Abstracts

Rationale: Moderate-severe delay may suggest multifocal epileptogenicity and global dysfunction. We assessed whether baseline developmental status negatively impacted postoperative seizure outcome, antiepileptic drug (AED) use, and development in children with focal cortical dysplasia (FCD).Methods: This was a single-center retrospective review of children with FCD identified from the Mayo Clinic Pathology Database between 2000 and 2014. Patients with <6-month follow-up were excluded. Date of last follow-up was subsequent surgery date in those with repeat interventions. Developmental quotient (DQ) was estimated from parents’ report at clinic visits. Developmental status was no-mild delay if DQ≥80 and moderate-severe delay if DQ≤79. Postoperative developmental gains was categorized as no change or improved based on available documentation. Seizure outcome at last follow-up was favorable if Engel class I and II and unfavorable if Engel class III and IV. Seizure-free outcome was separately analyzed. Results of general intellectual functioning were reviewed if both pre- and postoperative neuropsychological assessments were available.Results: Baseline development was no-mild delay in 19 patients and moderate-severe delay 17 patients. There was no difference between groups in median age at seizure onset, seizure onset in neonatal period, age at surgical intervention, epilepsy duration, prior AED trials, and number of ongoing AED. With median follow-up duration of 23 months (IQR 12-66 months), 18/19 patients with no-mild delay and 12/17 patients with moderate-severe delay achieved favorable seizure outcome (p=0.05). Seizure-free control was more likely in no-mild delay than moderate-severe delay (16/19 vs. 7/17 patients, OR 7.6, 95% CI 1.6-36, p=0.007). With seizure-free control, AED withdrawal was pursued in 5/16 vs. 1/7 patients (p=0.39) and AED reduction in 10/16 vs. 3/7 patients (p=0.06) with no-mild delay and moderate-severe delay, respectively. In 7 patients with favorable outcome but not seizure-free, AED reduction was possible in 5 patients (1 no-mild delay, 4 moderate-severe delay). All 4 patients who underwent subsequent surgery had baseline moderate-severe delay. Based on parent report, 2/28 patients had no developmental gain, both with moderate-severe delay at baseline and unfavorable outcome at last follow-up. None of the 8 patients with pre- and postoperative neuropsychological assessments demonstrated change in general intellectual functioning.Conclusions: Nearly half of the children with FCD had existing moderate-severe delay. Although severity of baseline delay negatively impacted seizure-free outcome, more than two-thirds of patients with moderate-severe delay achieved favorable seizure outcome. Seizure-free control with AED withdrawal and AED reduction were similar regardless of baseline developmental status. Despite parental report of developmental gains after surgery, neuropsychological assessments reflected consistent general intellectual functioning before and after epilepsy surgery.