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 ![[----------------Horizontal Rule----------------]](/webart/hrule.gif){kind=small}  Article 1: People with Down Syndrome: Characteristics Affecting the Development of Communication Skills.In 1866 John Langdon Down described characteristics of children with a syndrome later named for him.1 Occurring in 1 out of every 800 - 1,100 births, Down syndrome (DS) is a leading cause of mental retardation. The syndrome arises from an abnormality on a small portion of chromosome 21 with "trisomy 21" accounting for 95% of cases. There are two other subtypes of Down syndrome: 4-6% are a translocation of a portion of chromosome 21 to another chromosome and 1-4% are a mosaic of normal and trisomic cells.2 Down syndrome is not related to race, nationality, religion or socio-economic status. In fact, neither the cause, nor a means of prevention are currently known. The likelihood of children being born with DS does increase with maternal age; however, only 20% of all babies with DS are born to women over age 35. This is because most women give birth before they reach their mid-thirties and because there are other factors causing DS.3 Until recently many infants with DS did not survive, often because of associated congenital anomalies (e.g., 30-50% have heart defects and 3-12% have gastrointestinal tract abnormalities). Many times those who did survive were either institutionalized or educationally deprived. Such unfortunate practices reflected society's perception of "mental retardation" and limited expectations of people with DS. During the 1980s and 1990s, stereotypes surrounding individuals with DS have been challenged and are changing. Reasons? More enlightened attitudes about persons with disabilities in general and an increased understanding of and experience with people born with DS. Specifically: Biomedical advances have extended life expectancy.4 Even though associated congenital anomalies (heart defects, orthopedic and ophthalmologic disorders, increased incidence of leukemia, seizures, and ear, nose, and throat problems) are present in 50 percent of cases, medical science is able to manage many of these problems. Although the degree of retardation varies from minimal to severe, research shows most individuals with DS function in the mild-to-moderate range.4 Many children with DS now are raised at home, attend their local schools and as a result, have many more opportunities. Not surprisingly, individuals who have access to "mainstream experiences" are demonstrating competencies far exceeding what was heretofore expected.3 Finally, communities are more accepting of individuals with disabilities. In some areas employers are seeking and hiring adults with DS to work in hotels, restaurants, offices, the computer industry and many other settings. Life-long management As a result of medical and societal advances, researchers, clinicians, and families are being encouraged to "bring a life-span developmental perspective to bear in planning medical, educational and psychological interventions for children with DS." 5 Currently studies are underway that examine biomedical and neurodevelopmental aspects of DS, as well as issues of temperament, parent-child interaction, and the impact of caregiver expectations on opportunities. Understanding communication characteristics Communication skills are inherent to everyone's ability to meet basic needs and develop independence, to participate in social interaction and to have access to educational, leisure, and vocational opportunities. Prior to making intervention decisions, professionals should be knowledgeable about characteristics of children and adults with DS as well as behaviors unique to each individual. Characteristics to consider are: 1. Individuals with DS develop the same as other children, except more slowly; and, except in some specific areas. For example, many children with DS are described as having relatively advanced social skills and visual intelligence while lagging behind in language. With few exceptions, as chronological age increases, language and communication skills fail to keep pace with advancing cognitive skills.6 2. Specific cognitive deficits secondary to organic impairment are associated with DS. Data suggest the brain morphology of individuals with DS is different in some areas (e.g., Broca's area is smaller.) Many studies conclude people with DS have memory deficits and difficulty processing linguistic material (versus nonlinguistic information). Studies also document a slowing of the trajectory of IQ in DS children.4 Many hypothesize that individuals with DS have specific difficulty processing sequential information. Some, or all of these findings, may underlie the speech-motor control and language problems, as described below. 6,7 3. Language production is more affected than comprehension. Syntax is more affected than vocabulary. 4 Sixty to seventy-five percent of children with DS have deficits in language production when compared to non-verbal mental ages; but less than 5% have comprehension deficits.8 Although reasons for these findings are not yet clear, children with DS do have difficulty making transitions from single word to multi-word utterances. Nevertheless, they often have large vocabularies of single words. 9,10 4. Speech motor control deficits may interfere with the development of intelligible speech. Flaccid muscle tone combined with what appears to be neurological impairment can affect speech motor control and timing. Whether caused by a specific motor deficit or a more global problem with sequencing, these problems with speech intelligibility, described as verbal apraxia, are common.7-10 5. Otitis media persists throughout childhood. Because of middle ear problems (20-50% of cases), children with DS should be followed aggressively by a physician specializing in the ear, nose and throat (an ENT). Structural and functional aspects of the Eustachian tube probably underlie these problems. Chronic, untreated middle ear fluid dampens the acoustic signal. It may contribute to language learning problems and/or lead to fluctuating or permanent hearing loss. Thus, children with DS should have regular hearing screenings at least through elementary school years.7 6. Negative environmental variables. Environmental circumstances can alter the language-learning environment and negatively affect development.7 For example: • Decreased expectations for language and communication skill development, simply because a child has a diagnosis of DS. • Altered patterns of interaction. Studies show normal speaking partners change the way they interact when their partners are difficult to understand. They ask a preponderance of "yes/no" questions, interrupt, fail to recognize attempts at speaking or communicating, and don't give individuals with speaking impairments an opportunity to initiate or respond. • Diminished, lacking, or inappropriate feedback. Children who are not understood do not receive "good" feedback from their partners about the language they use. Feedback that is inappropriate, negative, or lacking altogether may decrease an individual's motivation to interact and may interfere with learning in other ways. • Limited practice. As described above, people with DS do not have adequate opportunities to practice talking. Practice is important, and AC specialists must not overlook speech programming when the focus of intervention shifts to teaching sign or the use of an augmentative device. Miller and others raise concerns about current language intervention practices. We need to investigate whether they may be contributing to prolonged unintelligibility in children with DS. 7. Prevalence of early Alzheimer-type symptoms in adults with DS. Geneticists have linked Alzheimer's disease to the 21st chromosome; however the neurobiological relation between DS and Alzheimer's disease shows some critical differences and is a focus of intense research interest.11 Augmentative communication programming Augmentative communication approaches often are considered useful as a way to:
3) assist families and professionals to determine what modalities are most helpful to someone with DS. The most common AAC approaches being used with people who have DS are manual signs and non-electronic aided techniques. Manual signs: The primary rationale for using signs is to offer a scaffold to individuals with DS who do not produce intelligible speech. Case studies and group data suggest signs have beneficial effects when used with young children as well as adults who have limited communication skills. In fact, speech production and intelligibility often improve after the introduction of signs.12 In a recent study of 46 children with DS (ages 1 to 9 years; mean=3 years, 11 months), Sedey, Rosin, & Miller13 reported eighty percent (80%) had used sign. Most parents (87%) felt signing was (or had been) beneficial for their child. Reasons for introducing signs were to "improve oral language" (51%), "provide some form of communication" (30%) or "alleviate a child's frustration" (27%). A speech-language pathologist or teacher initiated signing at approximately 24 months. The 25% who had discontinued using signs, did so because their child started talking (86%) or became more intelligible (53%). When comparing the lexicons of spoken and sign vocabulary acquisition in children with DS and typically developing children (mental ages=12 to 27 months), Miller, Sedey, Miolo, Ropsin, and Murray-Branch14 found children with DS did not increase their use of spoken words as rapidly. However, when signed-only lexical items used by subjects with DS were added, differences in vocabulary size were no longer significant. While many individuals with DS learn and use some signs, their use often is limited to single words or short, telegraphic phrases (e.g., I want___). Possible reasons include: Trouble forming signs because of motor planning problems; severe language problems restricting length of utterance across modalities; and limited exposure to fluent users of the language. In addition, most people do not understand manual signs. The bottom line? Signs cannot address the needs of individuals in all contexts, with all partners. Other communication modes are needed.
Graphic symbols, communication boards & devices To date, studies have not systematically addressed the use of communication boards and books or electronic voice output devices with people who have DS. However, graphic symbols have been shown to play a role in language acquisition and facilitate communication in specific environments. 15, 16 In addition, Iacono demonstrated value in using graphic symbols and voice output when teaching linguistic structures.10 The section on using multiple modalities explores further the use of multiple language modalities.
This article appears in ACN Volume 7, # 6. You may order this issue by clicking on Ordering Home Page Online Ordering 
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