Clinical characteristics, pathological features and surgical outcomes of focal cortical dysplasia (FCD) type II: correlation with pathological subtypes.

Focal cortical dysplasia (FCD) type II is a major cause of drug-resistant epilepsy. In order to gain insight into the possible correlations between FCD II pathological pattern and different clinical characteristics (including clinical information, imaging characteristics and surgical outcomes), different clinicopathological characteristics in two types of FCD II were analyzed (especially in FCD IIb). The mean age of seizure onset and disease duration of 78 patients was 11.0 and 11.2 years, respectively. Patients with FCD type IIb had earlier seizure onset compared with those with FCD type IIa. Pathological subtype IIb was predominantly in frontal lobe and subtype IIa was predominantly seen in temporal. Type IIb demonstrated significantly more signal abnormalities in fluid attenuated inversion recovery (FLAIR) images and T2 images than Type IIa. The rate of satisfactory seizure outcome was 67.64 % in the FCD IIa group, while relative higher, 88.63 %, in the FCD IIb group. All these characteristics may assist in their earlier diagnosis and improve the predictability of surgical management.