Journal
JOURNAL OF CHILD NEUROLOGY
Volume 23, Issue 4, Pages 368-380Publisher
SAGE PUBLICATIONS INC
DOI: 10.1177/0883073807309235
Keywords
dyslexia; AD H D cerebellum; phonological processing; phonological awareness; rapid naming; phonological short-term memory
Categories
Ask authors/readers for more resources
Recent evidence suggests that the primary source of dysfunction in dyslexia is the cerebellum. To examine the cerebellar deficit hypothesis of dyslexia, 20 children with dyslexia and 20 children without dyslexia were assessed using neuropsychological testing and quantitative magnetic resonance imaging. Results demonstrated that the volumes of both hemispheres and the vermis were not statistically significantly different between groups. However, children without dyslexia demonstrated greater rightward cerebellar hemisphere asymmetry. The relationship between cerebellar morphologic structure and phonological processing was assessed. For children without dyslexia, bilateral hemisphere volume moderately correlated with phonological awareness and phonological short-term memory. Hemisphere asymmetry moderately correlated with rapid naming errors, and the anterior vermis volume moderately correlated with phonological awareness. For children with dyslexia, the only statistically significant correlation was between rapid naming errors and the left hemisphere volume. Evidence suggests that atypical cerebellar morphologic structure may have a role in dyslexia for a subgroup of individuals. Although children with and without attention-deficit/hyperactivity disorder did not differ in cerebellar morphologic structure, the anterior vermis volume moderately correlated with inattention, hyperactivity, and impulsivity, while the right hemisphere volume moderately correlated with inat. tention and hyperactivity. Our findings provide mixed support for the cerebellar deficit hypothesis of dyslexia. Although cerebellar morphologic structure is atypical in some individuals with dyslexia, it is inconsistently related to cognitive or motor dysfunction. In our sample, cerebellar morphologic structure may be related to about one-third of cases of dyslexia. Hence, dyslexia may be best accounted for by a combination of cortical and cerebellar contributions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available