Predicting the outcome of specific language impairment at five years of age through early developmental assessment in preterm infants

Structural connectivity at term equivalent age and language in preterm children at 2 years corrected

We previously reported interhemispheric structural hyperconnectivity bypassing the corpus callosum in children born extremely preterm (<28 weeks) versus term children. This increased connectivity was positively associated with language performance at 4-6 years of age in our prior work. In the present study, we aim to investigate whether this extracallosal connectivity develops in extremely preterm infants at term equivalent age by leveraging a prospective cohort study of 350 very and extremely preterm infants followed longitudinally in the Cincinnati Infant Neurodevelopment Early Prediction Study. For this secondary analysis, we included only children born extremely preterm and without significant brain injury (n = 95). We use higher-order diffusion modelling to assess the degree to which extracallosal pathways are present in extremely preterm infants and predictive of later language scores at 22-26 months corrected age. We compare results obtained from two higher-order diffusion models: generalized q-sampling imaging and constrained spherical deconvolution. Advanced MRI was obtained at term equivalent age (39-44 weeks post-menstrual age). For structural connectometry analysis, we assessed the level of correlation between white matter connectivity at the whole-brain level at term equivalent age and language scores at 2 years corrected age, controlling for post-menstrual age, sex, brain abnormality score and social risk. For our constrained spherical deconvolution analyses, we performed connectivity-based fixel enhancement, using probabilistic tractography to inform statistical testing of the hypothesis that fibre metrics at term equivalent age relate to language scores at 2 years corrected age after adjusting for covariates. Ninety-five infants were extremely preterm with no significant brain injury. Of these, 53 had complete neurodevelopmental and imaging data sets that passed quality control. In the connectometry analyses adjusted for covariates and multiple comparisons (P < 0.05), the following tracks were inversely correlated with language: bilateral cerebellar white matter and middle cerebellar peduncles, bilateral corticospinal tracks, posterior commissure and the posterior inferior fronto-occipital fasciculus. No tracks from the constrained spherical deconvolution/connectivity-based fixel enhancement analyses remained significant after correction for multiple comparisons. Our findings provide critical information about the ontogeny of structural brain networks supporting language in extremely preterm children. Greater connectivity in more posterior tracks that include the cerebellum and connections to the regions of the temporal lobes at term equivalent age appears to be disadvantageous for language development.

What risk factors for Developmental Language Disorder can tell us about the neurobiological mechanisms of language development

Language is a complex multidimensional cognitive system that is connected to many neurocognitive capacities. The development of language is therefore strongly intertwined with the development of these capacities and their neurobiological substrates. Consequently, language problems, for example those of children with Developmental Language Disorder (DLD), are explained by a variety of etiological pathways and each of these pathways will be associated with specific risk factors. In this review, we attempt to link previously described factors that may interfere with language development to putative underlying neurobiological mechanisms of language development, hoping to uncover openings for future therapeutical approaches or interventions that can help children to optimally develop their language skills.

Language Outcomes of Children Born Very Preterm in Relation to Early Maternal Depression and Anxiety

Unaddressed maternal psychological distress within the first year postpartum is known to have numerous negative consequences on the child's developmental outcomes, including language acquisition. This study examined the relationship between early maternal psychosocial factors and the language outcomes of children born very preterm (VPT; ≤32 weeks gestational age). It used data from the Cincinnati Infant Neurodevelopment Early Prediction Study, an ongoing National-Institutes-of-Health-funded prospective, multicenter cohort investigation of VPT infants. A total of 243 (125 boys; 118 girls) children born VPT (M = 29.03 weeks of gestation; SD = 2.47) and their corresponding 207 mothers (34 with multiple infants) were included in this study. We did not find an association between maternal depression or anxiety and Bayley-III (M = 92.3, SD = 18.9) language scores. Additionally, maternal grit and self-efficacy did not modify the relationship between depression and anxiety and language scores. A higher level of maternal education and infant female sex were significantly associated with higher language scores. While preterm birth typically results in higher rates of depression and anxiety for parents, the findings suggest that maternal depression, anxiety, and grit and the self-efficacy of the mothers in this sample did not relate to the language development of their children, independent of maternal education and infant female sex.

Language outcomes at 4 years of linguistically diverse children born very preterm: an Australian retrospective single-centre study

BACKGROUND

Very preterm children are at increased risk of language delays. Concerns have been raised about the utility of standardised English language tools to diagnose language delay in linguistically diverse children. Our study investigated the incidence of language delay at 4 years in linguistically diverse very preterm children.

METHODS

Very preterm children born in South Western Sydney, Australia, between 2012 and 2016, were assessed with the Clinical Evaluation of Language Fundamentals Preschool-2 (CELF-P2) tool at 4 years of age. We sought to determine the incidence of language delay in this cohort using language scores from the CELF-P2 assessment tool, and explore potential predictors associated with language delay.

RESULTS

One hundred and sixty very preterm children attended the 4-year assessment out of the included 270 long-term survivors. At 4 years, 76 (52%) very preterm children had language delay diagnosed using the CELF-P2 assessment tool. Children who preferred a language other than English had lower average core language scores on the CELF-P2 assessment tool (75.1±14.4) compared with children that preferred English (86.5±17.9); p=0.002. Very preterm children growing up in households that preferenced a language other than English and those who were born from multiple births had higher odds of language delay at 4 years (AOR 10.30 (95% CI 2.82 to 38.28); p<0.001 and AOR 2.93 (95% CI 1.20 to 7.14); p=0.018, respectively). Assessing these children using an English language tool may have affected language scores at 4 years.

CONCLUSIONS

In this metropolitan setting, very preterm children from linguistically diverse backgrounds were found to be vulnerable to language delays at 4 years. Further large-scale studies evaluating the language outcomes of linguistically diverse preterm children with more culturally appropriate tools are warranted. We question the utility of standardised English language tools to assess language outcomes of linguistically diverse populations.

La habilidad lingüística en prematuros extremos en edad escolar

En España, el número de nacimientos prematuros es de 30.000, siendo una de las principales causas de mortalidad perinatal. En los últimos años, gracias a los avances médicos, la tasa de supervivencia de esta población se ha visto incrementada, lo cual ha evidenciado la aparición de nuevas morbilidades y comorbilidades que pueden interferir en su proceso de aprendizaje. Este estudio, de carácter cualitativo y longitudinal, cuenta con un muestreo no probabilístico por conveniencia. Su objeto es analizar la habilidad lingüística de cuatro menores grandes prematuros, con una edad gestacional al nacimiento igual o inferior a las 28 semanas, que actualmente cursan 4º de Educación Primaria, para detectar posibles dificultades en la adquisición y en el uso del lenguaje. Se les administró la Batería del Lenguaje Objetiva y Criterial Revisado (BLOC-SR) a la edad cronológica de 8 y 10 años. Los resultados sugieren que existen dificultades en la adquisición de los componentes del lenguaje: en el morfológico, por ejemplo, aparece en el uso de las formas verbales, en los sustantivos derivados, etc.; en el sintáctico, en las oraciones subordinadas de causa y condición, etc.; en el semántico se evidencian en los locativos, etc., y en el pragmático, en la realización de preguntas. A modo de conclusión, los menores prematuros extremos, debido a su condición de vulnerabilidad biológica al quedar interrumpida la maduración cerebral por su nacimiento temprano, necesitan potenciar las destrezas lingüísticas, entre las que destaca la conciencia semántica, siendo necesario diseñar propuestas de intervención para el ámbito escolar.

Stability of language difficulties among a clinical sample of preschoolers

BACKGROUND

Some data call into question the persistence of developmental language disorders (DLDs) identified during the preschool period. For this reason, speech-language pathologists (SLPs) often reassess children. However, it is unclear if the instability of the profiles documented in community sample studies is present in children referred to specialized clinics. Given the scarcity of SLP resources, is re-evaluating the language skills of these children a good use of clinical time?

AIM

To examine the stability of the findings from two SLP assessments in a sample of Canadian preschool children referred to a tertiary clinic between the ages of 2 and 6 years. It was hypothesized that children under the age of 4 years at first assessment and children with less severe initial deficits would show less stability of DLD diagnosis.

METHODS & PROCEDURES

The clinical files of children referred to an early childhood psychiatric clinic in Canada were reviewed. For 149 children with two SLPs assessment reports, persistence of language deficits was documented and tested with McNemar's statistics. Differences between preschoolers under the age of 4 versus 4 years and over, as well as between mildly and severely impaired children, were examined.

OUTCOMES & RESULTS

High level of agreement (94%) and McNemar's test (p = 0.180) supported the stability of initial diagnosis. The stability for children assessed before the age of 4 (n = 64) was 100%, and was significantly different from older children's (n = 85) stability of 89% (Fisher's exact test, p = 0.01; bilateral). The stability for children with mild impairments (n = 18) was 78%, which was significantly lower than the stability (97%) in children with severe impairments (n = 114) (Fisher's exact test, p = 0.007; bilateral).

CONCLUSIONS & IMPLICATIONS

No instability of language status was observed in children assessed before 4 years of age, which could be related to the significant severity of the difficulties that children in this age group presented and be specific to this type of clinical sample. The great stability of language status observed in preschoolers referred to a specialized clinic suggests that clinicians should limit reassessments to devote available resources to intervention efforts.

WHAT THIS PAPER ADDS

What is already known on this subject? Previous research that has demonstrated important instability in the classification of language impairment before 4 years of age gathered data mainly by screening the general population or was not based on a comprehensive clinical assessment. What this paper adds to existing knowledge? This study investigated the classification stability of DLD between two comprehensive SLP assessments in a clinical sample of Canadian preschoolers. The results indicate great stability of language status assessed before 4 years old in this population, suggesting that severity of impairments may trump the age factor in this group. What are the potential or actual clinical implications of this work? In the case of children referred to a specialized clinic, clinicians and policymakers should be aware that DLD diagnosis made before 4 years of age remains stable during preschool age, and that a best practice with this population would be to abandon unnecessary testing in favour of early intervention.

Impact of Differing Language Background Exposures on Bayley-III Language Assessment in a National Cohort of Children Born Less than 29 Weeks' Gestation

Preterm infants are at risk for adverse neurodevelopmental outcomes, especially language delay. Preterm infants < 29 weeks’ gestational age, cared for in Canadian Neonatal Follow-Up Network affiliated hospitals, were assessed between 18 to 21 months corrected age using the Bayley-III. Bayley-III Language Composite Scores were compared using univariate and multivariate analyses for children in three primary language groups: English, French and other. 6146 children were included. The primary language at home was English, French or another language for 3708 children (60%), 1312 children (21%) and 1126 children (18%), respectively, and overall, 44% were exposed to two or more languages at home. Univariate analysis showed that primary language was associated with lower Bayley-III Language scores; however, multivariate analyses demonstrated that neither primary language nor language of administration were significantly associated with lower language scores when adjusted for gestational age, other developmental delays and sociodemographic factors, but multiple language exposure was. Sociodemographic and other factors are more important in determining language development than primary language at home. Further studies are needed to examine the association between exposure to multiple languages and lower Bayley-III language scores in preterm infants.

Extracallosal Structural Connectivity Is Positively Associated With Language Performance in Well-Performing Children Born Extremely Preterm

Children born extremely preterm (<28 weeks gestation) are at risk for language delay or disorders. Decreased structural connectivity in preterm children has been associated with poor language outcome. Previously, we used multimodal imaging techniques to demonstrate that increased functional connectivity during a stories listening task was positively associated with language scores for preterm children. This functional connectivity was supported by extracallosal structural hyperconnectivity when compared to term-born children. Here, we attempt to validate this finding in a distinct cohort of well-performing extremely preterm children (EPT, n = 16) vs. term comparisons (TC, n = 28) and also compare this to structural connectivity in a group of extremely preterm children with a history of language delay or disorder (EPT-HLD, n = 8). All participants are 4-6 years of age. We perform q-space diffeomorphic reconstruction and functionally-constrained structural connectometry (based on fMRI activation), including a novel extension enabling between-groups comparisons with non-parametric ANOVA. There were no significant differences between groups in age, sex, race, ethnicity, parental education, family income, or language scores. For EPT, tracks positively associated with language scores included the bilateral posterior inferior fronto-occipital fasciculi and bilateral cerebellar peduncles and additional cerebellar white matter. Quantitative anisotropy in these pathways accounted for 55% of the variance in standardized language scores for the EPT group specifically. Future work will expand this cohort and follow longitudinally to investigate the impact of environmental factors on developing language networks and resiliency in the preterm brain.

Functional Hyperconnectivity during a Stories Listening Task in Magnetoencephalography Is Associated with Language Gains for Children Born Extremely Preterm

Extreme prematurity (EPT, <28 weeks gestation) is associated with language problems. We previously reported hyperconnectivity in EPT children versus term children (TC) using magnetoencephalography (MEG). Here, we aim to ascertain whether functional hyperconnectivity is a marker of language resiliency for EPT children, validating our earlier work with a distinct sample of contemporary well-performing EPT and preterm children with history of language delay (EPT-HLD). A total of 58 children (17 EPT, 9 EPT-HLD, and 32 TC) participated in stories listening during MEG and functional magnetic resonance imaging (fMRI) at 4–6 years. We compared connectivity in EPT and EPT-HLD, investigating relationships with language over time. We measured fMRI activation during stories listening and parcellated the activation map to obtain “nodes” for MEG connectivity analysis. There were no significant group differences in age, sex, race, ethnicity, parental education, income, language scores, or language representation on fMRI. MEG functional connectivity (weighted phase lag index) was significantly different between groups. Preterm children had increased connectivity, replicating our earlier work. EPT and EPT-HLD had hyperconnectivity versus TC at 24–26 Hz, with EPT-HLD exhibiting greatest connectivity. Network strength correlated with change in standardized scores from 2 years to 4–6 years of age, suggesting hyperconnectivity is a marker of advancing language development.

Prevalence of Language Delay among Healthy Preterm Children, Language Outcomes and Predictive Factors

Language delay (LD) and its relationship with later language impairment in preterm children is a topic of major concern. Previous studies comparing LD in preterm (PT) and full-term (FT) children were mainly carried out with samples of extremely preterm and very preterm children (sometimes with additional medical problems). Very few of them were longitudinal studies, which is essential to understand developmental relationships between LD and later language impairment. In this study, we compare the prevalence of LD in low-risk preterm children to that of FT children in a longitudinal design ranging from 10 to 60 months of age. We also analyze which variables are related to a higher risk of LD at 22, 30 and 60 months of age. Different language tests were administered to three groups of preterm children of different gestational ages and to one group of full-term children from the ages of 10 to 60 months. ANOVA comparisons between groups and logistic regression analyses to identify possible predictors of language delay at 22, 30 and 60 months of age were performed. The results found indicate that there were practically no differences between gestational age groups. Healthy PT children, therefore, do not have, in general terms, a higher risk of language delay than FT children. Previous language delay and cognitive delay are the strongest and longest-lasting predictors of later language impairment. Other factors, such as a scarce use of gestures at 10 months or male gender, affect early LD at 22 months of age, although their effect disappears as children grow older. Low maternal education appears to have a late effect. Gestational age does not have any significant effect on the appearance of LD.

Extremely preterm children demonstrate hyperconnectivity during verb generation: A multimodal approach

Children born extremely preterm (EPT, <28 weeks gestation) are at risk for delays in development, including language. We use fMRI-constrained magnetoencephalography (MEG) during a verb generation task to assess the extent and functional connectivity (phase locking value, or PLV) of language networks in a large cohort of EPT children and their term comparisons (TC). 73 participants, aged 4 to 6 years, were enrolled (42 TC, 31 EPT). There were no significant group differences in age, sex, race, ethnicity, parental education, or family income. There were significant group differences in expressive language scores (p < 0.05). Language representation was not significantly different between groups on fMRI, with task-specific activation involving bilateral temporal and left inferior frontal cortex. There were group differences in functional connectivity seen in MEG. To identify a possible subnetwork contributing to focal spectral differences in connectivity, we ran Network Based Statistics analyses. For both beta (20-25 Hz) and gamma (61-70 Hz) bands, we observed a subnetwork showing hyperconnectivity in the EPT group (p < 0.05). Network strength was computed for the beta and gamma subnetworks and assessed for correlation with language performance. For the EPT group exclusively, strength of the subnetwork identified in the gamma frequency band was positively correlated with expressive language scores (r = 0.318, p < 0.05). Thus, hyperconnectivity is positively related to language for EPT children and might represent a marker for resiliency in this population.

Extremely Preterm Children Demonstrate Interhemispheric Hyperconnectivity During Verb Generation: a Multimodal Approach

Children born extremely preterm (EPT, <28 weeks gestation) are at risk for delays in development, including language. We use fMRI-constrained magnetoencephalography (MEG) during a verb generation task to assess the extent and functional connectivity (phase locking value, or PLV) of language networks in a large cohort of EPT children and their term comparisons (TC). 73 participants, aged 4 to 6 years, were enrolled (42 TC, 31 EPT). There were no significant group differences in age, sex, race, ethnicity, parental education, or family income. There were significant group differences in expressive language scores (p<0.05). Language representation was not significantly different between groups on fMRI, with task-specific activation involving bilateral temporal and left inferior frontal cortex. There were group differences in functional connectivity seen in MEG. To identify a possible subnetwork contributing to focal spectral differences in connectivity, we ran Network Based Statistics analyses. For both beta (20-25 Hz) and gamma (61-70 Hz) bands, we observed a subnetwork showing hyperconnectivity in the EPT group (p<0.05). Network strength was computed for the beta and gamma subnetworks and assessed for correlation with language performance. For the EPT group, exclusively, strength of the subnetwork identified in the gamma frequency band was positively correlated with expressive language scores (r=0.318, p<0.05). Thus, interhemispheric hyperconnectivity is positively related to language for EPT children and might represent a marker for resiliency in this population.

Extremely preterm children exhibit altered cortical thickness in language areas

Children born extremely preterm (< 28 weeks gestation, EPT) are at increased risk for language and other neurocognitive deficits compared to term controls (TC). Prior studies have reported both increases and decreases in cortical thickness in EPT across the cerebrum. These studies have not formally normalized for intracranial volume (ICV), which is especially important as EPT children often have smaller stature, head size, and ICV. We previously reported increased interhemispheric functional and structural connectivity in a well-controlled group of school-aged EPT children with no known brain injury or neurological deficits. Functional and structural hyperconnectivity between left and right temporoparietal regions was positively related with language scores in EPT, which may be reflected in measures of cortical thickness. To characterize possible language network cortical thickness effects, 15 EPT children and 15 TC underwent standardized assessments of language and structural magnetic resonance imaging at 4 to 6 years of age. Images were subjected to volumetric and cortical thickness analyses using FreeSurfer. Whole-brain analyses of cortical thickness were conducted both with and without normalization by ICV. Non-normalized results showed thinner temporal cortex for EPT, while ICV-normalized results showed thicker cortical regions in the right temporal lobe (FDRq = 0.05). Only ICV-normalized results were significantly related to language scores, with right temporal cortical thickness being positively correlated with performance.

Rewiring the extremely preterm brain: Altered structural connectivity relates to language function

Children born preterm are at increased risk for cognitive impairment, with higher-order functions such as language being especially vulnerable. Previously, we and others have reported increased interhemispheric functional connectivity in children born extremely preterm; the finding appears at odds with literature showing decreased integrity of the corpus callosum, the primary commissural bundle, in preterm children. We address the apparent discrepancy by obtaining advanced measures of structural connectivity in twelve school-aged children born extremely preterm (<28 weeks) and ten term controls. We hypothesize increased extracallosal structural connectivity might support the functional hyperconnectivity we had previously observed. Participants were aged four to six years at time of study and groups did not differ in age, sex, race, ethnicity, or socioeconomic status. Whole-brain and language-network-specific (functionally-constrained) connectometry analyses were performed. At the whole-brain level, preterm children had decreased connectivity in the corpus callosum and increased connectivity in the cerebellum versus controls. Functionally-constrained analyses revealed significantly increased extracallosal connectivity between bilateral temporal regions in preterm children (FDRq <0.05). Connectivity within these extracallosal pathways was positively correlated with performance on standardized language assessments in children born preterm (FDRq <0.001), but unrelated to performance in controls. This is the first study to identify anatomical substrates for increased interhemispheric functional connectivity in children born preterm; increased reliance on an extracallosal pathway may represent a biomarker for resiliency following extremely preterm birth.

Sitting Matters! Differences Between Sitters and Nonsitters at 6 Months' Adjusted Age in Infants At-Risk and Born Preterm

PURPOSE

Sitting delays in infants born preterm compound cognitive and language deficits. This retrospective study examines differences in prematurity-related risk and compares developmental outcomes between sitters and nonsitters at 6 months' adjusted age.

METHODS

A total of 105 graduates of the neonatal intensive care unit met inclusion criteria. Infant demographic and medical risk profiles and 6-month Bayley Scales of Infant Development-3rd edition (BSID-III) cognitive and language scores were retrieved. Infants who sat with hands free greater than 60 seconds were classified as "sitters."

RESULTS

Sixty-nine percent of the sample were nonsitters and were born earlier, had lower birth weights, were chronologically older at follow-up, and spent more days with respiratory support. BSID-III scores were significantly higher in sitters but did not differ by gender, multiple birth, head ultrasound results, payment type, or race/ethnicity.

CONCLUSION

Sitting abilities at 6 months' adjusted age are associated with prematurity risk factors. Cognitive and language scores differ significantly between sitters and nonsitters.

Developmental influence of unconjugated hyperbilirubinemia and neurobehavioral disorders

Bilirubin-induced brain injury in the neonatal period has detrimental effects on neurodevelopment that persist into childhood and adulthood, contributing to childhood developmental disorders. Unconjugated bilirubin is a potent antioxidant that may be useful for protecting against oxidative injuries, but it becomes a potent neurotoxin once it crosses the blood brain barrier. Because bilirubin toxicity involves a myriad of pathological mechanisms, can damage most types of brain cells, and affects brain circuits or loops that influence cognition, learning, behavior, sensory, and language, the clinical effects of bilirubin-induced neurotoxicity are likely to be manifold. One possible effect that several experts have identified is bilirubin-induced neurological dysfunction (subtle kernicterus). However, the underlying biological mechanisms or pathways by which subtle kernicterus could lead to developmental disorders has not been elucidated previously. Our aim in this review is to describe a spectrum of developmental disorders that may reflect subtle kernicterus and outline plausible biological mechanisms for this possible association. We review existing evidence that support or refute the association between unconjugated hyperbilirubinemia and developmental disorders, and limitations associated with these studies.

The influence of prematurity on the development of phonological skills

ABSTRACT Purpose: to check the use of phonological processes in preterm infants. Methods: phonological evaluation was performed through the ABFW Child Language Test in 40 children, aged two to four years, i.e., 20 preterm and 20 full-term children, matched according to age, gender and socioeconomic level. Preterm children were evaluated at the State Center for Prevention and Rehabilitation of People with Disabilities - CEPRED; full-term children were selected and evaluated in a municipal nursery in the city of Salvador, BA, Brazil. The pertinent statistical tests were applied adopting the level of significance lower than 0.05%. Results: in the phonology test, the number of productive phonological processes not expected for the chronological age was statistically significant in the preterm group, especially syllable reduction, consonantal harmony, velar backing and liquid reduction. The high prevalence of cluster reduction and final consonant deletion, though still compatible with chronological age, shows the need to follow up the language acquisition of these children, after the age of four. Conclusion: the results evidenced the difficulty found by preterm infants in the development of phonological skills, emphasizing the importance of early diagnosis and speech-language monitoring in language acquisition.

Extremely preterm children exhibit increased interhemispheric connectivity for language: findings from fMRI-constrained MEG analysis

Children born extremely preterm are at significant risk for cognitive impairment, including language deficits. The relationship between preterm birth and neurological changes that underlie cognitive deficits is poorly understood. We use a stories-listening task in fMRI and MEG to characterize language network representation and connectivity in children born extremely preterm (n = 15, <28 weeks gestation, ages 4-6 years), and in a group of typically developing control participants (n = 15, term birth, 4-6 years). Participants completed a brief neuropsychological assessment. Conventional fMRI analyses revealed no significant differences in language network representation across groups (p > .05, corrected). The whole-group fMRI activation map was parcellated to define the language network as a set of discrete nodes, and the timecourse of neuronal activity at each position was estimated using linearly constrained minimum variance beamformer in MEG. Virtual timecourses were subjected to connectivity and network-based analyses. We observed significantly increased beta-band functional connectivity in extremely preterm compared to controls (p < .05). Specifically, we observed an increase in connectivity between left and right perisylvian cortex. Subsequent effective connectivity analyses revealed that hyperconnectivity in preterms was due to significantly increased information flux originating from the right hemisphere (p < 0.05). The total strength and density of the language network were not related to language or nonverbal performance, suggesting that the observed hyperconnectivity is a "pure" effect of prematurity. Although our extremely preterm children exhibited typical language network architecture, we observed significantly altered network dynamics, indicating reliance on an alternative neural strategy for the language task.

Prediction of three year outcomes using the Bayley-III for surgical, cardiac and healthy Australian infants at one year of age

BACKGROUND

Previous predictive research has predominantly focussed on infants who are preterm, low birth weight, who have a specific condition or who have undergone a specific procedure.

AIM

This study investigated the ability of outcomes at one year of age to predict outcomes at three years using the Bayley-III for infants who have undergone early major cardiac surgery (CS) or non-cardiac (NC) surgery and their healthy peers.

STUDY DESIGN

Participants who were part of the Development After Infant Surgery (DAISy) study who had complete Bayley-III assessments at one and three years of age were included in the analyses. This included 103 infants who had undergone CS, 158 who had NC surgery and 160 controls.

RESULTS

Bayley-III outcomes at one, although statistically significantly associated with three year outcomes in all domains were weak predictors of those outcomes for CS, NC surgical and healthy infants. Specificity for three year outcomes was good for cognitive, receptive language and fine motor domains for infants who had undergone CS and NC surgery. Sensitivity for <-1 SD at three years was poor for cognitive, expressive and receptive language, and fine motor outcomes for CS and NC surgical participants.

CONCLUSION

It remains difficult to predict how performance at one year on the Bayley-IIII predicts performance at three on the Bayley-III for infants who have undergone early major CS or NC surgery and for healthy Australian infants.

Stability of Developmental Problems after School Entry of Moderately-Late Preterm and Early Preterm-Born Children

OBJECTIVE

To assess the stability of developmental problems in moderately-late preterm-born children compared with early preterm and full term-born children before school entry at age 4 years and 1 year after school entry at age 5 years.

STUDY DESIGN

We included 376 early preterm, 688 born moderately-late preterm, and 403 full term-born children from the Longitudinal Preterm Outcome Project (LOLLIPOP) cohort study. Developmental problems were assessed by the total score and the 5 domain scores of the Ages and Stages Questionnaire at ages 4 (ASQ-4) and 5 (ASQ-5). From the combinations of normal and abnormal ASQ-4 and ASQ-5 scores we constructed 4 categories: consistently normal, emerging, resolving, and persistent problems.

RESULTS

The ASQ-4 total score was abnormal more frequently in moderately-late preterm (7.9%, P = .016) and early preterm-born children (13.0%, P < .001) than in full term-born children (4.1%). Compared with the ASQ-5 total score, moderately-late preterm-born children had persistence and change comparable with full term-born children, and early preterm-born children had significantly greater rates than full term-born children of persistent (8.4% vs 2.2%, P < .001) and emerging problems (7.8% vs 2.7% P = .001). On the underlying domains, both early preterm and moderately-late preterm-born children had mainly emerging motor problems and resolving communication problems, but the changing rates of moderately-late preterm-born children were lower.

CONCLUSIONS

After school entry, the overall development of moderately-late preterm-born children had stability patterns comparable with full term-born children, whereas early preterm-born children had greater rates of persistent and emerging problems. On the underlying domains, moderately-late preterm-born children had patterns comparable with early preterm-born children but at lower rates.

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.

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

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Variability in language correlates specifically with left perisylvian brain volume.

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

Language and hearing outcomes of preterm infants

Multiple factors including degree of prematurity, neonatal morbidities, illness severity, hearing status, gender, language environment in the neonatal intensive care unit and in the home, maternal education level, social and environmental status of the family, and access to early intervention all contribute to the language outcomes of extremely preterm infants with and without hearing loss. Early screening, early diagnosis, and early intervention services by 6 months of age are necessary to optimize the language outcomes of preterm infants with permanent hearing loss. There is increasing evidence of the potential for improved language skills with increasing age of extreme preterm infants and infants with hearing loss.

Brain Volumes at Term-Equivalent Age in Preterm Infants: Imaging Biomarkers for Neurodevelopmental Outcome through Early School Age

OBJECTIVE

To evaluate the relationship between brain volumes at term and neurodevelopmental outcome through early school age in preterm infants.

STUDY DESIGN

One hundred twelve preterm infants (born mean gestational age 28.6 ± 1.7 weeks) were studied prospectively with magnetic resonance imaging (imaged at mean 41.6 ± 1.0 weeks). T2- and T1-weighted images were automatically segmented, and volumes of 6 tissue types were related to neurodevelopmental outcome assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (cognitive, fine, and gross motor scores) at 24 months corrected age (n = 112), Griffiths Mental Development Scales (developmental quotient) at age 3.5 years (n = 98), Movement Assessment Battery for Children, Second Edition (n = 85), and Wechsler Preschool and Primary Scale of Intelligence, Third Edition at age 5.5 years (n = 44). Corrections were made for intracranial volume, maternal education, and severe brain lesions.

RESULTS

Ventricular volumes were negatively related to neurodevelopmental outcome at age 24 months and 3.5 years, as well as processing speed at age 5.5 years. Unmyelinated white matter (UWM) volume was positively associated with motor outcome at 24 months and with processing speed at age 5.5 years. Cortical gray matter (CGM) volume demonstrated a negative association with motor performance and cognition at 24 months and with developmental quotient at age 3.5 years. Cerebellar volume was positively related to cognition at these time points. Adjustment for brain lesions attenuated the relations between cerebellar and CGM volumes and cognition.

CONCLUSIONS

Brain volumes of ventricles, UWM, CGM, and cerebellum may serve as biomarkers for neurodevelopmental outcome in preterm infants. The relationship between larger CGM volumes and adverse neurodevelopment may reflect disturbances in neuronal and/or axonal migration at the UWM-CGM boundary and warrants further investigation.

Quality of life of individuals born preterm: a systematic review of assessment approaches

PURPOSE

To review the existing literature regarding factors associated with quality of life (QoL) of individuals who were born preterm. The review focuses on assessment approaches and information sources.

METHODS

A systematic review of empirical studies published in PubMed, PsycARTICLES, PsycINFO, LILACS, and SciELO databases between 2007 and 2015. Search terms were chosen that relate preterm birth to QoL.

RESULTS

Twenty-two articles were included. Of these, ten investigated QoL in children, six investigated adolescents, and six investigated adults. All studies used generic instruments to assess QoL. There was a high rate of parental report to assess QoL in studies of children. Adolescent and adult studies most often assessed QoL through self-report. Parents of children who were born preterm reported worse QoL for their children compared with parents of children born full term. Teenagers and adults who were born preterm self-reported more positive outcomes in their QoL. The main risk factors associated with worse QoL in children who were born preterm were congenital malformations, mechanical ventilation during the neonatal phase, cognitive impairments, behavioral problems, physical disabilities, low family income, and black race.

CONCLUSIONS

Agreement between parents and children about QoL in preterm individuals was lower in younger age groups compared with older age groups. The differences in QoL throughout the different age groups may have arisen because of developmental changes or differences in the source of information used (i.e., parent report or self-report). We recommend that QoL assessments in children born preterm should consider both parent report and self-report.

Neurobehavioral development prior to term-age of preterm infants and acute stressful events during neonatal hospitalization

BACKGROUND

Neonatal Intensive Care Units (NICUs) protect preterm infants; otherwise, this is a stressful environment including painful stimuli.

AIMS

To compare early neurobehavioral development prior to term-age in preterm infants at 34-36weeks of post-conceptional age in different gestational ages, and to examine the effects of prematurity level and acute stressful events during NICU hospitalization on neurobehavioral development.

STUDY DESIGN

Cross-sectional design.

SUBJECTS

Forth-five preterm infants, 34-36weeks of post-conceptional age, were distributed into groups: extreme preterm (EPT; 23-28weeks of gestational age; n=10), moderate preterm (MPT; 29-32weeks of gestational age; n=10), late preterm (LPT; 34-36weeks of gestational age; n=25).

OUTCOME MEASURES

All of the neonates were evaluated using the Neurobehavioral Assessment of Preterm Infant (NAPI) prior to 37weeks of post-conceptional age. The Neonatal Infant Stressor Scale (NISS) was applied for EPT and MPT infants during NICU hospitalization, and medical charts were analyzed.

RESULTS

The EPT group experienced significantly more acute stressful events during NICU hospitalization than the MPT group. The MPT group had lower scores in motor development and vigor than the EPT and LPT group, and they exhibited poorer quality crying than the LPT group. Motor development and vigor and alertness and orientation in preterm infants were predicted by prematurity level and acute stressful events.

CONCLUSION

The extreme preterm was exposed to higher stressful experiences than moderate and late preterm infants. However, the moderate preterm infants presented more vulnerable than the other counterparts in motor and vigor outcomes.

Bayley-III Cognitive and Language Scales in Preterm Children

BACKGROUND

This study aimed to assess the sensitivity and specificity of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III), Cognitive and Language scales at 24 months for predicting cognitive impairments in preterm children at 4 years.

METHODS

Children born <30 weeks' gestation completed the Bayley-III at 24 months and the Differential Ability Scale, Second Edition (DAS-II), at 4 years to assess cognitive functioning. Test norms and local term-born reference data were used to classify delay on the Bayley-III Cognitive and Language scales. Impairment on the DAS-II Global Conceptual Ability, Verbal, and Nonverbal Reasoning indices was classified relative to test norms. Scores < -1 SD relative to the mean were classified as mild/moderate delay or impairment, and scores < -2 SDs were classified as moderate delay or impairment.

RESULTS

A total of 105 children completed the Bayley-III and DAS-II. The sensitivity of mild/moderate cognitive delay on the Bayley-III for predicting impairment on DAS-II indices ranged from 29.4% to 38.5% and specificity ranged from 92.3% to 95.5%. The sensitivity of mild/moderate language delay on the Bayley-III for predicting impairment on DAS-II indices ranged from 40% to 46.7% and specificity ranged from 81.1% to 85.7%. The use of local reference data at 24 months to classify delay increased sensitivity but reduced specificity. Receiver operating curve analysis identified optimum cut-point scores for the Bayley-III that were more consistent with using local reference data than Bayley-III normative data.

CONCLUSIONS

In our cohort of very preterm children, delay on the Bayley-III Cognitive and Language scales was not strongly predictive of future impairments. More children destined for later cognitive impairment were identified by using cut-points based on local reference data than Bayley-III norms.