The Autism Society Event and Education Recordings Archive

Autism spectrum disorders (ASD) is a group of lifelong developmental disorders characterized by poor social interaction with others, repetitive stereotyped behavior and cognitive impairments including executive function. Executive function is an umbrella term covering a number of cognitive processes for mediating human organizational ability, and is widely accepted to be mediated by the frontal cortex and integrated action of multiple brain areas. Individuals with ASD have been found to have disrupted neural connectivity in the frontal lobes that mediate executive functions. While the cause of ASD is not well-understood, immune system abnormalities may play a role. Elevated incidence of immune disorders has been found in individuals with ASD. More interestingly, maternal viral infections increased the risk for ASD, and maternal influenza infection produced profound defects reminiscent of ASD in mice. It is further suggested that the production of auto-antibodies targeted at CNS proteins cause the destruction of neural tissues in the autistic brain. Indeed, a number of studies have reported supporting evidence in detecting the presence of anti-CNS auto-antibodies in the cerebrospinal fluid (CSF) of children with ASD. Thus, it is plausible that such abnormalities disrupt the neural connectivity in the brains of individuals with ASD which lead to executive function deficits in these individuals. The present study thus aimed to examine whether the immunologic abnormalities are associated with the disordered neural connectivity and cognitive dysfunction in children with ASD. Seventeen high-functioning (HFA) and 14 low-functioning (LFA) children with ASD, aged 8 to 17 years, participated voluntarily in the study. The two groups of children were compared on their general intelligence in terms of IQ; executive function as measured by the Hong Kong List Learning Test, D2 Test of Concentration, Five Point Test, Children’s Color Trail Test, Tower of California Test, and Go/No-Go task; neural connectivity as measured by theta coherence in the anterior and posterior regions; and immunologic function as measured by the level of circulating CD3+CD8+ suppressor/cytotoxic T lymphocytes in a blood sample. Results on executive function showed that LFA children performed significantly poorer than HFA children as shown on their lower Executive Composite as well as individual executive function scores. Results on neural connectivity showed that LFA children demonstrated a different pattern of electroencephalography (EEG) coherence from HFA children as shown in the significantly elevated theta coherence in the anterior network, as well as at the left intra-hemispheric (LA-LP) and right-to-left inter-hemisphere (RA-LP) connections of LFA children. In immunologic function, results showed that LFA children had significantly elevated level of suppressor/cytotoxic T lymphocytes (CD3+CD8+) (p < 0.05). In addition, the executive dysfunction, disordered neural connectivity, and abnormal immunologic function were found to be associated. These results provided some initial evidence to support the notion that immunologic factors may play a role in causing neuronal damage in the brains of children with ASD, which is reflected in their disordered neural connectivity and their executive dysfunctions.