Impaired delay and trace eyeblink conditioning in school-age children with fetal alcohol syndrome.

BACKGROUND: Classical eyeblink conditioning (EBC) involves contingent temporal pairing of a conditioned stimulus (e.g., tone) with an unconditioned stimulus (e.g., air puff). Impairment of EBC has been demonstrated in studies of alcohol-exposed animals and in children exposed prenatally at heavy levels. METHODS: Fetal alcohol syndrome (FAS) was diagnosed by expert dysmorphologists in a large sample of Cape Coloured, South African children. Delay EBC was examined in a new sample of 63 children at 11.3 years, and trace conditioning in 32 of the same children at 12.8 years. At each age, 2 sessions of 50 trials each were administered on the same day; 2 more sessions the next day, for children not meeting criterion for conditioning. RESULTS: Six of 34 (17.6%) children born to heavy drinkers were diagnosed with FAS, 28 were heavily exposed nonsyndromal (HE), and 29 were nonexposed controls. Only 33.3% with FAS and 42.9% of HE met criterion for delay conditioning, compared with 79.3% of controls. The more difficult trace conditioning task was also highly sensitive to fetal alcohol exposure. Only 16.7% of the FAS and 21.4% of HE met criterion for trace conditioning, compared with 66.7% of controls. The magnitude of the effect of diagnostic group on trace conditioning was not greater than the effect on short delay conditioning, findings consistent with recent rat studies. Longer latency to onset and peak eyeblink CR in exposed children indicated poor timing and failure to blink in anticipation of the puff. Extended training resulted in some but not all of the children reaching criterion. CONCLUSIONS: These data showing alcohol-related delay and trace conditioning deficits extend our earlier findings of impaired EBC in 5-year-olds to school-age. Alcohol-related impairment in the cerebellar circuitry required for both forms of conditioning may be sufficient to account for the deficit in both tasks. Extended training was beneficial for some exposed children. EBC provides a well-characterized model system for assessment of degree of cerebellar-related learning and memory dysfunction in fetal alcohol exposed children.

An FMRI study of number processing in children with fetal alcohol syndrome.

BACKGROUND: Number processing deficits are frequently seen in children exposed to alcohol in utero. METHODS: Functional magnetic resonance imaging was used to examine the neural correlates of number processing in 15 right-handed, 8- to 12-year-old children diagnosed with fetal alcohol syndrome (FAS) or partial FAS (PFAS) and 18 right-handed, age- and gender-matched controls from the Cape Coloured (mixed ancestry) community in Cape Town, South Africa, using Proximity Judgment and Exact Addition tasks. RESULTS: Control children activated the expected fronto-parietal network during both tasks, including the anterior horizontal intraparietal sulcus (HIPS), left posterior HIPS, left precentral sulcus, and posterior medial frontal cortex. By contrast, on the Proximity Judgment task, the exposed children recruited additional parietal pathways involving the right and left angular gyrus and posterior cingulate/precuneus, which may entail verbally mediated recitation of numbers and/or subtraction to assess relative numerical distances. During Exact Addition, the exposed children exhibited more diffuse and widespread activations, including the cerebellar vermis and cortex, which have been found to be activated in adults engaged in particularly challenging number processing problems. CONCLUSIONS: The data suggest that, whereas control children rely primarily on the fronto-parietal network identified in previous studies to mediate number processing, children with FAS/PFAS recruit a broader range of brain regions to perform these relatively simple number processing tasks. Our results are consistent with structural neuroimaging findings indicating that the parietal lobe is relatively more affected by prenatal alcohol exposure and provide the first evidence for brain activation abnormalities during number processing in children with FAS/PFAS, effects that persist even after controlling statistically for group differences in total intracranial volume and IQ.

Prenatal alcohol exposure and interhemispheric transfer of tactile information: Detroit and Cape Town findings.

BACKGROUND: Previous research has demonstrated that heavy prenatal alcohol exposure affects the size and shape of the corpus callosum (CC) and compromises interhemispheric transfer of information. The aim of this study was to confirm the previous reports of poorer performance on a finger localization test (FLT) of interhemispheric transfer in a cohort of heavily exposed children and to extend these findings to a cohort of moderately exposed young adults. METHODS: In Study 1, the FLT was administered to 40 heavily exposed and 23 nonexposed children from the Cape Coloured community of Cape Town, South Africa, who were evaluated for fetal alcohol syndrome (FAS) dysmorphology and growth. Anatomical images of the CC were obtained using structural MRI on a subset of these children. In Study 2, the FLT was administered to a cohort of 85 moderate-to-heavily exposed young adults participating in a 19-year follow-up assessment of the Detroit Prenatal Alcohol Exposure cohort, whose alcohol exposure had been ascertained prospectively during gestation. RESULTS: In Study 1, children with FAS showed more transfer-related errors than controls after adjustment for confounding, and increased transfer-related errors were associated with volume reductions in the isthmus and splenium of the CC. In Study 2, transfer-related errors were associated with quantity of alcohol consumed per occasion during pregnancy. More errors were made if the mother reported binge drinking (> or =5 standard drinks) during pregnancy than if she drank regularly (M > or = 1 drink/day) without binge drinking. CONCLUSIONS: These findings confirm a previous report of impaired interhemispheric transfer of tactile information in children heavily exposed to alcohol in utero and extend these findings to show that these deficits are also seen in more moderately exposed individuals, particularly those exposed to binge-like pregnancy drinking.

The effects of fetal alcohol syndrome on response execution and inhibition: an event-related potential study.

BACKGROUND: Both executive function deficits and slower processing speed are characteristic of children with fetal alcohol exposure, but the temporal dynamics of neural activity underlying cognitive processing deficits in fetal alcohol spectrum disorder have rarely been studied. To this end, event-related potentials (ERPs) were used to examine the nature of alcohol-related effects on response inhibition by identifying differences in neural activation during task performance. METHODS: We recorded ERPs during a Go/No-go response inhibition task in 2 groups of children in Cape Town, South Africa (M age = 11.7 years; range = 10 to 13)-one diagnosed with fetal alcohol syndrome (FAS) or partial FAS (FAS/PFAS; n = 7); the other, a control group whose mothers abstained or drank only minimally during pregnancy (n = 6). Children were instructed to press a "Go" response button to all letter stimuli presented except for the letter "X," the "No-go" stimulus, which occurred relatively infrequently. RESULTS: Task performance accuracy and reaction time did not differ between groups, but differences emerged for 3 ERP components-P2, N2, and P3. The FAS/PFAS group showed a slower latency to peak P2, suggesting less efficient processing of visual information at a relatively early stage ( approximately 200 ms after stimulus onset). Moreover, controls showed a larger P2 amplitude to Go versus No-go, indicating an early discrimination between conditions that was not seen in the FAS/PFAS group. Consistent with previous literature on tasks related to cognitive control, the control group showed a well-defined, larger N2 to No-go versus Go, which was not evident in the FAS/PFAS group. Both groups showed the expected larger P3 amplitude to No-go versus Go, but this condition difference persisted in a late slow wave for the FAS/PFAS group, suggesting increased cognitive effort. CONCLUSIONS: The timing and amplitude differences in the ERP measures suggest that slower, less efficient processing characterizes the FAS/PFAS group during initial stimulus identification. Moreover, the exposed children showed less sharply defined components throughout the stimulus and response evaluation processes involved in successful response inhibition. Although both groups were able to inhibit their responses equally well, the level of neural activation in the children with FAS/PFAS was greater, suggesting more cognitive effort. The specific deficits in response inhibition processing at discrete stages of neural activation may have implications for understanding the nature of alcohol-related deficits in other cognitive domains as well.

Impaired eyeblink conditioning in children with fetal alcohol syndrome.

BACKGROUND: Eyeblink conditioning (EBC) is a Pavlovian paradigm that involves contingent temporal pairing of a conditioned stimulus (e.g., tone) with an unconditioned stimulus (e.g., air puff). Animal studies have shown that binge consumption of alcohol during pregnancy impairs EBC and that this impairment is likely mediated by a loss of neurons in the inferior olive and the cerebellar cortex and deep nuclei, as well as by a reduction in neural plasticity in the cerebellar deep nuclei. METHODS: Short delay EBC was examined in 98 5-year-old children born to women from the Coloured (mixed ancestry) community in Cape Town, South Africa, who were recruited prenatally and are participating in the first prospective longitudinal study of children with fetal alcohol syndrome (FAS). FAS status was assessed at 5 years by expert dysmorphologists. Two sessions of 50 trials each were administered to the children; a third session was administered the following day to those children who did not meet criterion of 40% conditioned responses in session 2. RESULTS: Not a single child with FAS met criterion for conditioning as contrasted with 75.0% of the controls. Whereas 86.7% of the controls who were conditioned met criterion by the end of Session 2, a large proportion of the relatively few alcohol-exposed nonsyndromal children who conditioned did not do so until Session 3. These alcohol effects on EBC persisted after controlling for IQ. Three of 4 microcephalic children who were not exposed to alcohol were successfully conditioned. CONCLUSIONS: This is the first prospective study to demonstrate impaired EBC in children diagnosed with FAS. Successful EBC in a microcephalic group supports the inference that the EBC deficit is specific to prenatal alcohol exposure and a potential biomarker for diagnosis of exposed children lacking the distinctive FAS dysmorphology. Delay EBC has a high sensitivity for identifying individuals with a diagnosis of probable FAS.

The epidemiology of fetal alcohol syndrome and partial FAS in a South African community.

OBJECTIVES: The prevalence and characteristics of fetal alcohol syndrome (FAS) and partial fetal alcohol syndrome (PFAS) were determined in a third primary school cohort in a community in South Africa (SA). METHODS: An active case ascertainment, two-tier screening methodology, and the revised Institute of Medicine diagnostic criteria were employed among 818 first grade pupils. Characteristics of children with FAS and PFAS are contrasted with a randomly selected control group. Data were collected and analyzed for children in the study regarding: (1) physical growth and development, including dysmorphology, (2) intelligence and behavioral characteristics, and (3) their mother's social, behavioral, and physical characteristics. RESULTS: The rate of FAS and PFAS in this area continues as the highest reported in any overall community and is much higher than rates elsewhere. In this cohort it is 68.0-89.2 per 1000. Severe episodic drinking on weekends among mothers of children with FAS and PFAS accounts for 96% of all alcohol consumed. Various measures of maternal drinking are significantly correlated with negative outcomes of children in the areas of non-verbal intelligence (-0.26), verbal intelligence (-0.28), problem behavior (0.31), and overall dysmorphology score (0.59). Significantly more FAS and PFAS exists among children of rural residents (OR=3.79). CONCLUSIONS: A high rate of FAS and PFAS was again documented in this community, and it has increased. Given population similarities, we suspect that other communities in the Western Cape Province of South Africa also have high rates. Programs for prevention are needed.

Fetal alcohol syndrome epidemiology in a South African community: a second study of a very high prevalence area.

OBJECTIVE: The aim of the study was to determine the prevalence and characteristics of fetal alcohol syndrome (FAS) in a second primary school cohort in a community in South Africa. METHOD: Active case ascertainment, two-tier screening, and Institute of Medicine assessment methodology were employed among 857 first grade pupils, most born in 1993. Characteristics of children with FAS were contrasted with characteristics of a randomly selected control group from the same classrooms. Physical growth and development, dysmorphology and psychological characteristics of the children and measures of maternal alcohol use and smoking were analyzed. RESULTS: The rate of FAS found in this study is the highest yet reported in any overall community in the world, 65.2-74.2 per 1,000 children in the first grade population. These rates are 33-148 times greater than U.S. estimates and higher than in a previous cohort study in this same community (40.5-46.4 per 1,000). Detailed documentation of physical features indicates that FAS children in South Africa have characteristics similar to those elsewhere: poor growth and development, facial and limb dysmorphology, and lower intellectual functioning. Frequent, severe episodic drinking of beer and wine is common among mothers and fathers of FAS children. Their lives are characterized by serious familial, social and economic challenges, compared with controls. Heavy episodic maternal drinking is significantly associated with negative outcomes of children in the area of nonverbal intelligence but even more so in verbal intelligence, behavior and overall dysmorphology (physical anomalies). Significantly more FAS exists among children of women who were rural residents (odds ratio: 7.36, 95% confidence interval: 3.31-16.52), usually among workers on local farms. CONCLUSION: A high rate of FAS was documented in this community. Given social and economic similarities and racial admixture, we suspect that other communities in the Western Cape have rates that also are quite high.

Facial dysmorphism across the fetal alcohol spectrum.

OBJECTIVE: Classic facial characteristics of fetal alcohol syndrome (FAS) are shortened palpebral fissures, smooth philtrum, and thin upper vermillion. We aim to help pediatricians detect facial dysmorphism across the fetal alcohol spectrum, especially among nonsyndromal heavily exposed (HE) individuals without classic facial characteristics. METHODS: Of 192 Cape Coloured children recruited, 69 were born to women who reported abstaining from alcohol during pregnancy. According to multifaceted criteria, the remainder were allocated clinically to the FAS (n = 22), partial FAS (n = 26) or nonsyndromal HE (n = 75) categories. We used dense surface modeling and signature analyses of 3-dimensional facial photographs to determine agreement between clinical categorization and classifications induced from face shape alone, to visualize facial differences, and to consider predictive links between face shape and neurobehavior. RESULTS: Face classification achieved significant agreement with clinical categories for discrimination of nonexposed from FAS alone (face: 0.97-1.00; profile: 0.92) or with the addition of partial FAS (face: 0.90; profile: 0.92). Visualizations of face signatures delineated dysmorphism across the fetal alcohol spectrum and in half of the nonsyndromal HE category face signature graphs detected facial characteristics consistent with prenatal alcohol exposure. This subgroup performed less well on IQ and learning tests than did nonsyndromal subjects without classic facial characteristics. CONCLUSIONS: Heat maps and morphing visualizations of face signatures may help clinicians detect facial dysmorphism across the fetal alcohol spectrum. Face signature graphs show potential for identifying nonsyndromal heavily exposed children who lack the classic facial phenotype but have cognitive impairment.

Population differences in dysmorphic features among children with fetal alcohol spectrum disorders.

OBJECTIVE: To examine the variation in significant dysmorphic features in children from 3 different populations with the most dysmorphic forms of fetal alcohol spectrum disorders, fetal alcohol syndrome (FAS), and partial fetal alcohol syndrome (PFAS). METHOD: Advanced multiple regression techniques are used to determine the discriminating physical features in the diagnosis of FAS and PFAS among children from Northern Plains Indian communities, South Africa, and Italy. RESULTS: Within the range of physical features used to identify children with fetal alcohol spectrum disorders, specifically FAS and PFAS, there is some significant variation in salient diagnostic features from one population to the next. Intraclass correlations in diagnostic features between these 3 populations is 0.20, indicating that about 20% of the variability in dysmorphology core features is associated with location and, therefore, specific racial/ethnic population. The highly significant diagnostic indicators present in each population are identified for the full samples of FAS, PFAS, and normals and also among children with FAS only. A multilevel model for these populations combined indicates that these variables predict dysmorphology unambiguously: small palpebral fissures, narrow vermillion, smooth philtrum, flat nasal bridge, and fifth finger clinodactyly. Long philtrum varies substantially as a predictor in the 3 populations. Predictors not significantly related to fetal alcohol spectrum disorders dysmorphology across the 3 populations are centile of height (except in Italy) strabismus, interpupilary distance, intercanthal distance, and heart murmurs. CONCLUSION: The dysmorphology associated with FAS and PFAS vary across populations, yet a particular array of common features occurs in each population, which permits a consistent diagnosis across populations.

A practical clinical approach to diagnosis of fetal alcohol spectrum disorders: clarification of the 1996 institute of medicine criteria.

BACKGROUND: The adverse effects of alcohol on the developing human represent a spectrum of structural anomalies and behavioral and neurocognitive disabilities, most accurately termed fetal alcohol spectrum disorders (FASD). The first descriptions in the modern medical literature of a distinctly recognizable pattern of malformations associated with maternal alcohol abuse were reported in 1968 and 1973. Since that time, substantial progress has been made in developing specific criteria for defining and diagnosing this condition. Two sets of diagnostic criteria are now used most widely for evaluation of children with potential diagnoses in the FASD continuum, ie, the 1996 Institute of Medicine (IOM) criteria and the Washington criteria. Although both approaches have improved the clinical delineation of FASD, both suffer from significant drawbacks in their practical application in pediatric practice. OBJECTIVE: The purpose of this report is to present specific clarifications of the 1996 IOM criteria for the diagnosis of FASD, to facilitate their practical application in clinical pediatric practice. METHODS: A large cohort of children who were prenatally exposed to alcohol were identified, through active case-ascertainment methods, in 6 Native American communities in the United States and 1 community in the Western Cape Province of South Africa. The children and their families underwent standardized multidisciplinary evaluations, including a dysmorphology examination, developmental and neuropsychologic testing, and a structured maternal interview, which gathered data about prenatal drinking practices and other demographic and family information. Data for these subjects were analyzed, and revisions and clarifications of the existing IOM FASD diagnostic categories were formulated on the basis of the results. RESULTS: The revised IOM method defined accurately and completely the spectrum of disabilities among the children in our study. On the basis of this experience, we propose specific diagnostic criteria for fetal alcohol syndrome and partial fetal alcohol syndrome. We also define alcohol-related birth defects and alcohol-related neurodevelopmental disorder from a practical standpoint. CONCLUSIONS: The 1996 IOM criteria remain the most appropriate diagnostic approach for children prenatally exposed to alcohol. The proposed revisions presented here make these criteria applicable in clinical pediatric practice.

A pilot study of alcohol exposure and pharmacokinetics in women with or without children with fetal alcohol syndrome.

AIMS: To determine the alcohol exposure and pharmacokinetics of alcohol in a group of women who had given birth to children with FAS, compared with women who had not given birth to FAS children. METHODS: 10 women who had given birth to FAS children (FAS mothers) and 20 Controls were studied to determine how they metabolize alcohol in a single limited-access quasi-experimental session of voluntary consumption of alcohol. They had free choice in the consumption of any amount of their favourite beverage for approximately 2.5 h, but their drinking was terminated if the breath alcohol concentrations (BrAC) exceeded 150 mg%. BrACs was measured during ethanol consumption and for several hours after, for estimation of alcohol exposure and pharmacokinetics. RESULTS: FAS mothers consumed significantly larger amounts of alcohol, and achieved significantly higher peak BrAC levels than Controls. The rate of decline of alcohol from the circulation (beta-60) showed a 2-fold variation across subjects but there was no significant difference between the two groups. CONCLUSIONS: This study did not show any difference in alcohol pharmacokinetics in free-choice drinking by non-pregnant women, who either have given or have never given birth to FAS children. However, mothers of FAS children tend to consume more alcohol per session. Future studies in larger samples will be needed to confirm these findings and to examine drinking patterns and other factors that may increase the risk of FAS in children of women who drink alcohol during pregnancy.