Long-term Outcome of Surgery in Children with Drug Resistant Epilepsy and Focal Cortical Dysplasia

Introduction: Focal cortical dysplasia is notorious for failure of surgery. The aim of this study was to evaluate factors affecting outcome in children with drug resistant epilepsy and focal cortical dysplasia (FCD) who underwent surgery. The factors shall help in deciding the need for surgery for FCD with DRE

Methods: We analyzed data of 112 consecutive children operated at a tertiary referral centre for drug resistant epilepsy and a diagnosis of FCD on histopathology between January2005 and December 2015. The inclusion criteria were 1) isolated type I and/or type II FCD within the surgical specimen 2) at least five years post-surgery follow-up.

Results: The average age at onset of epilepsy was 4.56 ± 3.88 (0 – 18) years with mean duration of epilepsy of 6.50 ± 5.02 (0.3– 18) years. The average age at surgery was 10.27 ± 5.14 (2 – 18)years. Delayed development was observed in 39 (34.8%), while 56 (50.0%) had below average intelligence. Associated psychiatric disorder and /or behavioural problems were diagnosed in 67 (59.8%) patients. Inter-ictal EEG showed focal/regional epileptiform discharges in 55 (49.1%). Seizure semiology was lateralizing in 77 (68.8%) while 52 (46.4%) had regional ictal EEG onset. MRI showed clear cut FCD in 96 (85.7%). At the latest follow-up 73 (65.2%) patients had a favourable Engels outcome. Onset of seizures below two years of (30.1 vs 53.8%; p=0.024,) multiple types of seizures at presentation (21.9% vs 46.2%; p=0.010), developmental delay (23.3% vs 56.4%; p=0.001), generalized seizure semiology (54.8% vs 79.5%; p=0.013) and acute post-operative seizures (19.4% vs 48.7%; p=0.002), were associated with unfavourable outcome. Complete resection of the FCD (91.8% vs 46.2%; p< 0.001), type II FCD (51.4% vs 21.2%; p=0.027), lateralizing semiology (75.3% vs 56.4%; p=0.054) were associated with favourable outcome. The predictor for favourable outcome was complete resection.

Conclusion : Favorable outcome after surgery for DRE and FCD in children was seen in 65% and complete resection was the predictor of favourable outcome.