Abstracts

To determine the surgical outcome and prognostic factors in adult patients with intractable epilepsy and focal cortical dysplasia (FCD). We retrospectively studied the operative outcome in 21 consecutive adult patients with FCD who underwent surgical treatment for intractable partial epilepsy. Inclusion criteria were: (i) history of medically refractory seizure disorders (ii) epilepsy surgery at age [gt] 18 years (iii) histologically verified diagnosis of FCD using previously reported criteria (iv) comprehensive preoperative evaluation and (v) follow-up of at least one year. Medical records were analyzed for demographic data, clinical presentation, presurgical evaluation, medical and surgical treatment, and postoperative outcome. All patients underwent a comprehensive presurgical evaluation that included a neurological examination, epilepsy subspecialty consultation, neuropsychological study, routine electroencephalography (EEG), inpatient ictal video-EEG monitoring, and MRI head. Peri-ictal single photon emission computed tomography (SPECT) studies using the method of subtraction ictal SPECT co-registered to MRI (SISCOM) were performed in nine patients. In eight patients, chronic intracranial EEG monitoring with subdural strip and grid electrodes was required prior to surgery. Electrocorticography (ECoG) was performed in 16 patients. The mean age at surgery was 32.7 years (range, 18 to 58 years). The mean age at seizure onset was 11.7 years (range, 18 to 58 years). MRI revealed a focal lesion in 17 patients (81%) consistent with a malformation of cortical development. Of the nine individuals who underwent a SISCOM study, eight patients (89%) had a functional neuroimaging study that showed a localized hyperperfusion alteration concordant with the FCD. In the remaining patient SISCOM correctly lateralized, but falsely localized the lesion. The mean duration of surgical follow-up was 4.4 years (range, 1-10). The FCD was extratemporal in 11 patients, temporal lobe in eight patients, and multilobar in two patients. Postoperatively, 11 patients (52%) were seizure-free, four patients (19%) had greater than a 95% reduction in seizures, and two patients (10%) had an 80-94% reduction in seizures. A seizure-free outcome was associated with shorter duration of epilepsy (p=0.02). Adult patients with FCD may be candidates for surgical treatment of intractable partial epilepsy. Approximately one-half of individuals are rendered seizure-free and over 80% experience a significant reduction in seizures. (Supported by Mayo Foundation.)