Autism in South America. How does it compare?

A review of: Montiel-Nava, C., Pena, J.A. (2008). Epidemiological findings of pervasive developmental disorders in a Venezuelan study. Autism, 12(2), 191-202. DOI: 10.1177/1362361307086663

I decided to write a brief review of this article for two reasons. First, I often hear questions about how the rate of autism in the US, Canada, and the UK compare to that found in other countries. The answer to this question is relevant, although not as illuminating as most would like, to the major scientific debates regarding the perceived increase in rate in autism during the last two decades and the role of specific environmental factors in the development of autism. The second reason is more personal. Once upon a time, when Michael Jackson was on top of the charts, I called Venezuela my home.

The authors examined the rates of autism in a large metropolitan area of Venezuela, a country of 26,000,000 people with a large youth population (33% under the age of 14). In the first step of the study, the authors reviewed local medical records to identify children with a diagnosis of ASDs. The authors found 610 current cases in children between 3-9 years of age. Then, the authors independently confirmed the diagnosis in about 70% of the sample (N=430). The remaining children did not meet standard DSM-IV criteria or there was insufficient information to achieve an adequate diagnosis. This resulted in a prevalence rate of 1.7 per 1,000. Although this is much lower than reports in the US and other industrialized countries, the authors stated that unlike some previous reports, their methods provided rates for documented (identified) cases and did not include estimations of children that may be affected but have not yet been identified. In addition, the authors used only administrative sources for case identification (medical records) instead of large scale direct community assessments. Reliance on only administrative sources has been shown to provide lower prevalence rates. In summary, the rates of autism in Venezuela appear to be much lower than in other industrialized countries. However, the specific methods used in this study may have affected the results; in addition to the more common explanations, such as more limited access to specialized services, limited awareness about autism in the population, and higher stigma associated with these disorders, all of which limit service-utilization in developing countries.

A final note: I was informed by two Venezuelan MDs that thimerosal was still routinely used in vaccines in Venezuela. However, I sent a request for clarification to the pediatricians' organization in Venezuela and a governmental health official, since I was not able to confirm this information from any reliable online source.

Autism services in Canada and Neuropsychological evaluations

A review of:McLennan, J.D., Huculak, S., Sheehan, D. (2008). Brief Report: Pilot Investigation of Service Receipt by Young Children with Autistic Spectrum Disorders. Journal of Autism and Developmental Disorders DOI: 10.1007/s10803-007-0535-5

This is a brief report published in the Journal of Autism and Developmental Disorders. The authors contacted over 1,100 families who had obtained services from specialized clinics for children with developmental disabilities. The centers were located in Alberta, Canada. Sixty four of these families reported having at least one child with ASD. The authors examined the different services that these families received and compared these with the recommended practice guidelines. The percentage of families receiving specific services were as follows: Speech and Language assessment (94%), Psychological Assessment (42%), Genetic Testing (31%), Speech and Language therapy (88%), occupational therapy (78%). The authors concluded that the rates of services received did not correspond with the recommended practice guidelines. The authors reported the post-diagnosis evaluation guidelines as proposed by the American Academy of Child and Adolescent Psychiatry, the National Research Council, the American Academy of Neurology, and the child Neurology Society:
1. Screening for lead, tuberous sclerosis, and Fragile X
2. Neuropsychological testing (audiological function, cognition, adaptive function, and expressive-receptive language)
3. Occupational and physical therapy assessment if needed.

My clinical practice is in pediatric neuropsychology. While working at a large hospital in Michigan conducting mostly neuropsychological evaluations for children with ASD, I assumed that most families received this service. However, once I left that setting and was exposed to clinics that do not have neuropsychological services, I realized that only a small portion of these families receive a full neuropsychological evaluation. The reasons for this vary, from limited access to trained neuropsychologists, unfamiliarity with the possible benefits of these evaluations, and sadly, limited insurance coverage in some States. In my experience, if families are informed about the nature and limitations of these evaluations, Neuropsychological evaluations are very useful in helping coordinate and determine interventions that are targeted to the pattern of strengths and weaknesses of each child, and monitor the progress of the child over time. But I also agree that some families do not find these evaluations as useful.

Here are the sources of the guidelines:

Filipek, P. A., Accardo, P. J., Ashwal, S., Baranek, G. T., Cook, E. H. Jr., Dawson, G., et al. (2000). Practice parameter: Screening and diagnosis of autism: Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society. Neurology, 55(4), 468–479.

National Research Council (2001). Educating children with autism. Washington, DC: National Academy Press.

Volkmar, F., Cook, E. H. Jr., Pomeroy, J., Realmuto, G., & Tanguay, P. (1999). ractice parameters for the assessment and treatment of children, adolescents, and adults with autism and other pervasive developmental disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 38(12 Suppl),
32S–54S.

High Functioning Autism vs. Asperger’s: You say tomato I say tomahto

A review of:Kuusikko, S., Pollock-Wurman, R., Jussila, K., Carter, A.S., Mattila, M., Ebeling, H., Pauls, D.L., Moilanen, I. (2008). Social Anxiety in High-functioning Children and Adolescents with Autism and Asperger Syndrome. Journal of Autism and Developmental Disorders DOI: 10.1007/s10803-008-0555-9

When I first picked up this article I was excited because it seemed to directly address a clinical feature that some researchers and many clinicians have used to differentiate children with High Functioning Autism vs. Children with Asperger’s. We know that technically, based on DSM-IV diagnosis, the main difference between HFA and AS is the presence or absence of language delays. Kids with HFA, by definition, experience language delays, while kids with Asperger’s have typical language development. But in all clinical settings I have practiced, we have discussed other possible differences between these kids, specifically in regards to their neuropsychological profile and the nature of their limited social interaction with other peers. As for neuropsychological profile, HFA tend to have even verbal vs. non-verbal skills, while children with AS tend to have much higher verbal than non-verbal skills, consistent with the profile of children with “non-verbal learning disabilities”. In regards to their social interactions, in my clinical experience and interaction we colleagues, we see a difference in their ‘relative’ need for social companionship. In general children with HFA seem to just want to be by themselves without an explicit desire to interact with peers. They interact when necessary and when such interaction is functional, but not for the “intrinsic joy” of having social interactions. On the other hand, children with AS tend to desire close relationships with peers and explicitly talk about wanting more friends, but their social uniqueness make the establishing of such relation more difficult. Based on this last apparent clinical difference, you would expect that children with AS would experience more social anxiety due to a relative high need for social acceptance as compared to children with HFA. To test these hypotheses, a group in Finland compared 35 kids with AS, 21 kids with HFA (diagnosed via ADI and ADOS), and a large group of 353 typically developing kids of the same age (8-16 years old). The results were surprising: There was NO difference between the AS and the HFA in anxiety, social anxiety, social phobia, etc. As a group, the children with HFA/AS experienced higher level of anxiety and social phobia than the typically developing children. Furthermore, a developmental trajectory was observed. The anxiety problems tended to decrease with age in typically developing kids, but these problems increased with age in the children with HFA/AS. In summary, the data suggest that children with AS and HFA experience the same levels of social anxiety and phobias, which does not support the clinical view that these children may differ in regards to relative levels of social desirability.