Functional MRI in a 6-year-old boy with unilateral cortical malformation: concordant representation of both hands in the unaffected hemisphere.

Functional magnetic resonance imaging (fMRI) was performed in a 6-year-old boy with a complex malformation of the right hemisphere who suffered from pharmaco-refractory epilepsy. Clinical examination revealed left-sided hemiparesis and marked mirror movements of the opposite hand both during paretic and non-paretic hand movements. Functional MRI of repetitive unimanual grasping demonstrated that the two hands share a common cortical representation located in the central motor region of the unaffected left hemisphere. The affected right hemisphere did not show any activation during either task. This case study demonstrates the feasibility and usefulness of motor fMRI in young children before they undergo epilepsy surgery.