Cerebral Asymmetry in Developmental Dyslexia

The computed cranial tomograms (CCTs) of 26 dextral boys with developmental dyslexia were examined for asymmetry of width and length in the frontal and occipital regions. Contrary to several previous reports, reading disability was not associated with an increase in the frequency of reversed occipital widths. There were, however, proportionately more symmetric occipital widths than expected in comparison with a control sample and previously established norms. Differences in verbal or performance IQs were not related to relative cerebral size. Language delay was also not associated with brain measurements. The CCT may be increasing in use as a tool in the investigation of children with developmental dyslexia. We conclude that CCT is not warranted unless an underlying disorder associated with significant neurologic signs is discovered by examination.