Page 63

4
Diagnosis and Clinical Evaluation of
Fetal Alcohol Syndrome

Since the original description of fetal alcohol syndrome (FAS) approximately two decades ago, substantial progress has been made in developing specific criteria for delineating this syndrome. Nonetheless, a variety of key issues continue to sustain areas of controversy. The boundaries of the diagnosis, as well as the markers that should be used to delineate those boundaries, are perhaps the most vexing issues. Current discussions of FAS have also included discussions of a related condition known as "fetal alcohol effects." This latter condition has been variably defined, but often includes the concept that a subset of FAS features can occur and be related to a suspected maternal exposure to alcohol. Difficulties in obtaining an adequate history of alcohol intake, a widely recognized problem in medical evaluation, add to the complexity of this issue. The resolution of these issues is not trivial, for they have important implications for both patient care and social policy. Consequently, one charge of this committee was to evaluate existing diagnostic criteria and, in updating and expanding these, to consider the formulation of the best possible diagnostic guidelines, which could subsequently be used in epidemiologic, clinical, and basic research into this syndrome. In this context, it is helpful to step back and examine the process of diagnostic evaluation within its broadest context.

PURPOSE OF MEDICAL DIAGNOSES

A medical diagnosis serves several major purposes: to facilitate communication among clinicians; to facilitate communication between clinician and patient



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 63
Page 63 4 Diagnosis and Clinical Evaluation of Fetal Alcohol Syndrome Since the original description of fetal alcohol syndrome (FAS) approximately two decades ago, substantial progress has been made in developing specific criteria for delineating this syndrome. Nonetheless, a variety of key issues continue to sustain areas of controversy. The boundaries of the diagnosis, as well as the markers that should be used to delineate those boundaries, are perhaps the most vexing issues. Current discussions of FAS have also included discussions of a related condition known as "fetal alcohol effects." This latter condition has been variably defined, but often includes the concept that a subset of FAS features can occur and be related to a suspected maternal exposure to alcohol. Difficulties in obtaining an adequate history of alcohol intake, a widely recognized problem in medical evaluation, add to the complexity of this issue. The resolution of these issues is not trivial, for they have important implications for both patient care and social policy. Consequently, one charge of this committee was to evaluate existing diagnostic criteria and, in updating and expanding these, to consider the formulation of the best possible diagnostic guidelines, which could subsequently be used in epidemiologic, clinical, and basic research into this syndrome. In this context, it is helpful to step back and examine the process of diagnostic evaluation within its broadest context. PURPOSE OF MEDICAL DIAGNOSES A medical diagnosis serves several major purposes: to facilitate communication among clinicians; to facilitate communication between clinician and patient

OCR for page 63
Page 64 (including, in this instance, the parents of patients); to assist in the study of pathophysiology and etiology; and to guide treatment. Providing a diagnostic label for a condition gives clinicians a common language that is useful in discussion. Diagnoses such as measles or fetal alcohol syndrome provide clinicians with a term that invokes a concept. On hearing this term, they can immediately call on an array of related facts and concepts that assist them in conveying information in a consistent manner. For the term to be useful to clinicians the diagnosis should be used in exactly the same way by everyone for several reasons: epidemiologic data can then be accurately collected, and patient records transferred from one site to another will contain information that can be interpreted accurately. Diagnoses are also used in order to conduct clinical research, with the long-term goal of understanding the mechanisms that cause a particular illness. For this purpose, it is equally important that diagnoses be consistent and accurate. Finally, diagnoses are used to assist clinicians in selecting appropriate treatments. Quite often, the process of differential diagnosis provides a road map that directs the clinician in the choice of treatment programs that otherwise may be quite different. In the differential diagnosis of acute abdominal pain, a diagnosis of appendicitis will send the patient to an operating room, whereas cystitis will lead to a prescription for medication. USE OF DIAGNOSTIC CRITERIA Because of the obvious importance of diagnosis in clinical medicine, during recent years nosologists have stressed the necessity of making the diagnostic process more objective and explicit. This improvement in the diagnostic process has often been implemented through the development of "diagnostic criteria." One of the earliest efforts in this direction was achieved by the American Heart Association, which developed criteria for defining the stages of cardiac failure. The most comprehensive effort produced to date was initiated by the Task Force on Nosology of the American Psychiatric Association, which completed a comprehensive revision in the third edition of its Diagnostic and Statistical Manual (known as DSM-III), published in 1980. In this manual, for the first time a comprehensive list of diagnoses for mental illness was defined through the use of explicit diagnostic criteria. This process led to a careful conceptualization of the best way to develop diagnostic criteria for specific illnesses. STANDARDS FOR EVALUATING DIAGNOSTIC CRITERIA Two requirements are typically used to evaluate diagnostic criteria. First, the criteria must be reliable. Second, they must be as valid as possible. The concept of reliability refers to agreement among clinicians and consistency over time. In both cases, the essential feature is that the diagnosis be consistent and stable, so that good agreement occurs. Interrater reliability refers

OCR for page 63
Page 65 to the ability of two clinicians to look at the same phenomena and reach similar diagnostic conclusions. For example, two clinicians looking at a young patient with possible FAS would survey the clinical history, evaluate the facial features, examine any other ancillary data, and reach precisely the same diagnosis. Test-retest reliability refers to the ability to make the same diagnosis with time gaps between the assessment. Ideally, a child with FAS evaluated at 6 months, 12 months, 6 years, and 15 years of age would be given the same diagnosis even in the absence of information about previous clinicians' judgment. Diagnostic criteria operationalize the steps that are used in making a diagnosis by delineating the particular features to be stressed. They are typically designed to be comprehensive and general, so that they can be applied at any point in the patient's history. The components that are used to make the diagnosis, such as the characteristic symptoms, are selected because good interrater agreement can be achieved for these specific symptoms. Once criteria are developed, their reliability can be assessed objectively through well-designed clinical studies that examine interrater or test-retest reliability. Statistical methods for measuring reliability have reached a mature state, and consensus has been reached by nosologists that reliability coefficients at a minimal level of 0.5 or 0.6 are acceptable, while coefficients of 0.7 through 0.9 are preferable. Validity is the second important standard that is used to evaluate diagnostic criteria. Whereas reliability refers to precision of measurement or agreement, validity refers to the relevance or clinical utility of a set of diagnostic criteria. Theoretically, criteria can be highly reliable and yet totally invalid. If nosologists were to decide, for example, that height should be used as a criterion for diagnosing mental retardation, since it can be measured in a reliable manner, they would be choosing a criterion that had excellent reliability, but questionable validity. Clearly, therefore, it is important that diagnostic criteria contain components that are clinically meaningful and that lead to correct inferences about the nature of the pathological process. Validity is usually divided into three components. Face validity means simply that the criteria selected conform to common sense; that is the criteria include features that are familiar to most clinicians and are based on some consensus that they are helpful. Construct validity refers to the fact that a diagnosis and its criteria conform to some conceptual construct or theory. For example, the construct of aberration in cell proliferation modulated by a variety of genetic, immunologic, toxic, and other mechanisms unifies the concept of cancer. One of the major issues for FAS diagnosis is the importance of documenting exposure to alcohol. Predictive validity is the third type of validity considered to be important. Predictive validity assists clinicians in making some prediction about the future. This prediction may involve decisions about treatment or guidance about prognosis.

OCR for page 63
Page 66 ISSUES IN DECIDING ON DIAGNOSTIC CRITERIA In addition to the well-documented guidelines of good reliability and validity, a number of practical considerations also inform decisions about diagnostic criteria. While reliability and validity set important standards that should be achieved in a good diagnostic system, the day-to-day process of deciding which specific signs and symptoms or other diagnostic indicators should be applied may depend on the clinical context in which a set of criteria is likely to be used. In the everyday world, diagnostic criteria are used for a variety of purposes. A gatekeeping function is one practical purpose of diagnosis. That is, placing a patient in a diagnostic category confers both advantages and disadvantages. Sometimes these aspects work at cross-purposes to one another. For example, the diagnosis of FAS may validate a patient's disability and facilitate appropriate interventions and social benefits. On the other hand, the diagnosis may also be used to stigmatize and to create self-fulfilling prophecies about the future that could be detrimental to the patient and his or her family. Therefore, when diagnostic criteria are developed, nosologists must be sensitive to the various purposes for which these criteria will be used and choose the "gate" accordingly. A descriptive function is a second important practical purpose of diagnostic criteria. Once criteria for an illness are defined, they are typically used to train appropriate clinicians to make that diagnosis. The increasing interest in making diagnoses more objective and reliable has led to the widespread use of diagnostic criteria in a variety of settings: by epidemiologists, third-party payers, forensic experts, and educators, as well as the clinicians for whom they were originally developed. The items selected for inclusion in the criteria are typically assumed by these various "consumers" to be the definitive description of the disorder. If signs or symptoms are not included in the criteria, they are often considered unimportant. In this context, therefore, the descriptive function is an addition to the gatekeeping function. For some illnesses, only one or two criteria may be needed to "enter the diagnostic gate," but more criteria would be needed to convey the clinical richness and complexity of a given disorder. A final issue that arises in deciding on the explicit items to be used in diagnostic criteria is whether the conceptual construct should be narrow or broad. This issue is clearly related to both the gatekeeping function and the descriptive function. Decisions that are made within the context of this issue can have far-reaching implications. Setting criteria to a narrow window will improve the precision with which research on pathophysiology and etiology can be conducted by identifying rigorously defined groups. Such a strategy may be overly restrictive and result in research findings with poor generalizability to the population of individuals who may be suffering from the condition. On the other hand, if the window for diagnosis is set broadly reliability will be decreased, as will the precision of research, while generalizability is likely to be improved. There is no simple solution to the tension between these various goals, but the existence of

OCR for page 63
Page 67 this tension suggests the importance of attempting to identify a moderate position. One solution to resolving the "narrow versus broad" issue is to create two sets of criteria, one to be used for research and the other for clinical applications. If this is done, then the research criteria are typically more narrow, while the clinical criteria are more broad. SPECIFIC ISSUES TO BE ADDRESSED IN IDENTIFYING CRITERIA FOR FETAL ALCOHOL SYNDROME In this context, a number of specific issues have been recognized as relevant in identifying appropriate criteria for fetal alcohol syndrome and related disorders. These issues have important implications for case definition, research, and treatment. They exist within the practical tensions described above, such as the gatekeeping function, the descriptive function, the virtue of narrow or broad definitions, and the use of criteria for research or clinical decisionmaking. The key issues noted by the committee for identification of FAS include the following: 1. Should a documented history of exposure to alcohol be required for the diagnosis of FAS? 2. Which physical features should be used to define the disorder? 3. Can behavioral or cognitive features be used to define the disorder? 4. Is there a role for ancillary measures (e.g., magnetic resonance imaging [MRI]) in making the diagnosis? 5. Can criteria be designed to be used across the life span? 6. What is the relationship of so-called fetal alcohol effects to fetal alcohol syndrome? Exposure to Alcohol Although the criterion of exposure to alcohol appears easy to apply on the surface, it is in fact one of the most difficult issues in the study of fetal alcohol syndrome. It is well recognized that people are not always forthright about their history of alcohol intake, nor are they able to recall accurately the precise timing and severity of many different kinds of events from their past. A sensitive and specific biomarker of alcohol exposure could play an important role in this regard. This is discussed more fully in Chapter 7. The documentation of alcohol exposure in gestation is further complicated by the fact that some children who were exposed to alcohol during pregnancy were then subsequently adopted, so that the clinician cannot have direct access to the biological mother in order to obtain a history.

OCR for page 63
Page 68 In addition, a clear consensus is not available concerning the amount of alcohol that can actually be toxic to the fetus or the relevance of standard definitions and diagnoses of alcohol abuse or dependence to the risk of having a child with FAS. Alcohol abuse is generally thought of either in terms of the social effects on an individual's life or, more rarely, in terms of the amount of intake. These two approaches to its definition do not always lead to mutually consistent conclusions. The requirement for documented indicators of physiological dependence provides a more objective definition, but may also be excessively narrow and stringent. Finally, the existing research literature appears to suggest that alcohol exerts its greatest toxic effect on central nervous system (CNS) development when given in large boluses. In human situations, this translates into drinking binges. Such binges may be more difficult to document historically and to time chronologically. The toxic effects of mild low-level alcohol intake are unclear and controversial. Chapter 2 contains a discussion of this in the animal literature and Chapter 7 will discuss the implications for prevention efforts. As Chapter 1 outlined, the committee focused its diagnostic criteria work in this chapter on the effects of exposure to large amounts of alcohol. Any conclusions made concerning the definition of alcohol exposure for FAS will have wide-reaching public health and social implications; hence, this a not a minor issue. The committee has considered the scientific literature and has a working definition of that level of exposure. This definition is flexible to accommodate new research findings. Defining Physical Features Historically FAS has been defined by growth deficiency, a pattern of facial anomalies, and indicators of brain dysfunction. Controversy swirls around how to measure each of these components and the weight to be given to each of them. Alcohol affects each of these factors along a spectrum from mild to severe injury, and further, each of these factors is affected by multiple environmental and genetic influences that are unrelated to alcohol exposure. For example, birth weight is related to gestational age, maternal nutritional state, and maternal size. Each of the craniofacial features can vary from distinctive to close to the normal range; overlap with other clinical syndromes, or reflect nonspecific family traits. To the extent that identification of these anomalies requires special expertise, the criteria will be less broadly useful in diagnostic settings that lack such expertise. Finally, evidence of brain maldevelopment as reflected, for example, by small cranial size also ranges from clear-cut changes to those within the normal range, and reflects both genetic and environmental influences. Cutoff points will inevitably be arbitrary, and population norms may vary over time and geographic location.

OCR for page 63
Page 69 Behavioral or Cognitive Features A variety of behavioral and cognitive features have been proposed as indicators of brain dysfunction in FAS. Examples include poor performance on tests of intelligence and educational achievement, impaired language development, poor impulse control, and problems with memory and judgment. At present, however, no consensus has been achieved as to which features are most appropriate for the diagnosis of FAS, or indeed whether any are appropriate. To some extent, these features mirror the problems noted for physical features. They too are on a continuum that ranges from normality to impaired, and they are also influenced by other antecedents such as parental intelligence, educational experience, impoverished postnatal environment, and other social and cultural influences. In addition, these cognitive and behavioral features are less specific to FAS than are the physical features; they tend to change with time, and they also tend to occur in association with a wide range of childhood neurodevelopmental and psychiatric conditions, for example, fragile X syndrome and attention-deficit hyperactivity disorder. Further, the teratorgenic effects of alcohol on such cognitive and behavioral features are less well established through studies using rigorous experimental designs, although ample anecdotal evidence has been presented in the clinical literature. Role of Ancillary Measures Other indicators of the effects of alcohol on the brain may be provided through neuroimaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI). For example, recent studies suggest that well-documented cases of FAS may show a variety of abnormalities, such as callosal dysgenesis or agenesis or cerebellar hypoplasia. Further, MRI and CT can also provide a precise quantitative measure of brain volume, permitting more accurate and clinically meaningful assessment of microcephaly. Nonetheless, this technology is young; and consequently, normative data and the current evidentiary base are necessarily small. Consequently, the role of such ancillary measures is also controversial, and their utility in making a diagnosis of FAS is yet to be established. Norms for human fetal growth, including fetal size, biparietal diameter, and placental growth, are being established based on serial examination of normal pregnancies using noninvasive ultrasound and three-dimensional imaging. Application of such normative standards to pregnancies at risk for FAS can be expected to increase our ability to recognize fetal growth retardation and may contribute to earlier recognition of FAS. When the healthy human fetal growth curve is determined by serial ultrasound examinations of babies of normal size who go on to deliver at term, the fetal weight at each gestational age is greater than that described from birth

OCR for page 63
Page 70 weight data of babies delivering prematurely. Such new standards for intrauterine growth should increase the likelihood of recognizing intrauterine growth retardation earlier in pregnancy. In addition, it is possible that the introduction of three-dimensional imaging of placental volume will allow recognition of pregnancies that will develop fetal growth retardation several weeks earlier than such problems can now be diagnosed, by demonstrating reduced placental growth prior to recognizable fetal growth retardation (Wolf et al., 1989). Diagnosis Across the Life Span The indicators used to diagnose FAS were first codified in neonates, infants, and young children, but were then found to vary across the life span. The recognition that phenotype varies with age makes it more difficult to identify appropriate features for inclusion in diagnostic criteria that are not age specific. For example, some craniofacial anomalies may be less evident at birth, become more conspicuous during early infancy and childhood, and often diminish or even disappear during adolescence and adulthood. Furthermore, the decreased cranial size and reduced birth weight originally considered to be hallmarks of FAS have become less pathognomonic in the view of some clinicians who see children with FAS. As is always the case in defining growth disturbance, this may not be a striking feature, and there will always be cases that fall within normal ranges. Therefore, identification of these anomalies will be easier or more difficult depending on the age at which the child is assessed. Relationship of Fetal Alcohol Effects to Fetal Alcohol Syndrome The term fetal alcohol effects, as described below, was originally developed to describe abnormalities observed in animal studies, but was quickly adopted by clinicians. It soon came to be widely used to refer to behavioral and cognitive problems occurring in children exposed to alcohol in utero without the typical diagnostic features. Because of the difficulties inherent in measuring exposure to alcohol, coupled with the difficulties inherent in quantifying or demarcating behavioral and cognitive problems, the precision of this terminology (never very exact) has gradually been reduced. Many believe that the term should be abandoned altogether (Aase et al., 1995, Sokol and Clarren, 1989), although the term is still widely used. EVOLUTION OF THE DIAGNOSIS OF FETAL ALCOHOL SYNDROME The clinical recognition of virtually every multiple malformation syndrome has begun with a case report describing a small number of individuals. The patients in such a report typically have a highly similar (but not identical) set of

OCR for page 63
Page 71 anomalies that is made unique from previously described syndromes by the inclusion of some very rare anomalies or by an unusual association of more common anomalies. Such a new syndrome then evolves as more patients are recognized. Although the hallmark features of a new disorder generally do not change over time, the list of associated features is usually modified and revised by further clinical experience. When the etiology of a syndrome can be measured independently of clinical presentation (i.e., through chromosomal studies, metabolic testing, or pathologic findings), its presentation generally expands to include patients who do not have the ''classic" physical characteristics of syndromic expression. Additionally, some patients who had appeared to have the syndrome on clinical grounds will be excluded from the condition because the independent measure of the disorder is negative (phenocopies). In multiple malformation syndromes due to teratogens, phenotypic variability would be even more likely than in genetic disorders since variable patterns of dose exposure and frequency of exposure, combined with variations in fetal and maternal metabolism, should produce varying clinical presentations. Clinical geneticists and dysmorphologists have been reluctant to establish rigid case definitions for any birth defect syndrome. Rightly or wrongly, there has always been concern that imposing rigid diagnostic criteria on a syndrome with assumed phenotypic variability would tie clinicians' hands and prevent further description of the syndrome's full presentation. Fetal alcohol syndrome does not represent the full spectrum of alcohol teratogenesis, but rather comprises a subset of patients who were exposed to alcohol and who have a unique recognizable pattern of malformation. The condition has evolved from initial case reports by Lemoine in 1968 and Jones and Smith in 1973. The hallmark features of the disorder were a characteristic set of facial features, evidence of growth deficiency, evidence of structural or organic brain dysfunction, and occasionally, associated malformations of organ systems, such as the heart or skeleton. Of these anomalies, the facial gestalt was the most clinically unique, while CNS dysfunction was the most significant. Over the last 25 years, clinical observations from a dozen countries with thousands of patients have confirmed that alcohol exposure in utero can produce fetal alcohol syndrome as defined. However, the way each aspect of the phenotype is defined and assessed has been refined in terms both of descriptors per se and of presentation over a patient's life span. The progress in refining the FAS diagnosis can be traced by reviewing Clarren and Smith (1978), who summarized the available clinical reports from 1973 to 1976, and the reports from the fetal alcohol workshops of the Research Society on Alcoholism in 1980 and 1989 (Rosett, 1980; Sokol and Clarren, 1989). Experience with the FAS diagnosis remains somewhat circular at this time which is a typical problem in clinical syndromology and hardly unique to FAS. Clinical experts assert that certain patients have fetal alcohol syndrome and the

OCR for page 63
Page 72 abnormalities found in those patients are then used to refine the diagnosis. A truer case definition will be established only when a reliable biologic marker for alcohol teratogenesis is found or when a diagnostic tool is developed that can demonstrate high sensitivity and specificity in identifying dysmorphic individuals who were exposed in utero to potentially teratogenic doses of alcohol. At present, the facial anomalies observed in FAS remain the most unique feature of the disorder (see Figure 1 in Chapter 1). No one can receive an FAS diagnosis without an experienced clinician's assertion that the face, when taken as a whole, appears to be the FAS face. Unfortunately, the full complement of anomalies that produce this facial appearance has been difficult to reduce to verbal descriptors, and a reliable listing of properly weighted and verbally defined abnormalities has not yet been fully developed. Several Centers for Disease Control (CDC)-sponsored FAS projects are working to develop screening check lists. Photographic pattern recognition has proven up to now to be a better way to teach the facial gestalt of FAS. Generally, the anomalies that seem to create the FAS appearance are localized to the central facial region and form a sort of "T." The upper horizontal bar of the T is formed by the eyes and inner canthal region. In this area, the palpebral fissures (eye slits) are short, usually measuring well below -2 SD (standard deviation) for age, while the inner canthal distance is more variable and generally is normal for age or reflective of general family appearance unrelated to an alcohol effect. (It should be noted that population standards for palpebral fissures can be different in some ethnic groups; this can cause difficulties in making the diagnosis if this is not recognized.) Ptosis, high lateral arched eyebrows, and epicanthal folds are associated anomalies that may be present but do not define the horizontal bar without the shortened palpebral fissures. The vertical bar of the T is defined by the nose and philtral (premaxillary) region. In this area, the philtral furrows are flattened or hypoplastic, and the upper lip (the vermilion) is thinned. The medial midface, the maxillary area abutting the nose, is also flattened. At this time, no standards have been established for when features are specifically short enough, small enough, or flat enough for a true case definition. Yet all of these features seem necessary for the FAS facial gestalt to be present. Other anomalies of the mandible and outer ears may be seen, but do not seem to contribute to or detract from the FAS facial gestalt. No single expression of structural or functional brain damage is universal or pathognomonic when patients with the FAS face and a clear history of substantial alcohol exposure are reviewed. Evidence of abnormality in this field may be structural, neurologic, or functional. Microcephaly was emphasized as a necessary marker for structural damage in early reports, but many, if not most, clinicians who diagnose a lot of children with FAS do not regard this as a necessary finding now. Only 16 autopsies of humans with FAS have been published; these suggest a diversity of lesions in multiple sites (West and Pierce, 1986). CT and MRI images of the brain in FAS patients have been reported to display mild

OCR for page 63
Page 73 changes in ventricular size, disruptions in structure such as hypoplasia or agenesis of the corpus callosum, and decreased cerebellar size. Neurologic evidence for brain damage may include seizures, abnormalities in muscle tone, tremors, abnormalities in coordination, neurosensory hearing loss, or visual anomalies stemming from small optic globes. FAS finally can be characterized by behavioral or cognitive problems that are thought to result from organic brain damage, are not easily related to genetic background or environmental influences, and are resistant to improvement with traditionally effective intervention techniques. In most patients, neurodevelopmental problems are complex and multifaceted; they include cognitive delays (but not necessarily into the mental deficiency range); attention problems that do not seem to be classical attention-deficit hyperactivity disorder; learning disability, with better strength in reading and language, and poorer ability in math; and speech and language delays that are most apparent in the use of complex speech idiom and poor understanding of the meaning of paragraphs. There are frequently problems with reasoning and judgment often recognized as failure to learn from experience or to develop a logical approach to tasks of any type (e.g., social, moral, or academic). The initial cases of fetal alcohol syndrome were often culled from early assessments of children failing to thrive. Growth deficiency has historically been regarded as a major feature of the disorder. Abundant research in humans and in animals demonstrates that alcohol can have adverse impact on length and weight both prenatally and postnatally. However, it is probable that the major impact on fetal growth comes from alcohol exposure in the last half of gestation, whereas the facial anomalies and brain problems associated with alcohol teratogenesis are more likely of earlier gestational origin. However, many reports have noted that patients may present with the face of FAS and evidence of brain dysfunction of prenatal origin but have growth that is within the normal range. Some of these patients were born with height, weight, or head circumference within normal ranges. Others were well below normal ranges at birth but "caught up" in adolescence; this has been noted particularly with regard to weight in females. Should the FAS definition be adjusted for such patients? This issue is not resolved as yet. LONGITUDINAL PERSPECTIVES ON THE FAS DIAGNOSIS In general, experts have little difficulty making an FAS diagnosis in children between the ages of 2 and 11 years. Prior to age 2, some children with FAS do not show all the facial features in the vertical bar of the T or do not have clear evidence of CNS dysfunction of prenatal origin. After puberty, catch-up growth is common, and children who had been light for weight and below -2 SD for height and weight accelerate into the more normal range. Often the vertical bar of the T disappears again. Historical growth data

OCR for page 63
Page 74 and prepubertal photographs are often needed to establish an FAS diagnosis in these older patients. The fact that this syndrome is most easily diagnosed in a specific period of life is not unique to FAS. Many syndromes become easier or more difficult to diagnose with increasing patient age. For example, the Wiedemann-Beckwith syndrome is defined by macrosomia at birth and large viscera. Typically the tongue is quite large and there is an omphalocele present in the newborn period. In infants this is a readily apparent disorder, but as the child ages organ size and overall height normalize. After puberty the syndrome is extremely subtle and would generally not be considered without the neonatal description. The Prader-Willi syndrome is defined by hypotonia in infancy, mental retardation, hypogonadism, and progressive obesity in childhood. While the hyoptonia, hypogonadism and the minor anomalies are present in infancy, the diagnosis (prior to the recent advent of chromosomal testing) was withheld until the obesity and developmental delay become apparent in the second or third year of life. Similarly, the hallmark of Fragile-X syndrome is testicular enlargement which is generally not found until after puberty. Prior to the discovery of the genetic marker, Fragile-X syndrome was rarely diagnosed until the second decade of life. DIAGNOSTIC CATEGORIES One of the key charges to the committee was to review and evaluate the diagnostic criteria for FAS and related conditions. The committee studied the previous diagnostic criteria and felt that some of the issues confusing the clinical and research communities could be resolved with fairly minor changes in the diagnostic categories and criteria. These new criteria can be found in Table 4-1. The diagnostic criteria for FAS as described in the preceding section are found under Category 1, FAS with confirmed maternal alcohol exposure. A diagnosis is placed in this category when appropriate anomalies are found in face, brain, and growth, and a clear history of alcohol exposure is obtained. The committee currently defines the relevant history as one of a pattern of excessive intake characterized by substantial, regular intake or heavy episodic drinking. Evidence of this pattern may include: frequent episodes of intoxication, development of tolerance or withdrawal, social problems related to drinking, legal problems related to drinking, engaging in physically hazardous behavior while drinking, or alcohol-related medical problems such as hepatic disease. It is anticipated that patients in this category would remain the template for further delineation of the condition. Category 2, FAS without confirmed maternal alcohol exposure, is assigned to patients with all the clear phenotypic features necessary for an FAS diagnosis but without a confirmed history of alcohol exposure. Many patients with FAS are in foster or adoptive placements and their prenatal exposure histories are unavailable. In other cases, the birth mother honestly cannot recall the specifics of her

OCR for page 63
Page 75 alcohol use in gestation or remains in denial of her alcohol abuse. It is unfair to deny these patients the clinical benefits of a medical diagnosis, but it also seems imprudent to combine their cases with those in the first category. FAS with confirmed maternal alcohol exposure, when carrying out some forms of research. Therefore, it is recommended that they be grouped separately. It also remains theoretically possible that individuals might be found with the full FAS phenotype and a confirmed negative history of gestational alcohol exposure. (Phenocopies do exist for nearly every condition.) Although we are not aware that this situation has arisen yet, such cases should not be considered in category 2. They do not have FAS. Category 3, partial FAS with confirmed maternal alcohol exposure, is assigned to patients with a confirmed exposure to substantial amounts of alcohol in gestation, some components of the facial features of FAS, and any of the following: evidence of growth deficiency, CNS neurodevelopmental abnormalities, or a complex pattern of behavioral and cognitive abnormalities. This diagnostic category allows an FAS diagnosis to be given to someone who would not receive a Category 1 diagnosis, FAS with confirmed maternal alcohol exposure. This diagnosis could be particularly useful, for example, for some patients who present for diagnosis as an adult. The natural history of FAS is such that some of the "hallmark" indicators used in infancy or childhood are not maintained into adolescence or adulthood. For example, facial dysmorphia can become less distinct and some adolescents, particularly females, gain weight into or above normal ranges. Absent good medical records of growth retardation at birth and early infancy, an FAS diagnosis otherwise could not be given without Category 3. This diagnosis could also be given to those young children whose growth metrics are within normal ranges, which some studies suggest can occur if the mother cuts down her alcohol exposure in the third trimester. This diagnosis can also be used as a "holding" category as a means to defer a diagnosis of Category 1, FAS with confirmed maternal history of alcohol exposure, until more data collection or evaluation, including documentation as to whether behavioral and cognitive abnormalities persist over time, can support a more definitive diagnosis. In the newborn, for example, there is some controversy whether some behavioral abnormalities, such as abnormalities of state regulation, indicate or predict long-term dysfunction due to fetal alcohol exposure. In such cases, documentation of abnormalities over time would be important. The naming of this diagnostic category was challenging for the committee, who found no perfect solution. Terms considered were probable, partial, and atypical. "Probable" was unsatisfactory, because it denotes uncertainty about the etiology of the condition and because of concerns that appropriate services or reimbursement for these services would not be made for a "probable" condition. The committee intends for this diagnostic category to include people with signs and symptoms attributable to significant prenatal alcohol exposure and who need medical, social services, and other attention. "Atypical" has recently been discarded

OCR for page 63
Page 76 TABLE 4-1    Diagnostic Criteria for Fetal Alcohol Syndrome (FAS) and Alcohol-Related Effects Fetal Alcohol Syndrome   1. FAS with confirmed maternal alcohol exposurea   A. Confirmed maternal alcohol exposurea   B. Evidence of a characteristic pattern of facial anomalies that includes features such as short palpebral fissures and abnormalities in the premaxillary zone (e.g., flat upper lip, flattened philtrum, and flat midface)   C. Evidence of growth retardation, as in at least one of the following:     — low birth weight for gestational age     — decelerating weight over time not due to nutrition     — disproportional low weight to height   D. Evidence of CNS neurodevelopmental abnormalities, as in at least one of the following:     — decreased cranial size at birth     — structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the corpus callosum, cerebellar hypoplasia)     — neurological hard or soft signs (as age appropriate), such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination 2. FAS without confirmed maternal alcohol exposure   B, C, and D as above 3. Partial FAS with confirmed maternal alcohol exposure   A. Confirmed maternal alcohol exposurea   B. Evidence of some components of the pattern of characteristic facial anomalies   Either C or D or E   C. Evidence of growth retardation, as in at least one of the following:     — low birth weight for gestational age     — decelerating weight over time not due to nutrition     — disproportional low weight to height   D. Evidence of CNS neurodevelopmental abnormalities, as in:     — decreased cranial size at birth     — structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the corpus callosum, cerebellar hypoplasia)     — neurological hard or soft signs (as age appropriate) such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination   E. Evidence of a complex pattern of behavior or cognitive abnormalities that are inconsistent with developmental level and cannot be explained by familial background or environment alone, such as learning difficulties; deficits in school performance; poor impulse control; problems in social perception; deficits in higher level receptive and expressive language; poor capacity for abstraction or metacognition; specific deficits in mathematical skills; or problems in memory, attention, or judgment Alcohol-Related Effects Clinical conditions in which there is a history of maternal alcohol exposure,a,b and where clinical or animal research has linked maternal alcohol ingestion to an observed outcome.

OCR for page 63
Page 77 There are two categories, which may co-occur. If both diagnoses are present, then both diagnoses should be rendered: 4. Alcohol-related birth defects (ARBD)   List of congenital anomalies, including malformations and dysplasias Cardiac Atrial septal defects Aberrant great vessels   Ventricular septal defects Tetralogy of Fallot Skeletal Hypoplastic nails Clinodactyly   Shortened fifth digits Pectus excavatum and carinatum   Radioulnar synostosis Klippel-Feil syndrome   Flexion contractures Hemivertebrae   Camptodactyly Scoliosis Renal Aplastic, dysplastic, Ureteral duplications   hypoplastic kidneys Hydronephrosis   Horseshoe kidneys   Ocular Strabismus Refractive problems secondary to small globes   Retinal vascular anomalies   Auditory Conductive hearing loss Neurosensory hearing loss Other Virtually every malformation has been described in some patient with FAS. The etiologic specificity of most of these anomalies to alcohol teratogenesis remains uncertain. 5. Alcohol-related neurodevelopmental disorder (ARND)   Presence of:   A. Evidence of CNS neurodevelopmental abnormalities, as in any one of the following:     — decreased cranial size at birth     — structural brain abnormalities (e.g., microcephaly, partial or complete agenesis of the corpus callosum, cerebellar hypoplasia)     — neurological hard or soft signs (as age appropriate), such as impaired fine motor skills, neurosensory hearing loss, poor tandem gait, poor eye-hand coordination   and/or:   B. Evidence of a complex pattern of behavior or cognitive abnormalities that are inconsistent with developmental level and cannot be explained by familial background or environment alone, such as learning difficulties; deficits in school performance; poor impulse control; problems in social perception; deficits in higher level receptive and expressive language; poor capacity for abstraction or metacognition; specific deficits in mathematical skills; or problems in memory, attention, or judgment a A pattern of excessive intake characterized by substantial, regular intake or heavy episodic drinking. Evidence of this pattern may include frequent episodes of intoxication, development of tolerance or withdrawal, social problems related to drinking, legal problems related to drinking, engaging in physically hazardous behavior while drinking, or alcohol-related medical problems such as hepatic disease. b As further research is completed and as, or if, lower quantities or variable patterns of alcohol use are associated with ARBD or ARND, these patterns of alcohol use should be incorporated into the diagnostic criteria.

OCR for page 63
Page 78 by DSM-IV and the committee did not think that these patients were "not typical." In fact, all of their signs and symptoms are typical of FAS. "Partial" denotes, to some people, that the condition might not be as severe, which the committee did not wish to imply. The committee settled on the use of "partial" despite these reservations. This category, and its name, should remain flexible. As further research reveals the range of the manifestations of FAS, this diagnosis should evolve to be consonant with new data. This diagnosis can be used to categorize such patients for future use in studying and understanding the condition. The term fetal alcohol effects (FAE) was initially proposed (Clarren and Smith, 1978) as a term for use when an adverse birth outcome could be proven to be related to alcohol exposure in utero. Generally, this term is properly used in animal models of alcohol teratogenesis and in large prospective group studies of humans exposed to alcohol prenatally. The term was not meant for use with individual patients. Terms such as "suspected fetal alcohol effect" and "possible fetal alcohol effect" were suggested as entries on differential diagnostic lists, but this approach has not been well understood. Later, the term alcohol-related birth defects was suggested for clinical use with this category of patient (Sokol and Clarren, 1989). This term presents clinical problems because most patients who seek diagnosis and do not have FAS, but were alcohol-exposed, do not have major malformations of organs; rather, they have evidence of CNS neurodevelopmental abnormality. The term "birth defects" generally is understood by most lay people to refer to gross structural anomalies, although the March of Dimes defines birth defects as abnormalities of either structure or function. The committee believes that it may be helpful to subdivide this patient group of possible prenatal alcohol-related effects into two groups listed in Table 4-1 as categories 4 and 5. Category 4, "alcohol-related birth defects" (ARBD), is reserved for patients with physical anomalies, and category 5, "alcohol-related neurodevelopmental disorder" (ARND), is reserved for patients with neurodevelopmental problems. These diagnostic categories include clinical conditions for which clinical or animal research has linked maternal alcohol ingestion to an observed outcome. A history of confirmed maternal alcohol exposure is required for these diagnoses. The relevant history remains as defined for FAS, but the committee notes that as further research is completed and as, or if, lower quantities or variable patterns of alcohol use are associated with ARBD or ARND, these patterns of alcohol use should be incorporated into the diagnostic criteria. These final two diagnostic categories are intended to convey some degree of uncertainty whether prenatal alcohol exposure caused the adverse effects documented in an individual patient, or whether other factors were causative in this case. Whereas patients in categories 1, 2 and, 3 are mutually exclusive, patients could be in both categories 4 and 5. Because of the variability in the specific presentation of FAS, ARBD, or ARND, these diagnoses are most valuable clinically if accompanied

OCR for page 63
Page 79 by a description of the specific problems experienced at the time by the patient. Only with such data will FAS, ARBD, and ARND be better understood. DIFFERENTIAL DIAGNOSIS While the "classic" presentation of fetal alcohol syndrome is distinct and can be readily distinguished from other disorders by an expert, even an expert may have difficulty confirming the diagnosis of FAS when the phenotype is "incomplete" or "atypical." Syndromes that have been confused with fetal alcohol syndrome are conditions that feature growth deficiencies and facial anomalies that are suggestive of, but different overall from, FAS. Examples of conditions confused with FAS because of somewhat similar appearance are Aarskog syndrome, Williams syndrome, Noonan's syndrome, Dubowitz syndrome, Bloom syndrome, fetal hydantoin syndrome, maternal PKU (phenylketonuria) fetal effects, and fetal toluene syndrome. Other syndromes are confused with FAS because of similarities in complex cognitive and behavioral profiles, although the external phenotype is not really similar to FAS. Examples of conditions confused with FAS because of somewhat similar behavioral profiles are fragile X syndrome, velocardiofacial syndrome, Turner's syndrome, and Opitz syndrome. CLINICAL UTILITY OF FAS, ARBD, AND ARND DIAGNOSES In addition to the gatekeeping functions described for any diagnosis, identifying children with FAS or possible alcohol-related effects provides additional benefits to the mother, the child, and society. These are elaborated in Chapters 7 and 8 but can be summarized here. A comment about who should make this diagnosis needs to be made first, however. The committee believes that FAS, ARBD, and ARND will continue to be difficult diagnoses in many cases. The committee believes that a trained clinician can make the diagnosis for purposes of screening and referral but that a medical diagnosis of FAS remains the purview of dysmorphologists and clinical geneticists. Prevention The early identification of a child with FAS can be theoretically used as a marker that will lead to interventions with the mother for her own treatment and for the prevention of births of subsequent children with FAS. The diagnosis of FAS should stimulate efforts to lead the mother into sobriety. This is the best chance to prevent alcohol-related trauma and disease in the mother, increase the chance that she will be able to mother her child, decrease foster placement, and prevent the birth of more children with FAS. Chapter 7 contains further discussion of this issue.

OCR for page 63
Page 80 Prevention of Secondary Disabilities Children with FAS or ARND have impairments that cannot be normalized but possibly can be improved with appropriate interventions, and they can possibly be made worse when ignored or misunderstood. Generally, the diagnosis of FAS or ARND helps parents, educators, and others to understand that the child "can't" perform as opposed to "won't" perform. This change in awareness can prevent misinterpretation of the child's behavior and avoid inappropriate discipline and punishment. The diagnosis can lead to treatment plans that center around and support the child and prevent him or her from getting into situations that could lead to inappropriate behavior. Although cognitive problems are unavoidable, depression, anxiety, anger, antisocial behavior, and isolation do not need to result from this disorder. Recognizing the syndrome and diagnosing it correctly can be helpful to individuals at any age. There have been no studies to demonstrate that secondary disabilities are better prevented if the diagnosis is made in the birth to three-year versus four- to seven-year period, but most professionals believe that the diagnosis becomes increasingly less effective in maximizing outcomes if the disorder is left unrecognized into adolescence. RECOMMENDATIONS: DIAGNOSTIC CRITERIA The committee-revised diagnostic criteria aim to increase clarity, rigor, and consistency by expanding the traditional designations of fetal alcohol syndrome and other possible alcohol-related effects. The key recommendations inherent in this new diagnostic scheme include the following: • preserving the criteria for FAS diagnosis but now specifying whether or not prenatal alcohol exposure is documented; • subdividing the diagnosis of other alcohol-related effects to distinguish physical anomalies from neurobehavioral and cognitive deficits, which can occur separately; and • adoption and use of the revised criteria for classification and diagnosis by clinical and research professionals in the field. Research recommendations include • research to evaluate the utility, reliability, and validity of this scheme for classification and diagnosis; • research, both cross-sectional and longitudinal, to assess the characteristics and clinical expression of these syndromes across the life span, particularly after adolescence;

OCR for page 63
Page 81 • investigation of the differences in expression and specificity of behavioral and cognitive deficits in FAS and ARND; • research to identify potential structural or functional brain abnormalities and other neurobiological indices that may be associated with, or distinguish, FAS, ARBD, or ARND, and to relate these abnormalities and indices to cognitive and behavioral correlates; • further clinical research, as well as research using animal models, to examine the adverse developmental effects of prenatal alcohol exposure, and to develop more specific biologic markers for diagnosis (e.g., biomarkers to confirm maternal alcohol exposure, endocrine signals, imaging techniques); and • consideration of the potential role of fetal alcohol exposure, as appropriate, in developmental disability studies in general. REFERENCES Aase JM, Jones KL, Clarren SK. Do We Need the Term ''FAE"? Pediatrics 1995; 95:428-430. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: 3rd Edition. Washington, DC. 1980. Clarren SK, Smith DW. The fetal alcohol syndrome. New England Journal of Medicine 1978; 298:1063-1067. Jones KL, Smith DW. Recognition of the fetal alcohol syndrome in early infancy. Lancet 1973; 2:999-1001. Lemoine P, Harouseau H, Borteryu JT, Menuet JC. Les enfants des parents alcooliques: Anomalies observees apropos de 127 cas. Ouest Medical 1968; 21:476-482. Rosett HL. A clinical perspective of the Fetal Alcohol Syndrome. Alcoholism: Clinical and Experimental Research 1980; 4:119-122. Sokol RJ, Clarren SK. Guidelines for use of terminology describing the impact of prenatal alcohol on the offspring. Alcoholism: Clinical and Experimental Research 1989; 13:597-598. West JR, Pierce DR. Perinatal alcohol exposure and neuronal damage. Alcohol and Brain Development. J.R. West, (ed.). New York: Oxford University Press, 1986. Wolf H, Oosting H, Treffers PE. Second-trimester placental volume measurement by ultrasound: Prediction of fetal outcome. American Journal of Obstetrics and Gynecology 1989; 160:121-126.