Performance of Dyslexic Children on Cerebellar and Cognitive Tests.

In a previous study (A. J. Fawcett, R. I. Nicolson, & P. Dean, 1996), the authors had found strong behavioral evidence for cerebellar deficit in a panel of children with dyslexia. In the present study, the generality of those results was assessed. A battery of clinical tests for cerebellar dysfunction was administered, together with selected cognitive tests, to a further 59 dyslexic and 67 control children. The dyslexic children showed highly significant impairments on the cerebellar tests, with deficits on postural stability and muscle tone comparable in magnitude with their reading and spelling deficits. Furthermore, over 95&percent; of the dyslexic children showed clear evidence of deficit on muscle tone or stability. The findings provide further evidence of the generality of cerebellar impairment in dyslexia. The implications of the cerebellar tests for screening in dyslexia are discussed.