Hemispheric lateralization of language in epileptic right-handed children with unihemispheric discharge

The epileptic discharge of one hemisphere interferes with brain function. The present study assesses the linguistic disabilities of epileptic patients owing to discharge in one hemisphere. Subjects were classified by age and gender. A significant deterioration of linguistic abilities appeared in adult subjects discharging in the left hemisphere. In children, however, a more symmetric hemispheric pattern of epileptic discharge interference appears with age up to 14 years. Unihemispheric epileptic discharges could also provide information about the degree of lateralization that a given function presents in different developmental stages. This lateralization appears clearly established from the age of 14 to 21 years until late adulthood. These results imply that hemispheric specialization of language is not completed until adolescence. This absence of hemispheric specialization for language in childhood was statistically more significant in boys than in girls, suggesting that the maturation of cortical areas related to language occurs earlier in girls than in boys. Finally, the familial history of left-handedness is a factor delaying the age of left lateralization of language in right-handed children.