormal neuromotor and cognitive development. Increasingly sophisticated MR imaging setups allow scanning during early preterm life. In this review, we investigated how brain MR imaging in preterm infants should be timed to best predict long-term outcome. Given the strong evidence that structural brain abnormalities are related to long-term neurodevelopment, MR imaging should preferably be performed at term-equivalent age. Early MR imaging is promising because it can guide early intervention studies and is indispensable in research on preterm brain injury.