Reading impairment in adolescents with fetal alcohol spectrum disorders

PURPOSE

To date, research on effects of prenatal alcohol exposure (PAE) has focused on a broad range of cognitive impairments, but relatively few studies have examined effects of PAE on development of reading skills. Although PAE has been linked to poorer reading comprehension, it remains unclear whether this impairment is attributable to deficits in phonological processing, word reading, oral language skills, and/or executive functioning.

METHODS

A comprehensive reading battery was administered to 10 adolescents with fetal alcohol syndrome (FAS); 16 with partial FAS; 30 nonsyndromal heavily-exposed; 49 controls.

RESULTS

PAE was related to poorer reading comprehension but not to single word reading or phonological processing, suggesting that the mechanics of reading are intact in adolescents with fetal alcohol spectrum disorders at this age. PAE-related impairment in reading comprehension was mediated, in part, by deficits in mastery of oral language skills, including vocabulary, language structure, and verbal fluency.

CONCLUSIONS

These results are consistent with research showing that reading comprehension in adolescence relies increasingly on linguistic comprehension abilities, especially once word reading becomes automatic and text complexity increases. Our findings suggest that reading-impaired adolescents with PAE will benefit from intervention programs targeting vocabulary knowledge, language structure, verbal fluency, and reading comprehension skills.

Diagnosing intellectual disability in people with fetal alcohol spectrum disorder: A function of which diagnostic manual is used?

Fetal alcohol spectrum disorder (FASD) is the largest known cause of intellectual disability (ID), and forensic experts are often called upon to determine if a defendant with FASD qualifies for a diagnosis of ID. Whether such a diagnosis is made may depend upon the diagnosing expert's choice of diagnostic manual: guidelines published by the American Association on Intellectual and Developmental Disabilities (now in its 12th edition [AAIDD-12]) or the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Although both manuals use the same three diagnostic "prongs" (i.e., intellectual deficits, adaptive deficits, and developmental onset), there are substantial differences in the way all three prongs are assessed-differences that increased with the publication of AAIDD-12. In particular, AAIDD-12 uses a bureaucratic "disability" model, with narrow emphasis on a small number of quantitative indicators and limited opportunity for clinical integration, while DSM-5 (and the little-changed forthcoming DSM-5-TR) uses a medical "disorder" model, with flexible reliance on a broad array of indicators and opportunity for clinical integration. The origins and nature of these differences are explored, and an argument is made that compared to the AAIDD formulation, the DSM model provides a more valid basis for forensic diagnosis of ID in individuals with FASD.

The neurocognitive profiles of justice involved people with foetal alcohol spectrum disorder: A systematic review

Foetal alcohol spectrum disorder (FASD) is highly prevalent in criminal justice settings. Despite increased awareness of the neurocognitive deficits among justice-involved individuals with FASD, no systematic evaluation of the literature in the field has been conducted to date. We aimed to conduct a systematic review of the literature on the neurocognitive profiles of justice-involved individuals with FASD, by searching five key electronic databases, dissertations database, and Google scholar, up to January 2021. The findings indicate that when contrasted with comparison groups, justice-involved individuals with FASD display significant impairment in a greater number of neurocognitive domains including intellectual capacity, executive function, language, academic achievements, motor skills, and adaptive living skills. The relatively small number of the studies included in the review, along with the confounding effects of comorbidities among study participants, precludes drawing firm conclusions about the true extent and implications of neurocognitive deficits in this population. To advance the field further, there is an urgent need to conduct robust studies involving larger samples of justice-involved individuals with FASD and suitable comparison groups. Advancing knowledge in the field can have important implications for understanding of the antecedents of offending behaviour in this population, and informing strategies for early identification and intervention.

Chronic alcohol exposure during critical developmental periods differentially impacts persistence of deficits in cognitive flexibility and related circuitry

Cognitive flexibility in decision making depends on prefrontal cortical function and is used by individuals to adapt to environmental changes in circumstances. Cognitive flexibility can be measured in the laboratory using a variety of discrete, translational tasks, including those that involve reversal learning and/or set-shifting ability. Distinct components of flexible behavior rely upon overlapping brain circuits, including different prefrontal substructures that have separable impacts on decision making. Cognitive flexibility is impaired after chronic alcohol exposure, particularly during development when the brain undergoes rapid maturation. This review examines how cognitive flexibility, as indexed by reversal and set-shifting tasks, is impacted by chronic alcohol exposure in adulthood, adolescent, and prenatal periods in humans and animal models. We also discuss areas for future study, including mechanisms that may contribute to the persistence of cognitive deficits after developmental alcohol exposure and the compacting consequences from exposure across multiple critical periods.

Characterizing the role of early alcohol reexposure in associations of prenatal alcohol exposure with adolescent alcohol outcomes

BACKGROUND

Prenatal alcohol exposure has been linked to a host of negative outcomes, although it is largely unknown whether prenatal exposure leads to an earlier age of initiation of alcohol use or exacerbates early alcohol initiation. The current study examined whether adolescents exposed to heavy drinking during gestation began drinking earlier than their nonexposed peers and whether an earlier age of alcohol reexposure in adolescence exacerbated associations with adverse alcohol outcomes.

METHODS

Adolescents (17 years of age; 57% female; 96% White) from a longitudinal, population-based cohort study, the Avon Longitudinal Study of Parents and Children, reported on the age they first consumed a whole drink and other alcohol behaviors. Adolescents' mothers also reported on their own heavy drinking during pregnancy (i.e., any consumption of 4+ U.K. units in a drinking day at either 18 or 32 weeks of gestation).

RESULTS

Survival analyses indicated that prenatal heavy drinking exposure was not associated with an earlier initiation of alcohol use after controlling for potential demographic and parental mental health and substance use confounds. Generalized negative binomial models demonstrated that prenatal heavy drinking exposure moderated associations of the age of alcohol initiation with alcohol quantity and heavy drinking frequency (but not alcohol frequency or Alcohol Use Disorders Identification Test score), after controlling for the same demographic and parental confounds. Specifically, earlier alcohol initiation was associated with more adverse alcohol outcomes regardless of prenatal exposure. However, the protective associations of delayed alcohol initiation were lower among adolescents exposed to prenatal heavy drinking.

CONCLUSIONS

This study provides evidence for the interplay between prenatal and postnatal alcohol exposures. Importantly, adolescents who were prenatally exposed to heavy drinking appeared to be less protected by later alcohol initiation than those who were not exposed in utero.

Oral and written communication skills of adolescents with prenatal alcohol exposure (PAE) compared with those with no/low PAE: A systematic review

BACKGROUND

Prenatal alcohol exposure (PAE) is associated with growth deficits and neurodevelopmental impairment including foetal alcohol spectrum disorder (FASD). Difficulties with oral and written communication skills are common among children with PAE; however, less is known about how communication skills of adolescents who have PAE compare with those who do not. Adolescence is a critical time for development, supporting the transition into adulthood, but it is considered a high-risk period for those with FASD.

AIMS

We conducted a systematic review to synthesize evidence regarding oral and written communication skills of adolescents with PAE or FASD and how they compare with those with no PAE.

METHODS & PROCEDURES

A comprehensive search strategy used seven databases: Cochrane Library, Cinahl, Embase, Medline, PsycInfo, Eric and Web of Science. Included studies reported on at least one outcome related to oral and written communication for a PAE (or FASD) group as well as a no/low PAE group, both with age ranges of 10-24 years. Quality assessment was undertaken.

MAIN CONTRIBUTION

Communication skills most often assessed in the seven studies included in this review were semantic knowledge, semantic processing, and verbal learning and memory. These communication skills, in addition to reading and spelling, were commonly weaker among adolescents with PAE compared with those with no/low PAE. However, the findings were inconsistent across studies, and studies differed in their methodologies.

CONCLUSIONS & IMPLICATIONS

Our results emphasize that for adolescents with PAE, communication skills in both oral and written modalities should be comprehensively understood in assessment and when planning interventions. A key limitation of the existing literature is that comparison groups often include some participants with a low level of PAE, and that PAE definitions used to allocate participants to groups differ across studies.

WHAT THIS PAPER ADDS

What is already known on the subject PAE and FASD are associated with deficits in oral and written communication skills. Studies to date have mostly focused on children with a FASD diagnosis as well as combined groups of children and adolescents with FASD or PAE. There is a gap in what is known about oral and written communication skills of adolescents, specifically, who have PAE or FASD. This has implications for the provision of assessment and supports during a period of increased social and academic demands. What this study adds to existing knowledge This review provides systematic identification, assessment and synthesis of the current literature related to oral and written communication skills of adolescents with PAE compared with those with no/low PAE. The review revealed a small knowledge base with inconsistent methodologies and findings across studies. However, the findings overall highlight that adolescents with PAE have weaker skills in oral and written language than those with no/low PAE. Results are discussed in relation to education, social and emotional well-being, and forensic contexts. What are the potential or actual clinical implications of this work? Findings emphasize that for adolescents with PAE, comprehensive assessment of both oral and written communication skills, through both standardized and functional tasks, should be undertaken. Speech-language pathologists have a key role in assessment with individuals who have PAE.

Moderate Prenatal Alcohol Exposure Impairs Visual-Spatial Discrimination in a Sex-Specific Manner: Effects of Testing Order and Difficulty on Learning Performance

BACKGROUND

Exposure to high levels of alcohol during development leads to alterations in neurogenesis and deficits in hippocampal-dependent learning. Evidence suggests that even more moderate alcohol consumption during pregnancy can have negative impacts on the cognitive function of offspring. Methods for assessing impairments differ greatly across species, complicating translation of preclinical findings into potential therapeutics. We have demonstrated the utility of a touchscreen operant measure for assessing hippocampal function in mice.

METHODS

Here, we integrated a well-established "drinking-in-the-dark" exposure model that produces reliable, but more moderate, levels of maternal intoxication with a trial-unique, delayed nonmatching-to-location (TUNL) task to examine the effects of prenatal alcohol exposure (PAE) on hippocampal-sensitive behavior directly analogous to those used in clinical assessment. PAE and SAC offspring mice were trained to touch a single visual stimulus ("sample phase") in one of 10 possible spatial locations (2 × 5 grid) in a touchscreen operant system. After a delay, animals were simultaneously presented with the original stimulus and a rewarded stimulus in a novel location ("choice phase"). PAE and saccharin (SAC) control mice were trained on a series of problems that systematically increased the difficulty by decreasing the separation between the sample and choice stimuli. Next, a separate cohort of PAE and SAC animals were given a brief training and then tested on a challenging variant where both the separation and delay varied with each trial.

RESULTS

We found that PAE mice were generally able to perform at levels similar to SAC control mice at progressively more difficult separations. When tested on the most difficult unpredictable variant immediately, PAE showed a sex-specific deficit with PAE females performing worse during long delays.

CONCLUSIONS

Taken together, these data demonstrate the utility of the TUNL task for examining PAE related alterations in hippocampal function and underline the need to examine sex-by-treatment interactions in these models.

Moderate prenatal alcohol exposure impairs cognitive control, but not attention, on a rodent touchscreen continuous performance task

A common feature associated with fetal alcohol spectrum disorders is the inability to concentrate on a specific task while ignoring distractions. Human continuous performance tasks (CPT), measure vigilance and cognitive control simultaneously while these processes are traditionally measured separately in rodents. We recently established a touchscreen 5-choice CPT (5C-CPT) that measures vigilance and cognitive control simultaneously by incorporating both target and nontargets and showed it was sensitive to amphetamine-induced improvement in humans and mice. Here, we examined the effects of moderate prenatal alcohol exposure (PAE) in male and female mice on performance of the 5-choice serial reaction time task (5-CSRTT), which contained only target trials, and the 5C-CPT which incorporated both target and nontarget trials. In addition, we assessed gait and fine motor coordination in behavioral naïve PAE and control animals. We found that on the 5-CSRTT mice were able to respond to target presentations with similar hit rates regardless of sex or treatment. However, on the 5C-CPT PAE mice made significantly more false alarm responses vs controls. Compared with control animals, PAE mice had a significantly lower sensitivity index, a measure of ability to discriminate appropriate responses to stimuli types. During 5C-CPT, female mice, regardless of treatment, also had increased mean latency to respond when correct and omitted more target trials. Gait assessment showed no significant differences in PAE and SAC mice on any measure. These findings suggest that moderate exposure to alcohol during development can have long lasting effects on cognitive control unaffected by gross motor alterations.

Forty Years of Assessing Neurodevelopmental and Behavioral Effects of Prenatal Alcohol Exposure in Infants: What Have We Learned?

It has been known for over 4 decades that prenatal alcohol exposure (PAE) can adversely affect neurodevelopment and behavior (NDB). Yet, early detection of altered NDB due to PAE continues to present a major clinical challenge. Identification of altered NDB in the first 2 years of life, before higher-order cognitive processes develop, invites early interventions for affected children to improve long-term outcomes. Studies published in English from January of 1980 to July of 2018 were identified in PubMed/MEDLINE. The review focused on prospective birth cohort studies which used standardized NDB assessments in children up to 2 years of age, wherein PAE was the main exposure and NDB was the main outcome. NDB was categorized into the domains of neurocognitive, adaptive, and self-regulation based on the 2016 Updated Clinical Guidelines for Diagnosing fetal alcohol spectrum disorder. An initial search resulted in 1,867 articles for which we reviewed abstracts; 114 were selected for full-text review; and 3 additional abstracts were identified through review of references in eligible publications. Thirty-one publications met criteria and were included: of these, 24 reported neurocognitive outcomes, 24 reported adaptive behavior outcomes, and 12 reported outcomes in the domain of self-regulation. Although self-regulation was assessed in the fewest number of studies, 8/12 (75%) reported PAE-associated deficits. In contrast, results were mixed for the other 2 domains: 13/24 (54%) of the selected studies that included neurocognitive outcomes showed poorer performance following PAE, and 8/24 (33%) studies that assessed adaptive functioning found significant differences between PAE and comparison infants. There is considerable evidence to support the value of early-life assessments of infant NDB when PAE is known or suspected. More studies focusing on infant self-regulation, in particular, are needed to determine the utility of early evaluation of this critical developmental domain in infants with PAE.

Comparisons of Intelligence and Behavior in Children With Fetal Alcohol Spectrum Disorder and ADHD

OBJECTIVE

Children with fetal alcohol spectrum disorder (FASD) can easily be misdiagnosed as having ADHD.

METHOD

A total of 164 children were compared on cognitive and behavioral measures for four groups of children: FASD, ADHD, FASD + ADHD, and other neuropsychological disorders.

RESULTS

The ADHD group was not significantly different from the "other diagnosis" group on any of the measurements. The children with FASD were found to perform significantly worse than ADHD on externalizing problems, Full-Scale IQ, and indices of Verbal Comprehension, Perceptual Reasoning, and Working Memory. The comorbid FASD + ADHD group was significantly weaker than ADHD on verbal comprehension measures. The FASD children demonstrated significantly higher levels of atypicality and aggression relative to ADHD, and the FASD + ADHD group demonstrated significantly higher levels of hyperactivity and withdrawal relative to ADHD.

CONCLUSION

These results indicate that children with FASD display a differential behavioral and cognitive profile that is significantly poorer than children with ADHD and other types of neuropsychological disorders.

An investigation of intra-individual variability in children with fetal alcohol spectrum disorder (FASD)

Intra-individual variability (IIV) is defined as systematic within-person variation in performance either across test sessions (e.g., test/retest performance on the same task) or in one session (e.g., variations in performance on multiple trials of a single task). Higher levels of IIV have been noted as a characteristic of neurodevelopmental disorders such as attention deficit/hyperactivity disorder​ (ADHD), but IIV is yet to be investigated in fetal alcohol spectrum disorder (FASD). FASD is a term used to describe a range of conditions resulting from prenatal exposure to alcohol. As part of a comprehensive neuropsychological battery, four study groups (1. fetal alcohol syndrome/partial fetal alcohol syndrome; 2. static encephalopathy/alcohol exposed; 3. neurobehavioral disorder/alcohol exposed as diagnosed using the University of Washington FASD 4-Digit Code; 4. typically-developing (TD) age-matched children with no prenatal alcohol exposure) were administered measures of motor response and inhibitory control, attention, and adaptive behavior. The results indicate increased levels of IIV in those with FASD compared to the TD controls. It was found that IIV uniquely contributes to predicting adaptive behavior above and beyond attention, while attention partially mediates the relationship between IIV and adaptive behavior. This is the first study to the authors' knowledge to show the presence of increased IIV in children with FASD. It additionally provides evidence that IIV measures some inherent variability in performance independent of poor attention in children with FASD.

Complexities in understanding attentional functioning among children with fetal alcohol spectrum disorder

Parental reports of attention problems and clinical symptomatology of ADHD among children with fetal alcohol syndrome disorder (FASD) were assessed in relation to performance on standardized subtests of attentional control/shifting and selective attention from the Test of Everyday Attention for Children (TEA-Ch; Manly etal., 1998). The participants included 14 children with FASD with a mean chronological age (CA) of 11.7 years and a mean mental age (MA) of 9.7 years, and 14 typically developing (TD) children with no reported history of prenatal exposure to alcohol or attention problems with a mean CA of 8.4 years and a mean MA of 9.6 years. The children with FASD were rated by their caregivers as having clinically significant attention difficulties for their developmental age. The reported symptomatology for the majority of the children with FASD were consistent with a diagnosis of ADHD, combined type, and only one child had a score within the average range. These reports are consistent with the finding that the children with FASD demonstrated difficulties with attentional control/shifting, but inconsistent with the finding that they outperformed the TD children on a test assessing selective attention. These findings are considered within the context of the complexity in understanding attentional functioning among children with FASD and discrepancies across sources of information and components of attention.

A comparison of the different animal models of fetal alcohol spectrum disorders and their use in studying complex behaviors

Prenatal ethanol exposure (PNEE) has been linked to widespread impairments in brain structure and function. There are a number of animal models that are used to study the structural and functional deficits caused by PNEE, including, but not limited to invertebrates, fish, rodents, and non-human primates. Animal models enable a researcher to control important variables such as the route of ethanol administration, as well as the timing, frequency and amount of ethanol exposure. Each animal model and system of exposure has its place, depending on the research question being undertaken. In this review, we will examine the different routes of ethanol administration and the various animal models of fetal alcohol spectrum disorders (FASD) that are commonly used in research, emphasizing their strengths and limitations. We will also present an up-to-date summary on the effects of prenatal/neonatal ethanol exposure on behavior across the lifespan, focusing on learning and memory, olfaction, social, executive, and motor functions. Special emphasis will be placed where the various animal models best represent deficits observed in the human condition and offer a viable test bed to examine potential therapeutics for human beings with FASD.