Functional MRI in patients with band heterotopia

Functional activation associated with a motor task (fist movements) was stu died in three patients with band heterotopias by fMRI. In two patients, add itional visual fMRI studies were performed using a flickering checkerboard stimulus. In all patients activation of the outer cortex and of the inner n euronal band could be found during performance of the motor task. Visual st imulation elicited a normal activation pattern wit out activation of the ec topic neuronal layer in one patient; in another patient activation extended toward the ventricular wall, i.e., along the route of embryonic neuronal m igration. The potential participation of ectopic neuronal tissue in physiol ogic cerebral functions is of clinical impact in patients with neuronal het erotopias suffering from medically intractable seizures prior to epilepsy s urgery. (C) 2001 Academic Press.