Abstracts

Rationale: Focal cortical dysplasia (FCD) is associated with medically intractable epilepsy. FCD and its associated epileptogenic zone may contain eloquent cortical regions, particularly when they occur in the dominant frontal lobe. In children, a clinical dilemma may arise: safety concerns in surgical decision-making must be weighed against a decline in verbal performance in the setting of ongoing seizures and antiepileptic drugs (AEDs). We describe three children with this presentation and their surgical outcomes. Methods: A retrospective review of 3 consecutive patients, ages 8-12 years with left hemispheric dominance and frontal FCDs followed at the Comprehensive Epilepsy Center at Beth Israel Medical Center in New York, was performed. Pre and post-operative evaluations included: EEG recordings with video monitoring, MRI, PET scans, and fMRI. All patients were treated with staged operations using invasive monitoring with grid and strip electrodes spaced 7 days apart in all cases. Results: Three children (1M, 2F)(8-13 years) were included in this study. Duration of epilepsy ranged from 2-8 years. All children had a decline in school performance and had documented changes in cognitive and language measures on neuropsychological testing. In two patients, the FCD was evident on preoperative MRI scan in the left frontal lobe, involving middle and inferior frontal gyri, while in the third patient the FCD was evident on pathological analysis after an initial operation at another institution. Two of three patients had Type II FCD, while the third patient with a non-lesional MRI reading, had a Type I FCD. The epileptogenic zone was seen to extend anterior to the area of FCD on the scan in two patients, and involve superior, middle and inferior frontal gyri in the third patient. While there was no major long term operative morbidity, all three patients had short term motor and language deficits related to supplementary motor area (SMA) syndrome, with recoveries ranging between 1 hour and 2 weeks. All patients are seizure free at mean follow up of 18 months on tapering doses of AEDs, with no new neurological deficits and an improvement in language and cognitive measures. Conclusions: FCD in the dominant frontal lobe can be resected safely with staged epilepsy surgery and cortical mapping strategies. In children with declining school performance and a deterioration in cognitive and verbal skills in the setting of medically intractable frontal lobe epilepsy, focal resection of the FCD and the epileptogenic zone can result good seizure control and reversal of these trends without prohibitive risk.