Autism Spectrum Disorder

Todd T. Eckdahl

• Publisher: Momentum Press
• Year: 2018
• ISBN:
  9781944749606
• Topic: Biological Sciences
• Subtopic: Genetics & Genomics
• Index: Biological Sciences

This book is an overview of autism spectrum disorder (ASD), an early childhood condition that affects 1 in 68 children in the United States, and an estimated 1 to 2 percent of children worldwide. ASD causes impaired social skills, communication problems, and repetitive behaviors. The severity of ASD symptoms varies widely, ranging from mild effects with minimal impacts on functionality to severe effects that interfere with functionality and can prevent independent living. ASD is a complex trait disease caused by mutation of multiple ASD susceptibility genes, but it also occurs as part of monogenic genetic syndromes. Genetic testing for ASD is described in the book, and examples of ASD susceptibility genes. No treatments are available for the core symptoms of ASD, but the book describes therapies and drug treatments that can modulate them and address some of the health complications of ASD. The book presents new ASD biomarkers that can be used for better diagnosis and explores the hopeful prospect of personalized medicine for ASD.

CHAPTER 1

Symptoms and Diagnosis

Describing autism as a spectrum expresses the view that the three developmental disorders of autism disorder, Asperger’s syndrome, and pervasive developmental disorder not otherwise specified (PDD-NOS), are closely related, and produce a spectrum of overlapping symptoms. It also captures the observation that there is considerable variation in the primary symptoms and health complications of autism spectrum disorder (ASD) that produces a spectrum in the severity of functional impairment experienced by children and adults with ASD. The manifestations of verbal and nonverbal social communication deficits and restricted and repetitive patterns of behaviors, interests, or activities are different for each child with ASD, presenting unique challenges for early development and education. In adulthood, ASD brings challenges that affect the extent to which people can live independently and pursue productive and meaningful work.

Early Signs of ASD

Early signs of ASD occur in infants, but there are several reasons why they are difficult to notice. One is that there is considerable variation in the types and severity of the early symptoms of ASD among infants. The early signs are also subtle, and in many cases, they are not noticed at the time, but are recognized retrospectively after more obvious ASD symptoms arise. Early signs of ASD can occur in infants who do not have ASD, whereas some infants with ASD do not display some of the common early signs of it. Infants with ASD usually achieve physical developmental milestones such as rolling over, sitting up, crawling, and walking at a normal rate, and this makes it difficult for parents and healthcare providers to notice the subtle impact of ASD on the development of social and communication skills. Table 1.1 lists the most common early signs that occur in infants with ASD. Infants with ASD do not return a smile or other expressions of joy as often as other infants do. Infants usually learn how to express happiness by the age of 6 months. Typically developing infants learn to make eye contact with others by the age of 6 months, but infants with ASD often do not learn this behavior at all, or make limited eye contact. These children do not often engage in joint attention, during which two people connect socially by looking back and forth at an object and each other. They have a deficit or delay in the development of reciprocal social interaction, during which emotions are shared with sounds and facial expressions. They do not imitate smiles or laughter as typically developing infants do, and they often fail to respond to the calling of their name. Sometimes they seem to completely tune out any sound from their environment, but at other times, they are oversensitive to faint sounds. Infants with ASD have deficits in nonverbal communication, which typically develop by the age of 9 months. Children with ASD frequently do not learn how to use gestures to communicate nonverbally with others, such as turning their head to draw attention to themselves or waving goodbye, as is typical by 12 months. They also appear to be less interested in interacting physically with others. Infants with ASD are less likely to seek cuddling, or to enjoy it. They often seem content to be alone, and often develop unusual habits of repetitive physical action, including rocking back and forth, hand flapping, and head banging. They have attractions to unusual objects, often preferring to carry around a hard object such as a metal car or a stapler instead of a soft one, such as a blanket or a stuffed animal. ASD also affects the development of verbal communication skills. Compared with typically developing infants, infants with ASD do not typically babble and coo within their first year, say their first word by the age of 16 months, or express meaning with two or more words by the age of 2 years.

Table 1.1 Early signs of ASD in infants and toddlers

Age	Signs of ASD
6 months	Does not make eye contact Does not return social smiles Does not express joy with smiles, laughter, and body movements
12 months	Does not babble or coo Does not use communicative gestures, such as pointing or waving goodbye Does not respond to name when called
16 months	Does not use words Displays intense interest in specific objects Repeats unusual body movements such as hand flapping and back arching
24 months	Does not use original short phrases Seeks sensory stimulation Prefers to play alone

People with ASD Have Impaired Social and Emotional Responsiveness

The early signs of ASD in infants and young children transition to symptoms in older children and adults. One symptom is an impaired ability to respond to others socially and emotionally, and it results in a variety of behaviors. People with ASD frequently have trouble beginning a social interaction in a way that is viewed by others as appropriate. They do not have a typical sense of personal space, and might start an interaction by touching someone inappropriately, or even licking them. People with ASD rarely initiate a conversation, except when they need help. It is uncommon for them to respond to direct communication, even when their name is used. During conversation, they struggle to maintain a dialogue. They frequently make statements out of context, and fail to clarify themselves if they are not understood. For example, one of the children described by Leo Kanner frequently interrupted their conversations by saying, “motor transports” and “piggyback,” phrases with which she had become preoccupied.

Children and adults with ASD also have trouble developing shared interests with others. Despite having specific interests themselves, they often do not want to share them with other people. An obvious symptom of the impaired ability of people with ASD to respond to others emotionally is their failure to return a smile that is offered as a social greeting. It is rare for them to share their enjoyment or excitement, and they do not often display pleasure while interacting with others. People with ASD often show either an indifference to affectionate physical contact or reject such contact. They infrequently internalize the emotional states of others, and therefore do not offer comfort to them.

ASD Causes Deficits in Nonverbal Communication

Communication during social interaction involves both spoken language and nonverbal communication. Nonverbal communication in the form of facial expressions, gestures, and body language supplements the meaning of speech. Nonverbal communication is often difficult to control because it expresses underlying emotions. Many forms of nonverbal communication are instinctual, and cross the lines between cultures. They even cross the lines between species, indicating that they are primitive forms of communication that predate spoken language. A symptom of ASD is deficiency in the use of nonverbal communication during social interactions. Children and adults with ASD often fail to establish and maintain eye contact during a conversation, and fail to use body posture and position to engage in communication with another person, instead turning away from them during conversation. Leo Kanner observed this behavior in several of the children he interviewed, and reported that one of them never looked at the person talking to him and did not use gestures to communicate. When children and adults with ASD do use nonverbal communication, it is often an uncoordinated effort. For example, they might call attention to an object with hand gestures, but fail to reinforce the nonverbal communication by looking back and forth between the object and the person they are communicating with. People with ASD also have trouble integrating spoken language and nonverbal communication. They often fail to accompany their speech with appropriate facial expressions and gestures. Instead, they use gestures such as head nodding, head shaking, pointing, and waving in ways that are out of context with their speech, and do not contribute to their intended meaning. The ability of children and adults with ASD to convey meaning is often confounded by their use of atypical volume, pitch, intonation, stress, and rhythm during speech. People with ASD also have a deficit in their ability to understand and interpret nonverbal communication by others. The inability of people with ASD to use and understand nonverbal communication means they do not express their emotions clearly and have a limited ability to recognize and understand emotions conveyed by others.

People with ASD Have Difficulty with Relationships

Another symptom of ASD is having trouble relating to others in a variety of social situations. Children with ASD often have difficulties engaging in healthy play activities with other children. They seldom engage in cooperative play, during which children work together toward a common goal, and prefer parallel play instead, during which children play alone even though they are together. Although they engage in imaginative play, which includes role-playing and acting out past experiences, children with ASD rarely do so cooperatively with other children. They often fail to respond to social advances by other children, and are unaware that they are the subject of teasing. Children with ASD often pay more attention to objects than to other people, and seem unable to distinguish people from objects. For example, one of the children interviewed by Leo Kanner played with a hand presented to him as though it were a detached object, and blew out a lit match without any apparent acknowledgment of the person holding it. Another child responded to a slight pin prick with a reaction to the pin but not to the person holding it.

Children and adults with ASD often express emotions, ask questions, or make statements in an inappropriate social context. They often do not notice that another person is uninterested in an activity, or is upset about something. It is difficult for people with ASD to notice that they are being disparaged, or that they are unwelcome in a social situation. People with ASD also have a limited ability to recognize the effects of their behavior on the emotions of others. Many people with ASD have trouble making and maintaining close friendships with those who are not their primary caregiver. Some avoid friendships, whereas others are interested in making friends but lack the social awareness and skills to succeed in doing so. When children with ASD do make friends, their friends are often from a different age group. Some will display a partial or complete lack of interest in others. They often are unaware that others are present. When they do acknowledge others, they often show little interest in them, and have limited interaction with them. Many children and adults with ASD appear to be withdrawn into their own world. Leo Kanner learned of this type of behavior in one of the children he interviewed, whose father said that he displayed “an abstraction of mind which made him perfectly oblivious to everything around him.”

ASD Causes Stereotyped Speech

ASD also causes children to adopt specific patterns of oral communication, referred to as stereotyped speech. Many children with ASD engage in pedantic speech, during which they use formal language to try to speak with authority and sound like an adult. They become attracted to specific jargon, but use it out of proper context and without meaning. Some children with ASD frequently produce unusual vocalizations such as squealing, humming, and squeaking. Children and adults with ASD often have echolalia, which is the frequent and often meaningless repetition of words or phrases spoken by others. Echolalia is related to the tendency by people with ASD to use rote language, during which they recite what they have memorized, such as the alphabet, an advertising jingle, or a famous poem. It is also related to the tendency to use perseverative speech, which is the repetition of a word or phrase after the stimulus that led to it has stopped. For example, a boy interviewed by Leo Kanner developed a habit of saying, “the people in the hotel,” “candy is gone, candy is empty,” and “don’t throw the dog off the balcony.” His parents explained that each of these phrases originated from a prior experience. People with ASD often use idiosyncratic language, during which they make reference to words and phrases that do not make sense without knowing where they came from. Kanner reported several examples of this type of speech among the children he interviewed. One child often uttered “chrysanthemum,” “business,” and “the right one is on, the left one is off.” Another habitually said, “dinosaurs don’t cry,” “crayfish and forks live in children’s tummies,” and “gargoyles have milk bags.” Children and adults with ASD often use metaphorical language, during which an object is used to represent an abstract idea. For example, when asked to subtract 4 from 10, a boy interview by Kanner responded, “I’ll draw a hexagon.” Another characteristic symptom of ASD is pronoun reversal. A typically developing child learns how to properly use personal pronouns by the age of about 3 years, but children with ASD often do not. They often refer to themselves in the second person instead of the first person, using pronouns such as “he/him/his,” “she/her/hers,” and “you/yours” instead of “I/me/mine.” For example, one of the children interviewed by Kanner said “pull off your shoe” when he wanted his mother to take off his shoe, and “do you want a bath?” when he wanted a bath.

ASD Causes Restricted and Repetitive Behaviors

Children and adults with ASD develop abnormal restricted and repetitive behaviors (RRBs). RRBs can take the form of ritualized patterns of behavior, such as turning around in a circle whenever a room is entered, or jumping up and down before every meal. RRBs also include repetitive hand movements such as clapping, finger flicking, flapping, or picking, stereotyped body movements such as swaying, spinning, rocking from side to side, and clasping hands to the ears. One of the children interv...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of Figures
• List of Tables
• Acknowledgments
• Introduction
• Chapter 1 Symptoms and Diagnosis
• Chapter 2 Causes and Contributing Factors
• Chapter 3 Treatment and Therapy
• Chapter 4 Future Prospects
• Conclusion
• Glossary
• Bibliography
• About the Author
• Index