Abstracts

RATIONALE: Focal cortical dysplasia (FCD) is an increasingly recognized cause of intractable epilepsy in patients presenting for surgical resection. The success of epilepsy surgery relies on accurate diagnosis of the underlying epileptic syndrome, yet there is little known about the electro-clinical manifestations of adult patients with epilepsy and FCD. The purpose of this study is to describe the clinical characteristics of adults with FCD undergoing surgical resection for intractable epilepsy. METHODS: We reviewed demographic, video EEG, high-resolution MRI, and surgical outcome data on 53 patients, aged 17 to 36 years. All had a histopathological diagnosis of FCD. RESULTS: Lobar resections were performed on 49 patients, multilobar on 4. There were 36 temporal, 17 extra-temporal resections. Mean age at surgery was 29 years. Mean age at epilepsy onset was 10 years. Only 36% of patients had known epilepsy risk factors such as meningitis, febrile seizures, or major head trauma. The majority of patients (77%) had complex partial seizures, while 21% had simple partial seizures. Four patients had bilateral tonic seizures. Neurological exams were normal in 40 patients; 7 patients had mental retardation (MR), and 6 patients had focal neurological deficits. High-resolution MRI identified 13 patients with FCD pre-operatively. Dual pathology was found in 31 patients: 21 hippocampal sclerosis, 4 tumors, and 6 infarcts. Following surgery, 67% were seizure-free while 18% had no improvement. Compared to patients with temporal lobe resections, those with extra-temporal lobe resections were younger at epilepsy onset, were more likely to have MR or focal deficits, and were less likely to be seizure-free after surgery. CONCLUSIONS: In this series of adult epilepsy patients with FCD, the majority present with epilepsy in childhood, have no known epilepsy risk factors, have normal neurological exams, and have a high incidence of dual pathology. This patient population should be investigated further, to determine those clinical features most important in the presurgical evaluation of patients with intractable epilepsy due to FCD.