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Spring 99 Table of Contents
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Pervasive Developmental Disorders in Children with Visual Impairments

By Marnee Loftin, Psychologist, Texas School for the Blind and Visually Impaired

Pervasive Developmental Disorder is a psychiatric/psychological term for a broad category of disorders characterized by disturbed patterns of social interaction and language. PDD is also accompanied by a variety of unconventional self-stimulatory behaviors. These conditions are all generally noted early in life and often associated with an additional diagnosis of mental retardation. Although the specific cause of PDD is not known, it is often associated with other medical conditions, such as chromosomal abnormalities, congenital infections, and structural abnormalities of the central nervous system.

Within this broad category of PDD, there are four different types of disorders. These vary primarily according to the age at which the behaviors are first observed. Numerous excellent resources are available that completely describe each of these types of PDD. The following is a brief summary regarding each of these types.


Characteristics include:

Childhood Disintegrative Disorder

Characteristics include:

Autistic Disorder

Characteristics include:

Asperger's Disorder

Characteristics include:

Difference Between Autism and Asperger's Disorder

Though there are some similarities between Autism and Asperger's Disorders, there are also significant differences, including the following:


At this time there is no specific test or instrument to diagnose Asperger's. Much of the decision is based upon observation of the student as well as reports of family members and staff.

In general, individuals with Asperger's exhibit a number of disturbances in interpersonal relationships. They may express considerable interests in developing these relationships, but find this difficult to do. Relationships with peers are frequently one-sided with long conversations about a limited number of topics. Generally the topics will focus upon their own narrow topics of interest. They are unable to gauge the degree of interest (or disinterest) that others may have in their conversations. When peers attempt to direct their conversations to mutual topics of interest, the individual with Asperger's will ignore such attempts. They may refuse to respond or will simply redirect it back to their own area of interest.

In general, the topics of extreme interest for an individual with Asperger's are those that can best be learned in a rote manner such as weather, geography, construction, etc. They are less likely to choose topics that focus upon more aesthetic interests or abstract concepts. The topics may change over a period of time, and the individuals may not want to discuss topics that interested them during an earlier stage of development.

Individuals with Asperger's are quite often bright individuals who learn well in role play situations regarding specific social skills. However, they have great difficulty in generalizing a skill learned in one situation to another situation.

Psychological assessments will often reveal a pattern of strengths and weaknesses that is quite pronounced. These individuals have skills in rote learning of verbal concepts and verbal memory. They often have a large vocabulary and can easily repeat long strings of information. Reading skills are likely to be well developed, but they often have great difficulty making inferences based upon reading. Weaknesses are most obvious in tactile perception, psychomotor coordination, visual-spatial organization, and situations that involve interpretation of social cues.

One of the most difficult tasks in diagnosing Asperger's Disorder is to differentiate between this disorder and other conditions, specifically Attention Deficit Disorder and Anxiety Disorders.


At this time, there is no specific treatment or "cure" for Asperger's Disorder. Intervention usually consists of different psychological strategies or medication. Both types of intervention deal with decreasing the symptoms that appear. Examples of psychological strategies that might be used include:

Medications are available to treat a variety of behaviors that are exhibited. Psychiatric consultation is critical in making such a decision. Different medications have been used to address the following groups of behaviors:

PDD and Visual Impairments Diagnosis

The diagnosis of both Autistic Disorder and Asperger's Disorder is a complex task that is even more difficult when the child is severely visually impaired. Although the cause of PDD is not clearly established, PDD is often associated with congenital infections and structural abnormalities of the central nervous system. Both of these conditions are also often seen as causes of visual impairment. Therefore children with visual impairment may in fact be at increased risk for some type of PDD. The diagnosis of any form of PDD is challenging. That task is significantly more complicated in children with visual impairments because of their unique developmental patterns.

In spite of these difficulties, in recent years we have seen a significant increase in the number of young children with visual impairments who have also been diagnosed as having some form of PDD.

Two issues are critical in this process. (1) Someone with a clear understanding of the unique developmental patterns of visually impaired children should be involved in the diagnostic process, to differentiate and note behaviors that may be of concern. For example, echolalic language and difficulties in establishing peer relationships are frequent issues in young children with visual impairments. These behaviors have little diagnostic significance (i.e., not necessarily indications of Autism) although they may be noted as areas of need for remediation in the educational programs. (2) Many young children with visual impairments have great difficulty in establishing peer relations because of the lack of opportunities for incidental learning. This should be identified as a need for direct training rather than a symptom of Asperger's.

After areas of need are identified, our responsibility as educators is to allow adequate time for maturity to occur and new skills to be learned. For the vast majority of children with visual impairments, these behaviors and concerns will correct themselves with appropriate instruction and maturation.

When these behaviors continue to remain problematic, we need to ask ourselves why. We can be sensitive to the different developmental patterns of children with severe visual impairments, but we must not let this interfere with our ability to determine when these differences have become significant deviations from the usual developmental patterns for children. An important goal is to develop consistent means of gathering data that will allow us to monitor changes in social interactions, communication, and ritualistic/stereotypic behaviors that occur as a child matures and education progresses. Appropriate identification of children with visual impairments and some type of PDD will allow modifications of their educational program and better access to adult services.

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Last Revision: September 4, 2003