Neuroimaging of Focal Cortical Dysplasia

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1552-6569.2006.00025.x Byline: Peter Widdess-Walsh (1), Beate Diehl (1), Imad Najm (1) Keywords: Focal cortical dysplasia; MRI; MRS; PET; SPECT; diffusion imaging; functional HRI Abstract: ABSTRACT Focal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy that is amenable to surgical resective treatment. The identification of structural FCD by magnetic resonance imaging (MRI) can contribute to the detection of the epileptogenic zone and improve the outcome of epilepsy surgery. MR epilepsy protocols that include specific T1 and T2 weighted, and fluid-attenuated inversion recovery (FLAIR) sequences give complementary information about the characteristic imaging features of FCD; focal cortical thickening, blurring of the gray-white junction, high FLAIR signal, and gyral anatomical abnormalities. Novel imaging techniques such as magnetic resonance spectroscopy (MRS), magnetization transfer imaging (MTI), and diffusion tensor imaging (DTI) can improve the sensitivity of MR to localize the anatomical lesion. Functional/metabolic techniques such as positron emission tomography (PET), ictal subtraction single photon emission computed tomography (SPECT), functional MRI (fMRI), and magnetic source imaging (MSI) have the potential to visualize the metabolic, vascular, and epileptogenic properties of the FCD lesion, respectively. Identification of eloquent areas of cortex, to assist in the surgical resection plan, can be obtained non-invasively through the use of fMRI and MSI. Although a significant number of FCD lesions remain unidentified using current neuroimaging techniques, future advances should result in the identification of an increasing number of these cortical malformations. Author Affiliation: (1)From the Section of Adult Epilepsy and Clinical Neurophysiology, The Cleveland Clinic Epilepsy Center, Cleveland, Ohio. Article History: Received May 15, 2005, and in revised form October 14, 2005. Accepted for publication October 26, 2005. Article note: Address correspondence to Dr Imad Najm, Section of Adult Epilepsy, The Cleveland Clinic Foundation, 9500 Euclid Avenue, S51, Cleveland, Ohio 44195. E-mail: najmi@ccf.org.