The relation between measurements of the posterior temporal lobe, inferior frontal gyrus, cerebellum and whole brain, determined by MRI, and measures of reading, spelling, verbal intelligence and language skills was studied at the University of Florida, Gainesville, FL. Dyslexic children (14 males, 4 females) and controls (19 males, 13 females) in grades 4-6 were selected from a family genetics study. Dyslexics had specific deficits in word reading relative to the population mean and verbal IQ. Dyslexics had significantly smaller right anterior lobes of the cerebellum, pars triangularis bilaterally, and brain volume. Measures of the right cerebellar anterior lobe and the pars triangularis correctly classified 72% of the dyslexics and 88% of controls. These neuroanatomical measures were significantly correlated with reading, spelling and language measures related to dyslexia. Anomalies in a cerebellar-frontal circuit are proposed as a neuroanatomical basis for dyslexia. [1]

COMMENT. Anatomical deficits in a frontal-cerebellar system may lead to dyslexia. Measures of the right cerebellar anterior lobe and inferior frontal gyrus may be used to predict reading skills. Children with right cerebellar tumors have poor verbal and naming performance compared to patients with left-sided tumors (Scott et al, 2001; cited by Eckert et al).