PURPOSE: The purpose of this study is to determine the sensibility of each 
imaging tool in identifying focal cortical dysplasia (FCD) in children and 
adolescents with epilepsy and to define the prognostic factors of pediatric and 
adolescent epilepsy surgery.
METHODS: We identified 48 children with FCD who underwent resective surgery and 
analyzed their preoperative data. The results of various anatomic and functional 
neuroimaging studies were compared for accuracy in locating the lesion. We also 
investigated clinical factors that affected the outcome of surgical treatment.
KEY FINDINGS: Brain magnetic resonance imaging (MRI) was able to localize FCD in 
30 patients and fluorodeoxyglucose positron emission tomography (FDG-PET) and/or 
subtraction ictal single photon emission computed tomography (SPECT) 
coregistered with MRI provided additional information that helped to define the 
lesion in 13 patients. When comparing the pathologic results between a mild 
malformation of cortical development (MCD) and FCD type I and II, we noted a 
strong tendency for patients with FCD to have MRI abnormalities (p = 0.005). In 
addition, severe pathologic features (Palmini's classification, FCD type II) (p 
= 0.025) showed significant correlation with a better surgical outcome. To 
define the primary epileptogenic area, various interictal epileptiform 
discharges and the results of multimodal neuroimaging studies were helpful, and 
younger age at the time of operation could aid in more favorable surgical 
outcomes (p = 0.048).
SIGNIFICANCE: Our study showed a significant relationship between pathologic 
grade and the detectability of FCD by brain MRI. In addition, early surgery can 
be justified by showing that advanced neuroimaging studies in children with FCD 
and even with extensive epileptiform discharges have a higher rate of success.