Surgical resection for intractable epilepsy in "double cortex" syndrome yields inadequate results

Purpose: To analyze the results of surgical treatment of intractable epilep sy in patients with subcortical band heterotopia, or double cortex syndrome , a diffuse neuronal migration disorder. Methods: We studied eight patients (five women) with double cortex syndrome and intractable epilepsy. All had a comprehensive presurgical evaluation i ncluding prolonged video-EEG recordings and magnetic resonance imaging (MRI ). Results: All patients had partial seizures, with secondary generalization i n six of them. Neurologic examination was normal in all. Three were of norm al intelligence, and five were mildly retarded. Six patients underwent inva sive EEG recordings, three of them with subdural grids and three with stere otactic implanted depth electrodes (SEEG). Although EEG recordings showed m ultilobar epileptic abnormalities in most patients, regional or focal seizu re onset was recorded in all. MRI showed bilateral subcortical band heterot opia, asymmetric in thickness in three. An additional area of cortical thic kening in the left frontal lobe was found in one patient. Surgical procedur es included multiple subpial transections in two patients, frontal lesionec tomy in one, temporal lobectomy with amygdalohippocampectomy in five, and a n additional anterior callosotomy in one. Five patients had no significant improvement, two had some improvement, and one was greatly improved. Conclusion: Our results do not support focal surgical removal of epileptoge nic tissue in patients with double cortex syndrome, even in the presence of a relatively localized epileptogenic area.