Abstracts

Rationale: Focal cortical dysplasia (FCD) is one of the most common causes of intractable epilepsy leading to surgery in children. The predictors of seizure freedom following surgical management for FCD are still unclear. The objective of this study is a volumetric analysis of factors in the pre and post resection brain MRI scans of patients who had undergone resective epilepsy surgery for cortical dysplasia and the influence of these factors on seizure outcome.   Methods: The medical records and brain imaging scans of forty three consecutive patients who had undergone surgical treatment for refractory epilepsy with focal MRI abnormalities and pathological diagnosis of FCD were reviewed. Preoperative lesion volume and postoperative resection volume were calculated by manual segmentation using Osirix-Pro software. Results: Forty three patients underwent first time surgery for resection of cortical dysplasia. The age range at the time of surgery was 2 months to 21.8 years with a mean age of 7.3 years. Median duration of follow-up was 20 months. Mean age of onset was 31.6 months and a range of 1 day to 168 months. Complete resection of the area of focal cortical dysplasia as adjudged from the postoperative brain MRI scan was significantly associated with seizure control (p = 0.0005). The odds of having good seizure control among those who had compete resection is about 6 times those who did not have complete resection. Seizure control was not significantly associated with lesion volume (p = 0.46) or peri-lesional resection volume (p = 0.86)   Conclusions: Completeness of resection of radiological abnormality is a significant predictor of seizure freedom following resection of FCD in children. Lesion volume or further resection of perilesional tissue is not predictive of seizure freedom.