Abstracts

Rationale: Previous meta-analysis has demonstrated that the most important factor in seizure freedom following surgery for Focal Cortical Dysplasia (FCD) is completeness of resection. However, intraoperative detection of epileptogenic dysplastic cortical tissue remains a challenge, potentially leading to a partial resection and necessitating the need for reoperation. Intraoperative magnetic resonance imaging (iMRI) may have a role in the detection of FCD tissue in a real time manner in the intraoperative environment, and aid in the surgical localization and resection of these lesions.Methods: We retrospectively reviewed the medical records of pediatric subjects who underwent 1.5T iMRI assisted surgical resection of FCD at the Children’s National Medical Center between January 2014 and April 2015. Post-surgical seizure outcome was assessed utilizing the Engel Epilepsy Surgery Outcome Scale.Results: 12 consecutive pediatric subjects (8 females and 4 males) underwent iMRI guided resection of FCD lesions. The median age at the time of surgery was 8 years (range 0.7 to 18.8 years) and the mean duration of follow up was 2.2 months. The median age at seizure onset was 0.9 years (0.04 to 9 years). 2 patients had Type 1 FCD, 5 patients had Type 2A FCD, 2 patients had Type 2B FCD, and 3 patients had FCD of undetermined classification. The mean duration of surgery was 369 minutes. iMRI scan findings impacted intraoperative surgical decision making in 5 out of the 12 patients (42%) who were returned to the operating suite for further resection of residual dysplastic cortical tissue following the scans. At the time of the last postoperative follow up, 11 of the 12 patients (92%) were seizure free (Engel Class I). No patients required reoperation following iMRI-guided surgery.Conclusions: iMRI-guided surgical resection of FCD in pediatric subjects resulted in excellent rate of short term post-operative seizure freedom, and has reduced need for repeat surgery.