Comparison of Motor Delays in Young Children With Fetal Alcohol Syndrome to Those With Prenatal Alcohol Exposure and With No Prenatal Alcohol Exposure
ABSTRACT Researchers are increasingly considering the importance of motor functioning of children with fetal alcohol spectrum disorder (FASD). The purpose of this study was to assess the motor development of young children with fetal alcohol syndrome (FAS) to determine the presence and degree of delay in their motor skills and to compare their motor development with that of matched children without FAS.
The motor development of 14 children ages 20 to 68 months identified with FAS was assessed using the Vineland Adaptive Behavior Scales (VABS). In addition, 2 comparison groups were utilized. Eleven of the children with FAS were matched for chronological age, gender, ethnicity, and communication age to: (1) 11 children with prenatal alcohol exposure who did not have FAS and (2) 11 matched children without any reported prenatal alcohol exposure. The motor scores on the VABS were compared among the 3 groups.
Most of the young children with FAS in this study showed clinically important delays in their motor development as measured on the VABS Motor Domain, and their fine motor skills were significantly more delayed than their gross motor skills. In the group comparisons, the young children with FAS had significantly lower Motor Domain standard (MotorSS) scores than the children not exposed to alcohol prenatally. They also had significantly lower Fine Motor Developmental Quotients than the children in both the other groups. No significant group differences were found in gross motor scores. For MotorSS scores and Fine Motor Developmental Quotients, the means and standard errors indicated a continuum in the scores from FAS to prenatal alcohol exposure to nonexposure.
These findings strongly suggest that all young children with FAS should receive complete developmental evaluations that include assessment of their motor functioning, to identify problem areas and provide access to developmental intervention programs that target deficit areas such as fine motor skills. Fine motor delays in children with FAS may be related to specific neurobehavioral deficits that affect fine motor skills. The findings support the concept of an FASD continuum in some areas of motor development.
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ABSTRACT: Background The exposure of the human embryo to ethanol results in a spectrum of disorders involving multiple organ systems, including the impairment of the development of the central nervous system (CNS). In spite of the importance for human health, the molecular basis of prenatal ethanol exposure remains poorly understood, mainly to the difficulty of sample collection. Zebrafish is now emerging as a powerful organism for the modeling and the study of human diseases. In this work, we have assessed the sensitivity of specific subsets of neurons to ethanol exposure during embryogenesis and we have visualized the sensitive embryonic developmental periods for specific neuronal groups by the use of different transgenic zebrafish lines. Methodology/Principal Findings In order to evaluate the teratogenic effects of acute ethanol exposure, we exposed zebrafish embryos to ethanol in a given time window and analyzed the effects in neurogenesis, neuronal differentiation and brain patterning. Zebrafish larvae exposed to ethanol displayed small eyes and/or a reduction of the body length, phenotypical features similar to the observed in children with prenatal exposure to ethanol. When neuronal populations were analyzed, we observed a clear reduction in the number of differentiated neurons in the spinal cord upon ethanol exposure. There was a decrease in the population of sensory neurons mainly due to a decrease in cell proliferation and subsequent apoptosis during neuronal differentiation, with no effect in motoneuron specification. Conclusion Our investigation highlights that transient exposure to ethanol during early embryonic development affects neuronal differentiation although does not result in defects in early neurogenesis. These results establish the use of zebrafish embryos as an alternative research model to elucidate the molecular mechanism(s) of ethanol-induced developmental toxicity at very early stages of embryonic development.PLoS ONE 11/2014; 9(11):e112851. DOI:10.1371/journal.pone.0112851 · 3.53 Impact Factor
Article: VITA PHILIP A. MAY, Ph.D
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ABSTRACT: Children with fetal alcohol spectrum disorder (FASD) often exhibit sensorimotor dysfunctions that include deficits in motor coordination and fine motor control. Although the underlying causes for these motor abnormalities are unknown, they likely involve interactions between sensory and motor systems. Rodent animal models have been used to study the effects of prenatal alcohol exposure (PAE) on skilled reaching and on the development and organization of somatosensory barrel field cortex. To this end, PAE delayed the development of somatosensory cortex, reduced the size of whisker and forelimb representations in somatosensory barrel field cortex, and delayed acquisition time to learn a skilled reaching task. However, whether PAE also affects the motor cortex (MI) remains to be determined. In the present study, we investigated the effect of PAE on the size of the forelimb representation in rat MI, thresholds for activation, and the overlap between motor and sensory cortical forelimb maps in sensorimotor cortex. Pregnant Sprague-Dawley rats were assigned to alcohol (Alc), pair-fed (PF), and chow-fed (CF) groups on gestation day 1 (GD1). Rats in the Alc group (n=4) were chronically intubated daily with binge doses of alcohol (6g/kg body weight) from GD1 to GD20 that resulted in averaged blood alcohol levels measured on GD10 (mean=191.5+/-41.9mg/dL) and on GD17 (mean=247.0+/-72.4mg/dL). PF (n=2) and CF (n=3) groups of pregnant rats served as controls. The effect of PAE on the various dependent measures was obtained from multiple male offspring from each dam within treatment groups, and litter means were compared between the groups from alcohol-treated and control (Ct: CF and PF) dams. At approximately 8 weeks of age, rats were anesthetized with ketamine/xylazine and the skull opened over sensorimotor cortex. A tungsten microelectrode was then inserted into the depths of layer V and intracortical microstimulation was used to deliver trains of pulses to evoke muscle contractions and/or movements; maximum stimulating < or =100microA. When a motor response was observed, the threshold for movement was measured and the motor receptive field projected to the cortical surface to serve as representative point for that location. A motor map for the forelimb representation was generated by systematically stimulating at adjacent sites until current thresholds reached the maximum and/or motor responses were no longer evoked. The major findings in this study were as follows: (1) PAE significantly reduced the area of the forelimb representation in the Alc offspring (6.01mm(2), standard error of the mean=+/-0.278) compared with the Ct offspring (8.03mm(2)+/-0.586), (2) PAE did not significantly reduce the averaged threshold for activation of movements between groups, (3) PAE significantly reduced the percent overlap (Alc=31.1%, Ct=55.4%) between the forelimb representation in sensory and motor cortices, and (4) no significant differences were observed in averaged body weight, hemisphere weight, or age of animal between treatment groups. These findings suggest that the effects of PAE are not restricted to somatosensory barrel field cortex but also involve the MI and may underlie deficits in motor control and sensorimotor integration observed among children with FASD.Alcohol (Fayetteville, N.Y.) 03/2010; 44(2):185-94. DOI:10.1016/j.alcohol.2009.10.014 · 2.04 Impact Factor