White matter alterations in young children with prenatal alcohol exposure

Associations between low-moderate prenatal alcohol exposure and brain development in childhood

BACKGROUND

The effects of low-moderate prenatal alcohol exposure (PAE) on brain development have been infrequently studied.

AIM

To compare cortical and white matter structure between children aged 6 to 8 years with low-moderate PAE in trimester 1 only, low-moderate PAE throughout gestation, or no PAE.

METHODS

Women reported quantity and frequency of alcohol consumption before and during pregnancy. Magnetic resonance imaging was undertaken for 143 children aged 6 to 8 years with PAE during trimester 1 only (n = 44), PAE throughout gestation (n = 58), and no PAE (n = 41). T1-weighted images were processed using FreeSurfer, obtaining brain volume, area, and thickness of 34 cortical regions per hemisphere. Fibre density (FD), fibre cross-section (FC) and fibre density and cross-section (FDC) metrics were computed for diffusion images. Brain measures were compared between PAE groups adjusted for age and sex, then additionally for intracranial volume.

RESULTS

After adjustments, the right caudal anterior cingulate cortex volume (pFDR = 0.045) and area (pFDR = 0.008), and right cingulum tract cross-sectional area (pFWE < 0.05) were smaller in children exposed to alcohol throughout gestation compared with no PAE.

CONCLUSION

This study reports a relationship between low-moderate PAE throughout gestation and cingulate cortex and cingulum tract alterations, suggesting a teratogenic vulnerability. Further investigation is warranted.

Prenatal alcohol exposure and white matter microstructural changes across the first 6-7 years of life: A longitudinal diffusion tensor imaging study of a South African birth cohort

Prenatal alcohol exposure (PAE) can affect brain development in early life, but few studies have investigated the effects of PAE on trajectories of white matter tract maturation in young children. Here we used diffusion weighted imaging (DWI) repeated over three time points, to measure the effects of PAE on patterns of white matter microstructural development during the pre-school years. Participants were drawn from the Drakenstein Child Health Study (DCHS), an ongoing birth cohort study conducted in a peri-urban community in the Western Cape, South Africa. A total of 342 scans acquired from 237 children as neonates (N = 82 scans: 30 PAE; 52 controls) and at ages 2-3 (N = 121 scans: 27 PAE; 94 controls) and 6-7 years (N = 139 scans: 45 PAE; 94 controls) were included. Maternal alcohol use during pregnancy and other antenatal covariates were collected from 28 to 32 weeks' gestation. Linear mixed effects models with restricted maxium likelihood to accommodate missing data were implemented to investigate the effects of PAE on fractional anisotropy (FA) and mean diffusivity (MD) in specific white matter tracts over time, while adjusting for child sex and maternal education. We found significant PAE-by-time effects on trajectories of FA development in the left superior cerebellar peduncle (SCP-L: p = 0.001; survived FDR correction) and right superior longitudinal fasciculus (SLF-R: p = 0.046), suggesting altered white matter development among children with PAE. Compared with controls, children with PAE demonstrated a more rapid change in FA in these tracts from the neonatal period to 2-3 years of age, followed by a more tapered trajectory for the period from 2-3 to 6-7 years of age, with these trajectories differing from unexposed control children. Given their supporting roles in various aspects of neurocognitive functioning (i.e., motor regulation, learning, memory, language), altered patterns of maturation in the SCP and SLF may contribute to a spectrum of physical, social, emotional, and cognitive difficulties often experienced by children with PAE. This study highlights the value of repeated early imaging in longitudinal studies of PAE, and focus for early childhood as a critical window of potential susceptibility as well as an opportunity for early intervention.

Premature white matter microstructure in female children with a history of concussion

Childhood concussion may interfere with neurodevelopment and influence cognition. Females are more likely to experience persistent symptoms after concussion, yet the sex-specific impact of concussion on brain microstructure in children is understudied. This study examined white matter and cortical microstructure, based on neurite density (ND) from diffusion-weighted MRI, in 9-to-10-year-old children in the Adolescent Brain Cognitive Development Study with (n = 336) and without (n = 7368) a history of concussion, and its relationship with cognitive performance. Multivariate regression was used to investigate relationships between ND and group, sex, and age in deep and superficial white matter, subcortical structures, and cortex. Partial least square correlation was performed to identify associations between ND and performance on NIH Toolbox tasks in children with concussion. All tissue types demonstrated higher ND with age, reflecting brain maturation. Group comparisons revealed higher ND in deep and superficial white matter in females with concussion. In female but not male children with concussion, there were significant associations between ND and performance on cognitive tests. These results demonstrate a greater long-term impact of childhood concussion on white matter microstructure in females compared to males that is associated with cognitive function. The increase in ND in females may reflect premature white matter maturation.

Arcuate fasciculus and pre-reading language development in children with prenatal alcohol exposure

Introduction

Prenatal alcohol exposure (PAE) contributes to widespread neurodevelopmental challenges, including reading, and has been associated with altered white matter. Here, we aimed to investigate whether arcuate fasciculus (AF) development is associated with pre-reading language skills in young children with PAE.

Methods

A total of 51 children with confirmed PAE (25 males; 5.6 ± 1.1 years) and 116 unexposed controls (57 males; 4.6 ± 1.2 years) underwent longitudinal diffusion tensor imaging (DTI), for a total of 111 scans from participants with PAE and 381 scans in the unexposed control group. We delineated the left and right AF and extracted mean fractional anisotropy (FA) and mean diffusivity (MD). Pre-reading language ability was assessed using age-standardized phonological processing (PP) and speeded naming (SN) scores of the NEPSY-II. Linear mixed effects models were run to determine the relationship between diffusion metrics and age, group, sex, and age-by-group interactions, with subject modeled as a random factor. A secondary mixed effect model analysis assessed the influence of white matter microstructure and PAE on pre-reading language ability using diffusion metric-by-age-by-group interactions, with 51 age- and sex-matched unexposed controls.

Results

Phonological processing (PP) and SN scores were significantly lower in the PAE group (p < 0.001). In the right AF, there were significant age-by-group interactions for FA (p < 0.001) and MD (p = 0.0173). In the left AF, there was a nominally significant age-by-group interaction for MD that failed to survive correction (p = 0.0418). For the pre-reading analysis, a significant diffusion-by-age-by-group interaction was found for left FA (p = 0.0029) in predicting SN scores, and for the right FA (p = 0.00691) in predicting PP scores.

Discussion

Children with PAE showed altered developmental trajectories for the AF, compared with unexposed controls. Children with PAE, regardless of age, showed altered brain-language relationships that resembled those seen in younger typically developing children. Our findings support the contention that altered developmental trajectories in the AF may be associated with functional outcomes in young children with PAE.

Atypical developmental trajectories of white matter microstructure in prenatal alcohol exposure: Preliminary evidence from neurite orientation dispersion and density imaging

Introduction

Fetal alcohol spectrum disorder (FASD), a life-long condition resulting from prenatal alcohol exposure (PAE), is associated with structural brain anomalies and neurobehavioral differences. Evidence from longitudinal neuroimaging suggest trajectories of white matter microstructure maturation are atypical in PAE. We aimed to further characterize longitudinal trajectories of developmental white matter microstructure change in children and adolescents with PAE compared to typically-developing Controls using diffusion-weighted Neurite Orientation Dispersion and Density Imaging (NODDI).

Materials and methods

Participants: Youth with PAE (n = 34) and typically-developing Controls (n = 31) ages 8-17 years at enrollment. Participants underwent formal evaluation of growth and facial dysmorphology. Participants also completed two study visits (17 months apart on average), both of which involved cognitive testing and an MRI scan (data collected on a Siemens Prisma 3 T scanner). Age-related changes in the orientation dispersion index (ODI) and the neurite density index (NDI) were examined across five corpus callosum (CC) regions defined by tractography.

Results

While linear trajectories suggested similar overall microstructural integrity in PAE and Controls, analyses of symmetrized percent change (SPC) indicated group differences in the timing and magnitude of age-related increases in ODI (indexing the bending and fanning of axons) in the central region of the CC, with PAE participants demonstrating atypically steep increases in dispersion with age compared to Controls. Participants with PAE also demonstrated greater increases in ODI in the mid posterior CC (trend-level group difference). In addition, SPC in ODI and NDI was differentially correlated with executive function performance for PAE participants and Controls, suggesting an atypical relationship between white matter microstructure maturation and cognitive function in PAE.

Discussion

Preliminary findings suggest subtle atypicality in the timing and magnitude of age-related white matter microstructure maturation in PAE compared to typically-developing Controls. These findings add to the existing literature on neurodevelopmental trajectories in PAE and suggest that advanced biophysical diffusion modeling (NODDI) may be sensitive to biologically-meaningful microstructural changes in the CC that are disrupted by PAE. Findings of atypical brain maturation-behavior relationships in PAE highlight the need for further study. Further longitudinal research aimed at characterizing white matter neurodevelopmental trajectories in PAE will be important.

Exercise in Adolescence Enhances Callosal White Matter Refinement in the Female Brain in a Rat Model of Fetal Alcohol Spectrum Disorders

A total of 1 in 20 infants born annually are exposed to alcohol prenatally, which disrupts neurodevelopment and results in several disorders categorized under the umbrella term Fetal Alcohol Spectrum Disorders (FASD). Children and adolescents affected by FASD exhibit delayed maturation of cerebral white matter, which contributes to deficits in executive function, visuospatial processing, sensory integration, and interhemispheric communication. Research using animal models of FASD have uncovered that oligoglia proliferation, differentiation, and survival are vulnerable to alcohol teratogenesis in the male brain due in part to the activation of the neuroimmune system during gestation and infancy. A comprehensive investigation of prenatal alcohol exposure on white matter development in the female brain is limited. This study demonstrated that the number of mature oligodendrocytes and the production of myelin basic protein were reduced first in the female corpus callosum following alcohol exposure in a rat model of FASD. Analysis of myelin-related genes confirmed that myelination occurs earlier in the female corpus callosum compared to their counterparts, irrespective of postnatal treatment. Moreover, dysregulated oligodendrocyte number and myelin basic protein production was observed in the male and female FASD brain in adolescence. Targeted interventions that support white matter development in FASD-affected youth are nonexistent. The capacity for an adolescent exercise intervention to upregulate corpus callosum myelination was evaluated: we discovered that volunteer exercise increases the number of mature oligodendrocytes in alcohol-exposed female rats. This study provides critical evidence that oligoglia differentiation is difficult but not impossible to induce in the female FASD brain in adolescence following a behavioral intervention.

How Alcohol Damages Brain Development in Children

The world over, people drink in order to socialize, celebrate, and relax, despite the negative health effects of alcohol. Three periods of dynamic brain changes are evidenced to be particularly sensitive to the harmful effects of alcohol: gestation (from conception to birth), later adolescence (15-19 years), and older adulthood (over 65 years). This article is concentrated only on the negative effects of alcohol in children who have been exposed to alcohol before birth, known as foetal alcohol syndrome (FAS). This is a review based on published data in PubMed over the last two decades and is an analysis of more than 150 published papers. Alcohol use during pregnancy can cause miscarriage, stillbirth, and a range of lifelong physical, behavioural, and intellectual disabilities. The effects of ethanol are expressed on a set of molecules involved in neuroinflammation, myelination, neurotransmission, and neuron function. Modern neuroimaging techniques are able to specify some fine structural changes in the affected areas of the brain: volume reductions in the frontal lobe, including the middle frontal gyri in the prefrontal cortex, hippocampal structure, interhemispheric connectivity, abnormalities in glial cells, white matter deficits etc. Corpus callosum myelination is affected, resulting in a lack of the inter-hemispheric connectivity. This is known to facilitate autism, stroke, schizophrenia, as well as dementia, disrupts cognitive performance, and may lead to neurobehavioral deficits. It was pointed out that many symptoms and neuroimaging characteristics are similar in ADHD and FAS, thus the anamnesis for prenatal alcohol and nicotine exposure must be taken very seriously in order to better understand and interpret clinical symptoms.

Frontoparietal and temporal white matter diffusion MRI in children and youth with prenatal alcohol exposure

BACKGROUND

Prenatal alcohol exposure (PAE) is associated with brain alterations and neurocognitive deficits, but relationships between brain alterations and neurocognitive deficits remain unclear.

METHODS

Diffusion tensor imaging (DTI) data were obtained from 31 participants with PAE and 31 unexposed controls aged 7-15 years. Mean diffusivity (MD) and fractional anisotropy (FA) were derived from the genu, body, and splenium of the corpus callosum (CC), bilateral cingulum, and inferior and superior longitudinal fasciculus (ILF, SLF). Participants completed language subtests from the NEPSY-II. Executive functioning was measured using the Behavior Rating Inventory of Executive Functioning (BRIEF-PR) and verbal learning was assessed using the California Verbal Learning Test-Children's Version (CVLT-C) only in children with PAE. Group differences in diffusion metrics and cognitive scores were tested. Principal component analysis was used to reduce redundancy in cognitive and behavior variables; associations between components and brain measures were then assessed.

RESULTS

Children with PAE had lower MD in the right SLF compared with unexposed controls. FA was positively related to age in 6 of 9 tracts and MD negatively related to age in all tracts; there were no significant age-by-group interactions. Participants with PAE scored lower than unexposed peers on the NEPSY-II Comprehension of Instructions and Phonological Processing and above population norms (indicating worse performance) on the BRIEF-PR. Children with PAE had a negative association between a principal component closely associated with Speeded Naming and FA in the left SLF (PAE: p = 0.002) and left ILF (PAE: p = 0.002); unexposed controls showed no significant associations.

CONCLUSION

We found widespread cognitive difficulties in children with PAE, but relatively limited differences in brain metrics and associations with age. Different brain-cognitive relationships were found in children with PAE compared with controls. Overall, the results provide additional evidence that PAE may lead to cognitive difficulties and disrupt typical brain-function relationships.

Reduced and delayed myelination and volume of corpus callosum in an animal model of Fetal Alcohol Spectrum Disorders partially benefit from voluntary exercise

1 in 20 live births in the United States is affected by prenatal alcohol exposure annually, creating a major public health crisis. The teratogenic impact of alcohol on physical growth, neurodevelopment, and behavior is extensive, together resulting in clinical disorders which fall under the umbrella term of Fetal Alcohol Spectrum Disorders (FASD). FASD-related impairments to executive function and perceptual learning are prevalent among affected youth and are linked to disruptions to corpus callosum growth and myelination in adolescence. Targeted interventions that support neurodevelopment in FASD-affected youth are nonexistent. We evaluated the capacity of an adolescent exercise intervention, a stimulator of myelinogenesis, to upregulate corpus callosum myelination in a rat model of FASD (third trimester-equivalent alcohol exposure). This study employs in vivo diffusion tensor imaging (DTI) scanning to investigate the effects of: (1) neonatal alcohol exposure and (2) an adolescent exercise intervention on corpus callosum myelination in a rodent model of FASD. DTI scans were acquired twice longitudinally (pre- and post-intervention) in male and female rats using a 9.4 Tesla Bruker Biospec scanner to assess alterations to corpus callosum myelination noninvasively. Fractional anisotropy values as well as radial/axial diffusivity values were compared within-animal in a longitudinal study design. Analyses using mixed repeated measures ANOVA’s confirm that neonatal alcohol exposure in a rodent model of FASD delays the trajectory of corpus callosum growth and myelination across adolescence, with a heightened vulnerability in the male brain. Alterations to corpus callosum volume are correlated with reductions to forebrain volume which mediates an indirect relationship between body weight gain and corpus callosum growth. While we did not observe any significant effects of voluntary aerobic exercise on corpus callosum myelination immediately after completion of the 12-day intervention, we did observe a beneficial effect of exercise intervention on corpus callosum volume growth in all rats. In line with clinical findings, we have shown that prenatal alcohol exposure leads to hypomyelination of the corpus callosum in adolescence and that the severity of damage is sexually dimorphic. Further, exercise intervention improves corpus callosum growth in alcohol-exposed and control rats in adolescence.

Trajectories of brain white matter development in young children with prenatal alcohol exposure

Prenatal alcohol exposure (PAE) is associated with alterations to brain white matter microstructure. Previous studies of PAE have demonstrated different findings in young children compared to older children and adolescents, suggesting altered developmental trajectories and highlighting the need for longitudinal research. 122 datasets in 54 children with PAE (27 males) and 196 datasets in 89 children without PAE (45 males) were included in this analysis. Children underwent diffusion tensor imaging between 2 and 8 years of age, returning approximately every 6 months. Mean fractional anisotropy (FA) and mean diffusivity (MD) were obtained for 10 major brain white matter tracts and examined for age-related changes using linear mixed effects models with age, sex, group (PAE vs. control) and an age-by-group interaction. Children with PAE had slower decreases of MD over time in the genu of the corpus callosum, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, and uncinate fasciculus. No significant age-by-group interactions were noted for FA. These findings show slower white matter development in young children with PAE than in unexposed controls. This connects previous cross-sectional findings of lower MD in young children with PAE to findings of higher MD in older children and adolescents with PAE, and further helps to understand brain development in children with PAE. This deviation from typical development trajectories may reflect altered brain plasticity, which has implications for cognitive and behavioral learning in children with PAE.

Prenatal and Postnatal Choline Supplementation in Fetal Alcohol Spectrum Disorder

Fetal alcohol spectrum disorder (FASD) is common and represents a significant public health burden, yet very few interventions have been tested in FASD. Cognitive deficits are core features of FASD, ranging from broad intellectual impairment to selective problems in attention, executive functioning, memory, visual–perceptual/motor skills, social cognition, and academics. One potential intervention for the cognitive impairments associated with FASD is the essential nutrient choline, which is known to have numerous direct effects on brain and cognition in both typical and atypical development. We provide a summary of the literature supporting the use of choline as a neurodevelopmental intervention in those affected by prenatal alcohol. We first discuss how alcohol interferes with normal brain development. We then provide a comprehensive overview of the nutrient choline and discuss its role in typical brain development and its application in the optimization of brain development following early insult. Next, we review the preclinical literature that provides evidence of choline’s potential as an intervention following alcohol exposure. Then, we review a handful of existing human studies of choline supplementation in FASD. Lastly, we conclude with a review of practical considerations in choline supplementation, including dose, formulation, and feasibility in children.

Fetal alcohol spectrum disorder and confabulation in psycholegal settings: A beginner's guide for criminal justice, forensic mental health, and legal interviewers

Fetal alcohol spectrum disorders (FASD) are neurodevelopmental/neurobehavioral conditions caused by prenatal alcohol exposure (PAE). Impairments caused by PAE contribute to the over-representation of individuals with FASD in the United States juvenile and adult criminal justice systems. These same impairments can equally impact on individuals with FASD who are witnesses to or victims of crime who also have to navigate the complexities of the criminal justice system. Difficulties include increased susceptibility to confabulation throughout the legal process that, in turn, can contribute to increased rates of poor outcomes including false confessions and wrongful convictions. Individuals with FASD are particularity at risk of confabulation when they are subjected to tactics, such as stressful and anxiety-provoking situations, threats, and leading, suggestive, or coercive questioning. Many professionals in the forensic context are unfamiliar with FASD or related confabulation risk and may unintentionally utilize tactics that intensify impacts of pre-existing impairment. This article serves as a beginner's guide for professionals working in criminal justice settings by (a) providing research-based overviews of FASD and confabulation, (b) describing how FASD may lead to confabulation, and (c) suggesting ways that professionals can modify protocols when interacting with individuals with FASD. Suggestions in this article hold the potential to decrease the risk of confabulation in the criminal justice system and decrease problematic outcomes, such as false confessions and wrongful convictions among individuals with FASD.

Prenatal Exposure And Child brain and mental Health (PEACH) study: protocol for a cohort study of children and youth with prenatal alcohol exposure

INTRODUCTION

Fetal alcohol spectrum disorder (FASD), which is caused by prenatal alcohol exposure (PAE), affects an estimated 4% of North Americans, and is the most common preventable cause of intellectual disability. Mental health problems, including anxiety and depression, are experienced by nearly all individuals with FASD. However, there is very limited knowledge about effective mental health treatments for individuals with FASD; effective treatments are hindered in part due to a lack of understanding of the basic neurobiology underlying internalising disorders in youth with FASD.

METHODS AND ANALYSIS

The Prenatal Exposure And Child brain and mental Health (PEACH) study includes children aged 7-18 years. We will use longitudinal neuroimaging (anatomical T1-weighted, diffusion and passive viewing function MRI) and mental health assessments (Behaviour Assessment Scale for Children, Multi-dimensional Anxiety Scale for Children, Children's Depression Inventory (CDI-2), Kiddie Scale of Affective Disorders) to: (1) characterise brain development trajectories in youth with FASD, (2) determine whether brain alterations mediate increased anxiety and depression in youth with FASD and (3) identify baseline brain features that predict changes of anxiety and depression symptoms over the next 2 years. All of this will be done while considering sex and adverse postnatal experiences, which can significantly impact mental health and brain outcomes. This project will forge new understanding of FASD and mental health from a neurobiological perspective, highlighting key time periods (ie, sensitive windows) and brain regions (ie, that may be susceptible to neurostimulation), while identifying factors that predict individual trajectories of anxiety and depression symptoms.

ETHICS AND DISSEMINATION

This study was approved by the University of Calgary Conjoint Health Research Ethics Board and the University of Alberta Health Research Ethics Board. Study results will be disseminated in peer-reviewed journals, at relevant conferences and in conjunction with our knowledge mobilisation partners.