To summarize the clinical characteristics of pediatric focal cortical dysplasia and discuss the variables affecting surgical outcome.

A retrospective review was performed on the clinical data of children with a postoperative histological diagnosis of FCD at Department of Neurosurgery, Children's Hospital of Fudan University from January 2015 to October 2020. Age, gender, pathology subtypes, magnetic resonance imaging (MRI) results, and Engel classification after surgery were analyzed.

A total of 99 cases were enrolled, including 66 boys and 33 girls. The mean age of the patients was (6.4±3.8) years. The pathology subtypes could be divided into FCDⅠb (6 cases), FCD Ⅱa (26 cases), FCDⅡb (23 cases) and FCDⅢ(44 cases). Ninety-one (91.9%) cases were MRI positive and eight (8.1%) were negative. Eighty-six (86.9%) cases achieved Engel grade 1, three (3.0%) had grade 2, six (6.1%) cases had grade 3 and four (4.0%) had grade 4. Among the eight MRI-negative cases, only five (62.5%) achieved Engel grade 1 or 2, while three (37.5%) ended up with Engel grade 3 or 4. Chi-square test showed that negative findings on MRI was associated with a poor surgical outcome (P=0.032).

Surgery is the main component in treating FCD, and is highly effective. Negative findings on MRI are the most important predictive factor for worse seizure outcome.