CHAPTER TWO FETAL ALCOHOL SYNDROME
More than thirty years of research has shown that gestational alcohol exposure may cause cognitive impairments and physical alterations to a developing fetus (Jones & Smith, 1973; Bertrand, et all., 2005; Manning & Hoyme, 2007). Despite the evidence of compromises to physical and cognitive development, significant prenatal alcohol exposure continues to be a pervasive cause of birth defects, cognitive impairments, and learning problems (Kodituwakku, 2009; Kable & Coles, 2004a; Jacobson & Jacobson, 2002; Rasmussen & Bisanz, 2009). This chapter presents an overview of the diagnostic criteria for Fetal Alcohol Syndrome (FAS) and the prevalence of children affected by prenatal alcohol exposure in the United States and South Africa. The chapter also discusses the cognitive deficits associated with prenatal alcohol exposure that is considered to impede the learning of mathematics.
DIAGNOSIS OF FETAL ALCOHOL SYNDROME
In 1973, Kenneth Jones and David Smith indicated a pattern of growth deficiencies, dysmorphia, and alterations to the brain structure associated with significant intrauterine alcohol exposure. The authors based their premise upon information found in the historical record and from the results of their studies of infants born to alcoholic mothers (Abel, 2006). Jones and Smith (1973, p. 999) termed the disorder “Fetal Alcohol Syndrome” and established the groundwork for further investigation into the effects, diagnosis, and treatment of the disorder.
Guidelines for diagnosis of fetal alcohol syndrome
Subsequently, numerous studies have investigated the effects from prenatal alcohol exposure on physical and cognitive development (Abel, 2006). Studies have shown that significant prenatal exposure may cause growth deficiencies and changes to facial features or dysmorphia.
Dysmorphia is defined as abnormalities in the shape or form of human features “caused by genetics or other prenatal influences” (Accardo & Whiteman, 2002, p. 130).
Additionally, significant exposure to alcohol during gestation may compromise the development of the central nervous system. Compromises to the central nervous system may be exhibited by microcephaly, an abnormally small head circumference that suggests reduced brain volume, damage to specific structures of the brain, and/or deficits in cognitive functioning (Accardo & Whiteman, 2002; Bertrand et al., 2004; Kable & Coles, 2004a; Koditiwakku, 2009).
The cognitive impairments associated with the effects from prenatal alcohol exposure range from global intellectual impairments to specific processing deficits such as decreased processing speed, problems with encoding, and/or inefficient integration of verbal and visual information (Kable & Coles, 2004a; Chasnoff, Wells, Telford, Schmidt, & Messer, 2010; Burden et al., 2009; Kodituwakku, 2009).
Though numerous studies have shown that significant prenatal alcohol exposure may cause a spectrum of physical and neurodevelopmental deficits, researchers continue to debate the threshold of prenatal alcohol exposure that causes physical abnormalities and brain damage as well as the criteria for an FAS diagnosis (Abel, 2006; Bertrand et al., 2005). This resulted in a lack of uniformity in diagnostic procedures that confound the findings from studies investigating prevalence rates and outcomes from treatment studies (Urban et al., 2008). Attempts have been made to develop consistency in the diagnostic procedures when evaluating for FAS.
In 1996, the Institute of Medicine (IOM) developed guidelines in an attempt to establish consistency in diagnosing FAS (Stratton et al., 1996). The IOM identified four criteria to consider when evaluating for FAS: 1) dysmorphia, 2) growth retardation, 3) central nervous system damage, and 4) documented history of maternal alcohol consumption during pregnancy (Bertrand et al., 2004; Stratton et al., 1996). Researchers determined that the IOM guidelines lacked specificity regarding the dysmorphic features, the growth delays, and the cognitive impairments associated with the effects from prenatal alcohol exposure (Bertrand et al., 2004; Bertrand et al., 2005; Stratton et al., 1996). Yet, the IOM guidelines provided a starting point for clinicians and researchers to refine the diagnostic criteria.
In 2002, the United States Congress mandated the Centers for Disease Control and Prevention (CDC) to develop explicit diagnostic criteria to assess disorders related to prenatal alcohol exposure, to disseminate the information to medical practitioners, and to incorporate the information into the curriculum for medical students (Bertrand et al., 2005). The CDC formed a Scientific Working Group comprised of clinicians and researchers knowledgeable in the effects from prenatal alcohol exposure from federal agencies, research institutions, and non-governmental organizations. The Scientific Working Group and the National Task Force on Fetal Alcohol Syndrome and Fetal Alcohol Effects updated the IOM guidelines by specifying the physical and cognitive features needed to a diagnosis of FAS or pFAS (Bertrand et al., 2005). The CDC published the updated guidelines in 2004.
Criteria for diagnosing fetal alcohol syndrome
According to the 2004 guidelines, three facial abnormalities or dysmorphic features need to be present: 1) a smooth philtrum, 2) a thin vermillion border of upper lip, and 3) shortened palpebral fissures (Astley, 2004; Manning & Hoyme, 2007). In addition to changes to the philtrum and the vermillion border, evidence of shortened palepbral fissures or eye openings, measured below the 10th percentile as compared to the national average, need to be present (Bertrand et al., 2004). The presence of dysmporphic features is determined according to racial norms (Bertrand, et al., 2005). Figure 1 provides an example of the common dysmorphic facial features found in children with FAS.
Figure 1:Example of Facial Dysmorphia Associated with FAS. Reprinted by permission of the Maternal Substance Abuse and Child Development Program, Emory University, School of Medicine, Atlanta, Georgia.
The 2004 diagnostic guidelines suggested that evidence of prenatal and/or postnatal growth delays need to be confirmed. Delays in growth are shown by height, weight or both measured at or below the national 10th percentile and adjusted for gestational age, current age, gender, as well as for race and ethnicity (Bertrand et al., 2004, p. vii; Bertrand et al., 2005).
In addition to dysmorphia and growth deficiencies, evidence of central nervous system abnormalities need to be present. Anomalies in the central nervous system may be exhibited by changes in the brain structure, neurological problems, and/or functional deficits (Bertrand et al., 2004; Bertrand et al., 2005). Structural abnormalities may be exhibited by a small head circumference or microcephaly measured below the 10th percentile when adjusted for age and gender. Compromises to the central nervous system may be detected through the use of imaging techniques. Studies using imaging techniques have found a reduction in brain volume, alterations to the size and shape of the corpus callosum, cerebellum, and/or basal ganglia, as well as inconsistencies in white matter integrity associated with the effects from prenatal alcohol exposure (Bertrand et al., 2004; Fryer et al., 2009; Li, Coles, Lynch, & Hu, 2009; Lebel et al., 2008).
Not all children with FAS exhibit a small head circumference or abnormalities in brain structure viewed though imaging, but may display neurological problems or functional deficits. Neurological problems, such seizures or motor difficulties may be attributed to prenatal alcohol exposure if they cannot be explained by other medical causes or postnatal injuries (Bertrand et al., 2004)
According to the 2004 guidelines, overall cognitive impairments or functional deficits in at least three domains need to be present to receive a diagnosis of FAS (Bertrand et al., 2004). Global intellectual deficits are determined by scores that fall at or below the 3rd percentile or two more standard deviations below the mean on standardized tests that assess cognitive ability and adaptive functioning (Bertrand et al., 2004; Bertrand et al., 2005). Functional or processing deficits are identified by cognitive discrepancies among verbal, spatial, and nonverbal reasoning, or developmental delays, deficits in executive functioning, attention, motor skills, social skills, and/or in language pragmatics. Scores on standardized tests that assess the functional domains need to fall at or below the 16th percentile or at least one standard deviation below the mean (Bertrand et al., 2004).
The 2004 guidelines suggested that documented evidence of maternal alcohol consumption during pregnancy is preferred, however, children who exhibit alcohol-related dysmorphia, microcephaly, growth deficiencies, and cognitive deficits not accounted for by other genetic, developmental, or medical factors, may receive a diagnosis of FAS without documentation of maternal alcohol use during pregnancy (Kable & Coles, 2004a; Bertrand et al., 2005). Children who have alcohol related dysmorphia, exhibit one of the two core features associated with intrauterine alcohol exposure, and have documented evidence of prenatal alcohol exposure may receive a clinical diagnosis of pFAS (Kable & Coles, 2004a; Bertrand et al., 2004).
CHAPTER ONE ORIENTATION AND OVERVIEW
1.2 STUDY PARADIGM
1.3 STATEMENT OF THE PROBLEM
1.4 AIMS OF THE STUDY
1.5 STUDY QUESTIONS
1.8 DEFINITION OF TERMS
1.9 LITERATURE REVIEW
1.10 OVERVIEW OF STUDY DESIGN
1.11 STATISTICAL METHODS
1.13 CHAPTER DIVISIONS
CHAPTER TWO FETAL ALCOHOL SYNDROME
2.2 DIAGNOSIS OF FETAL ALCOHOL SYNDROME
2.3 PREVALENCE OF FETAL ALCOHOL SYNDROME
2.4 NEUROLOGIAL IMPAIRMENTS ASSOCIATED WITH FETAL ALCOHOL SYNDROM
2.5 FETAL ALCOHOL SYNDROME AND MATHEMATICS
2.6 SUMMARY OF CHAPTER TWO
CHAPTER THREE GESTURES, LEARNING, AND MATHEMATICS
3.3 GESTURES AND LEARNING MATHEMATICS
3.4 GESTURE USE BY CHILDREN WITH DEVELOPMENTAL DISABILITIES
3.5 ASSESSING LEARNING THROUGH GESTURES
3.6 SUMMARY OF CHAPTER THREE
CHAPTER FOUR DESIGN OF THE STUDY
4.2 STUDY DESIGN
4.4 STATISTICAL METHODS
4.5 SUMMARY OF CHAPTER FOUR
CHAPTER FIVE DATA ANALYSIS AND INTERPRETATION
5.4 RESULTS OF STATISTICAL ANALYSIS
CHAPTER SIX CONCLUSIONS, DISCUSSION, AND RECOMMENDATIONS
6.2 STUDY CONCLUSIONS
6.4 LIMITATIONS OF THE STUDY
6.5 EDUCATIONAL IMPLICATIONS
6.6 RECOMMENDATIONS FOR INSTRUCTIONAL PRACTICES
6.7 SUGGESTIONS FOR FUTURE RESEARCH
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