Objective      To investigate the clinical characters

preoperative evaluation

surgical procedures and outcomes of pediatric intractable epilepsy patients with malformation of cortical development (MCD).       Methods      The clinical data

epilepsy focus localization and surgical outcomes of 176 pediatric patients with MCD between 2005-2010 were retrospectively analyzed. The results of different subtypes of MCD were compared.       Results      MCD was the most important pathology of pediatric intractable epilepsy (34.2%). The postoperative follow-up on average of 3.3 years showed that 106 patients (60.2%) had an Engel Class Ⅰ outcome

31 patients (17.6%) had rare seizure (Engel Class Ⅱ)

21 patients had a decrease in seizure frequency (Engel Class Ⅲ)

and 14 patients had an Engel Class Ⅳ outcome. The mean intelligence quotient (IQ) improved from 66.5 to 72.9. The excellent rates of surgical outcomes in different subtypes of MCD were 100% in hemimegalencephaly

90.9% in tuberous sclerosis (TS)

76.8% in focal cortical dysplasia (FCD)

75.0% in pachygyria/agyria

66.7% in gray matter heterotopia and 62.5% in polymicrogyria. The outcomes of the patients with subtype Ⅱ FCD were better than those of the patients with subtype Ⅰ FCD (84.2% vs 70.5%)

the outcomes of the FCD patients complicated with tumor were better than those of the patients with FCD alone (86.4% vs 76.6%)

and the outcomes of the FCD patients complicated with hippocampal sclerosis were better than those of the FCD patients without hippocampal sclerosis (85.7% vs 76.7%). Significant improvement of IQ was shown in patients with FCD and TS as compared with other patients.       Conclusion      Different subtypes of MCD show distinct characteristics in clinical symptoms

imaging

neurophysiology

brain function and surgical outcome

and individual preoperative evaluation and different surgical strategies should be conducted for different subtypes of MCD.