Survey of Expressive Communication Skills in AS: an Update

Presentations at the 1st World Conference IASO - Tampere, Finland, 4-8 July, 2000
Presented by: Robin L. Alvares - Leigh Brezovsky Department of Speech and Communication Studies Edinboro University of Pennsylvania Edinboro, Pennsylvania USA

While Angelman syndrome was first documented in 1965, it is only recently that developmental profiles of individuals with AS have been studied. These reports describe a pattern of communication development specific to individuals with AS. This pattern includes difficulty with expressive modes of communication, particularly speech. The gap between receptive and expressive communication cannot be accounted for solely delays in receptive language and mental retardation.

In addition to the reported gap between receptive and expressive communication, most reports of individuals with AS suggested extremely limited expressive communication. Some references continue to describe the clinical profile of individuals with AS having 5 words (or manual signs) or less. Clinical observation and anecdotal reports, however, indicated that at least some individual with AS had a greater expressive vocabulary than had been reports. From my interactions with Angels and their families over the past 5 years, I can state that there are Angels who have expressive skills significantly beyond the 5-word level.

I was at the CASS Conference in Calgary discussing the importance of preverbal communication, gestures, etc. I basically said that the one thing we know about AS is that speech is not a viable communicative mode for Angels. A mother in the audience stood up and said, "I feel left out - my child, who is deletion positive, says about 100 words."

More recently, I was at the ASF Conference in Philadelphia. I met a 6 year-old young lady who was able to sustain a conversation in sign language. Her signs were not precise, but they were clear. Her mother told me about a time that the family had gone to visit relatives, and the young lady had watched her uncle play soccer. When she got home she signed, spontaneously, uncle play kick ball. This is the type of structure that would be used by a deaf but otherwise typically developing child of 3 ½ to four years. This is clearly beyond the 5-word level.

Within the last ten years, procedures have been developed which can confirm the existence of AS through genetic testing rather than clinical characteristics. The identification of individuals through genetic testing has revealed a greater range of abilities than previously believed.

However, many questions remain. A large scale, in-depth study of communication abilities in individuals with AS has yet to be done. A first step toward such a study is to identify factors warranting further investigation. The purpose of the present study was to identify factors that contributed to the expressive communication abilities exhibited in children with AS. We used a parent survey of expressive communication skills in children with Angelman to address the following questions:

Which factors contribute to the specific expressive delay described in individuals with Angelman syndrome? Why is the range of expressive communication ability in Angelman syndrome greater than previously believed?

Methods

A survey developed by Alvares and Downing (1998) was distributed via the angelman-l listserve. The survey consisted of closed- and open-ended data regarding the communication abilities of children with AS. A copy of the survey is in the handout. The listserve consisted of approximately 350 participants internationally, most of which were family members of individuals with AS, though there were some professionals who also subscribed to the listserve. Participants could complete and survey and return it by e-mail, or downloading the form, printing it, and sending it via the regular post (so called "snail mail").

Results & Discussion

We received 82 surveys, and the results of the survey are in the handout. We'd like to briefly go over our interpretation of the findings, emphasizing that this is a preliminary analysis of the data.

Factors Contributing to the Expressive/Recessive Gap

Each of these factors will be discussed individually, but at the outset it should be noted that the communication profiles observed in individuals with AS may be the result of a combination of these factors. In addition, the extent to which each of these factors or combination of factors may vary from individual.

Seizures

Seizures are reported in over 90% of individuals with AS, with most having onset before three years of age. Associated with seizures may be the regression or loss of communicative function, particularly in individuals with severe and profound mental retardation. Though it was not part of the study, many families have reported that their children began using some words and then stopped, though it is not clear if this loss of speech was a direct result of seizures. While seizures may explain the loss of previously learned information, they do not account for the receptive-expressive gap because they effect both receptive and expressive communication.

Medications

Most individuals with AS require anticonvulsant medications, such as Depakote Phenobarbitol, Dilantin, Tegretol, Klonpin and Risperdal, and some individuals take multiple medications. The benefits of anticonvulsant medications strongly outweigh the risks, however, they can affect learning an performance in individuals with disabilities. The effects of anticonvulsant medication on development and learning in individuals with mental retardation include memory loss, hyperactivity and difficulties with motor coordination. Side effects associated with anticonvulsant medication do not account for the receptive-expressive gap, they may effect the individual's ability to benefit from interventions. Increased understanding of the function of pharmaceutical interventions and drug interactions has led to treatments which control seizure activity with fewer side effects.

Vision

Seventy-three (73%) of the respondents reported vision problems. These findings support the findings of other studies that have documented a high incidence of strabismus in individuals with AS. Communication modalities such as sign language, picture communication systems and augmentative communication systems are difficult to use when vision is impaired. However, it is unlikely that visual impairments contribute to the receptive-expressive gap because visual impairments are affect the reception of communication as well as communication expression.

Hearing

A small percentage of individuals reported hearing problems (12%) though only 68% of the respondents indicated that their child's hearing had been tested. While a small percentage of individuals with AS may have a long-term sensorineural hearing loss, there is a possibility that individuals with AS may have intermittent or fluctuating hearing loss due to middle ear infections. This issue needs to be further addressed.

Motor

Gross and fine motor difficulties associated with the developmental course of the syndrome, and those resulting from medications, may lead to difficulty with all modalities of expressive communication. Because each may make a contribution, they will be discussed separately.

Gross Motor

Most individuals with AS display gait and movement disorders early in life. Voluntary movements are often irregular and uncoordinated, and gross motor milestones are delayed. In the present study, the age at which the individuals became ambulatory ranged from 14 months to 11 years, and approximately 20% percent of the children were non-ambulatory. Gross motor function has implications for the use of gestures, sign language and augmentative communicative devices, and the relationship between gross motor abilities and communication, especially expressive communication, is a potentially important area of study.

Fine Motor

Oral Motor/Feeding: In individuals with disabilities, motor and sensory problems lead to difficulties with the vegetative functions of the oral mechanism (drinking, chewing and swallowing) as well as speech production problems. In AS syndrome; feeding problems usually manifest early as difficulty in sucking or swallowing, tongue thrusting, and generalized oral-motor incoordination. In the present study, 45% of the respondents noted that their children had feeding and swallowing problems. Some of the feeding/swallowing problems reported in the present survey included immature chewing, tongue thrust, gastroesophageal reflux, such swallowing incoordination, and failure to thrive. Anecdotally, on the listserve, families have reported food aversions and choking. Based on the present study, oral-motor dysfunction as the primary factor for the receptive-expressive observed in AS.

As an aside, feeding and swallowing difficulties in AS underscore the importance of understanding sensory mechanisms in AS. It is commonly reported that individuals with AS have a fascination with water and this is clearly related to a need for a specific type of sensory feedback. Because sensory information in the form of tactile and kinesthetic feedback is vital in the coordination and integration of movement, it is very important for us to understand the effects of sensory integration problems on all aspects of development in AS.

Further evidence of an oral motor component to the receptive-expressive gap observed in AS comes from descriptions of voice quality. Many of the respondents reported that their children had atypical voice quality which they described as harsh (6%), nasal (73%), or guttural (22%). These aspects of voice quality are caused by damage or dysfunction of the neural pathways to the articulators and are further evidence of oral motor dysfunction including neuromotor control of the larynx and velum.

Phenotype

At this point, there is not a clear relationship between genetic phenotype and communication abilities, though there appear to be some promising studies that are being presented at a later session at this conference. At this point, the type or extent of deletion does not appear to be correlated with degree of communication impairment, however, a large scale study using factor analysis may provide sufficient data to detect phenotypic patterns in communication development.

Cognition

Nearly ½ (43%) of the respondents reported that their children engaged in symbolic (pretend play). While not a direct measure of receptive language, symbolic play requires symbolic cognitive abilities closely associated with the development of language. In typically developing children, the ability to engage in symbolic play begins to emerge around 18 months to 2 years. It is also at that time that children generally have an expressive vocabulary of about 50 words and are beginning to use two-term relations. These symbolic play abilities suggest that some children with AS possess the cognitive prerequisites for symbolic communication but have expressive difficulties for some other reason.

Hyperactivity

Hyperactivity (Attention Deficit Disorder with Hyperactivity) has be noted in virtually all individuals with AS. They have been described as hypermotoric with a short attention span. In addition, most children with AS do not receive drug therapy for ADHD and, in fact, ADHD may be a side effect of some anticonvulsants for some individuals with AS. Because ADHD does not lead to a receptive-expressive gap in other populations, it is unlikely to be the cause the receptive expressive gap observed in AS.

Factors Related to Range of Abilities

Diagnostic Procedures

Early diagnosis of AS was based on the manifestation of clinical criteria rather than genetic testing. One of the clinical criterion was lack of expressive communication, and individuals who did not meet this clinical criterion were not considered to have AS despite the existence of other clinical criteria. Now that diagnosis can be made based on genetic testing rather than behavior criteria, and individuals previously excluded from the diagnosis based on communication abilities are now included in the diagnosis.

Early Intervention

Early identification leads to early intervention. Virtually all of the families in the survey reported that their Angels received some type of early intervention. It is known that early intervention for other developmental disorders, including Down syndrome, cerebral palsy, deafness and autism, leads to greater development gains. It is likely that early communication intervention, even prior to the diagnosis of AS, has facilitated increased developmental gains in communication reported in individuals with AS.

Non-Verbal Communication Technology

Augmentative and alternative communication systems, including electronic devices, picture systems, sign language and gestures have received increasing attention from clinical researchers over the last fifteen years. Clinicians and clinical researchers in speech-language pathology, rehabilitation engineering, special education and psychology have studied methods of communication assessment and intervention for non-verbal individuals. Individuals with AS who previously had difficulty using speech or sign language for expressive communication now have access to electronic communication devices requiring minimal motor control. Further clinical research will help identify optimal communication modalities and more methods to help individuals with AS to use optimize those modalities.

Inclusion

While the relative benefits and costs of school inclusion continue to be debated, it is clear that individuals with disabilities who are included generally benefit from participating in an inclusive setting. Inclusive practices allow for frequent communicative interactions in a variety of communicative environments and with a greater number of communicative partners. Individuals benefiting from a greater number and variety of interactions will have better communication skills than those who have less access to such interactions. Alvares and Downing (1998) reported that a number of children with AS use communication for social purposes such as commenting and greeting. Families reported that many children with AS were aware of rules that govern communication interaction, such as gaining a listener's attention prior to gesturing or signing; others have been described as "very social". These findings are in contrast to the findings of Penner, et al. who found poor social communication skills in institutionalized adults with AS. It is clear that many individuals with AS benefit from greater access interactions with typically-developing peers and other communicative partners.

Conclusions

We have an overview of the findings of a survey of the expressive communication skills in children with AS. We use the study to address two basic questions:

What factors contribute to the receptive-expressive gap observed in Angelman syndrome? The findings of the survey point toward underlying dysfunction of sensory and motor aspects of oral motor mechanism. This dysfunction appears to limit the ability of most individuals with Angelman syndrome to use speech as their primary form of communication. Why is the range of communication abilities observed in AS greater than had been reported previously? Like all aspects of human behavior, communication abilities are the result of biological abilities and environmental interactions. In the last fifteen years, early intervention, naturalistic intervention and alternative forms of communication have allowed individuals with AS to achieve greater expressive communicative skills than previously predicted. It is clear that many individuals with AS have a greater potential for expressive communication than originally believed which is due, in part, to greater access to communicative experiences and communicative partners.

Because of these issues, we are calling for the establishment of a protocol for communication assessment in AS. Such a protocol will allow clinicians and researchers to systematically and easily compare the communication profiles of individuals with AS to develop more effective methods of treatment. This protocol should include standardized procedures for:

Evaluation of oral motor function;

Evaluation of vegetative functions of the oral mechanism;

Motor function (chewing, tongue movement, swallowing);

Sensory function (sensitivity);

Oral-pharyngeal motility study (swallowing);

Evaluation of expressive communication skills forms (modes) and intents;

Discourse skills;

Symbolic play;

Evaluation of modalities by qualified augmentative communication specialist;

Previous communication intervention and nature and type of intervention;

Additional info which should be part of protocol;

Vision and hearing screening;

Gross motor and fine motor screening;

OT and PT eval to determine gross and fine motor function and sensory abilities;

Medical information: developmental milestones, medications, seizures and deletion type, age of identification;

Verbal and nonverbal cognitive skills;

By using a standardized method to identify the continuum of communication behaviors, sufficient data may be obtained with will allow for the examination of the correlation between communication behaviors and other factors that may influence communication. Such data may lead to better experimental studies of treatment efficacy and better clinical outcomes for Angels.

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