The Pediatrician ’ s Role in the Diagnosis and Management of Autistic Spectrum Disorder in Children

Autism and its milder variants are not rare. Most pediatricians will have the opportunity to provide a medical home for a child with autism. This technical report serves to complement and expand on the information in the accompanying policy statement to increase the pediatrician’s fund of knowledge and comfort level in caring for children with autism. In so doing, it is anticipated that earlier diagnosis and referral for appropriate intervention will be possible and that this will, in turn, have a positive effect on long-term outcomes for children with autism and their families. Pediatrics 2001;107(5). URL: http://www.pediatrics. org/ cgi/content/full/107/5/e85; autism, autistic spectrum disorder, pervasive developmental disorder. ABBREVIATIONS. DSM, Diagnostic and Statistical Manual of Mental Disorders; AD, autistic disorder; PDD, pervasive development disorder; PDD-NOS, pervasive development disorder-not otherwise specified; ASD, autistic spectrum disorder; CHAT, Checklist for Autism in Toddlers; ADI-R, Autism Diagnostic InterviewRevised; ADOS, Autism Diagnostic Observation Schedule; TEACCH, Treatment and Education of Autistic and Communication Handicapped Children. In 1943, Dr Leo Kanner first described autism in a small group of children who demonstrated extreme aloofness and total indifference to other people.1 Additionally, the children made little eye contact and had severe language deficits associated with the apparent lack of desire to communicate. They reacted to the environment in very unusual ways and demonstrated no pretend or imaginative play. The term “infantile autism” first appeared as a diagnostic label in the Diagnostic and Statistical Manual of Mental Disorders (DSM), Third Edition.2 Throughout the years, the definition and criteria for diagnosis have been revised and broadened to include milder and more common forms of the disorder. The newest criteria are published in the DSM, Fourth Edition3 and the DSM for Primary Care, Child and Adolescent Version.4 These criteria differ from previous DSM versions in that the term “qualitative” has been added to reflect the recent view that a range of qualitative abnormalities exists. Autistic disorder (AD) is currently listed as 1 of 5 pervasive developmental disorders (PDDs). The remaining 4 PDDs are pervasive developmental disorder-not otherwise specified (PDD-NOS), Asperger syndrome, Rett syndrome, and childhood disintegrative disorder. Although clinical patterns vary depending on severity, all children with autism demonstrate some degree of qualitative impairment in reciprocal social interaction, qualitative impairment of communication, and restricted, repetitive, and stereotypic patterns of behaviors, interests, and activities. Table 1 lists the 12 DSM criteria that currently characterize AD. Diagnosis is dependent on the presence of at least 6 criteria, with at least 2 relating to disorders of social development and 1 each relating to disorders of communication and stereotypic behavior patterns. Delays or deviances in at least 1 of these areas must have an onset before 3 years of age. Although onset of symptoms for most children with autism occurs during late infancy, it is well recognized that some children demonstrate regression in speech and social skills, withdraw, and become indifferent to their surroundings during the second year of life after a period of relatively typical development.5,6 A diagnosis of PDD-NOS is made when a child meets some but not all criteria for AD. The DSM criteria were developed for children 3 years and older; a very young child may not demonstrate all of the criteria. In such cases, a diagnosis of PDD-NOS is given, which may later be revised to AD if additional symptoms appear later and the child meets full criteria. Asperger syndrome is characterized by poor peer relationships, lack of empathy, and a tendency to overfocus on certain topics. In contrast to AD, Asperger syndrome is associated with a typical IQ and relatively typical language skills. Controversy exists as to whether Asperger syndrome represents a highfunctioning form of autism or a separate entity. Nevertheless, Asperger syndrome, AD, and PDD-NOS are generally included under the umbrella of autistic spectrum disorder (ASD), a term that is also used at times to refer to all of the PDDs discussed here.7–9 The mildest forms of ASD may overlap with other language, behavior, and learning disorders, such as semantic-pragmatic language disorder, obsessivecompulsive disorder, or right hemisphere learning disorder. Rett syndrome is a neurodegenerative disorder that has recently been associated with a defined etiology (mutation in the gene MECP2). 10 The condition occurs almost exclusively in girls with onset during the first or second year of life after a period of typical development. It is characterized by loss of purposeful hand skills accompanied by stereotypic hand The recommendations in this statement do not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate. PEDIATRICS (ISSN 0031 4005). Copyright © 2001 by the American Academy of Pediatrics. http://www.pediatrics. org/cgi/content/full/107/5/e85 PEDIATRICS Vol. 107 No. 5 May 2001 1 of 18 movements, particularly hand wringing; gross motor and coordination skills associated with ataxia and tremor; language and cognitive skills; and social interaction skills. Abnormalities are detected on electroencephalograms for almost all children with Rett syndrome. The fifth PDD is childhood disintegrative disorder. This is extremely rare and is characterized by later onset (older than 24 months) and more profound losses in language, social, play, and motor skills than those seen in AD or PDD-NOS. There is no single pathognomonic developmental deficit or behavior that is characteristic of all children with autism; however, most children have some degree of impairment in joint attention and pretend play.11 Joint attention is the ability to use eye contact and pointing for the social purpose of sharing experiences with others. Several steps occur before it is fully developed at approximately 18 months old. At approximately 9 months of age, most typically developing children will follow a point when the caregiver points and exclaims, “Oh, look at the (familiar object)! ” At approximately 1 year of age, a typically developing child will attempt to obtain an object out of reach by getting the caregiver’s attention through pointing, verbalizing, and making eye contact. This is often labeled “protoimperative pointing. ” The child will look alternatively at the object and the caregiver in an effort to communicate his or her desire. The object is the goal; the caregiver is the means to the goal. The goal and means to the goal are reversed when a few months later, the typically developing child demonstrates “protodeclarative pointing. ” The child will point to an interesting object, verbalize, and look alternatively between the object and the caregiver not to obtain the object but simply to direct the adult’s attention to the object or event of interest. At about the same time, typically developing children also begin bringing objects to adults just to show them. Children with ASD demonstrate impairments in some or all of these joint attention activities. As noted above, ASD represents a heterogeneous neurogenetic disorder, with milder forms being more common than classic AD. Several excellent subject reviews and practice parameters describe the heterogeneous array of symptoms characteristic of ASD.8,9,12–20 Briefly, children with ASD may indeed make no eye contact and seem totally aloof. Others may demonstrate intermittent awareness of their environment, make some eye contact, smile, and hug. However, these seemingly affectionate gestures usually occur on the child’s own terms and may be difficult to elicit by another person. Children with ASD may be nonverbal or they may demonstrate seemingly advanced speech, which includes imitation of songs, rhymes, or television advertisement jingles. However, these utterances rarely have communicative intent. Intellectual functioning ranges from severe mental retardation to superior intellectual functioning, with performance skills often more advanced than verbal ones. However, formal intelligence testing can be challenging, and test results are not always reliable. Some children with autism demonstrate islands of developmentally typical abilities in certain areas of functioning. A few children may be particularly talented in specific areas, such as puzzles, art, music, reading, computer skills, or mathematical calculations. Many demonstrate highly visible stereotypic behaviors, such as hand flapping, finger flicking, or compulsive sniffing; others blend into group settings without any outward signs of underlying abnormalities in thought processes. Older studies estimated the prevalence of autism to be 4 to 5 in 10 000 children.21 The majority of studies conducted through 1998 showed the prevalence to be 1 in 1000 children and the prevalence of the broader ASD to be more than 1 in 500 children.22,23 There have been a few recent studies that have shown higher rates.24–28 These studies with higher rates have been in communities where intense case finding was used to try to identify every possibly affected child in the area. Population-based US TABLE 1. Diagnostic Criteria for 299.00 Autistic Disorder A. A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3): (1) qualitative impairment in social interaction, as manifested by at least two of the following: (a) marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction (b) failure to develop peer relationships appropriate to developmental level (c) a lack of spontaneous seeking to