Anterior corpus callosotomy was performed in a patient with pseudobulbar palsy, mild mental retardation and intractable epilepsy related to congenital bilateral perisylvian cortical dysplasia. Before surgery, she had daily atonic drop attacks, rare and mainly sleep-related oromotor seizures, and multifocal and diffuse paroxysmal EEG discharges; after callosotomy, less abrupt atonic drop attacks recurred monthly and the EEG epileptiform abnormalities disappeared. Video-EEG sleep recordings revealed the clinically unsuspected serial recurrence of oromotor seizures, probably related to the clinically observed aggravation of dysarthria. New surgical techniques, in addition or alternative to callosotomy, should be developed in order to avoid or reduce the risk of aggravating some types of partial seizures in patients with bilateral cortical displastic lesions, intractable epilepsy and epileptic falls.