Distinct developmental patterns identified in children with autism during their first

Discussion in 'Parenting News' started by runawaybunny, Oct 30, 2012.

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    runawaybunny Guest

    Kennedy Krieger researchers find a preclinical phase in children with autism that is not easily detected

    In the largest prospective study to date of children with early and later manifestation of autism spectrum disorders (Autism Spectrum Disorders (ASD)) compared to children without Autism Spectrum Disorders (ASD), researchers found two distinct patterns of language, social and motor development in the children with Autism Spectrum Disorders (ASD). The study found that early in development, children who display early signs of Autism Spectrum Disorders (ASD) show greater initial delay across multiple aspects of development compared to children whose Autism Spectrum Disorders (ASD) symptoms emerge later. However at 36 months of age, the early differences between these groups are no longer obvious. By the third birthday, the level of impairment between these symptom onset groups of children with Autism Spectrum Disorders (ASD) is comparable. Additionally, researchers uncovered a preclinical phase of Autism Spectrum Disorders (ASD) in which the signs of delay are not easily detected with existing clinical tests.

    Previous research by Kennedy Krieger Institute researchers found that approximately half of all children with Autism Spectrum Disorders (ASD) can be diagnosed around the first birthday, while the remaining half do not show diagnostic indicators until later. The current study builds upon these findings by further evaluating motor and language development in a wider age span of children diagnosed with Autism Spectrum Disorders (ASD) (6 to 36 months), and examining how development unfolds differently in each group.

    "Regardless of diagnosis, the development of children with and without Autism Spectrum Disorders (ASD) appears similar at six months of age on clinical tests," says Dr. Rebecca Landa, lead author and director of Kennedy Krieger's Center for Autism and Related Disorders. "However, for those children who went on to develop autism, the earliest signs of atypical development were non-specific to autism, such as general communication or motor delay."

    About the Study

    Participants included 204 infant siblings of children with Autism Spectrum Disorders (ASD), who are at a higher genetic risk for developing Autism Spectrum Disorders (ASD), and 31 infants with no family history of Autism Spectrum Disorders (ASD). The infants were examined at 6, 14, 18, 24, 30 and 36 months of age. Confirmation of Autism Spectrum Disorders (ASD) classification was made at the 30 or 36 month visit for all participants because diagnosis at this age is considered definitive. At each visit, researchers evaluated the infants for motor, language, communication, social-affective and symbolic abilities, as well as typical symptoms of Autism Spectrum Disorders (ASD).

    Based on gold standard Autism Spectrum Disorders (ASD) assessments, infants were divided into three groups: Early-Autism Spectrum Disorders (ASD), Later-Autism Spectrum Disorders (ASD) and Non-Autism Spectrum Disorders (ASD). Both Autism Spectrum Disorders (ASD) groups (54 infants total) were confirmed to have Autism Spectrum Disorders (ASD) at 36 months; however the Early-Autism Spectrum Disorders (ASD) group (28 infants) received a clinical judgment of Autism Spectrum Disorders (ASD) symptomology at 14 months, whereas the Later-Autism Spectrum Disorders (ASD) group (26 infants) did not. The Non-Autism Spectrum Disorders (ASD) group (181 infants) did not meet outcome criteria for Autism Spectrum Disorders (ASD).

    Developmental Patterns

    Early-Autism Spectrum Disorders (ASD) versus Later-Autism Spectrum Disorders (ASD)

    By 14 months, the Early-Autism Spectrum Disorders (ASD) group exhibited significantly lower expressive language and shared social smiling scores than the Later-Autism Spectrum Disorders (ASD) group.
    By 18 months, the Early-Autism Spectrum Disorders (ASD) group exhibited greater delays in receptive and expressive language development compared to the Later-Autism Spectrum Disorders (ASD) group.
    At 24 months, this gap between the Early- and Later-Autism Spectrum Disorders (ASD) groups had closed due to increasing impairment in the later-Autism Spectrum Disorders (ASD) group.
    At 30 and 36 months, there were no detectable differences between the Early- and Later-Autism Spectrum Disorders (ASD) groups.

    Early-Autism Spectrum Disorders (ASD) versus Non-Autism Spectrum Disorders (ASD) groups

    At 6 months, the Early-Autism Spectrum Disorders (ASD) and Non-Autism Spectrum Disorders (ASD) groups exhibited comparable development.
    At 14 months, the Early-Autism Spectrum Disorders (ASD) group diverged from Non-Autism Spectrum Disorders (ASD) development in all measured aspects of development, except for fine motor functioning.
    These differences were sustained through 36 months.

    Later-Autism Spectrum Disorders (ASD) versus Non-Autism Spectrum Disorders (ASD) groups

    At 6 months, the Later-Autism Spectrum Disorders (ASD) and Non-Autism Spectrum Disorders (ASD) groups exhibited comparable development.
    At 14 months, the Later-Autism Spectrum Disorders (ASD) group's scores were significantly lower than the Non-Autism Spectrum Disorders (ASD) group's for fine motor and some language skills.
    At 24 and 36 months, the Later-Autism Spectrum Disorders (ASD) group performed below the Non-Autism Spectrum Disorders (ASD) group on all abilities examined except fine motor functioning at 24 months.

    Dr. Landa noted that patterns of slowing, plateauing and decline in development in children with Autism Spectrum Disorders (ASD) occurred within the timeframe when parents report first concerns about children with Autism Spectrum Disorders (ASD). The subtlety of early signs and a gradual shift from typical development may not be detected by Autism Spectrum Disorders (ASD) screeners or by health professionals in a brief office visit. Thus, parent's expression of concern about their toddler's development or behavior requires careful consideration.

    "If parents aren't seeing their children steadily develop new skills, they should talk to their pediatrician or contact their local early intervention program," says Dr. Landa. "Results from this study show that communication delays are often present in the second year of life in children with autism, especially involving language comprehension."

    Further research is needed with a larger population of children with Autism Spectrum Disorders (ASD) and using behavioral and biological measures that may detect more subtle indicators of disrupted development in children with Autism Spectrum Disorders (ASD) in the first year of life. With larger studies, researchers can conduct more detailed analyses of developmental advances in children with Autism Spectrum Disorders (ASD), which may facilitate the development of better early Autism Spectrum Disorders (ASD) screening tools and thereby improving access to earlier intervention. Studies have shown that early intervention improves language, social and cognitive outcomes for children with Autism Spectrum Disorders (ASD).

    *

    Story Source:
    The above story is reprinted from materials provided by Kennedy Krieger Institute

    Study Reference:
    Published in the journal Child Development,

    Disclaimer:
    This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ConductDisorders or its staff
     
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