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Early Recognition of Infants at Risk for Developmental Retardation
Symposium on The Newborn
Early Recognition of Infants at Risk for Developmental Retardation
Nuhad D. Dinno, M.D., F.A.A.P.*
Developmental pediatrics is directly concerned with the diagnosis and supervision of child development. Early diagnosis of intellectual as well as physical deficiencies is important because many handicapped children may be significantly helped by early intervention. The pediatrician, having contact with children during the first few years of life, has a primary responsibility for the early detection of developmental problems.3 The magnitude of developmental disorders is staggering. Six per cent or more of all persons "suffer from developmental disorders manifest at birth or in early life, ranging from severe to mild, from curable through remediable to untreatable or even lethal."g When applied to the United States population alone, we speak of 12 to 15 million persons. Developmental deviations from expected norms are manifested as death, malformation, growth retardation, and functional deficit. In experimental situations, death and deformity often occur together in response to teratogenic stimuli. This suggests they are only differing degrees of expression to the same insult. As intrauterine development progresses, death and malformation of conceptus become less likely and the possibility of growth retardation and functional deficiency may increase. 13 Developmental retardation is estimated to be manifest in approximately 3 per cent of the general population. 1 With this significant number in mind, clinicians must familiarize themselves with methods of early detection in order that comprehensive care can be provided, either in the form of cure, remediation, or prevention. Mental subnormality is one of the most incapacitating handicaps a child or adult can have, and it is a lifelong situation; however, mental retardation is a symptom, in the broadest sense, and not a diagnosis. 14 The causes of mental retardation are numerous and complex; they may be genetic or environmental. The interplay of these factors forms a spectrum with genetics on one end and environment at the other,'with the majority of cases falling in between. Radiation, chemicals, dietary >, Associate Professor, Department of Pediatrics, Child Evaluation Center, University of Louis-
ville School of Medicine, Louisville, Kentucky Pediatric Clinics of North America- Vol. 24, No.3, August 1977
633
634
NUHAD D. DINNO
imbalance, infection, hypoxia, metabolic or endocrine imbalance, physical trauma, and placental failure and abnormality are but a few influencing factors. More often than not, an exhaustive evaluation to determine specific cause is extremely difficult, if not impossible. In assessing factors predisposing to mental retardation, one deals not only with low birth weight, prematurity, and perinatal complications, but also with over 2000 catalogued genetic disorders.7 In a significant percentage of these genetic disorders, mental retardation is present. Unfortunately, space does not allow a discussion of the causes of mental retardation. Instead, let us focus attention on high-risk predisposing factors aiding in early recognition of infants with developmental retardation or milder handicaps of educational importance: Family History Deafness, blindness Neurologic disease; cerebral palsy, epilepsy Congenital malformations Mental retardation Consanguinity Prenatal Factors Infections Placental abnormalities Maternal health; diabetes, thyrotoxicosis, phenylketonuria Maternal medication; phenytoin Exposure to radiation Multiple pregnancy Physical trauma Toxemia Maternal alcoholism Threatened abortion Hydramnios Perinatal Factors Prematurity, postmaturity Low birtIi weight for gestational age Asphyxia neonatorum Abnormal presentation. Prolonged labor Congenital abnormality Neonatal jaundice Postnatal Factors Feeding difficulties Convulsions, apneic spells Serious illness or infection in early infancy Trauma to the central nervous system
Often overlooked but important in the production of developmental retardation is environment. Children who may be well cared for physically but are subjected to maternal or sociocultural deprivation or are exposed to an emotionally sterile atmosphere are at risk. While it is true that the diagnosis of cerebral abnormality in neonates and early infancy prior to developmental delay is, as yet, highly em-
DEVELOPMENTAL RETARDATION
635
pirical, methods of developmental diagnosis and assessment are flexible. They can be adapted to meet the urgency of the problem at hand. Certainly, one need not wait until school time to make a diagnosis. Such diagnosis is readily made in infancy and early childhood. Prenatal recognition is possible for a number of metabolic disorders or chromosomal aberrations, when parents are known to be carriers. s Diagnostic approaches to mental retardation depend on the age of the individual, the nature of the handicap, and the degree of its severity. The earlier mental retardation is apparent, the more likely that it is of severe degree. Infant intelligence tests are highly reliable predictors of later intellectual development when given to a population of older multiply handicapped children. 4 When the diagnosis of mental subnormality is made in the first year of life, one is probably dealing with specific syndromes or gross neurological deficits. Mild forms may escape detection until the child starts kindergarten or grade school, where scholastic and social demands are greater. At this time, specific areas of dysfunction may become evident. Mild physical and sensory handicaps may also become more obvious and contribute to the general malfunctioning of the retarded child. Assessment of infant development as retarded may be made within the first year of life for the more severely retarded. In the neonatal period hypotonia, arching of the back, or fisting may identify a high-risk infant. The delay in the well known milestones of sitting alone, standing alone, and walking unaided can be useful in the prediction of mental retardation before the more obvious deficits in communication and socialization have had time to appearP Useful tools in guiding the physician in the assessment of infants are neurobehavioral abnormalities, coupled with evidence of delayed motor development and vocalization in early infancy. The mother's suspicion that "something is wrong" warrants serious consideration. Whether the parents or the physician raises the question about the child's development, it is the physician who is equipped to give an answer as to whether the behavior in question is pathological or simply represents a normal variant. The first step in the evaluation of infants is to identify specific behaviors which maximally discriminate between normal and deviant children. These behaviors should occur frequently in the natural environment, so that the parent and physican have ample opportunity for observation. Such behaviors include disturbances in sleep pattern, smiling, feeding, temperament, reaching for objects, vocalization, activity, sitting, and others. Obviously, the older the infant, the more parameters one is able to measure. Since development in infancy is subject to a great variety of adverse influences, observation over a period of time is essential in distinguishing a transient functional impairment from a permanent organic one. Among the several environmental variables which may markedly influence the child's behavior are illness, physical discomfort from any cause, separation from parents related to hospitalization, and so on. In these doubtful cases, predictions should not be made on the basis of a single test. Abnormal findings can only be validated when repeatedly encountered on several examinations.
636
NUHAD D. DINNO
A study of 454 children referred for diagnosis of developmental problems found smiling and sitting alone predicted the same percentage of children who were subsequently diagnosed as severely retarded. The onset of smiling, however, was considered to be more useful for purposes of early prediction because of its occurrence in nonretarded children by the age of 5 months.1O Screening tests, such as the Neonatal Behavioral Assessment Scale2 and the Denver Developmental Screening Test, can easly be used in the routine examination without overburdening the physician. 5 A nurse or trained personnel can easily evaluate a child with these tests. Helpful in assessing neonates and infants is the physical stigmata often associated with mental retardation. Certain combinations of these physical findings permit classification into a syndrome. Comparisons of observed anomalies of development with known mental retardation syndromes may be made using appropriate illustrated textbooks. 6 • 11 The physician is often faced with the question of where to begin and how to proceed with the evaluation. A careful prenatal and family history including high-risk factors is imperative. This must be coupled with a total assessment of the infant, which should include a thorough physical anQ neurological examination and neurobehavioral and psychomotor development evaluation. The presence of unusual stigmata obligates the physician to obtain a chromosomal analysis or antibody titer for cytomegalic inclusion, rubella, and toxoplasmosis. If there is no history of cerebral insult and physical examination is unremarkable, screening tests are in order. These include skull x-rays, metabolic screening, and chromosomal karyotype. Additional studies, such as endocrine evaluation, EEG, further radiologic examination, and others, may be warranted. The medical assessment is but a small part of the initial evaluation. If mental retardation is suspected, the physician is obligated to follow through. Comprehensive evaluations are then indicated for those who show abnormalities in their psychomotor development. At this point, the physician must recognize the limitations of his practice and initiate an approach utilizing a specialist in child development and the professional team of psychologists, educators, vocational counselors, and other skilled professionals. He will also feel much more comfortable if he is assisted by the specialist in child development in the process of interpreting the diagnosis and prognosis to the parents. If a developmental delay is observed, the physician should inform the parents as gently as possible and reassure them that the infant will be followed until the abnormal symptoms have been thoroughly clarified. Parental reaction must be anticipated and adaptation to this chronic handicap should be a major concern. The physician frequently becomes the focus of guidance involved in the care of those children. Insensitivity on his part to the needs of the child and family may be devastating to the family unit. Supportive counseling by professionals should be provided to help parents cope with their feelings toward having a handicapped child. Habilitation, adequate social adjustment, even employment and self-sufficiency of the retarded individual, are major undertakings. They
637
DEVELOPMENTAL RETARDATION
are possible, however, and optimal results are much more readily achieved if identification and training occur at an early age.
REFERENCES 1. Birch, H., Richardson, S. A., Baird, D., et al.: Mental Subnormality: A Clinical and Epidemiologic Study in the Community. Baltimore, Williams & Wilkins Co., 1970. 2. Brazelton, T. B.: Neonatal Behavioral Assessment Scale. Clin. Dev. Med., 50: 1973. 3. Browder, J. A.: Mental retardation-Every physician's responsibility. Rocky Mt. Med. J., 63:50-51,1966. 4. DuBose, R F.: Predictive value of infant intelligence scales with multiply handicapped children. Am. J. Ment. Def., 81 :388-390, 1976. 5. Frankenburg, W. K., and Dodds, J. B.: The Denver development screening test. J. Pediat., 71 :181, 1967. 6. Holmes, L. B., Moser, H. W., Halldorsson, S., et al.: Mental Retardation, An Atlas. New York, MacMillan Co., 1972. 7. McKusick, V.: Mendelian Inheritance in Man. Edition 4. Baltimore, Johns Hopkins University Press, 1975. 8. Milunsky, A.: The Prevention of Genetic Disease and Mental Retardation. Philadelphia, W. B. Saunders Co., 1975. 9. Polani, P. E.: Incidence of developmental and other genetic abnormalities. Proc. Roy. Soc. Med., 66:1118, 1973. 10. Schmitt, R, and Erickson, M. T.: Early predictors of mental retardation. Ment. Retard., 11 :27-29, 1973. 11. Smith, D.: Recognizable Patterns of Human Malformations. Philadelphia, W. B. Saunders Co., 1976. '12. Tenbrinck, M. D.: Early prediction of mental retardation using the developmental milestones of sitting, standing, and walking. J. Am. Med. Worn. Assoc.,29:72-75, 1974. 13. Wilson, J. G.: Environment and Birth Defects. New York, Academic Press, 1973. 14. Wright, S., and Tarjan, C.: Mental retardation: A review for pediatricians. Am. J. Dis. Child., 105:511, 1963.
Department of Pediatrics Child Evaluation Center University of Louisville School of Medicine 540 South Preston Louisville, Kentucky 40201
Early Recognition of Infants at Risk for Developmental Retardation
Nuhad D. Dinno, M.D., F.A.A.P.*
Developmental pediatrics is directly concerned with the diagnosis and supervision of child development. Early diagnosis of intellectual as well as physical deficiencies is important because many handicapped children may be significantly helped by early intervention. The pediatrician, having contact with children during the first few years of life, has a primary responsibility for the early detection of developmental problems.3 The magnitude of developmental disorders is staggering. Six per cent or more of all persons "suffer from developmental disorders manifest at birth or in early life, ranging from severe to mild, from curable through remediable to untreatable or even lethal."g When applied to the United States population alone, we speak of 12 to 15 million persons. Developmental deviations from expected norms are manifested as death, malformation, growth retardation, and functional deficit. In experimental situations, death and deformity often occur together in response to teratogenic stimuli. This suggests they are only differing degrees of expression to the same insult. As intrauterine development progresses, death and malformation of conceptus become less likely and the possibility of growth retardation and functional deficiency may increase. 13 Developmental retardation is estimated to be manifest in approximately 3 per cent of the general population. 1 With this significant number in mind, clinicians must familiarize themselves with methods of early detection in order that comprehensive care can be provided, either in the form of cure, remediation, or prevention. Mental subnormality is one of the most incapacitating handicaps a child or adult can have, and it is a lifelong situation; however, mental retardation is a symptom, in the broadest sense, and not a diagnosis. 14 The causes of mental retardation are numerous and complex; they may be genetic or environmental. The interplay of these factors forms a spectrum with genetics on one end and environment at the other,'with the majority of cases falling in between. Radiation, chemicals, dietary >, Associate Professor, Department of Pediatrics, Child Evaluation Center, University of Louis-
ville School of Medicine, Louisville, Kentucky Pediatric Clinics of North America- Vol. 24, No.3, August 1977
633
634
NUHAD D. DINNO
imbalance, infection, hypoxia, metabolic or endocrine imbalance, physical trauma, and placental failure and abnormality are but a few influencing factors. More often than not, an exhaustive evaluation to determine specific cause is extremely difficult, if not impossible. In assessing factors predisposing to mental retardation, one deals not only with low birth weight, prematurity, and perinatal complications, but also with over 2000 catalogued genetic disorders.7 In a significant percentage of these genetic disorders, mental retardation is present. Unfortunately, space does not allow a discussion of the causes of mental retardation. Instead, let us focus attention on high-risk predisposing factors aiding in early recognition of infants with developmental retardation or milder handicaps of educational importance: Family History Deafness, blindness Neurologic disease; cerebral palsy, epilepsy Congenital malformations Mental retardation Consanguinity Prenatal Factors Infections Placental abnormalities Maternal health; diabetes, thyrotoxicosis, phenylketonuria Maternal medication; phenytoin Exposure to radiation Multiple pregnancy Physical trauma Toxemia Maternal alcoholism Threatened abortion Hydramnios Perinatal Factors Prematurity, postmaturity Low birtIi weight for gestational age Asphyxia neonatorum Abnormal presentation. Prolonged labor Congenital abnormality Neonatal jaundice Postnatal Factors Feeding difficulties Convulsions, apneic spells Serious illness or infection in early infancy Trauma to the central nervous system
Often overlooked but important in the production of developmental retardation is environment. Children who may be well cared for physically but are subjected to maternal or sociocultural deprivation or are exposed to an emotionally sterile atmosphere are at risk. While it is true that the diagnosis of cerebral abnormality in neonates and early infancy prior to developmental delay is, as yet, highly em-
DEVELOPMENTAL RETARDATION
635
pirical, methods of developmental diagnosis and assessment are flexible. They can be adapted to meet the urgency of the problem at hand. Certainly, one need not wait until school time to make a diagnosis. Such diagnosis is readily made in infancy and early childhood. Prenatal recognition is possible for a number of metabolic disorders or chromosomal aberrations, when parents are known to be carriers. s Diagnostic approaches to mental retardation depend on the age of the individual, the nature of the handicap, and the degree of its severity. The earlier mental retardation is apparent, the more likely that it is of severe degree. Infant intelligence tests are highly reliable predictors of later intellectual development when given to a population of older multiply handicapped children. 4 When the diagnosis of mental subnormality is made in the first year of life, one is probably dealing with specific syndromes or gross neurological deficits. Mild forms may escape detection until the child starts kindergarten or grade school, where scholastic and social demands are greater. At this time, specific areas of dysfunction may become evident. Mild physical and sensory handicaps may also become more obvious and contribute to the general malfunctioning of the retarded child. Assessment of infant development as retarded may be made within the first year of life for the more severely retarded. In the neonatal period hypotonia, arching of the back, or fisting may identify a high-risk infant. The delay in the well known milestones of sitting alone, standing alone, and walking unaided can be useful in the prediction of mental retardation before the more obvious deficits in communication and socialization have had time to appearP Useful tools in guiding the physician in the assessment of infants are neurobehavioral abnormalities, coupled with evidence of delayed motor development and vocalization in early infancy. The mother's suspicion that "something is wrong" warrants serious consideration. Whether the parents or the physician raises the question about the child's development, it is the physician who is equipped to give an answer as to whether the behavior in question is pathological or simply represents a normal variant. The first step in the evaluation of infants is to identify specific behaviors which maximally discriminate between normal and deviant children. These behaviors should occur frequently in the natural environment, so that the parent and physican have ample opportunity for observation. Such behaviors include disturbances in sleep pattern, smiling, feeding, temperament, reaching for objects, vocalization, activity, sitting, and others. Obviously, the older the infant, the more parameters one is able to measure. Since development in infancy is subject to a great variety of adverse influences, observation over a period of time is essential in distinguishing a transient functional impairment from a permanent organic one. Among the several environmental variables which may markedly influence the child's behavior are illness, physical discomfort from any cause, separation from parents related to hospitalization, and so on. In these doubtful cases, predictions should not be made on the basis of a single test. Abnormal findings can only be validated when repeatedly encountered on several examinations.
636
NUHAD D. DINNO
A study of 454 children referred for diagnosis of developmental problems found smiling and sitting alone predicted the same percentage of children who were subsequently diagnosed as severely retarded. The onset of smiling, however, was considered to be more useful for purposes of early prediction because of its occurrence in nonretarded children by the age of 5 months.1O Screening tests, such as the Neonatal Behavioral Assessment Scale2 and the Denver Developmental Screening Test, can easly be used in the routine examination without overburdening the physician. 5 A nurse or trained personnel can easily evaluate a child with these tests. Helpful in assessing neonates and infants is the physical stigmata often associated with mental retardation. Certain combinations of these physical findings permit classification into a syndrome. Comparisons of observed anomalies of development with known mental retardation syndromes may be made using appropriate illustrated textbooks. 6 • 11 The physician is often faced with the question of where to begin and how to proceed with the evaluation. A careful prenatal and family history including high-risk factors is imperative. This must be coupled with a total assessment of the infant, which should include a thorough physical anQ neurological examination and neurobehavioral and psychomotor development evaluation. The presence of unusual stigmata obligates the physician to obtain a chromosomal analysis or antibody titer for cytomegalic inclusion, rubella, and toxoplasmosis. If there is no history of cerebral insult and physical examination is unremarkable, screening tests are in order. These include skull x-rays, metabolic screening, and chromosomal karyotype. Additional studies, such as endocrine evaluation, EEG, further radiologic examination, and others, may be warranted. The medical assessment is but a small part of the initial evaluation. If mental retardation is suspected, the physician is obligated to follow through. Comprehensive evaluations are then indicated for those who show abnormalities in their psychomotor development. At this point, the physician must recognize the limitations of his practice and initiate an approach utilizing a specialist in child development and the professional team of psychologists, educators, vocational counselors, and other skilled professionals. He will also feel much more comfortable if he is assisted by the specialist in child development in the process of interpreting the diagnosis and prognosis to the parents. If a developmental delay is observed, the physician should inform the parents as gently as possible and reassure them that the infant will be followed until the abnormal symptoms have been thoroughly clarified. Parental reaction must be anticipated and adaptation to this chronic handicap should be a major concern. The physician frequently becomes the focus of guidance involved in the care of those children. Insensitivity on his part to the needs of the child and family may be devastating to the family unit. Supportive counseling by professionals should be provided to help parents cope with their feelings toward having a handicapped child. Habilitation, adequate social adjustment, even employment and self-sufficiency of the retarded individual, are major undertakings. They
637
DEVELOPMENTAL RETARDATION
are possible, however, and optimal results are much more readily achieved if identification and training occur at an early age.
REFERENCES 1. Birch, H., Richardson, S. A., Baird, D., et al.: Mental Subnormality: A Clinical and Epidemiologic Study in the Community. Baltimore, Williams & Wilkins Co., 1970. 2. Brazelton, T. B.: Neonatal Behavioral Assessment Scale. Clin. Dev. Med., 50: 1973. 3. Browder, J. A.: Mental retardation-Every physician's responsibility. Rocky Mt. Med. J., 63:50-51,1966. 4. DuBose, R F.: Predictive value of infant intelligence scales with multiply handicapped children. Am. J. Ment. Def., 81 :388-390, 1976. 5. Frankenburg, W. K., and Dodds, J. B.: The Denver development screening test. J. Pediat., 71 :181, 1967. 6. Holmes, L. B., Moser, H. W., Halldorsson, S., et al.: Mental Retardation, An Atlas. New York, MacMillan Co., 1972. 7. McKusick, V.: Mendelian Inheritance in Man. Edition 4. Baltimore, Johns Hopkins University Press, 1975. 8. Milunsky, A.: The Prevention of Genetic Disease and Mental Retardation. Philadelphia, W. B. Saunders Co., 1975. 9. Polani, P. E.: Incidence of developmental and other genetic abnormalities. Proc. Roy. Soc. Med., 66:1118, 1973. 10. Schmitt, R, and Erickson, M. T.: Early predictors of mental retardation. Ment. Retard., 11 :27-29, 1973. 11. Smith, D.: Recognizable Patterns of Human Malformations. Philadelphia, W. B. Saunders Co., 1976. '12. Tenbrinck, M. D.: Early prediction of mental retardation using the developmental milestones of sitting, standing, and walking. J. Am. Med. Worn. Assoc.,29:72-75, 1974. 13. Wilson, J. G.: Environment and Birth Defects. New York, Academic Press, 1973. 14. Wright, S., and Tarjan, C.: Mental retardation: A review for pediatricians. Am. J. Dis. Child., 105:511, 1963.
Department of Pediatrics Child Evaluation Center University of Louisville School of Medicine 540 South Preston Louisville, Kentucky 40201