The asymmetry of frontal language cortex in boys with autism, previously reported, was investigated further in a sample of 22 boys with autism compared to 9 boys with specific language impairment (SLI) and 11 normal controls, in a study at Massachusetts General Hospital and Harvard Medical School, Boston. Of the boys with autism, 16 were language impaired (ALI) and 6 had normal language ability (ALN). Their ages ranged from 6.2 to 13.4 years; they were all right-handed. As predicted, MRI brain scans showed group differences in volumetric asymmetry in language-related regions in inferior lateral frontal (Broca’s area) and posterior superior temporal cortex. Language impaired boys with autism (ALI) and boys with SLI both had significant reversal of asymmetry in frontal language-related cortex. Language-related areas were larger on the right side in both ALI and SLI groups and larger on the left in both normal language groups. The boys with unimpaired language and autism (ALN) had similar asymmetry to that of control groups. Broca’s area asymmetry reversal is correlated more with language impairment than with autism. The findings strengthen a proposed phenotypic link between ALI and SLI in boys. [1]

COMMENT. The abnormal asymmetry in language-related brain areas in boys with specific language impairment (SLI) or language impairment and autism is more closely related to language impairment than to autism. The authors conclude that their findings support the hypothesis of a common neurobiological basis of language impairment in autism and SLI. Language function is variable but is often impaired in autism. Autistic children with impaired language have a similar profile of language impairment to that of SLI, and a common genetic linkage is likely (Kjelgaard MM, Tager-Flusberg H, 2001).

Developmental stuttering is associated with atypical planum temporale asymmetry, in a study by Foundas AL et al, 2001, and cited in an editorial [2]. Cortical structures implicated in language deficits are not smaller but larger, and “bigger is not always better.” Foundas proposes that the alterations in cellular morphology may affect a single cortical layer or may be more extensive and associated with minor heterotopias. The relation between brain morphology, language, and genetics is a potentially important area of research in autism and SLI.

Discordant mental and physical efforts in autism. Ming X, et al [3] monitor brainstem autonomic function to detect mental effort in a child with autism and non-compliance. The patient showed decreases in cardiac vagal tone and cardiac sensitivity to baroreflex, and sustained increases of mean arterial blood pressure and heart rate concurrently, indicating an appropriate autonomic response to a mental effort but failed physical effort. The discordant mental and physical efforts indicate that the autistic patient does comply with commands mentally, and attempts to modify behavior through medications or behavioral intervention may be ill-advised.

Children’s Communication Checklist to differentiate autism and ADHD. Compared to normal controls, children with High Functioning Autism showed language deficits on all CCC scales, and the information obtained on the CCC was different for ADHD and autism patients. Information obtained from both parent and teacher increased patient identification compared to that of parent alone. [4]