Medically-refractory epilepsy may lead to expansion of the epileptic circuitry to involve complex cortical-subcortical interactions and formation of secondary epileptic foci. Advances in both functional and structural neuroimaging, such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), have improved our understanding of epileptic circuitries, expanded our knowledge on the functional consequences of chronic epilepsy and have altered our surgical approaches. PET studies of brain glucose metabolism have shown expansion of the areas of cortical glucose hypometabolism with seizure intractability. In intractable partial seizures, DTI has identified structural changes in subcortical structures and in the white matter fiber tracts that extend beyond the conventional-MRI identified abnormalities.
展开▼
