Cerebral asymmetry in developmental dyslexia
R. H. Haslam, J. T. Dalby, R. D. Johns and A. W. Rademaker
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.
