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Early Manifestations of Autism Spectrum Disorders

The Random Behaviorist — Tue, 28 Jul 2009 20:45:00 GMT

Early Manifestations of ASD

According the Diagnostic and Statistical Manual (DSM-IV-TR) Autism must be identified before the age of three years of age. Although there is consensus that signs of Autism appear before the age of three, when does it first appear and why?   The existing body of research literature indicates that the earlier treatment is initiated, the better the prognosis and results of the intervention(s).

The introduction of early intervention programs counts on cerebral plasticity (the ability of the brains neurons to adapt, grow, and compensate). Young children up through the ages of 6 and 7 have been shown to have great cerebral plasticity; retaining the existing brain neurons that continuously make new and adapted connections in response to the child’s interactions with his or her environment. The existence of the so-called critical periods (birth through the age of 7) has been widely accepted and demonstrated, from the point of view of neurobiology. If determined synaptic connections are not made early in development, it is improbable that they will be made later.   This has enormous negative implications for the development of the child as they go into adulthood.

For this research article, Perez, Gonzalez, Comi, and Nieto (2007) utilized 39 relevant studies published since 1975. The following are the major conclusions the authors were able to draw out of the analysis of these studies.

At what age are the first symptoms observed?

First symptoms are generally observed by the parents between one-and-a-half and two years of age. It is also probable that the earliest symptoms appear before the parents are aware that something is wrong.    Children with cognitive impairment exhibit signs of cognitive impairment before those with autism and tend to have different characteristics. Overall, the research literature suggests that early signs of autism are difficult to observe or detect before the close of the first year.

What are the first symptoms?

The first symptoms appear to be social, interpersonal and intersubjective factors. Conjoint attention skills such as eye contact, looking at the face, object indicating behaviors, pointing, orienting to name, etc., are all important factors. Failures and differences in attending to social stimuli are detected and are seen together with differences in shared attention frequently.

Some aspects associated with sensory and perceptive anomalies, such as reduced capacity for inhibitory control and difficulties in changing the focus of attention, centering on objects or parts of objects over prolonged periods of time, have also been shown as early symptoms,

How is the disorder presented and what is its course?

The most frequent to be observed in the majority of children with autism is the regressive type, in which the children experience a period of normal development until approximately a year to a year-and-a-half.

A progressive and fluctuating type has also been described in the literature, which may support the hypothesis of a similar developmental sequence, at least with respect to communication skills.

Can a relationship be established between time of onset and prognosis?

This review did not establish a clear and consistent relationship between time of onset and prognosis of the disorder. No clear relationship was able to be established between age at presentation and severity of symptoms or between the age at presentation and other variables such as IQ and educational level of the parents.

What are the differences between normal developing children and children with Autism?

Differences between normally developing children and children with Autism are clearly observed from the first year-and-a-half and beyond. Before the end of the first year, the differences were few.   Differences become more evident when children begin walking between 31 and 42 months. Normally developing children spend much more time inventing new means for new ends, while autistic children spend more time repeating the same actions. Goal directed behaviors are reduced and continuous action is increased.    Differences are also found in orientation tasks, temperament and receptive and expressive language.

When comparing development of children with Autism and Mental Retardation, children with Autism demonstrate an unusual response to sounds.

Comparing children with language disorders and children with Autism, the most distinguishing symptoms between the two groups are Stereotypic behaviors, isolation and scarce eye contact.

References

Perez, J.M., Gonzalez, P.M., Comi, M.L., Nieto, C. (2007). Early manifestations of autistic spectrum disorder during the first two years of
     life. In Perez, J.M., Gonzalez, P.M., Comi, M.L., Nieto, C., New developments in autism: The future is today, (pp. 33-57). London, UK:
     Jessica Kinglsley Publishers

Facts About the Prevalence of Autism

The Random Behaviorist — Mon, 27 Jul 2009 18:11:00 GMT

How often does Autism Occur: The Facts

In an article written for the Association of Parents of People with Autism, which took place in Madrid on May 5th, 2005, Dr. Eric Fombonne undertook an exhaustive review of the epidemiology of Autism Spectrum Disorder (ASD).   Overall Fombonne used 36 studies published between 1966 and 2003 involving 14 countries and a sample size of 7,514 children diagnosed with an ASD to conduct his analysis.

The following is a list of findings based on empirical evidence from the analysis of the 7,514 children diagnosed with an ASD:

    Intellectual Functioning

    29.6% of children were found to have no intellectual impairment

    70.4% of children were found to have some form of intellectual impairment; of these

   Of these children;

            29.3% were found to have mild to moderate intellectual impairment
            38.5% were found to have moderate to severe intellectual impairment

Gender Differences

   4.3 males for every 1 female

    Looking at the children with Autism and no intellectual impairment, the gender differences were more pronounced; 5.5 males for every     1 female.

    In the group of children with Autism that had moderate to severe intellectual impairments the gender ratio was 1.95 males for every 1     female.   This supports the statement that female’s diagnosed with Autism are much more likely to experience moderate to severe     intellectual impairments.

Prevalence Rates

    Autism

   13 children for every 10,000 children born

    Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)

   20.8 children for every 10,000 children born

    Asperger Syndrome

   2.6 children for every 10,000 children born

    Childhood Disintegrative Disorder

    1.9 children for every 100,000 children born

    Overall, Fombonne states that the best estimate for the prevalence of PDDs currently available is 60 children for every 10,000 children     born. This translates to 1 child out of 167 (0.6%) children born being diagnosed with a Pervasive Developmental Disorder.     Interestingly, Rett’s disorder, one of the 5 PDD diagnoses included in the Diagnostic and Statistical Manual, was not included in these     estimates.

Social Class

    There is no apparent correlation of the occurrence of autism within specific social classes.   Autism doesn’t discriminate.

Conclusion

In the arena of Autism, it’s critical that empirical evidence, rational thinking and skepticism rule the day. Armed with scientific evidence, parents, professionals and interested parties can make good, informed decisions for the children with autism they are concerned with. This Fombonne article reviews empirical scientific evidence to provide us with some good information about some of the many dimensions of the diagnosis of Autism and Pervasive Developmental Disorders.

References

Perez, J.M., Gonzalez, P.M., Comi, M.L., Nieto, C. (2007). New developments in autism:   The future is today. Great Britain, Athanaeum Press.

Biologists have created a living computer from E. coli bacteria that can solve complex mathematical problems

The Random Behaviorist — Mon, 27 Jul 2009 15:39:00 GMT

The UK Guardian provides a very interesting story about how biological engineers have created a computer that uses "bacteria" to calculate complex math problems faster than silcon based computers.
Read story: http://www.guardian.co.uk/science/blog/2009/jul/24/bacteria-computer

Welcome

The Random Behaviorist — Wed, 28 Jan 2009 10:31:07 GMT

Welcome to my blog. Please check back soon for new entries.