Application of MSI in MRI-negative focal cortical dysplasia patients with epilepsy.

BACKGROUND Focal cortical dysplasia (FCD) is the most common cause of intractable epilepsy in children and adolescent. PURPOSE To evaluate the application value of magnetic source imaging (MSI) in treatment of magnetic resonance imaging (MRI)-negative FCD patients with epilepsy. METHODS MSI characteristics of 17 cases of MRI-negative focal cortical dysplasia patients with epilepsy were retrospectively analyzed. All patients were treated by surgery. RESULTS In 17 patients, there were 3 cases of FCD Ia, 7 cases of FCDIb, 3 cases of FCDIIa and 4 cases of FCDIIb. FCD was located at temporal lobe in 8 cases, occipital lobe in 3 cases, frontal lobe in 2 cases and two lobes in 4 cases. In follow-up, 14 patients obtained satisfied curative effect. 1 patient was improved significantly and 2 patients were fine. The concordance between MSI and electrocorticogram in localizing epileptogenic foci was 65%. CONCLUSION MSI is a new prospective noninvasive functional neuroimaging technique for identifying and delineating epileptogenic foci in MRI-negative FCD patients.