Autistic Spectrum Disorder: A Disorder of Extremes
by Carole Samango-Sprouse, EDD

Introduction
Features of Autism
Etiology
Identification
Summary

References

Introduction

• Severely impaired social interactions

• Bizarre and narrow range of interests

• Severe speech and language disorder

Asperger syndrome and autism are quite similar in behavioral symptoms. In Asperger syndrome, the severe language delay or regression in behavior is not present in the early preschool years. In recent years, atypical sensory systems with both hypo and hypersensitivity to a variety of sensory stimulation has been added to the classic diagnostic symptoms of these disorders (Bauman and Kemper, 1994).

The diagnosis of autism is confirmed by the presence or absence of behavioral symptoms using the DSM-IV manual. Since this is a clinical diagnosis and there is no definitive medical test for autism yet, the initial evaluation is of great importance and should include an in-depth history from the primary caregivers, observation of the child, medical and neurological examination and standardized developmental testing. Additionally, most pediatric specialists will perform a variety of routine blood tests to identify possible medical causes for the child's developmental delay. It is important that the examiner be very experienced with autism and its presentation in children since this is a clinical diagnosis.

For research purposes, the Autism Diagnostic Inventory (ADI) and the Autism Diagnostic Observation Schedule (ADOS) developed by Drs. Catherine Lord and Michael Rutter are considered the state-of-the-art research tools to determine the diagnosis of autism and utilized in well-designed studies (Le Couteur et al., 1988; Lord et al, 1989). The ADOS is a detailed observation and rating of the child's behavior by a certified examiner. The ADI is a comprehensive behavioral evaluation of the child based on parental report by a certified examiner as well.
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Features of Autism

Autism is a disability characterized by extremes in behavior and skills. The research literature reports that over 60% of the children are mentally retarded while the remainder have near normal or above normal IQ (Piven and Folstein, 1994). The higher functioning children have remarkable uneven abilities across developmental domains. They often have extremely good visual-spatial skills and visual memory skills. There are some children who are savants in such areas as drawing, calendars skills, numbers or schedules.

In the sensory domain, these children have a profile consistent in its variability. They are often hypo and hypersensitive to various forms of stimulation. Auditorially, as young children, they often are suspected of "deafness" because they are so unresponsive. Yet, they are extremely hypersensitive to some environmental sounds, such as lawn mowers, vacuum cleaners, or blenders. Visually, they are usually fascinated by lights, shiny objects and spinning toys.

These extremes in behavior are apparent in the attentional processes, too. Children with autism may spend hours performing repetitive activities or watching the same video over and over. This hyper attention to repetitive stimulation is often obsessive in nature. Conversely. these very same children are remarkably inattentive, distractible and disorganized in interactive play and verbal tasks. This profile of inattention, distractibility and hyperactivity has resulted in the speculation that autism could be an extreme form of Attention Deficit Hyperactive Disorder (ADHD). The use of stimulants has been effective for many children with autism and extreme hyperactivity.

Most children with autism usually have a significant language delay which initially brings them to the attention of medical personnel. They are often capable of repeating long verses from a favorite videotape or echoing previously heard conversations but they are unable to answer "wh" questions and sustain a turn taking conversation without intensive training. There are many children with autism who may never speak because of the severity of their deficits. Controversy remains regarding the evolution of the language deficits but there is agreement that skills are impaired in semantics, pragmatics, receptive language skills and speech production.
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Etiology

At the present, there is no known cause for this very common and heterogeneous disorder (1/1,000) which occurs in all races, ethnic groups and socioeconomic levels. The research literature supports that it is more common in males than females (4:1) when the intellectual quotient is greater than 50 but there is a 1:1 gender ratio in the children who are more intellectually impaired (IQ<50, Piven and Folstein, 1997).

At this time, there are several biological etiologies for autism in small subsets of children such as Fragile X, PKU, NFI and sex chromosomes (Piven and Folstein, 1997). In these cases, the genetic diagnosis is useful for counseling regarding recurrence risks for future pregnancies. Conversely, the presence of any genetic condition should not preclude the practitioner from considering the diagnosis of autism if the child's clinical presentation has the characteristic neuro-behavioral profile.

For the majority of families with an autistic child and an unknown etiology, counseling is problematic. The research reveals that a family is at 2.7% risk after one child with autism. This data is somewhat confounded by the "Reproductive Stoppage Rules" since many parents stop reproducing after the birth of a severely handicapped child (Jones and Szatmeri, 1988). In 1989, Ritvo evaluated the risk of autism in those families with one autistic child who did choose to reproduce. He found 8.6% prevalence in these families (Ritvo et al, 1989). Although the genetics of autism remains unclear, families with an autistic child should receive counseling when considering a future pregnancy in order to receive the most current information on their reproductive risks.

Research is being conducted to identify ' the chromosomal location and eventually the multiple genes responsible for autism. Because of the twin studies and population genetics, it is believed that there will be 3 to 5 genes responsible for autism. Presently, preliminary data suggests chromosomes 7, 9, and 15 may be good locations for further investigation.
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Identification

The early identification and appropriate intervention of the child with autism is very important since this disorder is disabling for both the child and the family. The characteristic developmental profile and their extreme behaviors should be the "red flags" that alert early interventionists and medical personnel to suspect the diagnosis. Unfortunately, it is a too common occurrence that families have sought numerous and various evaluations before the diagnosis is confirmed.

The social impairment can be identified by observation of several pertinent skills in toddlers under two years of age. They are the inability to:

• Demonstrate joint attention between parents and a shared toy

• Imitate motor and speech actions

• Produce and imitate a variety of play schemes (peek-a-boo)

• Relate appropriately to family and primary caregivers in a social setting

The absence of these behaviors in the presence of speech/language delay, repetitive behaviors and/or atypical sensory reactions should alert the practitioner to screen for autism.

The Checklist for Autism in Toddlers (CHAT) was developed in Britain by Baron-Cohen and associates in 1996 (Baron-Cohen et al, 1996) to screen for autism in toddlers. It is completed by parental report and observation of the child in 8 to 10 minutes. In Britain, it was shown to be highly reliable in identifying toddlers who are high risk for autism and need further evaluation. The results of this screening and the observation by interventionists could result in the earlier diagnosis of many children with autism.
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Summary

References

Kanner,L. (1943). Autistic disturbances of affective contact. Nervous Child, 10:217-50.

Asperger, H. (1944). Diesutistischen Psychopathen' im Kindesalter. Archive for Psychiatric und Nervenkrankheiten, 127:76-136. Translated and annotated by U. Frith in U. Frith (Ed.), 1991. Autismand Asperger Syndrome, 37-92. Cambridge: Cambridge University Press.

Bauman, M.L„ & Kemper, T.L. (1994). The neurobiology of autism. Baltimore: Hopkins Press. 4. Le Couteur, A., Rutter, M., Lord, D., Rios, R., ^Robertson, S., Hoidgrafer, M., & McLennan, J. (1989). Autism diagnostic interview: A standardized investigator-based instrument. Journal ofAutism and Developmental Disorders, 19:363-87.

Lord, D., Rutter, M., Goode, S„ Heernsbergen, J., Mawhood, L., & Schopler, E.. (1989). Autism diagnostic observation schedule: A standardized observation of communicative and social behavior. Journal of Autism and Developmental Disorders, 19:185-212.

Piven,J.,&Folstein,S. (1994). The genetics of autism. In M.L. Bauman & T.L. Kemper (Eds.), The neurobiology of autism (pp.l8-41). Baltimore: Hopkins Press.

Jones, M.B.,&Szatmari, P. (1988). Stoppage rules and genetic studies of autism. Journal of Autism and Developmental Disorders, 18:31-40.

Ritvo, E.R., Jorde, L.B,, Mason-Brothers, A., Freeman, B.J., Pingree, C., Jones, M.B., McMahon, W.M., Petersen, P.B., Jenson, W.R., & Mo, A. (1989). The UCLA-University of Utah epidemiologic survey of autism: Recurrence risk estimates and genetic counseling. American Journal of Psychiatry, 146:1032-36.

Baron-Cohen, S„ Alien, J., & Gilberg, C. (1996). Can autism be detected at 18 months: The needle, the haystack and the CHAT. British Journal of Psychiatry, 161,839-843.
Carole Samango-Sprouse is the Director of Infant and Child Studies at Children's National Medical Center, Washington, DC 20010. She is an Assistant Professor of Pediatrics at George Washington University. Dr. Samango-Sprouse serves on the AAHBEI News

Exchange Editorial Board.

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