Autism, Aspergers, and the BrainAdrienne Dorrah

Definition Autism and Aspergers are developmental disorders on a

larger spectrum called Autism Spectrum Disorders (ASDs).

Autism – usually have significant language delays, social and communication challenges, unusual behaviors and interests; may have intellectual disability

Aspergers – may have social challenges and unusual behaviors and interests; typically do not have language problems or intellectual disability

http://www.cdc.gov/NCBDDD/autism/videos/whatisautism.html - this is a link to a short video that explains the signs and symptoms related to ASDs.

Source: (Center for Disease Control, 2012)

General Information

1 in 88 children have been identified with an autism spectrum disorder

Typically diagnosed between the ages of 2 and 4

Because of the late diagnosis, brain development in autism is largely unstudied during the first 2 years of life – the “crucial period”

Source: (Center for Disease Control, 2012)

Source: (Center for Disease Control, 2012)

Head Circumference Typically normal average at birth – 25th %ile

By 6-14 months, head circumference is at 84th %ile; growth slows down at end of 2nd year

Brain volume of autistic 3-4 years old about 10% larger than normal (1.5 cm)

Cerebrum, cerebellum, and amygdala also larger than normal

Source: (Courchesne, 2004)

Source: (University of California, San Diego, 2003)

In 2-4 year olds, brain enlargement was found to be due to significant increases in cerebral white matter (18%), cerebral gray matter (12%), cerebellar white matter (39%), but not cerebellar gray matter.

Grey matter volume reaches a peak between ages 4 & 6, then decreases constantly

White matter volume increase in the first decade of life and stays relatively stable

Sources: (Courchesne 2004) (Predescu, et. al. 2010

Gray Matter & White Matter

Photo Credit: (Courchesne, et. al., 2007)

Picture Source: (Health on Care)

Brain dysfunction in autism is correlated with abnormal patterns of development affecting the whole brain as well as circuits involving the prefrontal cortex, the limbic system, and cerebellum. The amygdala and hippocampus increase in size through adolescence.

Source: Predescu et. al. 2010)

Affected Parts of the Brain The most consistent changes were in the

amygdala, hippocampus, and functionally related entorhinal cortex and mammillary body.

Using SPECT techniques, researchers reported that blood flow is significantly reduced in the left temporal region in high-functioning autism, while a more recent study reported a correlation between reduced temporal lobe blood flow and the severity of the disorder.

Source: (Lathe, 2006)

Boys vs. Girls

Girls with autism showed substantial reduction in cerebellar gray matter volumes as compared to normal girls as well as to boys with autism

Brain development abnormalities appear to be more severe in girls than in boys with autism

Every structural volume abnormality present in boys with autism was also present in girls with autism

Source: (Courchesne, 2004)

Reference List Center for Disease Control. (29, March 2012). Data and statistics. Retrieved

from http://www.cdc.gov/ncbddd/autism/data.html/

This site gave statistical information and data related to Autism. It also talks about diagnosis and economic costs of autism. A basic chart with data about the prevalence of ASDs was extracted from this site.

Center for Disease Control. (29, March 2012). Facts about asds. Retrieved from http://www.cdc.gov/ncbddd/autism/facts.html

This website gave general information about Autism Spectrum Disorders. It discusses the different types of ASDs, signs and symptoms, treatments, and risk factors, among other information.

Courchesne, E. (2004). Brain development in autism: Early overgrowth followed by premature arrest of growth. Mental Retardation & Developmental Disabilities Research Reviews, 10(2), 106-111.

*This article discusses brain development and growth in autism. Circumference of the head, rate of growth, growth at different ages, and regional differences are all discussed.

References Cont’d Courchesne, E., K. Pierce, C. M. Schumann, E. Redcay, J. A. Buckwalter, D. P.

Kennedy, and J. Morgan. "Mapping Early Brain Development in Autism." Neuron. 56.2 (2007): 399-413. Web. 13 Aug. 2012.

*This article talks about findings during the first few years of life and argues that early brain overgrowth is a key factor in the onset of autism. The article also includes graphs that map out data related to overgrowth in the brain.

Health on Care. (n.d.). Autism – causes, symptoms and treatment. Retrieved from http://www.healthoncare.com/autism-causes-symptoms-and-treatment.html

This website gave a brief overview of what autism is and the causes and symptoms of autism. The site has a picture of the brain that shows which parts of the brain which are affected by autism. This photo was extracted for my presentation.

References Cont’d Lathe, Richard. Autism, Brain and Environment. London: Jessica Kingsley Publishers,

2006.

*This is a book about autism that discusses how autism affects the brain and the abnormalities and dysfunction associated with the disorder. The book also discusses how the environment has an effect on the onset of autism.

Predescu, E., Sipos, P., Sipos, R., Iftene, F., & Balázsi, R. (2010). BRAIN VOLUMES IN AUTISM AND DEVELOPMENTAL DELAY -- A MRI STUDY. Journal Of Cognitive & Behavioral Psychotherapies, 10(1), 25-38.

This article compared children with ASD and children with developmental delay. It compared total brain volume of both sets of children as well as volume of gray matter and white matter between the groups of children.

University of California, San Diego. (2003). Ucsd researchers find brain overgrowth during first year of life in autism. Retrieved from http://health.ucsd.edu/news/2003/07_15_courchesne.html

This website contained an article talking about brain growth in children with autism during their first year of life. The website contained a photo comparing the size of an average brain with the size of a brain with autism. This photo was extracted for my presentation.