Presurgical Evaluations in Children with Pathology Confirmed Focal Cortical Dysplasia (S60.007)

OBJECTIVE: To describe presurgical evaluations in children with pathology confirmed focal cortical dysplasia. BACKGROUND: Focal cortical dysplasia (FCD) is a common pathology in children with medically refractory epilepsy. Presurgical evaluations rely on MRI and other noninvasive modalities in the absence of concordant focal MRI or EEG findings. DESIGN/METHODS: Single-center, retrospective study of children <18 years who underwent resective surgery between 2000 and 2012 with pathology proven FCD. Favorable surgical outcome was defined as Engel class I/II, and unfavorable as III/IV. RESULTS: Thirty-nine children were identified (male 67%). The median age of seizure onset was 11 months (IQR 1-48); median duration of epilepsy prior to surgery was 43 months (IQR 11-116). Focal seizures were present in 37 patients (95%). Two patients (5%) had epileptic spasms only. MRI brain was consistent with FCD (MRI+FCD) in 18 patients (46%), showed other abnormalities (MRI+abnormal) in 18 (46%) and was normal (MRI-) in 3 (8%). Noninvasive video-EEG in 11/18 patients (61%) showed focal ictal onset concordant with MRI+FCD. Among those without focal ictal EEG onset, subtraction ictal SPECT co-registered to MRI (SISCOM) revealed localizing abnormality in 12/19 patients (63%) and FDG-PET in 5/19 (37%). Intracranial video-EEG monitoring was performed in MRI+FCD 4/18 patients (22%), MRI+abnormal 9/18 (50%), and MRI- 3/3 (100%). Overall, 27/39 patients (69%) achieved favorable outcome at median last follow up of 16 months (IQR 7-50), including 20 who were seizure-free. Among those with MRI+FCD, favorable outcome was seen in all 4 patients who underwent intracranial EEG monitoring vs 9/14 (64%) who did not (p>0.05). CONCLUSIONS: Among children with pathology-confirmed FCD, about half of the patients have MRI+FCD findings. Noninvasive modalities such as SISCOM/PET should be considered to further localize seizure focus. Favorable outcome is achieved in about 2/3 of patients and does not seem to be affected by intracranial EEG monitoring. Disclosure: Dr. Mrelashvili has nothing to disclose. Dr. Nickels has nothing to disclose. Dr. Wirrell has received research support from the Mayo Foundation. Dr. Wong-Kisiel has nothing to disclose.